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Assessment of Scapular Morphology and Surgical Technique as Predictors of Notching in Reverse Shoulder Arthroplasty
Reverse shoulder arthroplasty (RSA) is a treatment option for a spectrum of diseases in shoulders with rotator cuff deficiency. There are distinct morphologic changes in the scapular and glenoid anatomy in patients with chronic rotator cuff tears.1 A muscular imbalance that occurs in the joint as a result of rotator cuff deficiency leads to morphologic changes that eliminate the compressive forces that hold the humeral head against the glenoid.2 RSA effectively stabilizes the glenohumeral joint in shoulders with deficient rotator cuffs.3,4 In early work, Grammont proposed that the glenosphere center of rotation should be medialized (concentric to the central axis of the metaglene or baseplate) and lowered.5 Although the medialized center of rotation in Grammont prostheses decreases shear forces and improves the deltoid lever arm, it also tends to result in mechanical impingement between the superomedial aspect of the humeral polyethylene insert and the scapular neck—so-called inferior scapular notching.6-9
Notching, which has been reported in 50% to 96% of patients who receive a Delta III prosthesis, typically appears within the first few months after surgery but may be seen as late as 14 months after surgery.5,10-12 Postmortem studies have shown that notching corresponds with erosion of the inferior pole of the glenoid and scapular neck, thought to be caused by the polyethylene cup of the implant.13 Although some studies have found that notching stabilizes after 1 year, others have shown notching progressing for up to 4 years after surgery.11,12,14 The clinical relevance of notching continues to be controversial, but notching has been associated with poorer clinical outcomes, polyethylene wear, and local osteolysis. Component loosening has also been reported with notching of grade 3 or more.8,10 Ultimately, there is concern that scapular notching could progress, ultimately leading to late glenoid loosening and potentially catastrophic failure.
Scapular anatomy has become an area of increased focus in rotator cuff disorders and in effects on RSA biomechanics.9 Recent reports have described important scapular morphology variations that suggest more individualized adjustments are needed during RSA.9,15 In addition, some investigators have reported that development of notching appears to depend on the height and inclination of the implanted glenoid component, where an inferior position of the glenosphere leads to less impingement and better range of motion.8,16 Simovitch and colleagues8 found the angle between the glenosphere and scapular neck and the craniocaudal position of the glenosphere to be highly correlated with inferior notching. They combined these 2 parameters into a predictive algorithm that provides a guideline (notching index, <35) for prevention of notching.
We conducted a study to evaluate the scapular notching index as a predictive tool and to consider other factors that may be associated with scapular notching occurring with use of Grammont reverse replacement systems. We hypothesized that patients with a notching index of less than 35 would not develop notching and that patients with an index of more than 35 would have increased incidence and severity of notching.
Materials and Methods
Patients treated with RSA for painful cuff tear arthropathy or irreparable rotator cuff tear with pseudoparesis (inability to actively elevate shoulder >90° in presence of free passive anterior elevation) were included in this retrospective review. All patients were treated between 2006 and 2010 by 1 of 2 established senior shoulder subspecialty surgeons. Patients treated with a Delta (DePuy Orthopaedics, Warsaw, Indiana) or an Aequalis (Tornier, Edina, Minnesota) reverse shoulder implant were included in the study. A standard polyethylene liner was used for all patients. These prostheses have the same neck shaft angle, 155º, as they have similar geometric designs, both based on the Grammont design—semiconstrained inverted with a fixed, lowered, medialized center of rotation. Standard instrumentation was used for all procedures. Patients were excluded if any nonstandard techniques or components were used (constrained or high-mobility liner, glenoid bone grafting). Patients who underwent revision for a previous reverse total arthroplasty, a total shoulder arthroplasty, or a hemiarthroplasty, or for treatment of acute fracture, posttraumatic deformity, or posttraumatic arthritis, were also excluded from our analyses. Minimum follow-up for study inclusion was 24 months.
All procedures were performed with the patient in the semi-beach-chair position and with use of a deltopectoral approach. The glenoid was prepared such that minimal reaming was needed to preserve the subchondral plate. The glenoid baseplate was positioned in the recommended inferior position to minimize notching and optimize functional outcomes.13 After surgery, all patients were managed with a simple soft immobilizer with or without a pillow with the arm at the patient’s side in internal rotation. Immediate passive mobilization was begun under the direction of physical therapists. Passive and active-assisted exercises were continued with gradual progression to independent activities of daily living at 6 weeks. Clinical evaluations were performed before and after surgery by the operating surgeon or independent research nurse. Active forward flexion, passive external rotation, strength, and visual analog scale (VAS) pain scores were reviewed and recorded. Case-specific complications were also reviewed.
Preoperative and postoperative anteroposterior radiographs were evaluated by 2 independent observers (attending surgeon, junior resident). Per standard technique, each radiograph was positioned horizontal to the scapular plane. Of the 91 patients, 66 had preoperative shoulder radiographs of acceptable quality, with complete visualization of scapular morphology. Radiographs were reviewed to measure the scapular neck angle (SNA), inferior scapular notching, prosthesis–scapular neck angle (PSNA), and peg glenoid rim distance (PGRD) (Figure 1). For the 66 patients with acceptable preoperative radiographs, SNA was determined by subtracting preoperative SNA from postoperative PSNA. Postoperative anteroposterior radiographs were used to classify degree of inferior scapular notching based on the Nerot grading scale (0-4). In addition, glenosphere overhang and glenosphere inclination were measured on postoperative radiographs.
The 91 shoulders were sorted into 2 groups based on degree of scapular notching: group 1, Nerot grade 0 (no inferior notching) and grade 1, and group 2, Nerot grades 2, 3, and 4. Group 1 had 37 patients with a size 36 glenosphere, 3 patients with size 38, and 8 patients with size 42; group 2 had 34 patients with a size 36 glenosphere, 1 patient with size 38, and 8 patients with size 42. All measurements were normalized to account for differences in glenosphere size. Groups 1 and 2 were compared on each radiographic parameter (inferior scapular notching, PSNA, PGRD, SNA).
Notching indexes were calculated ([PSNA × 0.13] + PGRD) and compared with the suggested index of 35.8 Simovitch and colleagues8 demonstrated that a notching index of more than 35 had 91% sensitivity and 88% specificity in predicting inferior notching, whereas a notching index of 35 or less avoided inferior notching 91% of the time. In this study, notching index was calculated for each patient, and then the mean values of groups 1 and 2 were compared (Table 1).
The effect of scapular notching and other individual radiographic parameters on outcomes was also evaluated with respect to forward flexion, external rotation, VAS pain score, complications, and external rotation lag sign. Mann-Whitney U test was used to test these variables; Spearman rank test was performed to determine correlation between each variable and scapular notching; logistic regression was used to explore the relationship of variables (PGRD, PSNA) as predictors of Nerot degree of inferior scapular notching, and postoperative complications; and independent-samples t test was used to determine group differences for each variable. For each investigation, the level of significance was set at P < .05. A biostatistician performed all statistical analyses using SPSS Version 19 (IBM, Armonk, New York).
Results
Our study cohort consisted of 91 shoulders. Mean follow-up was 41.8 months (range, 24.0-80.8 months). Seventy-five (82%) of the 91 shoulders developed scapular notching. Mean (SD) SNA on preoperative radiographs, used to assess preoperative scapular morphology, was 103.9° (14.5°). For all 91 shoulders, mean (SD) PSNA was 125.6° (16°), and mean (SD) PGRD was 16 (5.4) mm (Table 1). Inclination measurements were available for 86 patients. Mean (SD) inclination from 90° was 2.5° (10.3°) (range, 21°-30°). Mean (SD) SNA (postoperative PSNA minus preoperative SNA) for the 66 patients with acceptable preoperative radiographs was 24.3° (21.3°) (Table 1). Forty-eight of the 91 shoulders were placed in scapular notching group 1 (16 grade-0 shoulders, 32 grade-1 shoulders); the other 43 shoulders were placed in group 2 (33 grade-2 shoulders, 9 grade-3 shoulders, 1 grade-4 shoulder). Mean follow-up was 40 months for group 1 and 43 months for group 2.
There were no significant differences between groups 1 and 2 in SNA (102.8° vs 105.4°; P = .3), PGRD (15.4 vs 16.8 mm; P = . 47), or PSNA (125.8° vs 125.4°; P = .82) (Table 1). In addition, groups 1 and 2 had no significant differences (P > .05) in glenoid overhang and glenosphere inclination (other possible factors influencing notching).
Mean (SD) notching index was 31.8 (4.4) for group 1 and 33.1 (7.2) for group 2. These values were not significantly different (P = .29) (Table 1, Figure 2).8 Each was below the recommended threshold of 35 for prevention of notching (Table 1, Figure 2).
To try to understand why mean scapular notching index was low for both groups, we examined the contributing factors individually. Our cohort’s mean PGRD of 16.1 mm (15.4 and 16.8 mm for groups 1 and 2, respectively) was significantly lower than the cohort mean reported by Simovitch and colleagues8 (Table 2). Given that PGRD is more strongly weighted in the originally described notching index ([PSNA × 0.13] + PGRD),8 it was the primary driver for our notching index results, even though on average our results demonstrated a PSNA higher than that found by Simovitch and colleagues8 (Table 2; Figures 3, 4). Analyzing PGRD and PSNA together, we found no relationship between these variables and increased severity of inferior notching (Figure 5).
Regarding the effects of notching severity on outcomes in our study cohort, there were no significant differences between groups 1 and 2 in postoperative function, including forward flexion (123° vs 112.4°; P = .11), external rotation (18.8° vs 16.7°; P = .76), positive lag sign (P = .2), and VAS pain scores (1.2 vs 2.1; P = .15). There were also no significant differences between groups in the rate of complications (P = .92). Regression analysis determined that PSNA, PGRD, glenosphere inclination, glenosphere overhang, and implant manufacturer were not significant predictors of complications.
Discussion
RSA has provided good pain relief and restored function in patients with irreparable rotator cuff disease associated with arthritis.5,12,17,18 Scapular notching is a complex, multifactorial process. Nevertheless, surgeons remain cautious about the implications of inferior scapular notching, which is being reported by a significant number of patients. Our cohort’s high incidence of scapular notching (82%) in the early postoperative period clearly highlights the importance of predictive models, such as the notching index.8 Although concerns about consequences of notching have been expressed, notching severity did not affect outcomes or increase complications in this cohort.5,8,11,12,17-19
We conducted this study to examine use of a predictive tool for scapular notching, the notching index, in a large cohort of patients who underwent primary RSA. This index combines 2 well-established factors that contribute to notching—craniocaudal position and PSNA—into a predictive formula based on statistical analyses performed in a prospective cohort study.4,5,8,12,18 In their clinical study, Simovitch and colleagues8 found that both craniocaudal position and PSNA were tightly coupled with inferior scapular notching, and they developed a notching index that accounts for this relationship. We hypothesized that patients with a notching index of less than the recommended 35 would not develop notching and that patients with a notching index of more than 35 would have increased incidence and severity of notching. With our cohort, the recommended index of 35 was not an appropriate threshold predictive of notching. Furthermore, the 35 threshold applied to our cohort had 89% sensitivity and 21% specificity in predicting notching. Although the sensitivity is high, and correctly predicted true instances of notching, the low specificity compromises the precision of the notching formula ([PSNA × 0.13] + PGRD).
From the formula, it can be inferred that higher PSNA values can be compensated for by decreasing PGRD and inferiorizing the glenosphere. However, this recommendation appears limited based on increasing PSNA values, as in our cohort. The previously described notching formula cannot be universally applied to all patients treated with RSA because of the complexity of this relationship and patient-specific anatomy.
We assessed other possible anatomical and surgical factors, specific to scapular morphology, that could contribute to scapular notching. In other studies, reaming that produced an inferior tilt of the glenoid increased the likelihood of inferior notching.8,20,21 Furthermore, we expected less inferior glenoid overhang and smaller glenosphere would predispose patients to more notching.8,12,19 In our cohort, notching grade was not correlated with inferior tilt, glenoid overhang, or glenosphere size, which may be attributed to minimal variability in glenosphere size and a small range of glenosphere overhang.
There were limitations to this study. We examined only 2 types of RSA systems, and they had very similar Grammont designs. Other RSA designs might not have similar shortcomings with respect to inferior notching. In addition, we examined patient cases at a single time point and did not evaluate the effect of notching over time.
Overall, our results suggest that PGRD and PSNA have little effect on development of higher grade notching, particularly with use of Grammont prostheses. With newer surgical techniques, the recommendation is for inferior craniocaudal placement of the glenosphere, but this may not prevent notching with some types of patient-specific scapular morphology. Clearer surgical guidelines and techniques may help delineate the contribution of each parameter causing inferior scapular notching. Surgeons must weigh the evidence to determine how to correct patient-specific glenoid pathology and orient the glenosphere. Recent studies on bony increased-offset reverse shoulder arthroplasty (bio-RSA) techniques or newer prosthetic designs that considerably alter PSNA and the center of rotation may prevent inferior notching and provide a promising alternative to Grammont designs. Ultimately, longer follow-up is also needed to understand the clinical relevance of increased scapular notching.
1. Woodruff MJ, Cohen AP, Bradley JG. Arthroplasty of the shoulder in rheumatoid arthritis with rotator cuff dysfunction. Int Orthop. 2003;27(1):7-10.
2. Inman VT, Saunders JB, Abbott LC. Observations of the function of the shoulder joint. 1944. Clin Orthop. 1996;(330):3-12.
3. Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: the Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg. 2006;15(5):527-540.
4. Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg. 2005;14(1 suppl S):147S-161S.
5. Sirveaux F, Favard L, Oudet D, Huquet D, Walch G, Molé D. Grammont inverted total shoulder arthroplasty in the treatment of glenohumeral osteoarthritis with massive rupture of the cuff. Results of a multicentre study of 80 shoulders. J Bone Joint Surg Br. 2004;86(3):388-395.
6. Kowalsky MS, Galatz LM, Shia DS, Steger-May K, Keener JD. The relationship between scapular notching and reverse shoulder arthroplasty prosthesis design. J Shoulder Elbow Surg. 2012;21(10):1430-1441.
7. Lévigne C, Boileau P, Favard L, et al. Scapular notching in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2008;17(6):925-935.
8. Simovitch RW, Zumstein MA, Lohri E, Helmy N, Gerber C. Predictors of scapular notching in patients managed with the Delta III reverse total shoulder replacement. J Bone Joint Surg Am. 2007;89(3):588-600.
9. Torrens C, Corrales M, Gonzalez G, Solano A, Caceres E. Morphology of the scapula relative to the reverse shoulder prosthesis. J Orthop Surg (Hong Kong). 2009;17(2):146-150.
10. McFarland EG, Sanguanjit P, Tasaki A, Keyurapan E, Fishman EK, Fayad LM. The reverse shoulder prosthesis: a review of imaging features and complications. Skeletal Radiol. 2006;35(7):488-496.
11. Valenti PH, Boutens D, Nerot C. Delta 3 reversed prosthesis for osteoarthritis with massive rotator cuff tear: long-term results (>5 years). In: Walch G, Boileau P, Molé D, eds. Shoulder Prosthesis: Two to Ten Years Follow-Up. Montpellier, France: Sauramps Medical; 2001:253-259.
12. Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am. 2005;87(7):1476-1486.
13. Nyffeler RW, Werner CM, Simmen BR, Gerber C. Analysis of a retrieved Delta III total shoulder prosthesis. J Bone Joint Surg Br. 2004;86(8):1187-1191.
14. Grassi FA, Murena L, Valli F, Alberio R. Six-year experience with the Delta III reverse shoulder prosthesis. J Orthop Surg (Hong Kong). 2009;17(2):151-156.
15. Lévigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop. 2011;469(9):2512-2520.
16. Nyffeler RW, Werner CM, Gerber C. Biomechanical relevance of glenoid component positioning in the reverse Delta III total shoulder prosthesis. J Shoulder Elbow Surg. 2005;14(5):524-528.
17. Rittmeister M, Kerschbaumer F. Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions. J Shoulder Elbow Surg. 2001;10(1):17-22.
18. Vanhove B, Beugnies A. Grammont’s reverse shoulder prosthesis for rotator cuff arthropathy. A retrospective study of 32 cases. Acta Orthop Belg. 2004;70(3):219-225.
19. Kempton LB, Balasubramaniam M, Ankerson E, Wiater JM. A radiographic analysis of the effects of glenosphere position on scapular notching following reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2011;20(6):968-974.
20. Gutiérrez S, Greiwe RM, Frankle MA, Siegal S, Lee WE. Biomechanical comparison of component position and hardware failure in the reverse shoulder prosthesis. J Shoulder Elbow Surg. 2007;16(3 suppl):S9-S12.
21. Roche CP, Diep P, Hamilton M, et al. Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty. Bull Hosp Jt Dis. 2013;71(4):284-293.
Reverse shoulder arthroplasty (RSA) is a treatment option for a spectrum of diseases in shoulders with rotator cuff deficiency. There are distinct morphologic changes in the scapular and glenoid anatomy in patients with chronic rotator cuff tears.1 A muscular imbalance that occurs in the joint as a result of rotator cuff deficiency leads to morphologic changes that eliminate the compressive forces that hold the humeral head against the glenoid.2 RSA effectively stabilizes the glenohumeral joint in shoulders with deficient rotator cuffs.3,4 In early work, Grammont proposed that the glenosphere center of rotation should be medialized (concentric to the central axis of the metaglene or baseplate) and lowered.5 Although the medialized center of rotation in Grammont prostheses decreases shear forces and improves the deltoid lever arm, it also tends to result in mechanical impingement between the superomedial aspect of the humeral polyethylene insert and the scapular neck—so-called inferior scapular notching.6-9
Notching, which has been reported in 50% to 96% of patients who receive a Delta III prosthesis, typically appears within the first few months after surgery but may be seen as late as 14 months after surgery.5,10-12 Postmortem studies have shown that notching corresponds with erosion of the inferior pole of the glenoid and scapular neck, thought to be caused by the polyethylene cup of the implant.13 Although some studies have found that notching stabilizes after 1 year, others have shown notching progressing for up to 4 years after surgery.11,12,14 The clinical relevance of notching continues to be controversial, but notching has been associated with poorer clinical outcomes, polyethylene wear, and local osteolysis. Component loosening has also been reported with notching of grade 3 or more.8,10 Ultimately, there is concern that scapular notching could progress, ultimately leading to late glenoid loosening and potentially catastrophic failure.
Scapular anatomy has become an area of increased focus in rotator cuff disorders and in effects on RSA biomechanics.9 Recent reports have described important scapular morphology variations that suggest more individualized adjustments are needed during RSA.9,15 In addition, some investigators have reported that development of notching appears to depend on the height and inclination of the implanted glenoid component, where an inferior position of the glenosphere leads to less impingement and better range of motion.8,16 Simovitch and colleagues8 found the angle between the glenosphere and scapular neck and the craniocaudal position of the glenosphere to be highly correlated with inferior notching. They combined these 2 parameters into a predictive algorithm that provides a guideline (notching index, <35) for prevention of notching.
We conducted a study to evaluate the scapular notching index as a predictive tool and to consider other factors that may be associated with scapular notching occurring with use of Grammont reverse replacement systems. We hypothesized that patients with a notching index of less than 35 would not develop notching and that patients with an index of more than 35 would have increased incidence and severity of notching.
Materials and Methods
Patients treated with RSA for painful cuff tear arthropathy or irreparable rotator cuff tear with pseudoparesis (inability to actively elevate shoulder >90° in presence of free passive anterior elevation) were included in this retrospective review. All patients were treated between 2006 and 2010 by 1 of 2 established senior shoulder subspecialty surgeons. Patients treated with a Delta (DePuy Orthopaedics, Warsaw, Indiana) or an Aequalis (Tornier, Edina, Minnesota) reverse shoulder implant were included in the study. A standard polyethylene liner was used for all patients. These prostheses have the same neck shaft angle, 155º, as they have similar geometric designs, both based on the Grammont design—semiconstrained inverted with a fixed, lowered, medialized center of rotation. Standard instrumentation was used for all procedures. Patients were excluded if any nonstandard techniques or components were used (constrained or high-mobility liner, glenoid bone grafting). Patients who underwent revision for a previous reverse total arthroplasty, a total shoulder arthroplasty, or a hemiarthroplasty, or for treatment of acute fracture, posttraumatic deformity, or posttraumatic arthritis, were also excluded from our analyses. Minimum follow-up for study inclusion was 24 months.
All procedures were performed with the patient in the semi-beach-chair position and with use of a deltopectoral approach. The glenoid was prepared such that minimal reaming was needed to preserve the subchondral plate. The glenoid baseplate was positioned in the recommended inferior position to minimize notching and optimize functional outcomes.13 After surgery, all patients were managed with a simple soft immobilizer with or without a pillow with the arm at the patient’s side in internal rotation. Immediate passive mobilization was begun under the direction of physical therapists. Passive and active-assisted exercises were continued with gradual progression to independent activities of daily living at 6 weeks. Clinical evaluations were performed before and after surgery by the operating surgeon or independent research nurse. Active forward flexion, passive external rotation, strength, and visual analog scale (VAS) pain scores were reviewed and recorded. Case-specific complications were also reviewed.
Preoperative and postoperative anteroposterior radiographs were evaluated by 2 independent observers (attending surgeon, junior resident). Per standard technique, each radiograph was positioned horizontal to the scapular plane. Of the 91 patients, 66 had preoperative shoulder radiographs of acceptable quality, with complete visualization of scapular morphology. Radiographs were reviewed to measure the scapular neck angle (SNA), inferior scapular notching, prosthesis–scapular neck angle (PSNA), and peg glenoid rim distance (PGRD) (Figure 1). For the 66 patients with acceptable preoperative radiographs, SNA was determined by subtracting preoperative SNA from postoperative PSNA. Postoperative anteroposterior radiographs were used to classify degree of inferior scapular notching based on the Nerot grading scale (0-4). In addition, glenosphere overhang and glenosphere inclination were measured on postoperative radiographs.
The 91 shoulders were sorted into 2 groups based on degree of scapular notching: group 1, Nerot grade 0 (no inferior notching) and grade 1, and group 2, Nerot grades 2, 3, and 4. Group 1 had 37 patients with a size 36 glenosphere, 3 patients with size 38, and 8 patients with size 42; group 2 had 34 patients with a size 36 glenosphere, 1 patient with size 38, and 8 patients with size 42. All measurements were normalized to account for differences in glenosphere size. Groups 1 and 2 were compared on each radiographic parameter (inferior scapular notching, PSNA, PGRD, SNA).
Notching indexes were calculated ([PSNA × 0.13] + PGRD) and compared with the suggested index of 35.8 Simovitch and colleagues8 demonstrated that a notching index of more than 35 had 91% sensitivity and 88% specificity in predicting inferior notching, whereas a notching index of 35 or less avoided inferior notching 91% of the time. In this study, notching index was calculated for each patient, and then the mean values of groups 1 and 2 were compared (Table 1).
The effect of scapular notching and other individual radiographic parameters on outcomes was also evaluated with respect to forward flexion, external rotation, VAS pain score, complications, and external rotation lag sign. Mann-Whitney U test was used to test these variables; Spearman rank test was performed to determine correlation between each variable and scapular notching; logistic regression was used to explore the relationship of variables (PGRD, PSNA) as predictors of Nerot degree of inferior scapular notching, and postoperative complications; and independent-samples t test was used to determine group differences for each variable. For each investigation, the level of significance was set at P < .05. A biostatistician performed all statistical analyses using SPSS Version 19 (IBM, Armonk, New York).
Results
Our study cohort consisted of 91 shoulders. Mean follow-up was 41.8 months (range, 24.0-80.8 months). Seventy-five (82%) of the 91 shoulders developed scapular notching. Mean (SD) SNA on preoperative radiographs, used to assess preoperative scapular morphology, was 103.9° (14.5°). For all 91 shoulders, mean (SD) PSNA was 125.6° (16°), and mean (SD) PGRD was 16 (5.4) mm (Table 1). Inclination measurements were available for 86 patients. Mean (SD) inclination from 90° was 2.5° (10.3°) (range, 21°-30°). Mean (SD) SNA (postoperative PSNA minus preoperative SNA) for the 66 patients with acceptable preoperative radiographs was 24.3° (21.3°) (Table 1). Forty-eight of the 91 shoulders were placed in scapular notching group 1 (16 grade-0 shoulders, 32 grade-1 shoulders); the other 43 shoulders were placed in group 2 (33 grade-2 shoulders, 9 grade-3 shoulders, 1 grade-4 shoulder). Mean follow-up was 40 months for group 1 and 43 months for group 2.
There were no significant differences between groups 1 and 2 in SNA (102.8° vs 105.4°; P = .3), PGRD (15.4 vs 16.8 mm; P = . 47), or PSNA (125.8° vs 125.4°; P = .82) (Table 1). In addition, groups 1 and 2 had no significant differences (P > .05) in glenoid overhang and glenosphere inclination (other possible factors influencing notching).
Mean (SD) notching index was 31.8 (4.4) for group 1 and 33.1 (7.2) for group 2. These values were not significantly different (P = .29) (Table 1, Figure 2).8 Each was below the recommended threshold of 35 for prevention of notching (Table 1, Figure 2).
To try to understand why mean scapular notching index was low for both groups, we examined the contributing factors individually. Our cohort’s mean PGRD of 16.1 mm (15.4 and 16.8 mm for groups 1 and 2, respectively) was significantly lower than the cohort mean reported by Simovitch and colleagues8 (Table 2). Given that PGRD is more strongly weighted in the originally described notching index ([PSNA × 0.13] + PGRD),8 it was the primary driver for our notching index results, even though on average our results demonstrated a PSNA higher than that found by Simovitch and colleagues8 (Table 2; Figures 3, 4). Analyzing PGRD and PSNA together, we found no relationship between these variables and increased severity of inferior notching (Figure 5).
Regarding the effects of notching severity on outcomes in our study cohort, there were no significant differences between groups 1 and 2 in postoperative function, including forward flexion (123° vs 112.4°; P = .11), external rotation (18.8° vs 16.7°; P = .76), positive lag sign (P = .2), and VAS pain scores (1.2 vs 2.1; P = .15). There were also no significant differences between groups in the rate of complications (P = .92). Regression analysis determined that PSNA, PGRD, glenosphere inclination, glenosphere overhang, and implant manufacturer were not significant predictors of complications.
Discussion
RSA has provided good pain relief and restored function in patients with irreparable rotator cuff disease associated with arthritis.5,12,17,18 Scapular notching is a complex, multifactorial process. Nevertheless, surgeons remain cautious about the implications of inferior scapular notching, which is being reported by a significant number of patients. Our cohort’s high incidence of scapular notching (82%) in the early postoperative period clearly highlights the importance of predictive models, such as the notching index.8 Although concerns about consequences of notching have been expressed, notching severity did not affect outcomes or increase complications in this cohort.5,8,11,12,17-19
We conducted this study to examine use of a predictive tool for scapular notching, the notching index, in a large cohort of patients who underwent primary RSA. This index combines 2 well-established factors that contribute to notching—craniocaudal position and PSNA—into a predictive formula based on statistical analyses performed in a prospective cohort study.4,5,8,12,18 In their clinical study, Simovitch and colleagues8 found that both craniocaudal position and PSNA were tightly coupled with inferior scapular notching, and they developed a notching index that accounts for this relationship. We hypothesized that patients with a notching index of less than the recommended 35 would not develop notching and that patients with a notching index of more than 35 would have increased incidence and severity of notching. With our cohort, the recommended index of 35 was not an appropriate threshold predictive of notching. Furthermore, the 35 threshold applied to our cohort had 89% sensitivity and 21% specificity in predicting notching. Although the sensitivity is high, and correctly predicted true instances of notching, the low specificity compromises the precision of the notching formula ([PSNA × 0.13] + PGRD).
From the formula, it can be inferred that higher PSNA values can be compensated for by decreasing PGRD and inferiorizing the glenosphere. However, this recommendation appears limited based on increasing PSNA values, as in our cohort. The previously described notching formula cannot be universally applied to all patients treated with RSA because of the complexity of this relationship and patient-specific anatomy.
We assessed other possible anatomical and surgical factors, specific to scapular morphology, that could contribute to scapular notching. In other studies, reaming that produced an inferior tilt of the glenoid increased the likelihood of inferior notching.8,20,21 Furthermore, we expected less inferior glenoid overhang and smaller glenosphere would predispose patients to more notching.8,12,19 In our cohort, notching grade was not correlated with inferior tilt, glenoid overhang, or glenosphere size, which may be attributed to minimal variability in glenosphere size and a small range of glenosphere overhang.
There were limitations to this study. We examined only 2 types of RSA systems, and they had very similar Grammont designs. Other RSA designs might not have similar shortcomings with respect to inferior notching. In addition, we examined patient cases at a single time point and did not evaluate the effect of notching over time.
Overall, our results suggest that PGRD and PSNA have little effect on development of higher grade notching, particularly with use of Grammont prostheses. With newer surgical techniques, the recommendation is for inferior craniocaudal placement of the glenosphere, but this may not prevent notching with some types of patient-specific scapular morphology. Clearer surgical guidelines and techniques may help delineate the contribution of each parameter causing inferior scapular notching. Surgeons must weigh the evidence to determine how to correct patient-specific glenoid pathology and orient the glenosphere. Recent studies on bony increased-offset reverse shoulder arthroplasty (bio-RSA) techniques or newer prosthetic designs that considerably alter PSNA and the center of rotation may prevent inferior notching and provide a promising alternative to Grammont designs. Ultimately, longer follow-up is also needed to understand the clinical relevance of increased scapular notching.
Reverse shoulder arthroplasty (RSA) is a treatment option for a spectrum of diseases in shoulders with rotator cuff deficiency. There are distinct morphologic changes in the scapular and glenoid anatomy in patients with chronic rotator cuff tears.1 A muscular imbalance that occurs in the joint as a result of rotator cuff deficiency leads to morphologic changes that eliminate the compressive forces that hold the humeral head against the glenoid.2 RSA effectively stabilizes the glenohumeral joint in shoulders with deficient rotator cuffs.3,4 In early work, Grammont proposed that the glenosphere center of rotation should be medialized (concentric to the central axis of the metaglene or baseplate) and lowered.5 Although the medialized center of rotation in Grammont prostheses decreases shear forces and improves the deltoid lever arm, it also tends to result in mechanical impingement between the superomedial aspect of the humeral polyethylene insert and the scapular neck—so-called inferior scapular notching.6-9
Notching, which has been reported in 50% to 96% of patients who receive a Delta III prosthesis, typically appears within the first few months after surgery but may be seen as late as 14 months after surgery.5,10-12 Postmortem studies have shown that notching corresponds with erosion of the inferior pole of the glenoid and scapular neck, thought to be caused by the polyethylene cup of the implant.13 Although some studies have found that notching stabilizes after 1 year, others have shown notching progressing for up to 4 years after surgery.11,12,14 The clinical relevance of notching continues to be controversial, but notching has been associated with poorer clinical outcomes, polyethylene wear, and local osteolysis. Component loosening has also been reported with notching of grade 3 or more.8,10 Ultimately, there is concern that scapular notching could progress, ultimately leading to late glenoid loosening and potentially catastrophic failure.
Scapular anatomy has become an area of increased focus in rotator cuff disorders and in effects on RSA biomechanics.9 Recent reports have described important scapular morphology variations that suggest more individualized adjustments are needed during RSA.9,15 In addition, some investigators have reported that development of notching appears to depend on the height and inclination of the implanted glenoid component, where an inferior position of the glenosphere leads to less impingement and better range of motion.8,16 Simovitch and colleagues8 found the angle between the glenosphere and scapular neck and the craniocaudal position of the glenosphere to be highly correlated with inferior notching. They combined these 2 parameters into a predictive algorithm that provides a guideline (notching index, <35) for prevention of notching.
We conducted a study to evaluate the scapular notching index as a predictive tool and to consider other factors that may be associated with scapular notching occurring with use of Grammont reverse replacement systems. We hypothesized that patients with a notching index of less than 35 would not develop notching and that patients with an index of more than 35 would have increased incidence and severity of notching.
Materials and Methods
Patients treated with RSA for painful cuff tear arthropathy or irreparable rotator cuff tear with pseudoparesis (inability to actively elevate shoulder >90° in presence of free passive anterior elevation) were included in this retrospective review. All patients were treated between 2006 and 2010 by 1 of 2 established senior shoulder subspecialty surgeons. Patients treated with a Delta (DePuy Orthopaedics, Warsaw, Indiana) or an Aequalis (Tornier, Edina, Minnesota) reverse shoulder implant were included in the study. A standard polyethylene liner was used for all patients. These prostheses have the same neck shaft angle, 155º, as they have similar geometric designs, both based on the Grammont design—semiconstrained inverted with a fixed, lowered, medialized center of rotation. Standard instrumentation was used for all procedures. Patients were excluded if any nonstandard techniques or components were used (constrained or high-mobility liner, glenoid bone grafting). Patients who underwent revision for a previous reverse total arthroplasty, a total shoulder arthroplasty, or a hemiarthroplasty, or for treatment of acute fracture, posttraumatic deformity, or posttraumatic arthritis, were also excluded from our analyses. Minimum follow-up for study inclusion was 24 months.
All procedures were performed with the patient in the semi-beach-chair position and with use of a deltopectoral approach. The glenoid was prepared such that minimal reaming was needed to preserve the subchondral plate. The glenoid baseplate was positioned in the recommended inferior position to minimize notching and optimize functional outcomes.13 After surgery, all patients were managed with a simple soft immobilizer with or without a pillow with the arm at the patient’s side in internal rotation. Immediate passive mobilization was begun under the direction of physical therapists. Passive and active-assisted exercises were continued with gradual progression to independent activities of daily living at 6 weeks. Clinical evaluations were performed before and after surgery by the operating surgeon or independent research nurse. Active forward flexion, passive external rotation, strength, and visual analog scale (VAS) pain scores were reviewed and recorded. Case-specific complications were also reviewed.
Preoperative and postoperative anteroposterior radiographs were evaluated by 2 independent observers (attending surgeon, junior resident). Per standard technique, each radiograph was positioned horizontal to the scapular plane. Of the 91 patients, 66 had preoperative shoulder radiographs of acceptable quality, with complete visualization of scapular morphology. Radiographs were reviewed to measure the scapular neck angle (SNA), inferior scapular notching, prosthesis–scapular neck angle (PSNA), and peg glenoid rim distance (PGRD) (Figure 1). For the 66 patients with acceptable preoperative radiographs, SNA was determined by subtracting preoperative SNA from postoperative PSNA. Postoperative anteroposterior radiographs were used to classify degree of inferior scapular notching based on the Nerot grading scale (0-4). In addition, glenosphere overhang and glenosphere inclination were measured on postoperative radiographs.
The 91 shoulders were sorted into 2 groups based on degree of scapular notching: group 1, Nerot grade 0 (no inferior notching) and grade 1, and group 2, Nerot grades 2, 3, and 4. Group 1 had 37 patients with a size 36 glenosphere, 3 patients with size 38, and 8 patients with size 42; group 2 had 34 patients with a size 36 glenosphere, 1 patient with size 38, and 8 patients with size 42. All measurements were normalized to account for differences in glenosphere size. Groups 1 and 2 were compared on each radiographic parameter (inferior scapular notching, PSNA, PGRD, SNA).
Notching indexes were calculated ([PSNA × 0.13] + PGRD) and compared with the suggested index of 35.8 Simovitch and colleagues8 demonstrated that a notching index of more than 35 had 91% sensitivity and 88% specificity in predicting inferior notching, whereas a notching index of 35 or less avoided inferior notching 91% of the time. In this study, notching index was calculated for each patient, and then the mean values of groups 1 and 2 were compared (Table 1).
The effect of scapular notching and other individual radiographic parameters on outcomes was also evaluated with respect to forward flexion, external rotation, VAS pain score, complications, and external rotation lag sign. Mann-Whitney U test was used to test these variables; Spearman rank test was performed to determine correlation between each variable and scapular notching; logistic regression was used to explore the relationship of variables (PGRD, PSNA) as predictors of Nerot degree of inferior scapular notching, and postoperative complications; and independent-samples t test was used to determine group differences for each variable. For each investigation, the level of significance was set at P < .05. A biostatistician performed all statistical analyses using SPSS Version 19 (IBM, Armonk, New York).
Results
Our study cohort consisted of 91 shoulders. Mean follow-up was 41.8 months (range, 24.0-80.8 months). Seventy-five (82%) of the 91 shoulders developed scapular notching. Mean (SD) SNA on preoperative radiographs, used to assess preoperative scapular morphology, was 103.9° (14.5°). For all 91 shoulders, mean (SD) PSNA was 125.6° (16°), and mean (SD) PGRD was 16 (5.4) mm (Table 1). Inclination measurements were available for 86 patients. Mean (SD) inclination from 90° was 2.5° (10.3°) (range, 21°-30°). Mean (SD) SNA (postoperative PSNA minus preoperative SNA) for the 66 patients with acceptable preoperative radiographs was 24.3° (21.3°) (Table 1). Forty-eight of the 91 shoulders were placed in scapular notching group 1 (16 grade-0 shoulders, 32 grade-1 shoulders); the other 43 shoulders were placed in group 2 (33 grade-2 shoulders, 9 grade-3 shoulders, 1 grade-4 shoulder). Mean follow-up was 40 months for group 1 and 43 months for group 2.
There were no significant differences between groups 1 and 2 in SNA (102.8° vs 105.4°; P = .3), PGRD (15.4 vs 16.8 mm; P = . 47), or PSNA (125.8° vs 125.4°; P = .82) (Table 1). In addition, groups 1 and 2 had no significant differences (P > .05) in glenoid overhang and glenosphere inclination (other possible factors influencing notching).
Mean (SD) notching index was 31.8 (4.4) for group 1 and 33.1 (7.2) for group 2. These values were not significantly different (P = .29) (Table 1, Figure 2).8 Each was below the recommended threshold of 35 for prevention of notching (Table 1, Figure 2).
To try to understand why mean scapular notching index was low for both groups, we examined the contributing factors individually. Our cohort’s mean PGRD of 16.1 mm (15.4 and 16.8 mm for groups 1 and 2, respectively) was significantly lower than the cohort mean reported by Simovitch and colleagues8 (Table 2). Given that PGRD is more strongly weighted in the originally described notching index ([PSNA × 0.13] + PGRD),8 it was the primary driver for our notching index results, even though on average our results demonstrated a PSNA higher than that found by Simovitch and colleagues8 (Table 2; Figures 3, 4). Analyzing PGRD and PSNA together, we found no relationship between these variables and increased severity of inferior notching (Figure 5).
Regarding the effects of notching severity on outcomes in our study cohort, there were no significant differences between groups 1 and 2 in postoperative function, including forward flexion (123° vs 112.4°; P = .11), external rotation (18.8° vs 16.7°; P = .76), positive lag sign (P = .2), and VAS pain scores (1.2 vs 2.1; P = .15). There were also no significant differences between groups in the rate of complications (P = .92). Regression analysis determined that PSNA, PGRD, glenosphere inclination, glenosphere overhang, and implant manufacturer were not significant predictors of complications.
Discussion
RSA has provided good pain relief and restored function in patients with irreparable rotator cuff disease associated with arthritis.5,12,17,18 Scapular notching is a complex, multifactorial process. Nevertheless, surgeons remain cautious about the implications of inferior scapular notching, which is being reported by a significant number of patients. Our cohort’s high incidence of scapular notching (82%) in the early postoperative period clearly highlights the importance of predictive models, such as the notching index.8 Although concerns about consequences of notching have been expressed, notching severity did not affect outcomes or increase complications in this cohort.5,8,11,12,17-19
We conducted this study to examine use of a predictive tool for scapular notching, the notching index, in a large cohort of patients who underwent primary RSA. This index combines 2 well-established factors that contribute to notching—craniocaudal position and PSNA—into a predictive formula based on statistical analyses performed in a prospective cohort study.4,5,8,12,18 In their clinical study, Simovitch and colleagues8 found that both craniocaudal position and PSNA were tightly coupled with inferior scapular notching, and they developed a notching index that accounts for this relationship. We hypothesized that patients with a notching index of less than the recommended 35 would not develop notching and that patients with a notching index of more than 35 would have increased incidence and severity of notching. With our cohort, the recommended index of 35 was not an appropriate threshold predictive of notching. Furthermore, the 35 threshold applied to our cohort had 89% sensitivity and 21% specificity in predicting notching. Although the sensitivity is high, and correctly predicted true instances of notching, the low specificity compromises the precision of the notching formula ([PSNA × 0.13] + PGRD).
From the formula, it can be inferred that higher PSNA values can be compensated for by decreasing PGRD and inferiorizing the glenosphere. However, this recommendation appears limited based on increasing PSNA values, as in our cohort. The previously described notching formula cannot be universally applied to all patients treated with RSA because of the complexity of this relationship and patient-specific anatomy.
We assessed other possible anatomical and surgical factors, specific to scapular morphology, that could contribute to scapular notching. In other studies, reaming that produced an inferior tilt of the glenoid increased the likelihood of inferior notching.8,20,21 Furthermore, we expected less inferior glenoid overhang and smaller glenosphere would predispose patients to more notching.8,12,19 In our cohort, notching grade was not correlated with inferior tilt, glenoid overhang, or glenosphere size, which may be attributed to minimal variability in glenosphere size and a small range of glenosphere overhang.
There were limitations to this study. We examined only 2 types of RSA systems, and they had very similar Grammont designs. Other RSA designs might not have similar shortcomings with respect to inferior notching. In addition, we examined patient cases at a single time point and did not evaluate the effect of notching over time.
Overall, our results suggest that PGRD and PSNA have little effect on development of higher grade notching, particularly with use of Grammont prostheses. With newer surgical techniques, the recommendation is for inferior craniocaudal placement of the glenosphere, but this may not prevent notching with some types of patient-specific scapular morphology. Clearer surgical guidelines and techniques may help delineate the contribution of each parameter causing inferior scapular notching. Surgeons must weigh the evidence to determine how to correct patient-specific glenoid pathology and orient the glenosphere. Recent studies on bony increased-offset reverse shoulder arthroplasty (bio-RSA) techniques or newer prosthetic designs that considerably alter PSNA and the center of rotation may prevent inferior notching and provide a promising alternative to Grammont designs. Ultimately, longer follow-up is also needed to understand the clinical relevance of increased scapular notching.
1. Woodruff MJ, Cohen AP, Bradley JG. Arthroplasty of the shoulder in rheumatoid arthritis with rotator cuff dysfunction. Int Orthop. 2003;27(1):7-10.
2. Inman VT, Saunders JB, Abbott LC. Observations of the function of the shoulder joint. 1944. Clin Orthop. 1996;(330):3-12.
3. Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: the Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg. 2006;15(5):527-540.
4. Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg. 2005;14(1 suppl S):147S-161S.
5. Sirveaux F, Favard L, Oudet D, Huquet D, Walch G, Molé D. Grammont inverted total shoulder arthroplasty in the treatment of glenohumeral osteoarthritis with massive rupture of the cuff. Results of a multicentre study of 80 shoulders. J Bone Joint Surg Br. 2004;86(3):388-395.
6. Kowalsky MS, Galatz LM, Shia DS, Steger-May K, Keener JD. The relationship between scapular notching and reverse shoulder arthroplasty prosthesis design. J Shoulder Elbow Surg. 2012;21(10):1430-1441.
7. Lévigne C, Boileau P, Favard L, et al. Scapular notching in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2008;17(6):925-935.
8. Simovitch RW, Zumstein MA, Lohri E, Helmy N, Gerber C. Predictors of scapular notching in patients managed with the Delta III reverse total shoulder replacement. J Bone Joint Surg Am. 2007;89(3):588-600.
9. Torrens C, Corrales M, Gonzalez G, Solano A, Caceres E. Morphology of the scapula relative to the reverse shoulder prosthesis. J Orthop Surg (Hong Kong). 2009;17(2):146-150.
10. McFarland EG, Sanguanjit P, Tasaki A, Keyurapan E, Fishman EK, Fayad LM. The reverse shoulder prosthesis: a review of imaging features and complications. Skeletal Radiol. 2006;35(7):488-496.
11. Valenti PH, Boutens D, Nerot C. Delta 3 reversed prosthesis for osteoarthritis with massive rotator cuff tear: long-term results (>5 years). In: Walch G, Boileau P, Molé D, eds. Shoulder Prosthesis: Two to Ten Years Follow-Up. Montpellier, France: Sauramps Medical; 2001:253-259.
12. Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am. 2005;87(7):1476-1486.
13. Nyffeler RW, Werner CM, Simmen BR, Gerber C. Analysis of a retrieved Delta III total shoulder prosthesis. J Bone Joint Surg Br. 2004;86(8):1187-1191.
14. Grassi FA, Murena L, Valli F, Alberio R. Six-year experience with the Delta III reverse shoulder prosthesis. J Orthop Surg (Hong Kong). 2009;17(2):151-156.
15. Lévigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop. 2011;469(9):2512-2520.
16. Nyffeler RW, Werner CM, Gerber C. Biomechanical relevance of glenoid component positioning in the reverse Delta III total shoulder prosthesis. J Shoulder Elbow Surg. 2005;14(5):524-528.
17. Rittmeister M, Kerschbaumer F. Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions. J Shoulder Elbow Surg. 2001;10(1):17-22.
18. Vanhove B, Beugnies A. Grammont’s reverse shoulder prosthesis for rotator cuff arthropathy. A retrospective study of 32 cases. Acta Orthop Belg. 2004;70(3):219-225.
19. Kempton LB, Balasubramaniam M, Ankerson E, Wiater JM. A radiographic analysis of the effects of glenosphere position on scapular notching following reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2011;20(6):968-974.
20. Gutiérrez S, Greiwe RM, Frankle MA, Siegal S, Lee WE. Biomechanical comparison of component position and hardware failure in the reverse shoulder prosthesis. J Shoulder Elbow Surg. 2007;16(3 suppl):S9-S12.
21. Roche CP, Diep P, Hamilton M, et al. Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty. Bull Hosp Jt Dis. 2013;71(4):284-293.
1. Woodruff MJ, Cohen AP, Bradley JG. Arthroplasty of the shoulder in rheumatoid arthritis with rotator cuff dysfunction. Int Orthop. 2003;27(1):7-10.
2. Inman VT, Saunders JB, Abbott LC. Observations of the function of the shoulder joint. 1944. Clin Orthop. 1996;(330):3-12.
3. Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: the Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg. 2006;15(5):527-540.
4. Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg. 2005;14(1 suppl S):147S-161S.
5. Sirveaux F, Favard L, Oudet D, Huquet D, Walch G, Molé D. Grammont inverted total shoulder arthroplasty in the treatment of glenohumeral osteoarthritis with massive rupture of the cuff. Results of a multicentre study of 80 shoulders. J Bone Joint Surg Br. 2004;86(3):388-395.
6. Kowalsky MS, Galatz LM, Shia DS, Steger-May K, Keener JD. The relationship between scapular notching and reverse shoulder arthroplasty prosthesis design. J Shoulder Elbow Surg. 2012;21(10):1430-1441.
7. Lévigne C, Boileau P, Favard L, et al. Scapular notching in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2008;17(6):925-935.
8. Simovitch RW, Zumstein MA, Lohri E, Helmy N, Gerber C. Predictors of scapular notching in patients managed with the Delta III reverse total shoulder replacement. J Bone Joint Surg Am. 2007;89(3):588-600.
9. Torrens C, Corrales M, Gonzalez G, Solano A, Caceres E. Morphology of the scapula relative to the reverse shoulder prosthesis. J Orthop Surg (Hong Kong). 2009;17(2):146-150.
10. McFarland EG, Sanguanjit P, Tasaki A, Keyurapan E, Fishman EK, Fayad LM. The reverse shoulder prosthesis: a review of imaging features and complications. Skeletal Radiol. 2006;35(7):488-496.
11. Valenti PH, Boutens D, Nerot C. Delta 3 reversed prosthesis for osteoarthritis with massive rotator cuff tear: long-term results (>5 years). In: Walch G, Boileau P, Molé D, eds. Shoulder Prosthesis: Two to Ten Years Follow-Up. Montpellier, France: Sauramps Medical; 2001:253-259.
12. Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am. 2005;87(7):1476-1486.
13. Nyffeler RW, Werner CM, Simmen BR, Gerber C. Analysis of a retrieved Delta III total shoulder prosthesis. J Bone Joint Surg Br. 2004;86(8):1187-1191.
14. Grassi FA, Murena L, Valli F, Alberio R. Six-year experience with the Delta III reverse shoulder prosthesis. J Orthop Surg (Hong Kong). 2009;17(2):151-156.
15. Lévigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop. 2011;469(9):2512-2520.
16. Nyffeler RW, Werner CM, Gerber C. Biomechanical relevance of glenoid component positioning in the reverse Delta III total shoulder prosthesis. J Shoulder Elbow Surg. 2005;14(5):524-528.
17. Rittmeister M, Kerschbaumer F. Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions. J Shoulder Elbow Surg. 2001;10(1):17-22.
18. Vanhove B, Beugnies A. Grammont’s reverse shoulder prosthesis for rotator cuff arthropathy. A retrospective study of 32 cases. Acta Orthop Belg. 2004;70(3):219-225.
19. Kempton LB, Balasubramaniam M, Ankerson E, Wiater JM. A radiographic analysis of the effects of glenosphere position on scapular notching following reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2011;20(6):968-974.
20. Gutiérrez S, Greiwe RM, Frankle MA, Siegal S, Lee WE. Biomechanical comparison of component position and hardware failure in the reverse shoulder prosthesis. J Shoulder Elbow Surg. 2007;16(3 suppl):S9-S12.
21. Roche CP, Diep P, Hamilton M, et al. Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty. Bull Hosp Jt Dis. 2013;71(4):284-293.
Risk Factors for In-Hospital Myocardial Infarction After Shoulder Arthroplasty
The incidence of shoulder arthroplasty in the United States is increasing annually,1-3 and the majority of these operations occur in older patients.4-6 Elderly patients with cardiovascular, pulmonary, cerebral, renal, and hepatic disease are increasingly susceptible to numerous surgical complications.4 Myocardial infarction (MI) is a complication that occurs in 0.7% of noncardiac surgeries. This figure increases to 1.1% in patients with coronary artery disease.7-11 Perioperative MI increases morbidity and mortality,8 and perioperative cardiac morbidity is the leading cause of death after anesthesia and surgery.12 The financial effects of perioperative cardiac morbidity and mortality must also be considered. A 2009 claims analysis study estimated charges associated with a perioperative MI at $15,000 and the cost of cardiac death at $21,909.13
Cardiovascular complications are associated with a significant degree of morbidity and mortality in patients who undergo arthroplasty.14-16 Although studies have elucidated 30- and 90-day morbidity and mortality rates after shoulder arthroplasty, in hip and knee arthroplasty17-19 little has been done to determine predictors of perioperative MI in a representative database of patients. Given the increasing incidence of shoulder arthroplasty in the United States, the elective nature of this procedure, and the percentage of the US population with cardiovascular risk factors,20 it is important to establish predictors of perioperative MI to ensure patients and physicians have the necessary resources to make informed decisions.
We conducted a study to examine the risk factors for perioperative MI in a large cohort of patients admitted for shoulder arthroplasty to US hospitals. We wanted to evaluate the association between perioperative MI and shoulder arthroplasty with respect to demographics, primary diagnosis, medical comorbidities, and perioperative complications. Specifically, we tested the null hypothesis that, among patients undergoing shoulder arthroplasty, and accounting for confounding variables, there would be no difference in risk factors for patients who have a perioperative MI.
Materials and Methods
This study was exempt from approval by our institutional review board. All data used in this project were deidentified before use.
Nationwide Inpatient Sample (NIS)
The Nationwide Inpatient Sample (NIS), an annual survey of hospitals, is conducted by the Healthcare Cost and Utilization Project (HCUP) and sponsored by the Agency for Healthcare Research and Quality (AHRQ). This database is the largest publicly available all-payer inpatient discharge database in the United States.21 Sampling 8 million hospital stays each year, NIS includes information from a representative batch of 20% of US hospitals. In 2011, 46 states and 1045 hospitals contributed information to the database, representing 97% of the US population.22 This large sample allows researchers to analyze a robust set of medical conditions and uncommon treatments. The survey, conducted each year since 1988, includes demographic, clinical, and resource use data.23 Discharge weight files are provided by NIS to arrive at valid national estimates.
This database is particularly useful because it provides information on up to 25 medical diagnoses and 15 procedures, which are recorded with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Researchers can use this database to analyze patient and hospital characteristics as well as inpatient outcomes.24,25 Numerous studies have used NIS to address pertinent queries across the medical landscape.22,26
Patient Selection and Analysis
We used NIS to isolate a population of 422,371 adults (≥18 years old) who underwent total shoulder arthroplasty (TSA) or hemi–shoulder arthroplasty (HSA) between January 1, 2002 and December 31, 2011. We then placed the patients in this population into 1 of 2 cohorts. The first cohort had an acute MI during the perioperative period after TSA, and the second, larger cohort did not have an acute MI after TSA. Acute MI was identified using ICD-9-CM code 410.xx. To identify a population of shoulder arthroplasty patients, we included discharges with an ICD-9-CM procedure code of 81.80 or 81.88 (both TSA) or 81.81 (HSA) in the sample. We then considered the degree to which each of 5 variables—primary diagnosis, age, sex, race, and select medical comorbidities—was predictive of in-hospital MI after TSA.
Statistical Analysis
Given the large sample used in this study, normal distribution of data was assumed. Using bivariate analysis, Pearson χ2 test for categorical data, and independent-samples t test for continuous data, we compared the nonacute MI and acute MI groups. Multivariable binary logistic regression analyses allowed us to isolate the extent that primary diagnosis, age, sex, race, and medical comorbidities were predictors of acute MI after shoulder arthroplasty. Statistical significance was set at P < .05. SPSS Version 22.0 (SPSS, Chicago, Illinois) was used for all statistical analyses and data modeling.
Results
Between January 1, 2002 and December 31, 2011, an estimated total of 422,371 patients underwent shoulder arthroplasty (59.3% TSA, 40.7% HSA). Of these patients, 1174 (0.28%) had a perioperative MI, and 421,197 (99.72%) did not (Table 1). Patients with a primary diagnosis of proximal humerus fracture (33.8% vs 16.6%; P < .001) or rotator cuff arthropathy (10.1% vs 9.9%; P < .001) were more likely than patients with other diagnoses to have an in-hospital MI.
Our review of the demographics found that patients who underwent shoulder arthroplasty and had a perioperative MI were likely older (75±8.9 years vs 69±11 years; P < .001), Caucasian (94.2% vs 91.9%; P = .002), male (43.2% vs 39.7%; P = .013), in the highest median household income bracket of $63,000 or more (30.8% vs 25.6%; P < .001), and using Medicare (80.9% vs 66.3%; P < .001). They were more likely to be treated in a medical center of medium size (25.6% vs 23.7%; P = .042) or larger (61.8% vs 61.2%; P = .042). MIs occurred more often in urban environments (91.4% vs 88.5%; P = .002) and in HSA patients (55% vs 40.6%; P < .001), resulting in longer hospital stays (9.4±7.9 days vs 2.7±2.5 days; P < .001) and higher probability of death (6.5% vs 0.1%; P < .001).
We then analyzed the 2 cohorts for medical comorbidities (Table 2). Patients in the MI cohort presented with a significantly higher incidence of congestive heart failure, previous MI, angina pectoris, chronic lung disease, hypertension, diabetes, renal failure, fluid and electrolyte disorders, pulmonary circulatory disease, coagulopathy, and deficiency anemia (P < .001) but not liver disease and obesity. Bivariate analysis of perioperative outcomes (Table 3) indicated that these patients also had a statistically higher rate of numerous other complications: pulmonary embolism (4.9% vs 0.2%; P < .001), pneumonia (15.1% vs 1.2%; P < .001), deep venous thrombosis (2.6% vs 0.2%; P < .001), cerebrovascular event (1.6% vs 0.1%; P < .001), acute renal failure (15.1% vs 1.2%; P < .001), gastrointestinal complication (1.2% vs 0.3%; P < .001), mechanical ventilation (1.2% vs 0.3%; P < .001), transfusion (33.4% vs 8.8%; P < .001), and nonroutine discharge (73.3% vs 36.0%; P < .001).
Multivariable logistic regression analysis was performed to determine independent predictors of perioperative MI after shoulder arthroplasty (Table 4). Patients with a primary diagnosis of proximal humerus fracture (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.15-1.65; P < .001) were more likely than patients with a primary diagnosis of osteoarthritis to have an MI. The odds of postoperative MI increased with age (OR, 1.04 per year; 95% CI, 1.03-1.05; P < .001) and were higher in males (OR, 1.72; 95% CI, 1.52-1.96; P < .001). Compared with Caucasians, African Americans (OR, 0.19; 95% CI, 0.09-0.40; P < .001) were less likely to have an in-hospital MI after shoulder arthroplasty. After shoulder arthroplasty, the odds of MI in the perioperative period increased with each subsequent day of care (OR, 1.10; 95% CI, 1.10-1.11; P < .001).
Regarding independent comorbidities, multivariable logistic regression analysis also determined that history of congestive heart failure (OR, 4.86; 95% CI, 4.20-5.61; P < .001), angina pectoris (OR, 2.90; 95% CI, 2.02-4.17; P < .001), complicated diabetes (OR, 1.96; 95% CI, 1.49-2.57; P < .001), renal failure (OR, 1.42; 95% CI, 1.17-1.72; P < .001), fluid and electrolyte disorders (OR, 1.42; 95% CI, 1.21-1.67; P < .001), and deficiency anemia (OR, 1.62; 95% CI, 1.40-1.88; P < .001) were significant predictors of perioperative MI after shoulder arthroplasty.
Discussion
Results of other studies have elucidated 30- and 90-day mortality rates and postoperative complications after shoulder arthroplasty, but, relative to hip and knee arthroplasty,17-19 little has been done to determine predictors of perioperative MI in a large sample of shoulder arthroplasty patients. Given the increasing rates of shoulder arthroplasty1-3 and the demographics of this population,4-6 it is likely that postoperative cardiovascular events will increase in frequency. We found that, in order of decreasing significance, the top 4 risk predictors for acute MI after shoulder arthroplasty were congestive heart failure, angina pectoralis, complicated diabetes mellitus, and male sex. Other pertinent risk factors included older age, Caucasian ethnicity, and a primary diagnosis of proximal humerus fracture. The rate of acute MI in patients who were older than 75 years when they underwent HSA for proximal humerus fracture was 0.80%.
Demographics
We found that patients who had an acute MI after shoulder arthroplasty were likely older, male, and Caucasian. Age and male sex are well-established risk factors for increased cardiac complications after arthroplasty.27-29 Previous studies have indicated that the rate of cardiac events increases in arthroplasty patients older than 65 years.19,28,29 In our study, more than 50% of the patients who had an acute perioperative MI were older than 85 years. Less explainable is the increased occurrence of acute MI in Caucasian patients and wealthy patients, given that minorities in the United States have higher rates of cardiovascular disease.30 Shoulder arthroplasty is an elective procedure, more likely to be undertaken by Caucasians. Therefore, at-risk minority groups and financially challenged groups may be less likely to have this procedure.
Primary Diagnosis
In this series, patients with a primary diagnosis of proximal humerus fracture were more likely to have an in-hospital MI. This finding is consistent with previous studies indicating a higher rate of complications for proximal humerus fracture patients than for shoulder arthroplasty patients.31,32 Given that more than 75% of patients who present with a proximal humerus fracture are older than 70 years, it would be prudent to examine operative indications after this diagnosis,33 particularly as benefit from surgery for fractures has not been definitively demonstrated.34-37
Comorbidities
Many of the patients in our MI cohort presented with congestive heart failure, angina pectoris, complicated diabetes, renal failure, fluid and electrolyte disorders, or deficiency anemia. This is in keeping with other studies indicating that preexisting cardiovascular morbidity increases the rate of MI after various forms of arthroplasty.7-11 Patients in our MI cohort were also susceptible to a variety of post-MI perioperative complications, including pulmonary embolism, pneumonia, deep venous thrombosis, cerebrovascular event, acute renal failure, gastrointestinal complication, mechanical ventilation, transfusion, and nonroutine discharge, and their incidence of death was higher. These findings are consistent with reports that postoperative cardiovascular complications increase the degree of morbidity and mortality in arthroplasty patients.14-16 It is also worth noting that the odds of MI in the perioperative period increase with each subsequent day of care. This is understandable given that patients presenting with numerous comorbidities are at increased risk for perioperative complications38 resulting in hospital readmission.39
The literature indicates that MI occurs as a complication in 0.7% of patients who undergo noncardiac surgery,7 though some series have shown it is more prevalent after arthroplasty procedures.28,40 MI significantly increases the rate of perioperative morbidity and mortality,8 and perioperative cardiac morbidity is a leading cause of death after anesthesia and surgery.12 Furthermore, the most common cause of death after lower extremity arthroplasty is cardiovascular-related.41,42 In patients who presented for elective hip arthroplasty, cardiorespiratory disease was one of the main risk factors (with older age and male sex) shown to increase perioperative mortality.43
Perioperative cardiovascular complications increase postoperative morbidity and mortality.12 The rate of cardiovascular complications after shoulder arthroplasty ranges from 0.8% to 2.6%, and the incidence of MI hovers between 0.3% and 0.9%.17,19,28,40,44 A recent study in 793 patients found that, over a 30-day period, cardiovascular complications accounted for more than one-fourth of all complications.17 Singh and colleagues19 analyzed cardiopulmonary complications after primary shoulder arthroplasty in a total of 3480 patients (4019 arthroplasties) and found this group had a 90-day cardiac morbidity (MI, congestive heart failure, arrhythmia) rate of 2.6%. In that study, a Deyo-Charlson index of 1 or more was a significant independent risk factor for cardiac complications following surgery. Scores on this weighted index of 17 comorbidities are used to assess the complexities of a patient population. Given the severity of cardiovascular perioperative complications, it is important to preoperatively identify high-risk population groups and sufficiently study and optimize patients before shoulder arthroplasty.
There is much debate about the effectiveness of perioperative β-blockers in reducing perioperative cardiac morbidity and mortality.45-48 Such a discussion is outside of the scope of this article, but it may be prudent to seek a cardiology consultation for patients presenting with risk factors for perioperative MI. β-Blockers may prove useful in reducing cardiac morbidity in high-risk patients after noncardiac surgery.45,49
Many limitations are inherent in studies that use a nationally represented database such as NIS, which we used in this study. It is highly likely that NIS does not capture all potential postoperative complications, as this database is very large and subject to errors in data entry and clinical coding. In addition, detailed clinical information (eg, severity of certain comorbid diseases before shoulder arthroplasty, details about the intraoperative course) was not readily available for analysis. Another limitation, which may have led to an underestimate of complication rates, was our not being able to obtain information about postdischarge complications.
Despite these limitations, NIS and other databases have helped researchers answer questions about low-incidence conditions and generalize findings to a national population. In the present study, we analyzed 2 cohorts, patients with and without acute MI after shoulder arthroplasty, to determine predictors for and complications of postarthroplasty MI. We identified numerous predictors for acute MI: congestive heart failure, angina pectoris, complicated diabetes, renal failure, fluid and electrolyte disorders, and deficiency anemia prior to arthroplasty. As perioperative MI is associated with significant morbidity,14-16 it would be wise to screen patients for such comorbid conditions, assess the severity of these conditions, and offer shoulder arthroplasty with prudence.
Conclusion
The top 4 predictors for acute MI after shoulder arthroplasty were congestive heart failure, angina pectoralis, complicated diabetes mellitus, and male sex. Other pertinent risk factors included older age, Caucasian ethnicity, and primary diagnosis of proximal humerus fracture. Surgeons and patients must be aware of predictors for adverse surgical outcomes such as perioperative MI and understand the extent to which these events increase perioperative morbidity and mortality.
1. Day JS, Lau E, Ong KL, Williams GR, Ramsey ML, Kurtz SM. Prevalence and projections of total shoulder and elbow arthroplasty in the United States to 2015. J Shoulder Elbow Surg. 2010;19(8):1115-1120.
2. Kim SH, Wise BL, Zhang Y, Szabo RM. Increasing incidence of shoulder arthroplasty in the United States. J Bone Joint Surg Am. 2011;93(24):2249-2254.
3. Kurtz SM, Lau E, Ong K, Zhao K, Kelly M, Bozic KJ. Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030. Clin Orthop. 2009;467(10):2606-2612.
4. Boettcher WG. Total hip arthroplasties in the elderly. Morbidity, mortality, and cost effectiveness. Clin Orthop. 1992;(274):30-34.
5. Greenfield S, Apolone G, McNeil BJ, Cleary PD. The importance of co-existent disease in the occurrence of postoperative complications and one-year recovery in patients undergoing total hip replacement. Comorbidity and outcomes after hip replacement. Med Care. 1993;31(2):141-154.
6. Kreder HJ, Williams JI, Jaglal S, Hu R, Axcell T, Stephen D. Are complication rates for elective primary total hip arthroplasty in Ontario related to surgeon and hospital volumes? A preliminary investigation. Can J Surg. 1998;41(6):431-437.
7. Botto F, Alonso-Coello P, Chan MT, et al. Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes. Anesthesiology. 2014;120(3):564-578.
8. Mangano DT, Browner WS, Hollenberg M, London MJ, Tubau JF, Tateo IM. Association of perioperative myocardial ischemia with cardiac morbidity and mortality in men undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group. N Engl J Med. 1990;323(26):1781-1788.
9. Tarhan S, Moffitt EA, Taylor WF, Giuliani ER. Myocardial infarction after general anesthesia. JAMA. 1972;220(11):1451-1454.
10. Landesberg G, Mosseri M, Zahger D, et al. Myocardial infarction after vascular surgery: the role of prolonged stress-induced, ST depression-type ischemia. J Am Coll Cardiol. 2001;37(7):1839-1845.
11. van Waes JA, Nathoe HM, de Graaff JC, et al. Myocardial injury after noncardiac surgery and its association with short-term mortality. Circulation. 2013;127(23):2264-2271.
12. Mangano DT. Perioperative cardiac morbidity. Anesthesiology. 1990;72(1):153-184.
13. Fleisher LA, Corbett W, Berry C, Poldermans D. Cost-effectiveness of differing perioperative beta-blockade strategies in vascular surgery patients. J Cardiothorac Vasc Anesth. 2004;18(1):7-13.
14. Aynardi M, Pulido L, Parvizi J, Sharkey PF, Rothman RH. Early mortality after modern total hip arthroplasty. Clin Orthop. 2009;467(1):213-218.
15. Gangireddy C, Rectenwald JR, Upchurch GR, et al. Risk factors and clinical impact of postoperative symptomatic venous thromboembolism. J Vasc Surg. 2007;45(2):335-341.
16. Baser O, Supina D, Sengupta N, Wang L, Kwong L. Impact of postoperative venous thromboembolism on Medicare recipients undergoing total hip replacement or total knee replacement surgery. Am J Health Syst Pharm. 2010;67(17):1438-1445.
17. Fehringer EV, Mikuls TR, Michaud KD, Henderson WG, O’Dell JR. Shoulder arthroplasties have fewer complications than hip or knee arthroplasties in US veterans. Clin Orthop. 2010;468(3):717-722.
18. Farmer KW, Hammond JW, Queale WS, Keyurapan E, McFarland EG. Shoulder arthroplasty versus hip and knee arthroplasties: a comparison of outcomes. Clin Orthop. 2007;(455):183-189.
19. Singh JA, Sperling JW, Cofield RH. Cardiopulmonary complications after primary shoulder arthroplasty: a cohort study. Semin Arthritis Rheum. 2012;41(5):689-697.
20. Go AS, Mozaffarian D, Roger VL, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2014 update: a report from the American Heart Association. Circulation. 2014;129(3):e28-e292.
21. Lin CA, Kuo AC, Takemoto S. Comorbidities and perioperative complications in HIV-positive patients undergoing primary total hip and knee arthroplasty. J Bone Joint Surg Am. 2013;95(11):1028-1036.
22. Maynard C, Sales AE. Changes in the use of coronary artery revascularization procedures in the Department of Veterans Affairs, the National Hospital Discharge Survey, and the Nationwide Inpatient Sample, 1991–1999. BMC Health Serv Res. 2003;3(1):12.
23. Griffin JW, Novicoff WM, Browne JA, Brockmeier SF. Obstructive sleep apnea as a risk factor after shoulder arthroplasty. J Shoulder Elbow Surg. 2013;22(12):e6-e9.
24. Hambright D, Henderson RA, Cook C, Worrell T, Moorman CT, Bolognesi MP. A comparison of perioperative outcomes in patients with and without rheumatoid arthritis after receiving a total shoulder replacement arthroplasty. J Shoulder Elbow Surg. 2011;20(1):77-85.
25. Odum SM, Troyer JL, Kelly MP, Dedini RD, Bozic KJ. A cost-utility analysis comparing the cost-effectiveness of simultaneous and staged bilateral total knee arthroplasty. J Bone Joint Surg Am. 2013;95(16):1441-1449.
26. Ponce BA, Menendez ME, Oladeji LO, Soldado F. Diabetes as a risk factor for poorer early postoperative outcomes after shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(5):671-678.
27. Alfonso DT, Toussaint RJ, Alfonso BD, Strauss EJ, Steiger DT, Di Cesare PE. Nonsurgical complications after total hip and knee arthroplasty. Am J Orthop. 2006;35(11):503-510.
28. Mantilla CB, Horlocker TT, Schroeder DR, Berry DJ, Brown DL. Frequency of myocardial infarction, pulmonary embolism, deep venous thrombosis, and death following primary hip or knee arthroplasty. Anesthesiology. 2002;96(5):1140-1146.
29. Singh JA, Jensen MR, Harmsen WS, Gabriel SE, Lewallen DG. Cardiac and thromboembolic complications and mortality in patients undergoing total hip and total knee arthroplasty. Ann Rheum Dis. 2011;70(12):2082-2088.
30. Kurian AK, Cardarelli KM. Racial and ethnic differences in cardiovascular disease risk factors: a systematic review. Ethn Dis. 2007;17(1):143-152.
31. Zhang AL, Schairer WW, Feeley BT. Hospital readmissions after surgical treatment of proximal humerus fractures: is arthroplasty safer than open reduction internal fixation? Clin Orthop. 2014;472(8):2317-2324.
32. Schairer WW, Zhang AL, Feeley BT. Hospital readmissions after primary shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(9):1349-1355.
33. de Kruijf M, Vroemen JP, de Leur K, van der Voort EA, Vos DI, Van der Laan L. Proximal fractures of the humerus in patients older than 75 years of age: should we consider operative treatment? J Orthop Traumatol. 2014;15(2):111-115.
34. Hauschild O, Konrad G, Audige L, et al. Operative versus non-operative treatment for two-part surgical neck fractures of the proximal humerus. Arch Orthop Trauma Surg. 2013;133(10):1385-1393.
35. Hanson B, Neidenbach P, de Boer P, Stengel D. Functional outcomes after nonoperative management of fractures of the proximal humerus. J Shoulder Elbow Surg. 2009;18(4):612-621.
36. Handoll HH, Ollivere BJ, Rollins KE. Interventions for treating proximal humeral fractures in adults. Cochrane Database Syst Rev. 2012;12:CD000434.
37. Court-Brown CM, Cattermole H, McQueen MM. Impacted valgus fractures (B1.1) of the proximal humerus. The results of non-operative treatment. J Bone Joint Surg Br. 2002;84(4):504-508.
38. Chalmers PN, Gupta AK, Rahman Z, Bruce B, Romeo AA, Nicholson GP. Predictors of early complications of total shoulder arthroplasty. J Arthroplasty. 2014;29(4):856-860.
39. Mahoney A, Bosco JA 3rd, Zuckerman JD. Readmission after shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(3):377-381.
40. Khan SK, Malviya A, Muller SD, et al. Reduced short-term complications and mortality following Enhanced Recovery primary hip and knee arthroplasty: results from 6,000 consecutive procedures. Acta Orthop. 2014;85(1):26-31.
41. Paavolainen P, Pukkala E, Pulkkinen P, Visuri T. Causes of death after total hip arthroplasty: a nationwide cohort study with 24,638 patients. J Arthroplasty. 2002;17(3):274-281.
42. Sharrock NE, Cazan MG, Hargett MJ, Williams-Russo P, Wilson PD Jr. Changes in mortality after total hip and knee arthroplasty over a ten-year period. Anesth Analg. 1995;80(2):242-248.
43. Parvizi J, Johnson BG, Rowland C, Ereth MH, Lewallen DG. Thirty-day mortality after elective total hip arthroplasty. J Bone Joint Surg Am. 2001;83(10):1524-1528.
44. Morris MJ, Molli RG, Berend KR, Lombardi AV Jr. Mortality and perioperative complications after unicompartmental knee arthroplasty. Knee. 2013;20(3):218-220.
45. Lindenauer PK, Pekow P, Wang K, Mamidi DK, Gutierrez B, Benjamin EM. Perioperative beta-blocker therapy and mortality after major noncardiac surgery. N Engl J Med. 2005;353(4):349-361.
46. Wijeysundera DN, Beattie WS, Wijeysundera HC, Yun L, Austin PC, Ko DT. Duration of preoperative beta-blockade and outcomes after major elective noncardiac surgery. Can J Cardiol. 2014;30(2):217-223.
47. Andersson C, Merie C, Jorgensen M, et al. Association of beta-blocker therapy with risks of adverse cardiovascular events and deaths in patients with ischemic heart disease undergoing noncardiac surgery: a Danish nationwide cohort study. JAMA Int Med. 2014;174(3):336-344.
48. Bakker EJ, Ravensbergen NJ, Poldermans D. Perioperative cardiac evaluation, monitoring, and risk reduction strategies in noncardiac surgery patients. Curr Opin Crit Care. 2011;17(5):409-415.
49. Auerbach AD, Goldman L. Beta-blockers and reduction of cardiac events in noncardiac surgery: scientific review. JAMA. 2002;287(11):1435-1444.
The incidence of shoulder arthroplasty in the United States is increasing annually,1-3 and the majority of these operations occur in older patients.4-6 Elderly patients with cardiovascular, pulmonary, cerebral, renal, and hepatic disease are increasingly susceptible to numerous surgical complications.4 Myocardial infarction (MI) is a complication that occurs in 0.7% of noncardiac surgeries. This figure increases to 1.1% in patients with coronary artery disease.7-11 Perioperative MI increases morbidity and mortality,8 and perioperative cardiac morbidity is the leading cause of death after anesthesia and surgery.12 The financial effects of perioperative cardiac morbidity and mortality must also be considered. A 2009 claims analysis study estimated charges associated with a perioperative MI at $15,000 and the cost of cardiac death at $21,909.13
Cardiovascular complications are associated with a significant degree of morbidity and mortality in patients who undergo arthroplasty.14-16 Although studies have elucidated 30- and 90-day morbidity and mortality rates after shoulder arthroplasty, in hip and knee arthroplasty17-19 little has been done to determine predictors of perioperative MI in a representative database of patients. Given the increasing incidence of shoulder arthroplasty in the United States, the elective nature of this procedure, and the percentage of the US population with cardiovascular risk factors,20 it is important to establish predictors of perioperative MI to ensure patients and physicians have the necessary resources to make informed decisions.
We conducted a study to examine the risk factors for perioperative MI in a large cohort of patients admitted for shoulder arthroplasty to US hospitals. We wanted to evaluate the association between perioperative MI and shoulder arthroplasty with respect to demographics, primary diagnosis, medical comorbidities, and perioperative complications. Specifically, we tested the null hypothesis that, among patients undergoing shoulder arthroplasty, and accounting for confounding variables, there would be no difference in risk factors for patients who have a perioperative MI.
Materials and Methods
This study was exempt from approval by our institutional review board. All data used in this project were deidentified before use.
Nationwide Inpatient Sample (NIS)
The Nationwide Inpatient Sample (NIS), an annual survey of hospitals, is conducted by the Healthcare Cost and Utilization Project (HCUP) and sponsored by the Agency for Healthcare Research and Quality (AHRQ). This database is the largest publicly available all-payer inpatient discharge database in the United States.21 Sampling 8 million hospital stays each year, NIS includes information from a representative batch of 20% of US hospitals. In 2011, 46 states and 1045 hospitals contributed information to the database, representing 97% of the US population.22 This large sample allows researchers to analyze a robust set of medical conditions and uncommon treatments. The survey, conducted each year since 1988, includes demographic, clinical, and resource use data.23 Discharge weight files are provided by NIS to arrive at valid national estimates.
This database is particularly useful because it provides information on up to 25 medical diagnoses and 15 procedures, which are recorded with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Researchers can use this database to analyze patient and hospital characteristics as well as inpatient outcomes.24,25 Numerous studies have used NIS to address pertinent queries across the medical landscape.22,26
Patient Selection and Analysis
We used NIS to isolate a population of 422,371 adults (≥18 years old) who underwent total shoulder arthroplasty (TSA) or hemi–shoulder arthroplasty (HSA) between January 1, 2002 and December 31, 2011. We then placed the patients in this population into 1 of 2 cohorts. The first cohort had an acute MI during the perioperative period after TSA, and the second, larger cohort did not have an acute MI after TSA. Acute MI was identified using ICD-9-CM code 410.xx. To identify a population of shoulder arthroplasty patients, we included discharges with an ICD-9-CM procedure code of 81.80 or 81.88 (both TSA) or 81.81 (HSA) in the sample. We then considered the degree to which each of 5 variables—primary diagnosis, age, sex, race, and select medical comorbidities—was predictive of in-hospital MI after TSA.
Statistical Analysis
Given the large sample used in this study, normal distribution of data was assumed. Using bivariate analysis, Pearson χ2 test for categorical data, and independent-samples t test for continuous data, we compared the nonacute MI and acute MI groups. Multivariable binary logistic regression analyses allowed us to isolate the extent that primary diagnosis, age, sex, race, and medical comorbidities were predictors of acute MI after shoulder arthroplasty. Statistical significance was set at P < .05. SPSS Version 22.0 (SPSS, Chicago, Illinois) was used for all statistical analyses and data modeling.
Results
Between January 1, 2002 and December 31, 2011, an estimated total of 422,371 patients underwent shoulder arthroplasty (59.3% TSA, 40.7% HSA). Of these patients, 1174 (0.28%) had a perioperative MI, and 421,197 (99.72%) did not (Table 1). Patients with a primary diagnosis of proximal humerus fracture (33.8% vs 16.6%; P < .001) or rotator cuff arthropathy (10.1% vs 9.9%; P < .001) were more likely than patients with other diagnoses to have an in-hospital MI.
Our review of the demographics found that patients who underwent shoulder arthroplasty and had a perioperative MI were likely older (75±8.9 years vs 69±11 years; P < .001), Caucasian (94.2% vs 91.9%; P = .002), male (43.2% vs 39.7%; P = .013), in the highest median household income bracket of $63,000 or more (30.8% vs 25.6%; P < .001), and using Medicare (80.9% vs 66.3%; P < .001). They were more likely to be treated in a medical center of medium size (25.6% vs 23.7%; P = .042) or larger (61.8% vs 61.2%; P = .042). MIs occurred more often in urban environments (91.4% vs 88.5%; P = .002) and in HSA patients (55% vs 40.6%; P < .001), resulting in longer hospital stays (9.4±7.9 days vs 2.7±2.5 days; P < .001) and higher probability of death (6.5% vs 0.1%; P < .001).
We then analyzed the 2 cohorts for medical comorbidities (Table 2). Patients in the MI cohort presented with a significantly higher incidence of congestive heart failure, previous MI, angina pectoris, chronic lung disease, hypertension, diabetes, renal failure, fluid and electrolyte disorders, pulmonary circulatory disease, coagulopathy, and deficiency anemia (P < .001) but not liver disease and obesity. Bivariate analysis of perioperative outcomes (Table 3) indicated that these patients also had a statistically higher rate of numerous other complications: pulmonary embolism (4.9% vs 0.2%; P < .001), pneumonia (15.1% vs 1.2%; P < .001), deep venous thrombosis (2.6% vs 0.2%; P < .001), cerebrovascular event (1.6% vs 0.1%; P < .001), acute renal failure (15.1% vs 1.2%; P < .001), gastrointestinal complication (1.2% vs 0.3%; P < .001), mechanical ventilation (1.2% vs 0.3%; P < .001), transfusion (33.4% vs 8.8%; P < .001), and nonroutine discharge (73.3% vs 36.0%; P < .001).
Multivariable logistic regression analysis was performed to determine independent predictors of perioperative MI after shoulder arthroplasty (Table 4). Patients with a primary diagnosis of proximal humerus fracture (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.15-1.65; P < .001) were more likely than patients with a primary diagnosis of osteoarthritis to have an MI. The odds of postoperative MI increased with age (OR, 1.04 per year; 95% CI, 1.03-1.05; P < .001) and were higher in males (OR, 1.72; 95% CI, 1.52-1.96; P < .001). Compared with Caucasians, African Americans (OR, 0.19; 95% CI, 0.09-0.40; P < .001) were less likely to have an in-hospital MI after shoulder arthroplasty. After shoulder arthroplasty, the odds of MI in the perioperative period increased with each subsequent day of care (OR, 1.10; 95% CI, 1.10-1.11; P < .001).
Regarding independent comorbidities, multivariable logistic regression analysis also determined that history of congestive heart failure (OR, 4.86; 95% CI, 4.20-5.61; P < .001), angina pectoris (OR, 2.90; 95% CI, 2.02-4.17; P < .001), complicated diabetes (OR, 1.96; 95% CI, 1.49-2.57; P < .001), renal failure (OR, 1.42; 95% CI, 1.17-1.72; P < .001), fluid and electrolyte disorders (OR, 1.42; 95% CI, 1.21-1.67; P < .001), and deficiency anemia (OR, 1.62; 95% CI, 1.40-1.88; P < .001) were significant predictors of perioperative MI after shoulder arthroplasty.
Discussion
Results of other studies have elucidated 30- and 90-day mortality rates and postoperative complications after shoulder arthroplasty, but, relative to hip and knee arthroplasty,17-19 little has been done to determine predictors of perioperative MI in a large sample of shoulder arthroplasty patients. Given the increasing rates of shoulder arthroplasty1-3 and the demographics of this population,4-6 it is likely that postoperative cardiovascular events will increase in frequency. We found that, in order of decreasing significance, the top 4 risk predictors for acute MI after shoulder arthroplasty were congestive heart failure, angina pectoralis, complicated diabetes mellitus, and male sex. Other pertinent risk factors included older age, Caucasian ethnicity, and a primary diagnosis of proximal humerus fracture. The rate of acute MI in patients who were older than 75 years when they underwent HSA for proximal humerus fracture was 0.80%.
Demographics
We found that patients who had an acute MI after shoulder arthroplasty were likely older, male, and Caucasian. Age and male sex are well-established risk factors for increased cardiac complications after arthroplasty.27-29 Previous studies have indicated that the rate of cardiac events increases in arthroplasty patients older than 65 years.19,28,29 In our study, more than 50% of the patients who had an acute perioperative MI were older than 85 years. Less explainable is the increased occurrence of acute MI in Caucasian patients and wealthy patients, given that minorities in the United States have higher rates of cardiovascular disease.30 Shoulder arthroplasty is an elective procedure, more likely to be undertaken by Caucasians. Therefore, at-risk minority groups and financially challenged groups may be less likely to have this procedure.
Primary Diagnosis
In this series, patients with a primary diagnosis of proximal humerus fracture were more likely to have an in-hospital MI. This finding is consistent with previous studies indicating a higher rate of complications for proximal humerus fracture patients than for shoulder arthroplasty patients.31,32 Given that more than 75% of patients who present with a proximal humerus fracture are older than 70 years, it would be prudent to examine operative indications after this diagnosis,33 particularly as benefit from surgery for fractures has not been definitively demonstrated.34-37
Comorbidities
Many of the patients in our MI cohort presented with congestive heart failure, angina pectoris, complicated diabetes, renal failure, fluid and electrolyte disorders, or deficiency anemia. This is in keeping with other studies indicating that preexisting cardiovascular morbidity increases the rate of MI after various forms of arthroplasty.7-11 Patients in our MI cohort were also susceptible to a variety of post-MI perioperative complications, including pulmonary embolism, pneumonia, deep venous thrombosis, cerebrovascular event, acute renal failure, gastrointestinal complication, mechanical ventilation, transfusion, and nonroutine discharge, and their incidence of death was higher. These findings are consistent with reports that postoperative cardiovascular complications increase the degree of morbidity and mortality in arthroplasty patients.14-16 It is also worth noting that the odds of MI in the perioperative period increase with each subsequent day of care. This is understandable given that patients presenting with numerous comorbidities are at increased risk for perioperative complications38 resulting in hospital readmission.39
The literature indicates that MI occurs as a complication in 0.7% of patients who undergo noncardiac surgery,7 though some series have shown it is more prevalent after arthroplasty procedures.28,40 MI significantly increases the rate of perioperative morbidity and mortality,8 and perioperative cardiac morbidity is a leading cause of death after anesthesia and surgery.12 Furthermore, the most common cause of death after lower extremity arthroplasty is cardiovascular-related.41,42 In patients who presented for elective hip arthroplasty, cardiorespiratory disease was one of the main risk factors (with older age and male sex) shown to increase perioperative mortality.43
Perioperative cardiovascular complications increase postoperative morbidity and mortality.12 The rate of cardiovascular complications after shoulder arthroplasty ranges from 0.8% to 2.6%, and the incidence of MI hovers between 0.3% and 0.9%.17,19,28,40,44 A recent study in 793 patients found that, over a 30-day period, cardiovascular complications accounted for more than one-fourth of all complications.17 Singh and colleagues19 analyzed cardiopulmonary complications after primary shoulder arthroplasty in a total of 3480 patients (4019 arthroplasties) and found this group had a 90-day cardiac morbidity (MI, congestive heart failure, arrhythmia) rate of 2.6%. In that study, a Deyo-Charlson index of 1 or more was a significant independent risk factor for cardiac complications following surgery. Scores on this weighted index of 17 comorbidities are used to assess the complexities of a patient population. Given the severity of cardiovascular perioperative complications, it is important to preoperatively identify high-risk population groups and sufficiently study and optimize patients before shoulder arthroplasty.
There is much debate about the effectiveness of perioperative β-blockers in reducing perioperative cardiac morbidity and mortality.45-48 Such a discussion is outside of the scope of this article, but it may be prudent to seek a cardiology consultation for patients presenting with risk factors for perioperative MI. β-Blockers may prove useful in reducing cardiac morbidity in high-risk patients after noncardiac surgery.45,49
Many limitations are inherent in studies that use a nationally represented database such as NIS, which we used in this study. It is highly likely that NIS does not capture all potential postoperative complications, as this database is very large and subject to errors in data entry and clinical coding. In addition, detailed clinical information (eg, severity of certain comorbid diseases before shoulder arthroplasty, details about the intraoperative course) was not readily available for analysis. Another limitation, which may have led to an underestimate of complication rates, was our not being able to obtain information about postdischarge complications.
Despite these limitations, NIS and other databases have helped researchers answer questions about low-incidence conditions and generalize findings to a national population. In the present study, we analyzed 2 cohorts, patients with and without acute MI after shoulder arthroplasty, to determine predictors for and complications of postarthroplasty MI. We identified numerous predictors for acute MI: congestive heart failure, angina pectoris, complicated diabetes, renal failure, fluid and electrolyte disorders, and deficiency anemia prior to arthroplasty. As perioperative MI is associated with significant morbidity,14-16 it would be wise to screen patients for such comorbid conditions, assess the severity of these conditions, and offer shoulder arthroplasty with prudence.
Conclusion
The top 4 predictors for acute MI after shoulder arthroplasty were congestive heart failure, angina pectoralis, complicated diabetes mellitus, and male sex. Other pertinent risk factors included older age, Caucasian ethnicity, and primary diagnosis of proximal humerus fracture. Surgeons and patients must be aware of predictors for adverse surgical outcomes such as perioperative MI and understand the extent to which these events increase perioperative morbidity and mortality.
The incidence of shoulder arthroplasty in the United States is increasing annually,1-3 and the majority of these operations occur in older patients.4-6 Elderly patients with cardiovascular, pulmonary, cerebral, renal, and hepatic disease are increasingly susceptible to numerous surgical complications.4 Myocardial infarction (MI) is a complication that occurs in 0.7% of noncardiac surgeries. This figure increases to 1.1% in patients with coronary artery disease.7-11 Perioperative MI increases morbidity and mortality,8 and perioperative cardiac morbidity is the leading cause of death after anesthesia and surgery.12 The financial effects of perioperative cardiac morbidity and mortality must also be considered. A 2009 claims analysis study estimated charges associated with a perioperative MI at $15,000 and the cost of cardiac death at $21,909.13
Cardiovascular complications are associated with a significant degree of morbidity and mortality in patients who undergo arthroplasty.14-16 Although studies have elucidated 30- and 90-day morbidity and mortality rates after shoulder arthroplasty, in hip and knee arthroplasty17-19 little has been done to determine predictors of perioperative MI in a representative database of patients. Given the increasing incidence of shoulder arthroplasty in the United States, the elective nature of this procedure, and the percentage of the US population with cardiovascular risk factors,20 it is important to establish predictors of perioperative MI to ensure patients and physicians have the necessary resources to make informed decisions.
We conducted a study to examine the risk factors for perioperative MI in a large cohort of patients admitted for shoulder arthroplasty to US hospitals. We wanted to evaluate the association between perioperative MI and shoulder arthroplasty with respect to demographics, primary diagnosis, medical comorbidities, and perioperative complications. Specifically, we tested the null hypothesis that, among patients undergoing shoulder arthroplasty, and accounting for confounding variables, there would be no difference in risk factors for patients who have a perioperative MI.
Materials and Methods
This study was exempt from approval by our institutional review board. All data used in this project were deidentified before use.
Nationwide Inpatient Sample (NIS)
The Nationwide Inpatient Sample (NIS), an annual survey of hospitals, is conducted by the Healthcare Cost and Utilization Project (HCUP) and sponsored by the Agency for Healthcare Research and Quality (AHRQ). This database is the largest publicly available all-payer inpatient discharge database in the United States.21 Sampling 8 million hospital stays each year, NIS includes information from a representative batch of 20% of US hospitals. In 2011, 46 states and 1045 hospitals contributed information to the database, representing 97% of the US population.22 This large sample allows researchers to analyze a robust set of medical conditions and uncommon treatments. The survey, conducted each year since 1988, includes demographic, clinical, and resource use data.23 Discharge weight files are provided by NIS to arrive at valid national estimates.
This database is particularly useful because it provides information on up to 25 medical diagnoses and 15 procedures, which are recorded with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Researchers can use this database to analyze patient and hospital characteristics as well as inpatient outcomes.24,25 Numerous studies have used NIS to address pertinent queries across the medical landscape.22,26
Patient Selection and Analysis
We used NIS to isolate a population of 422,371 adults (≥18 years old) who underwent total shoulder arthroplasty (TSA) or hemi–shoulder arthroplasty (HSA) between January 1, 2002 and December 31, 2011. We then placed the patients in this population into 1 of 2 cohorts. The first cohort had an acute MI during the perioperative period after TSA, and the second, larger cohort did not have an acute MI after TSA. Acute MI was identified using ICD-9-CM code 410.xx. To identify a population of shoulder arthroplasty patients, we included discharges with an ICD-9-CM procedure code of 81.80 or 81.88 (both TSA) or 81.81 (HSA) in the sample. We then considered the degree to which each of 5 variables—primary diagnosis, age, sex, race, and select medical comorbidities—was predictive of in-hospital MI after TSA.
Statistical Analysis
Given the large sample used in this study, normal distribution of data was assumed. Using bivariate analysis, Pearson χ2 test for categorical data, and independent-samples t test for continuous data, we compared the nonacute MI and acute MI groups. Multivariable binary logistic regression analyses allowed us to isolate the extent that primary diagnosis, age, sex, race, and medical comorbidities were predictors of acute MI after shoulder arthroplasty. Statistical significance was set at P < .05. SPSS Version 22.0 (SPSS, Chicago, Illinois) was used for all statistical analyses and data modeling.
Results
Between January 1, 2002 and December 31, 2011, an estimated total of 422,371 patients underwent shoulder arthroplasty (59.3% TSA, 40.7% HSA). Of these patients, 1174 (0.28%) had a perioperative MI, and 421,197 (99.72%) did not (Table 1). Patients with a primary diagnosis of proximal humerus fracture (33.8% vs 16.6%; P < .001) or rotator cuff arthropathy (10.1% vs 9.9%; P < .001) were more likely than patients with other diagnoses to have an in-hospital MI.
Our review of the demographics found that patients who underwent shoulder arthroplasty and had a perioperative MI were likely older (75±8.9 years vs 69±11 years; P < .001), Caucasian (94.2% vs 91.9%; P = .002), male (43.2% vs 39.7%; P = .013), in the highest median household income bracket of $63,000 or more (30.8% vs 25.6%; P < .001), and using Medicare (80.9% vs 66.3%; P < .001). They were more likely to be treated in a medical center of medium size (25.6% vs 23.7%; P = .042) or larger (61.8% vs 61.2%; P = .042). MIs occurred more often in urban environments (91.4% vs 88.5%; P = .002) and in HSA patients (55% vs 40.6%; P < .001), resulting in longer hospital stays (9.4±7.9 days vs 2.7±2.5 days; P < .001) and higher probability of death (6.5% vs 0.1%; P < .001).
We then analyzed the 2 cohorts for medical comorbidities (Table 2). Patients in the MI cohort presented with a significantly higher incidence of congestive heart failure, previous MI, angina pectoris, chronic lung disease, hypertension, diabetes, renal failure, fluid and electrolyte disorders, pulmonary circulatory disease, coagulopathy, and deficiency anemia (P < .001) but not liver disease and obesity. Bivariate analysis of perioperative outcomes (Table 3) indicated that these patients also had a statistically higher rate of numerous other complications: pulmonary embolism (4.9% vs 0.2%; P < .001), pneumonia (15.1% vs 1.2%; P < .001), deep venous thrombosis (2.6% vs 0.2%; P < .001), cerebrovascular event (1.6% vs 0.1%; P < .001), acute renal failure (15.1% vs 1.2%; P < .001), gastrointestinal complication (1.2% vs 0.3%; P < .001), mechanical ventilation (1.2% vs 0.3%; P < .001), transfusion (33.4% vs 8.8%; P < .001), and nonroutine discharge (73.3% vs 36.0%; P < .001).
Multivariable logistic regression analysis was performed to determine independent predictors of perioperative MI after shoulder arthroplasty (Table 4). Patients with a primary diagnosis of proximal humerus fracture (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.15-1.65; P < .001) were more likely than patients with a primary diagnosis of osteoarthritis to have an MI. The odds of postoperative MI increased with age (OR, 1.04 per year; 95% CI, 1.03-1.05; P < .001) and were higher in males (OR, 1.72; 95% CI, 1.52-1.96; P < .001). Compared with Caucasians, African Americans (OR, 0.19; 95% CI, 0.09-0.40; P < .001) were less likely to have an in-hospital MI after shoulder arthroplasty. After shoulder arthroplasty, the odds of MI in the perioperative period increased with each subsequent day of care (OR, 1.10; 95% CI, 1.10-1.11; P < .001).
Regarding independent comorbidities, multivariable logistic regression analysis also determined that history of congestive heart failure (OR, 4.86; 95% CI, 4.20-5.61; P < .001), angina pectoris (OR, 2.90; 95% CI, 2.02-4.17; P < .001), complicated diabetes (OR, 1.96; 95% CI, 1.49-2.57; P < .001), renal failure (OR, 1.42; 95% CI, 1.17-1.72; P < .001), fluid and electrolyte disorders (OR, 1.42; 95% CI, 1.21-1.67; P < .001), and deficiency anemia (OR, 1.62; 95% CI, 1.40-1.88; P < .001) were significant predictors of perioperative MI after shoulder arthroplasty.
Discussion
Results of other studies have elucidated 30- and 90-day mortality rates and postoperative complications after shoulder arthroplasty, but, relative to hip and knee arthroplasty,17-19 little has been done to determine predictors of perioperative MI in a large sample of shoulder arthroplasty patients. Given the increasing rates of shoulder arthroplasty1-3 and the demographics of this population,4-6 it is likely that postoperative cardiovascular events will increase in frequency. We found that, in order of decreasing significance, the top 4 risk predictors for acute MI after shoulder arthroplasty were congestive heart failure, angina pectoralis, complicated diabetes mellitus, and male sex. Other pertinent risk factors included older age, Caucasian ethnicity, and a primary diagnosis of proximal humerus fracture. The rate of acute MI in patients who were older than 75 years when they underwent HSA for proximal humerus fracture was 0.80%.
Demographics
We found that patients who had an acute MI after shoulder arthroplasty were likely older, male, and Caucasian. Age and male sex are well-established risk factors for increased cardiac complications after arthroplasty.27-29 Previous studies have indicated that the rate of cardiac events increases in arthroplasty patients older than 65 years.19,28,29 In our study, more than 50% of the patients who had an acute perioperative MI were older than 85 years. Less explainable is the increased occurrence of acute MI in Caucasian patients and wealthy patients, given that minorities in the United States have higher rates of cardiovascular disease.30 Shoulder arthroplasty is an elective procedure, more likely to be undertaken by Caucasians. Therefore, at-risk minority groups and financially challenged groups may be less likely to have this procedure.
Primary Diagnosis
In this series, patients with a primary diagnosis of proximal humerus fracture were more likely to have an in-hospital MI. This finding is consistent with previous studies indicating a higher rate of complications for proximal humerus fracture patients than for shoulder arthroplasty patients.31,32 Given that more than 75% of patients who present with a proximal humerus fracture are older than 70 years, it would be prudent to examine operative indications after this diagnosis,33 particularly as benefit from surgery for fractures has not been definitively demonstrated.34-37
Comorbidities
Many of the patients in our MI cohort presented with congestive heart failure, angina pectoris, complicated diabetes, renal failure, fluid and electrolyte disorders, or deficiency anemia. This is in keeping with other studies indicating that preexisting cardiovascular morbidity increases the rate of MI after various forms of arthroplasty.7-11 Patients in our MI cohort were also susceptible to a variety of post-MI perioperative complications, including pulmonary embolism, pneumonia, deep venous thrombosis, cerebrovascular event, acute renal failure, gastrointestinal complication, mechanical ventilation, transfusion, and nonroutine discharge, and their incidence of death was higher. These findings are consistent with reports that postoperative cardiovascular complications increase the degree of morbidity and mortality in arthroplasty patients.14-16 It is also worth noting that the odds of MI in the perioperative period increase with each subsequent day of care. This is understandable given that patients presenting with numerous comorbidities are at increased risk for perioperative complications38 resulting in hospital readmission.39
The literature indicates that MI occurs as a complication in 0.7% of patients who undergo noncardiac surgery,7 though some series have shown it is more prevalent after arthroplasty procedures.28,40 MI significantly increases the rate of perioperative morbidity and mortality,8 and perioperative cardiac morbidity is a leading cause of death after anesthesia and surgery.12 Furthermore, the most common cause of death after lower extremity arthroplasty is cardiovascular-related.41,42 In patients who presented for elective hip arthroplasty, cardiorespiratory disease was one of the main risk factors (with older age and male sex) shown to increase perioperative mortality.43
Perioperative cardiovascular complications increase postoperative morbidity and mortality.12 The rate of cardiovascular complications after shoulder arthroplasty ranges from 0.8% to 2.6%, and the incidence of MI hovers between 0.3% and 0.9%.17,19,28,40,44 A recent study in 793 patients found that, over a 30-day period, cardiovascular complications accounted for more than one-fourth of all complications.17 Singh and colleagues19 analyzed cardiopulmonary complications after primary shoulder arthroplasty in a total of 3480 patients (4019 arthroplasties) and found this group had a 90-day cardiac morbidity (MI, congestive heart failure, arrhythmia) rate of 2.6%. In that study, a Deyo-Charlson index of 1 or more was a significant independent risk factor for cardiac complications following surgery. Scores on this weighted index of 17 comorbidities are used to assess the complexities of a patient population. Given the severity of cardiovascular perioperative complications, it is important to preoperatively identify high-risk population groups and sufficiently study and optimize patients before shoulder arthroplasty.
There is much debate about the effectiveness of perioperative β-blockers in reducing perioperative cardiac morbidity and mortality.45-48 Such a discussion is outside of the scope of this article, but it may be prudent to seek a cardiology consultation for patients presenting with risk factors for perioperative MI. β-Blockers may prove useful in reducing cardiac morbidity in high-risk patients after noncardiac surgery.45,49
Many limitations are inherent in studies that use a nationally represented database such as NIS, which we used in this study. It is highly likely that NIS does not capture all potential postoperative complications, as this database is very large and subject to errors in data entry and clinical coding. In addition, detailed clinical information (eg, severity of certain comorbid diseases before shoulder arthroplasty, details about the intraoperative course) was not readily available for analysis. Another limitation, which may have led to an underestimate of complication rates, was our not being able to obtain information about postdischarge complications.
Despite these limitations, NIS and other databases have helped researchers answer questions about low-incidence conditions and generalize findings to a national population. In the present study, we analyzed 2 cohorts, patients with and without acute MI after shoulder arthroplasty, to determine predictors for and complications of postarthroplasty MI. We identified numerous predictors for acute MI: congestive heart failure, angina pectoris, complicated diabetes, renal failure, fluid and electrolyte disorders, and deficiency anemia prior to arthroplasty. As perioperative MI is associated with significant morbidity,14-16 it would be wise to screen patients for such comorbid conditions, assess the severity of these conditions, and offer shoulder arthroplasty with prudence.
Conclusion
The top 4 predictors for acute MI after shoulder arthroplasty were congestive heart failure, angina pectoralis, complicated diabetes mellitus, and male sex. Other pertinent risk factors included older age, Caucasian ethnicity, and primary diagnosis of proximal humerus fracture. Surgeons and patients must be aware of predictors for adverse surgical outcomes such as perioperative MI and understand the extent to which these events increase perioperative morbidity and mortality.
1. Day JS, Lau E, Ong KL, Williams GR, Ramsey ML, Kurtz SM. Prevalence and projections of total shoulder and elbow arthroplasty in the United States to 2015. J Shoulder Elbow Surg. 2010;19(8):1115-1120.
2. Kim SH, Wise BL, Zhang Y, Szabo RM. Increasing incidence of shoulder arthroplasty in the United States. J Bone Joint Surg Am. 2011;93(24):2249-2254.
3. Kurtz SM, Lau E, Ong K, Zhao K, Kelly M, Bozic KJ. Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030. Clin Orthop. 2009;467(10):2606-2612.
4. Boettcher WG. Total hip arthroplasties in the elderly. Morbidity, mortality, and cost effectiveness. Clin Orthop. 1992;(274):30-34.
5. Greenfield S, Apolone G, McNeil BJ, Cleary PD. The importance of co-existent disease in the occurrence of postoperative complications and one-year recovery in patients undergoing total hip replacement. Comorbidity and outcomes after hip replacement. Med Care. 1993;31(2):141-154.
6. Kreder HJ, Williams JI, Jaglal S, Hu R, Axcell T, Stephen D. Are complication rates for elective primary total hip arthroplasty in Ontario related to surgeon and hospital volumes? A preliminary investigation. Can J Surg. 1998;41(6):431-437.
7. Botto F, Alonso-Coello P, Chan MT, et al. Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes. Anesthesiology. 2014;120(3):564-578.
8. Mangano DT, Browner WS, Hollenberg M, London MJ, Tubau JF, Tateo IM. Association of perioperative myocardial ischemia with cardiac morbidity and mortality in men undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group. N Engl J Med. 1990;323(26):1781-1788.
9. Tarhan S, Moffitt EA, Taylor WF, Giuliani ER. Myocardial infarction after general anesthesia. JAMA. 1972;220(11):1451-1454.
10. Landesberg G, Mosseri M, Zahger D, et al. Myocardial infarction after vascular surgery: the role of prolonged stress-induced, ST depression-type ischemia. J Am Coll Cardiol. 2001;37(7):1839-1845.
11. van Waes JA, Nathoe HM, de Graaff JC, et al. Myocardial injury after noncardiac surgery and its association with short-term mortality. Circulation. 2013;127(23):2264-2271.
12. Mangano DT. Perioperative cardiac morbidity. Anesthesiology. 1990;72(1):153-184.
13. Fleisher LA, Corbett W, Berry C, Poldermans D. Cost-effectiveness of differing perioperative beta-blockade strategies in vascular surgery patients. J Cardiothorac Vasc Anesth. 2004;18(1):7-13.
14. Aynardi M, Pulido L, Parvizi J, Sharkey PF, Rothman RH. Early mortality after modern total hip arthroplasty. Clin Orthop. 2009;467(1):213-218.
15. Gangireddy C, Rectenwald JR, Upchurch GR, et al. Risk factors and clinical impact of postoperative symptomatic venous thromboembolism. J Vasc Surg. 2007;45(2):335-341.
16. Baser O, Supina D, Sengupta N, Wang L, Kwong L. Impact of postoperative venous thromboembolism on Medicare recipients undergoing total hip replacement or total knee replacement surgery. Am J Health Syst Pharm. 2010;67(17):1438-1445.
17. Fehringer EV, Mikuls TR, Michaud KD, Henderson WG, O’Dell JR. Shoulder arthroplasties have fewer complications than hip or knee arthroplasties in US veterans. Clin Orthop. 2010;468(3):717-722.
18. Farmer KW, Hammond JW, Queale WS, Keyurapan E, McFarland EG. Shoulder arthroplasty versus hip and knee arthroplasties: a comparison of outcomes. Clin Orthop. 2007;(455):183-189.
19. Singh JA, Sperling JW, Cofield RH. Cardiopulmonary complications after primary shoulder arthroplasty: a cohort study. Semin Arthritis Rheum. 2012;41(5):689-697.
20. Go AS, Mozaffarian D, Roger VL, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2014 update: a report from the American Heart Association. Circulation. 2014;129(3):e28-e292.
21. Lin CA, Kuo AC, Takemoto S. Comorbidities and perioperative complications in HIV-positive patients undergoing primary total hip and knee arthroplasty. J Bone Joint Surg Am. 2013;95(11):1028-1036.
22. Maynard C, Sales AE. Changes in the use of coronary artery revascularization procedures in the Department of Veterans Affairs, the National Hospital Discharge Survey, and the Nationwide Inpatient Sample, 1991–1999. BMC Health Serv Res. 2003;3(1):12.
23. Griffin JW, Novicoff WM, Browne JA, Brockmeier SF. Obstructive sleep apnea as a risk factor after shoulder arthroplasty. J Shoulder Elbow Surg. 2013;22(12):e6-e9.
24. Hambright D, Henderson RA, Cook C, Worrell T, Moorman CT, Bolognesi MP. A comparison of perioperative outcomes in patients with and without rheumatoid arthritis after receiving a total shoulder replacement arthroplasty. J Shoulder Elbow Surg. 2011;20(1):77-85.
25. Odum SM, Troyer JL, Kelly MP, Dedini RD, Bozic KJ. A cost-utility analysis comparing the cost-effectiveness of simultaneous and staged bilateral total knee arthroplasty. J Bone Joint Surg Am. 2013;95(16):1441-1449.
26. Ponce BA, Menendez ME, Oladeji LO, Soldado F. Diabetes as a risk factor for poorer early postoperative outcomes after shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(5):671-678.
27. Alfonso DT, Toussaint RJ, Alfonso BD, Strauss EJ, Steiger DT, Di Cesare PE. Nonsurgical complications after total hip and knee arthroplasty. Am J Orthop. 2006;35(11):503-510.
28. Mantilla CB, Horlocker TT, Schroeder DR, Berry DJ, Brown DL. Frequency of myocardial infarction, pulmonary embolism, deep venous thrombosis, and death following primary hip or knee arthroplasty. Anesthesiology. 2002;96(5):1140-1146.
29. Singh JA, Jensen MR, Harmsen WS, Gabriel SE, Lewallen DG. Cardiac and thromboembolic complications and mortality in patients undergoing total hip and total knee arthroplasty. Ann Rheum Dis. 2011;70(12):2082-2088.
30. Kurian AK, Cardarelli KM. Racial and ethnic differences in cardiovascular disease risk factors: a systematic review. Ethn Dis. 2007;17(1):143-152.
31. Zhang AL, Schairer WW, Feeley BT. Hospital readmissions after surgical treatment of proximal humerus fractures: is arthroplasty safer than open reduction internal fixation? Clin Orthop. 2014;472(8):2317-2324.
32. Schairer WW, Zhang AL, Feeley BT. Hospital readmissions after primary shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(9):1349-1355.
33. de Kruijf M, Vroemen JP, de Leur K, van der Voort EA, Vos DI, Van der Laan L. Proximal fractures of the humerus in patients older than 75 years of age: should we consider operative treatment? J Orthop Traumatol. 2014;15(2):111-115.
34. Hauschild O, Konrad G, Audige L, et al. Operative versus non-operative treatment for two-part surgical neck fractures of the proximal humerus. Arch Orthop Trauma Surg. 2013;133(10):1385-1393.
35. Hanson B, Neidenbach P, de Boer P, Stengel D. Functional outcomes after nonoperative management of fractures of the proximal humerus. J Shoulder Elbow Surg. 2009;18(4):612-621.
36. Handoll HH, Ollivere BJ, Rollins KE. Interventions for treating proximal humeral fractures in adults. Cochrane Database Syst Rev. 2012;12:CD000434.
37. Court-Brown CM, Cattermole H, McQueen MM. Impacted valgus fractures (B1.1) of the proximal humerus. The results of non-operative treatment. J Bone Joint Surg Br. 2002;84(4):504-508.
38. Chalmers PN, Gupta AK, Rahman Z, Bruce B, Romeo AA, Nicholson GP. Predictors of early complications of total shoulder arthroplasty. J Arthroplasty. 2014;29(4):856-860.
39. Mahoney A, Bosco JA 3rd, Zuckerman JD. Readmission after shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(3):377-381.
40. Khan SK, Malviya A, Muller SD, et al. Reduced short-term complications and mortality following Enhanced Recovery primary hip and knee arthroplasty: results from 6,000 consecutive procedures. Acta Orthop. 2014;85(1):26-31.
41. Paavolainen P, Pukkala E, Pulkkinen P, Visuri T. Causes of death after total hip arthroplasty: a nationwide cohort study with 24,638 patients. J Arthroplasty. 2002;17(3):274-281.
42. Sharrock NE, Cazan MG, Hargett MJ, Williams-Russo P, Wilson PD Jr. Changes in mortality after total hip and knee arthroplasty over a ten-year period. Anesth Analg. 1995;80(2):242-248.
43. Parvizi J, Johnson BG, Rowland C, Ereth MH, Lewallen DG. Thirty-day mortality after elective total hip arthroplasty. J Bone Joint Surg Am. 2001;83(10):1524-1528.
44. Morris MJ, Molli RG, Berend KR, Lombardi AV Jr. Mortality and perioperative complications after unicompartmental knee arthroplasty. Knee. 2013;20(3):218-220.
45. Lindenauer PK, Pekow P, Wang K, Mamidi DK, Gutierrez B, Benjamin EM. Perioperative beta-blocker therapy and mortality after major noncardiac surgery. N Engl J Med. 2005;353(4):349-361.
46. Wijeysundera DN, Beattie WS, Wijeysundera HC, Yun L, Austin PC, Ko DT. Duration of preoperative beta-blockade and outcomes after major elective noncardiac surgery. Can J Cardiol. 2014;30(2):217-223.
47. Andersson C, Merie C, Jorgensen M, et al. Association of beta-blocker therapy with risks of adverse cardiovascular events and deaths in patients with ischemic heart disease undergoing noncardiac surgery: a Danish nationwide cohort study. JAMA Int Med. 2014;174(3):336-344.
48. Bakker EJ, Ravensbergen NJ, Poldermans D. Perioperative cardiac evaluation, monitoring, and risk reduction strategies in noncardiac surgery patients. Curr Opin Crit Care. 2011;17(5):409-415.
49. Auerbach AD, Goldman L. Beta-blockers and reduction of cardiac events in noncardiac surgery: scientific review. JAMA. 2002;287(11):1435-1444.
1. Day JS, Lau E, Ong KL, Williams GR, Ramsey ML, Kurtz SM. Prevalence and projections of total shoulder and elbow arthroplasty in the United States to 2015. J Shoulder Elbow Surg. 2010;19(8):1115-1120.
2. Kim SH, Wise BL, Zhang Y, Szabo RM. Increasing incidence of shoulder arthroplasty in the United States. J Bone Joint Surg Am. 2011;93(24):2249-2254.
3. Kurtz SM, Lau E, Ong K, Zhao K, Kelly M, Bozic KJ. Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030. Clin Orthop. 2009;467(10):2606-2612.
4. Boettcher WG. Total hip arthroplasties in the elderly. Morbidity, mortality, and cost effectiveness. Clin Orthop. 1992;(274):30-34.
5. Greenfield S, Apolone G, McNeil BJ, Cleary PD. The importance of co-existent disease in the occurrence of postoperative complications and one-year recovery in patients undergoing total hip replacement. Comorbidity and outcomes after hip replacement. Med Care. 1993;31(2):141-154.
6. Kreder HJ, Williams JI, Jaglal S, Hu R, Axcell T, Stephen D. Are complication rates for elective primary total hip arthroplasty in Ontario related to surgeon and hospital volumes? A preliminary investigation. Can J Surg. 1998;41(6):431-437.
7. Botto F, Alonso-Coello P, Chan MT, et al. Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes. Anesthesiology. 2014;120(3):564-578.
8. Mangano DT, Browner WS, Hollenberg M, London MJ, Tubau JF, Tateo IM. Association of perioperative myocardial ischemia with cardiac morbidity and mortality in men undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group. N Engl J Med. 1990;323(26):1781-1788.
9. Tarhan S, Moffitt EA, Taylor WF, Giuliani ER. Myocardial infarction after general anesthesia. JAMA. 1972;220(11):1451-1454.
10. Landesberg G, Mosseri M, Zahger D, et al. Myocardial infarction after vascular surgery: the role of prolonged stress-induced, ST depression-type ischemia. J Am Coll Cardiol. 2001;37(7):1839-1845.
11. van Waes JA, Nathoe HM, de Graaff JC, et al. Myocardial injury after noncardiac surgery and its association with short-term mortality. Circulation. 2013;127(23):2264-2271.
12. Mangano DT. Perioperative cardiac morbidity. Anesthesiology. 1990;72(1):153-184.
13. Fleisher LA, Corbett W, Berry C, Poldermans D. Cost-effectiveness of differing perioperative beta-blockade strategies in vascular surgery patients. J Cardiothorac Vasc Anesth. 2004;18(1):7-13.
14. Aynardi M, Pulido L, Parvizi J, Sharkey PF, Rothman RH. Early mortality after modern total hip arthroplasty. Clin Orthop. 2009;467(1):213-218.
15. Gangireddy C, Rectenwald JR, Upchurch GR, et al. Risk factors and clinical impact of postoperative symptomatic venous thromboembolism. J Vasc Surg. 2007;45(2):335-341.
16. Baser O, Supina D, Sengupta N, Wang L, Kwong L. Impact of postoperative venous thromboembolism on Medicare recipients undergoing total hip replacement or total knee replacement surgery. Am J Health Syst Pharm. 2010;67(17):1438-1445.
17. Fehringer EV, Mikuls TR, Michaud KD, Henderson WG, O’Dell JR. Shoulder arthroplasties have fewer complications than hip or knee arthroplasties in US veterans. Clin Orthop. 2010;468(3):717-722.
18. Farmer KW, Hammond JW, Queale WS, Keyurapan E, McFarland EG. Shoulder arthroplasty versus hip and knee arthroplasties: a comparison of outcomes. Clin Orthop. 2007;(455):183-189.
19. Singh JA, Sperling JW, Cofield RH. Cardiopulmonary complications after primary shoulder arthroplasty: a cohort study. Semin Arthritis Rheum. 2012;41(5):689-697.
20. Go AS, Mozaffarian D, Roger VL, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2014 update: a report from the American Heart Association. Circulation. 2014;129(3):e28-e292.
21. Lin CA, Kuo AC, Takemoto S. Comorbidities and perioperative complications in HIV-positive patients undergoing primary total hip and knee arthroplasty. J Bone Joint Surg Am. 2013;95(11):1028-1036.
22. Maynard C, Sales AE. Changes in the use of coronary artery revascularization procedures in the Department of Veterans Affairs, the National Hospital Discharge Survey, and the Nationwide Inpatient Sample, 1991–1999. BMC Health Serv Res. 2003;3(1):12.
23. Griffin JW, Novicoff WM, Browne JA, Brockmeier SF. Obstructive sleep apnea as a risk factor after shoulder arthroplasty. J Shoulder Elbow Surg. 2013;22(12):e6-e9.
24. Hambright D, Henderson RA, Cook C, Worrell T, Moorman CT, Bolognesi MP. A comparison of perioperative outcomes in patients with and without rheumatoid arthritis after receiving a total shoulder replacement arthroplasty. J Shoulder Elbow Surg. 2011;20(1):77-85.
25. Odum SM, Troyer JL, Kelly MP, Dedini RD, Bozic KJ. A cost-utility analysis comparing the cost-effectiveness of simultaneous and staged bilateral total knee arthroplasty. J Bone Joint Surg Am. 2013;95(16):1441-1449.
26. Ponce BA, Menendez ME, Oladeji LO, Soldado F. Diabetes as a risk factor for poorer early postoperative outcomes after shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(5):671-678.
27. Alfonso DT, Toussaint RJ, Alfonso BD, Strauss EJ, Steiger DT, Di Cesare PE. Nonsurgical complications after total hip and knee arthroplasty. Am J Orthop. 2006;35(11):503-510.
28. Mantilla CB, Horlocker TT, Schroeder DR, Berry DJ, Brown DL. Frequency of myocardial infarction, pulmonary embolism, deep venous thrombosis, and death following primary hip or knee arthroplasty. Anesthesiology. 2002;96(5):1140-1146.
29. Singh JA, Jensen MR, Harmsen WS, Gabriel SE, Lewallen DG. Cardiac and thromboembolic complications and mortality in patients undergoing total hip and total knee arthroplasty. Ann Rheum Dis. 2011;70(12):2082-2088.
30. Kurian AK, Cardarelli KM. Racial and ethnic differences in cardiovascular disease risk factors: a systematic review. Ethn Dis. 2007;17(1):143-152.
31. Zhang AL, Schairer WW, Feeley BT. Hospital readmissions after surgical treatment of proximal humerus fractures: is arthroplasty safer than open reduction internal fixation? Clin Orthop. 2014;472(8):2317-2324.
32. Schairer WW, Zhang AL, Feeley BT. Hospital readmissions after primary shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(9):1349-1355.
33. de Kruijf M, Vroemen JP, de Leur K, van der Voort EA, Vos DI, Van der Laan L. Proximal fractures of the humerus in patients older than 75 years of age: should we consider operative treatment? J Orthop Traumatol. 2014;15(2):111-115.
34. Hauschild O, Konrad G, Audige L, et al. Operative versus non-operative treatment for two-part surgical neck fractures of the proximal humerus. Arch Orthop Trauma Surg. 2013;133(10):1385-1393.
35. Hanson B, Neidenbach P, de Boer P, Stengel D. Functional outcomes after nonoperative management of fractures of the proximal humerus. J Shoulder Elbow Surg. 2009;18(4):612-621.
36. Handoll HH, Ollivere BJ, Rollins KE. Interventions for treating proximal humeral fractures in adults. Cochrane Database Syst Rev. 2012;12:CD000434.
37. Court-Brown CM, Cattermole H, McQueen MM. Impacted valgus fractures (B1.1) of the proximal humerus. The results of non-operative treatment. J Bone Joint Surg Br. 2002;84(4):504-508.
38. Chalmers PN, Gupta AK, Rahman Z, Bruce B, Romeo AA, Nicholson GP. Predictors of early complications of total shoulder arthroplasty. J Arthroplasty. 2014;29(4):856-860.
39. Mahoney A, Bosco JA 3rd, Zuckerman JD. Readmission after shoulder arthroplasty. J Shoulder Elbow Surg. 2014;23(3):377-381.
40. Khan SK, Malviya A, Muller SD, et al. Reduced short-term complications and mortality following Enhanced Recovery primary hip and knee arthroplasty: results from 6,000 consecutive procedures. Acta Orthop. 2014;85(1):26-31.
41. Paavolainen P, Pukkala E, Pulkkinen P, Visuri T. Causes of death after total hip arthroplasty: a nationwide cohort study with 24,638 patients. J Arthroplasty. 2002;17(3):274-281.
42. Sharrock NE, Cazan MG, Hargett MJ, Williams-Russo P, Wilson PD Jr. Changes in mortality after total hip and knee arthroplasty over a ten-year period. Anesth Analg. 1995;80(2):242-248.
43. Parvizi J, Johnson BG, Rowland C, Ereth MH, Lewallen DG. Thirty-day mortality after elective total hip arthroplasty. J Bone Joint Surg Am. 2001;83(10):1524-1528.
44. Morris MJ, Molli RG, Berend KR, Lombardi AV Jr. Mortality and perioperative complications after unicompartmental knee arthroplasty. Knee. 2013;20(3):218-220.
45. Lindenauer PK, Pekow P, Wang K, Mamidi DK, Gutierrez B, Benjamin EM. Perioperative beta-blocker therapy and mortality after major noncardiac surgery. N Engl J Med. 2005;353(4):349-361.
46. Wijeysundera DN, Beattie WS, Wijeysundera HC, Yun L, Austin PC, Ko DT. Duration of preoperative beta-blockade and outcomes after major elective noncardiac surgery. Can J Cardiol. 2014;30(2):217-223.
47. Andersson C, Merie C, Jorgensen M, et al. Association of beta-blocker therapy with risks of adverse cardiovascular events and deaths in patients with ischemic heart disease undergoing noncardiac surgery: a Danish nationwide cohort study. JAMA Int Med. 2014;174(3):336-344.
48. Bakker EJ, Ravensbergen NJ, Poldermans D. Perioperative cardiac evaluation, monitoring, and risk reduction strategies in noncardiac surgery patients. Curr Opin Crit Care. 2011;17(5):409-415.
49. Auerbach AD, Goldman L. Beta-blockers and reduction of cardiac events in noncardiac surgery: scientific review. JAMA. 2002;287(11):1435-1444.
Patients’ Perceptions of the Costs of Total Hip and Knee Arthroplasty
Medical economics has been a major sociopolitical issue in the United States for the past 20 years, with concerns focused on increasing medical spending. These costs are projected to continue to rise, from 15.3% of gross domestic product in 2002 to 19.6% in 2017.1
Multiple steps have been taken to help reduce the cost of health care, many of which center on physician reimbursement. The Balanced Budget Act of 1997 worked to control Medicare spending by increasing reimbursement for clinic visits by setting reductions for procedural reimbursements. This specifically affects orthopedic surgeons, who between 1991 and 2002 experienced a 28% reduction in reimbursement, after inflation, for commonly performed orthopedic procedures, including hip and knee arthroplasty.2 Unfortunately, this system does not take into account the value of services as perceived by patients.
Total hip and knee arthroplasty (THA, TKA) are well-established surgical treatments for advanced osteoarthritis of the hip and knee, respectively. Much research has been done on patient satisfaction with these procedures and on their long-term results and cost-effectiveness. These procedures rank among the highest in patient satisfaction, and improvements in technique and technology have steadily improved long-term results. THA and TKA have proved to be cost-effective in appropriately indicated patients.
The demand for THA and TKA is projected to increase by 174% and 673%, respectively, from 2005 to 2030.3 Legislators, payers, health care providers, and patients are understandably concerned about the rising cost of health care and the implications for access to elective surgical procedures. In a recent study by Foran and colleagues,4 surveyed postoperative patients indicated that Medicare reimbursement was “much lower” for arthroplasty than it should be. In addition, they overestimated (compared with national averages) what Medicare reimburses for hip and knee arthroplasty. Many raised concerns that orthopedic surgeons might drop Medicare entirely.4
These misconceptions about reimbursement may stem partly from the inaccessibility of health care cost information. Rosenthal and colleagues5 recently queried a random selection of US hospitals and demonstrated the difficulty in obtaining THA pricing information.
In a system in which consumers and payers are often not one and the same, it is unclear if consumers understand the cost of their health care. We conducted a study to assess patients’ perceptions of the cost of total joint arthroplasty (TJA) and gain insight into their understanding of health care costs and their sense of the value of this elective surgical procedure.
Materials and Methods
After obtaining institutional review board approval and informed consent for this study, we surveyed 284 consecutive patients who underwent THA or TKA at an academic medical center. Patients had either primary or revision surgery performed (by Dr. Hallstrom or Dr. Urquhart) and were surveyed during their first (2-week) postoperative visit, between March 1, 2012 and December 20, 2012.
Surveys were labeled with patient identifiers to facilitate abstraction of data from electronic medical records. Operative reports and discharge summaries were reviewed for data that included sex, age, diagnosis, procedure, surgeon, implant, admission date, and length of stay.
The survey asked for demographic information, including level of education, insurance coverage, and annual household income, and included a question to verify the surgical procedure and a question to determine if the patient had reviewed a hospital billing statement pertaining to the patient’s admission. The survey also included these questions about reimbursement and cost:
- How much do you feel your orthopedic surgeon was reimbursed for your surgery? (EXCLUDING payments to the hospital)
- How much do you think your surgeon gets reimbursed to see you IN THE HOSPITAL after surgery?
- How much do you think your surgeon gets reimbursed per visit to see you IN CLINIC for follow-up during the first 3 months after surgery?
- How much do you think the implant used in your surgery cost?
- How much do you think the hospital was reimbursed for your surgery and admission to the hospital after surgery? (EXCLUDING payments to the surgeon)
- How much do you think it cost the hospital to provide your surgery and admission to the hospital after surgery?
Responses were limited to numeric currency format using a response area as shown in Figure 1. Overall patient satisfaction was elicited with use of a 5-point scale ranging from 1 (very unsatisfied) to 5 (very satisfied). Regarding type of implant used, patients could select from 6 prominent vendors or indicate “other” or “don’t know.” They were also asked which of several factors should primarily determine surgeon reimbursement: overall patient satisfaction, technical difficulty, amount of risk/possible harm, duration/amount of time, and rate of complications. A free-response comments section was provided at the end of the survey.
Data from the survey and the electronic medical records were collected using Research Electronic Data Capture (REDCap; Vanderbilt University, Nashville, Tennessee). Statistical analysis was performed with SAS Version 9.3 (SAS Institute, Cary, North Carolina). Data were screened before further analysis. Patients who provided nonnumeric responses in numeric response fields were excluded from further analysis. Numeric ranges were applied in subsequent analysis using the mean of the range. Implausible responses resulted in the removal of the entire encounter from subsequent analysis.
Demographic data used to define categories for further subgroup analysis are presented as percentages of the group. Medians, means, and interquartile ranges were calculated for all responses regarding reimbursement and cost. Differences in perceptions of reimbursement and cost based on subgroups, including procedure type, diagnosis, education level, and satisfaction, were calculated. Independent-samples Student t tests were used to determine the statistical significance of the differences detected.
Results
Of the 400 eligible patients seen at the first postoperative follow-up, 284 (71%) were enrolled in the study. Mean (SD) age was 62.6 (12.6) years. Of the 284 patients enrolled, 154 (54%) were female. Of the participants who reported their education and income, 125 (44%) had a bachelor’s degree or higher degree, and 68 (23.9%) reported income of more than $100,000 per year. The largest payers reported by patients were private insurance (80%) and Medicare (46%). Additional demographic details are listed in Table 1.
Of the 284 patients enrolled in the study, 159 (56%) had THA, and 88 (31%) had TKA (Table 2). Thirty-seven patients (13%) underwent revision procedures. Only 5 patients (2%) indicated they had reviewed their hospital billing statement from their most recent admission. Two hundred forty-two patients (85%) were satisfied or very satisfied with their procedure.
Regarding the implant used in their surgery, 216 patients (76%) indicated they did not know which company manufactured it. Of the 68 patients (24%) who named a manufacturer, 53 (78%) were correct in their selection (intraoperative records were checked). Patients indicated they thought the implant used in their surgery cost $6447 on average (95% CI, $5581-$7312).
On average, patients thought their surgeon was reimbursed $12,014 (95% CI, $10,845-$13,183) for their procedure, and they estimated that the hospital was reimbursed $28,392 (95% CI, $25,271-$31,512) for their perioperative care and that it cost the hospital $24,389 (95% CI, $21,612-$27,165) to provide it. Means, confidence intervals, medians, and interquartile ranges for parameters of reimbursement and cost are listed in Table 3. Seventy-one patients (25%) thought on average that the hospital took a net loss for each TJA performed, and 146 patients (51%) thought on average that the hospital generated a net profit for each TJA.
On average, patients thought surgeons were reimbursed $11,872 for a THA and $12,263 for a TKA. Patients also estimated a higher hospital cost (THA, $22,981; TKA, $26,998) and reimbursement (THA, $27,366; TKA, $30,230) after TKA than THA. These differences in perceptions of cost and reimbursement for THA and TKA appear in Table 4 and Figure 2.
Statistically significant differences were also found in perceptions of cost and reimbursement based on level of education and overall patient satisfaction. Patients with a bachelor’s degree or higher estimated physician reimbursement at $11,006, whereas patients with a lower level of education estimated reimbursement at $12,890. In addition, patients with a lower level of education gave estimates of hospital cost and reimbursement that were $7698 and $10,799 higher, respectively, than the estimates given by patients with a higher level of education (Table 5, Figure 3). Patients who were satisfied or very satisfied with their overall TJA experience estimated surgeon reimbursement at $11,673. Patients who indicated they were unsatisfied, very unsatisfied, or neutral regarding their overall experience gave a higher estimate of surgeon reimbursement: $14,317 (Table 6, Figure 4).
Because of the small number of enrolled patients who had revision surgery and the high variability in patient responses, there were no meaningful or statistically significant differences in perceptions of cost and reimbursement based on revision or primary surgery.
Patients also estimated substantial additional reimbursements to physicians for services included at no additional charge with the global surgical package. Median estimates were $300 for reimbursement to a physician making rounds in the hospital and $250 for reimbursement for an outpatient follow-up. Only 47 patients (17%) and 35 patients (12%) correctly indicated there is no additional payment for making rounds and outpatient follow-up, respectively. Estimates of these reimbursements varied by education level, procedure, and overall satisfaction (Tables 4–6).
Discussion
The sustainable growth rate (SGR) formula, part of the Balanced Budget Act of 1997, was constructed to manage health care costs in the context of overall economic growth. By 2001, Medicare health care expenditures had begun to outpace economic growth, and the SGR formula dictated a reduction in reimbursement to physicians. Each year over the past decade, Congress has passed legislation providing a temporary reprieve, staving off a drastic reduction of as much as 25% in 2010.6 Despite these adjustments, reimbursement continues to decrease because of overall inflation.
More worrisome is that “more than half of the nearly trillion dollar price tag for expanding coverage under the Affordable Care Act (ACA) will be paid by decreasing spending for the more than 46.3 million individuals covered by Medicare.”7 ACA provisions will also create an Independent Payment Advisory Board (IPAB) to oversee health care costs and reduce Medicare spending when it is expected to exceed target levels.8 As IPAB cannot recommend increasing revenues or changing benefits, and because it is initially prohibited from recommending decreasing payments to hospitals, the decreases will likely have the greatest impact on physician reimbursement.7-9
Health care policy has been a major campaign issue during recent US elections. The public and popular media remain engaged in this important discussion. Although patients, policymakers, and physicians are understandably concerned about cost and access to health care, it is unclear if patients understand the distribution of health care cost and reimbursement.
Other authors have studied patients’ perceptions of physician reimbursement for TJA. Hayden and colleagues10 surveyed 1000 residents of a Texas city. The 121 who responded to the survey thought that fair compensation for performing a TKA was $5080, on average.10 Although this was significantly higher than the actual Medicare reimbursement at the time, a later study, by Foran and colleagues,4 found patients’ estimates of both fair reimbursement and Medicare reimbursement for TJA to be even higher. Foran and colleagues4 surveyed 1120 patients who thought surgeons deserved to be paid $14,358 for THA and $13,322 for TKA, on average. These reimbursement values are nearly an order of magnitude higher than actual reimbursements. For Medicare payments, patients lowered their estimates to $8212 for THA and $7196 for TKA.4
To our knowledge, the present study is the first to use a “postconsumer” survey to assess patients’ perceptions of THA and TKA costs. Our results confirmed that patients substantially overestimated reimbursement for THA and TKA at $11,872 and $12,263, respectively, relative to the average Medicare reimbursements of $1467 and $1530, respectively.11 We also found that patients overestimated both hospital cost and reimbursement for THA at $22,981 and $27,366, respectively, relative to recently published hospital economic analyses showing THA cost and reimbursement to be $11,688 and $15,789, respectively.12 Few patients enrolled in our study demonstrated an understanding of the services included in the global surgical package. Only about 12% of patients correctly indicated there was no additional payment to the physician for initial follow-up appointments. However, patients were fairly accurate in their estimates of implant cost. On average, patients who underwent THA priced their implant at $6823, which is only about 9% higher than the reported median cost of $6072 to $6400.13,14
We also found significant differences in perceptions of cost based on level of education, joint replaced, and overall level of satisfaction. On average, patients with a bachelor’s degree or higher gave estimates of cost and reimbursement that were lower than those given by patients with a lower level of education. Estimates of physician reimbursement and hospital reimbursement and cost were higher from patients who had TKA than from patients who had THA.
Comparing perceptions of reimbursement for appendectomy and coronary artery bypass with perceptions for TJA, Foran and colleagues4 found that patients understood the relative complexity of each procedure, as evidenced by their estimates of fair reimbursement for each. However, in comparing patient estimates for the different components of cost and reimbursement for TJA, we found great variability in understanding. Patients in our study overestimated payments to the hospital by 73% but overestimated the cost of the THA implant by only 9%. However, the same patients overestimated physician reimbursement for THA by about 800%. If these patients’ estimates of reimbursement are considered surrogates for relative value, then physicians, based on actual payments, are grossly undervalued relative to implant manufacturers.
Our study had several limitations. First, the enrolled patients were all seen at one medical center, in Ann Arbor, Michigan, and our results may not be generalizable outside the region. Second, the survey respondents were postoperative patients who had an established relationship with the study’s principal investigators—a relationship that may have been a source of bias in the consideration of reimbursement as a function of value. Third, despite our efforts to carefully design a survey with open-ended responses, the order in which the survey questions were presented may have influenced patient responses. Fourth, the open-ended question design may have had an impact on responses where the correct answer would have required entering 0.00.
Despite these limitations, our study results demonstrated general public misconceptions about cost and reimbursement for common orthopedic procedures. Although more transparency in health care cost information may not immediately result in a more well-informed population,15 our patients, given the opportunity to develop an understanding of the economics of their own medical treatment, may become better prepared to make informed choices regarding changes in health care policy.
1. Kumar S, Ghildayal NS, Shah RN. Examining quality and efficiency of the U.S. healthcare system. Int J Health Care Qual Assur. 2011;24(5):366-388.
2. Hariri S, Bozic KJ, Lavernia C, Prestipino A, Rubash HE. Medicare physician reimbursement: past, present, and future. J Bone Joint Surg Am. 2007;89(11):2536-2546.
3. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007;89(4):780-785.
4. Foran JR, Sheth NP, Ward SR, et al. Patient perception of physician reimbursement in elective total hip and knee arthroplasty. J Arthroplasty. 2012;27(5):703-709.
5. Rosenthal JA, Lu X, Cram P. Availability of consumer prices from US hospitals for a common surgical procedure. JAMA Intern Med. 2013;173(6):427-432.
6. US Senate Committee on Finance. H.R. 4994: the Medicare and Medicaid Extenders Act of 2010. http://www.finance.senate.gov/legislation/details/?id=9f97aa2e-5056-a032-52d4-8db158b12b11. Accessed March 25, 2015.
7. Zinberg JM. When patients call, will physicians respond? JAMA. 2011;305(19):2011-2012.
8. Jost TS. The Independent Payment Advisory Board. N Engl J Med. 2010;363(2):103-105.
9. US Department of Health and Human Services, Centers for Medicare & Medicaid Services. Estimated financial effects of the “Patient Protection and Affordable Care Act,” as amended. 2010. http://www.cms.gov/Research-Statistics-Data-and-Systems/Research/ActuarialStudies/downloads/PPACA_2010-04-22.pdf. Accessed March 25, 2015.
10. Hayden SA, Hayden D, White LW. The U.S. public’s perceived value of the surgeon’s fee for total knee replacement. Abstract presented at: 75th Annual Meeting of the American Academy of Orthopaedic Surgeons; March 5-9, 2008; San Francisco, CA. Abstract 214.
11. Centers for Medicare & Medicaid Services. Physician Fee Schedule Search Tool. http://www.cms.gov/apps/physician-fee-schedule/search/search-criteria.aspx. Accessed March 25, 2015.
12. Rana AJ, Iorio R, Healy WL. Hospital economics of primary THA decreasing reimbursement and increasing cost, 1990 to 2008. Clin Orthop. 2011;469(2):355-361.
13. Lavernia CJ, Hernandez VH, Rossi MD. Payment analysis of total hip replacement. Curr Opin Orthop. 2007;18(1):23-27.
14. Robinson JC, Pozen A, Tseng S, Bozic KJ. Variability in costs associated with total hip and knee replacement implants. J Bone Joint Surg Am. 2012;94(18):1693-1698.
15. Smolders JM, Van Loon CJ, Rijnberg WJ, Van Susante JL. Patients poorly estimate the overall costs of a total knee arthroplasty and strongly overestimate the surgeon’s fee. Acta Orthop Belg. 2007;73(3):339-344.
Medical economics has been a major sociopolitical issue in the United States for the past 20 years, with concerns focused on increasing medical spending. These costs are projected to continue to rise, from 15.3% of gross domestic product in 2002 to 19.6% in 2017.1
Multiple steps have been taken to help reduce the cost of health care, many of which center on physician reimbursement. The Balanced Budget Act of 1997 worked to control Medicare spending by increasing reimbursement for clinic visits by setting reductions for procedural reimbursements. This specifically affects orthopedic surgeons, who between 1991 and 2002 experienced a 28% reduction in reimbursement, after inflation, for commonly performed orthopedic procedures, including hip and knee arthroplasty.2 Unfortunately, this system does not take into account the value of services as perceived by patients.
Total hip and knee arthroplasty (THA, TKA) are well-established surgical treatments for advanced osteoarthritis of the hip and knee, respectively. Much research has been done on patient satisfaction with these procedures and on their long-term results and cost-effectiveness. These procedures rank among the highest in patient satisfaction, and improvements in technique and technology have steadily improved long-term results. THA and TKA have proved to be cost-effective in appropriately indicated patients.
The demand for THA and TKA is projected to increase by 174% and 673%, respectively, from 2005 to 2030.3 Legislators, payers, health care providers, and patients are understandably concerned about the rising cost of health care and the implications for access to elective surgical procedures. In a recent study by Foran and colleagues,4 surveyed postoperative patients indicated that Medicare reimbursement was “much lower” for arthroplasty than it should be. In addition, they overestimated (compared with national averages) what Medicare reimburses for hip and knee arthroplasty. Many raised concerns that orthopedic surgeons might drop Medicare entirely.4
These misconceptions about reimbursement may stem partly from the inaccessibility of health care cost information. Rosenthal and colleagues5 recently queried a random selection of US hospitals and demonstrated the difficulty in obtaining THA pricing information.
In a system in which consumers and payers are often not one and the same, it is unclear if consumers understand the cost of their health care. We conducted a study to assess patients’ perceptions of the cost of total joint arthroplasty (TJA) and gain insight into their understanding of health care costs and their sense of the value of this elective surgical procedure.
Materials and Methods
After obtaining institutional review board approval and informed consent for this study, we surveyed 284 consecutive patients who underwent THA or TKA at an academic medical center. Patients had either primary or revision surgery performed (by Dr. Hallstrom or Dr. Urquhart) and were surveyed during their first (2-week) postoperative visit, between March 1, 2012 and December 20, 2012.
Surveys were labeled with patient identifiers to facilitate abstraction of data from electronic medical records. Operative reports and discharge summaries were reviewed for data that included sex, age, diagnosis, procedure, surgeon, implant, admission date, and length of stay.
The survey asked for demographic information, including level of education, insurance coverage, and annual household income, and included a question to verify the surgical procedure and a question to determine if the patient had reviewed a hospital billing statement pertaining to the patient’s admission. The survey also included these questions about reimbursement and cost:
- How much do you feel your orthopedic surgeon was reimbursed for your surgery? (EXCLUDING payments to the hospital)
- How much do you think your surgeon gets reimbursed to see you IN THE HOSPITAL after surgery?
- How much do you think your surgeon gets reimbursed per visit to see you IN CLINIC for follow-up during the first 3 months after surgery?
- How much do you think the implant used in your surgery cost?
- How much do you think the hospital was reimbursed for your surgery and admission to the hospital after surgery? (EXCLUDING payments to the surgeon)
- How much do you think it cost the hospital to provide your surgery and admission to the hospital after surgery?
Responses were limited to numeric currency format using a response area as shown in Figure 1. Overall patient satisfaction was elicited with use of a 5-point scale ranging from 1 (very unsatisfied) to 5 (very satisfied). Regarding type of implant used, patients could select from 6 prominent vendors or indicate “other” or “don’t know.” They were also asked which of several factors should primarily determine surgeon reimbursement: overall patient satisfaction, technical difficulty, amount of risk/possible harm, duration/amount of time, and rate of complications. A free-response comments section was provided at the end of the survey.
Data from the survey and the electronic medical records were collected using Research Electronic Data Capture (REDCap; Vanderbilt University, Nashville, Tennessee). Statistical analysis was performed with SAS Version 9.3 (SAS Institute, Cary, North Carolina). Data were screened before further analysis. Patients who provided nonnumeric responses in numeric response fields were excluded from further analysis. Numeric ranges were applied in subsequent analysis using the mean of the range. Implausible responses resulted in the removal of the entire encounter from subsequent analysis.
Demographic data used to define categories for further subgroup analysis are presented as percentages of the group. Medians, means, and interquartile ranges were calculated for all responses regarding reimbursement and cost. Differences in perceptions of reimbursement and cost based on subgroups, including procedure type, diagnosis, education level, and satisfaction, were calculated. Independent-samples Student t tests were used to determine the statistical significance of the differences detected.
Results
Of the 400 eligible patients seen at the first postoperative follow-up, 284 (71%) were enrolled in the study. Mean (SD) age was 62.6 (12.6) years. Of the 284 patients enrolled, 154 (54%) were female. Of the participants who reported their education and income, 125 (44%) had a bachelor’s degree or higher degree, and 68 (23.9%) reported income of more than $100,000 per year. The largest payers reported by patients were private insurance (80%) and Medicare (46%). Additional demographic details are listed in Table 1.
Of the 284 patients enrolled in the study, 159 (56%) had THA, and 88 (31%) had TKA (Table 2). Thirty-seven patients (13%) underwent revision procedures. Only 5 patients (2%) indicated they had reviewed their hospital billing statement from their most recent admission. Two hundred forty-two patients (85%) were satisfied or very satisfied with their procedure.
Regarding the implant used in their surgery, 216 patients (76%) indicated they did not know which company manufactured it. Of the 68 patients (24%) who named a manufacturer, 53 (78%) were correct in their selection (intraoperative records were checked). Patients indicated they thought the implant used in their surgery cost $6447 on average (95% CI, $5581-$7312).
On average, patients thought their surgeon was reimbursed $12,014 (95% CI, $10,845-$13,183) for their procedure, and they estimated that the hospital was reimbursed $28,392 (95% CI, $25,271-$31,512) for their perioperative care and that it cost the hospital $24,389 (95% CI, $21,612-$27,165) to provide it. Means, confidence intervals, medians, and interquartile ranges for parameters of reimbursement and cost are listed in Table 3. Seventy-one patients (25%) thought on average that the hospital took a net loss for each TJA performed, and 146 patients (51%) thought on average that the hospital generated a net profit for each TJA.
On average, patients thought surgeons were reimbursed $11,872 for a THA and $12,263 for a TKA. Patients also estimated a higher hospital cost (THA, $22,981; TKA, $26,998) and reimbursement (THA, $27,366; TKA, $30,230) after TKA than THA. These differences in perceptions of cost and reimbursement for THA and TKA appear in Table 4 and Figure 2.
Statistically significant differences were also found in perceptions of cost and reimbursement based on level of education and overall patient satisfaction. Patients with a bachelor’s degree or higher estimated physician reimbursement at $11,006, whereas patients with a lower level of education estimated reimbursement at $12,890. In addition, patients with a lower level of education gave estimates of hospital cost and reimbursement that were $7698 and $10,799 higher, respectively, than the estimates given by patients with a higher level of education (Table 5, Figure 3). Patients who were satisfied or very satisfied with their overall TJA experience estimated surgeon reimbursement at $11,673. Patients who indicated they were unsatisfied, very unsatisfied, or neutral regarding their overall experience gave a higher estimate of surgeon reimbursement: $14,317 (Table 6, Figure 4).
Because of the small number of enrolled patients who had revision surgery and the high variability in patient responses, there were no meaningful or statistically significant differences in perceptions of cost and reimbursement based on revision or primary surgery.
Patients also estimated substantial additional reimbursements to physicians for services included at no additional charge with the global surgical package. Median estimates were $300 for reimbursement to a physician making rounds in the hospital and $250 for reimbursement for an outpatient follow-up. Only 47 patients (17%) and 35 patients (12%) correctly indicated there is no additional payment for making rounds and outpatient follow-up, respectively. Estimates of these reimbursements varied by education level, procedure, and overall satisfaction (Tables 4–6).
Discussion
The sustainable growth rate (SGR) formula, part of the Balanced Budget Act of 1997, was constructed to manage health care costs in the context of overall economic growth. By 2001, Medicare health care expenditures had begun to outpace economic growth, and the SGR formula dictated a reduction in reimbursement to physicians. Each year over the past decade, Congress has passed legislation providing a temporary reprieve, staving off a drastic reduction of as much as 25% in 2010.6 Despite these adjustments, reimbursement continues to decrease because of overall inflation.
More worrisome is that “more than half of the nearly trillion dollar price tag for expanding coverage under the Affordable Care Act (ACA) will be paid by decreasing spending for the more than 46.3 million individuals covered by Medicare.”7 ACA provisions will also create an Independent Payment Advisory Board (IPAB) to oversee health care costs and reduce Medicare spending when it is expected to exceed target levels.8 As IPAB cannot recommend increasing revenues or changing benefits, and because it is initially prohibited from recommending decreasing payments to hospitals, the decreases will likely have the greatest impact on physician reimbursement.7-9
Health care policy has been a major campaign issue during recent US elections. The public and popular media remain engaged in this important discussion. Although patients, policymakers, and physicians are understandably concerned about cost and access to health care, it is unclear if patients understand the distribution of health care cost and reimbursement.
Other authors have studied patients’ perceptions of physician reimbursement for TJA. Hayden and colleagues10 surveyed 1000 residents of a Texas city. The 121 who responded to the survey thought that fair compensation for performing a TKA was $5080, on average.10 Although this was significantly higher than the actual Medicare reimbursement at the time, a later study, by Foran and colleagues,4 found patients’ estimates of both fair reimbursement and Medicare reimbursement for TJA to be even higher. Foran and colleagues4 surveyed 1120 patients who thought surgeons deserved to be paid $14,358 for THA and $13,322 for TKA, on average. These reimbursement values are nearly an order of magnitude higher than actual reimbursements. For Medicare payments, patients lowered their estimates to $8212 for THA and $7196 for TKA.4
To our knowledge, the present study is the first to use a “postconsumer” survey to assess patients’ perceptions of THA and TKA costs. Our results confirmed that patients substantially overestimated reimbursement for THA and TKA at $11,872 and $12,263, respectively, relative to the average Medicare reimbursements of $1467 and $1530, respectively.11 We also found that patients overestimated both hospital cost and reimbursement for THA at $22,981 and $27,366, respectively, relative to recently published hospital economic analyses showing THA cost and reimbursement to be $11,688 and $15,789, respectively.12 Few patients enrolled in our study demonstrated an understanding of the services included in the global surgical package. Only about 12% of patients correctly indicated there was no additional payment to the physician for initial follow-up appointments. However, patients were fairly accurate in their estimates of implant cost. On average, patients who underwent THA priced their implant at $6823, which is only about 9% higher than the reported median cost of $6072 to $6400.13,14
We also found significant differences in perceptions of cost based on level of education, joint replaced, and overall level of satisfaction. On average, patients with a bachelor’s degree or higher gave estimates of cost and reimbursement that were lower than those given by patients with a lower level of education. Estimates of physician reimbursement and hospital reimbursement and cost were higher from patients who had TKA than from patients who had THA.
Comparing perceptions of reimbursement for appendectomy and coronary artery bypass with perceptions for TJA, Foran and colleagues4 found that patients understood the relative complexity of each procedure, as evidenced by their estimates of fair reimbursement for each. However, in comparing patient estimates for the different components of cost and reimbursement for TJA, we found great variability in understanding. Patients in our study overestimated payments to the hospital by 73% but overestimated the cost of the THA implant by only 9%. However, the same patients overestimated physician reimbursement for THA by about 800%. If these patients’ estimates of reimbursement are considered surrogates for relative value, then physicians, based on actual payments, are grossly undervalued relative to implant manufacturers.
Our study had several limitations. First, the enrolled patients were all seen at one medical center, in Ann Arbor, Michigan, and our results may not be generalizable outside the region. Second, the survey respondents were postoperative patients who had an established relationship with the study’s principal investigators—a relationship that may have been a source of bias in the consideration of reimbursement as a function of value. Third, despite our efforts to carefully design a survey with open-ended responses, the order in which the survey questions were presented may have influenced patient responses. Fourth, the open-ended question design may have had an impact on responses where the correct answer would have required entering 0.00.
Despite these limitations, our study results demonstrated general public misconceptions about cost and reimbursement for common orthopedic procedures. Although more transparency in health care cost information may not immediately result in a more well-informed population,15 our patients, given the opportunity to develop an understanding of the economics of their own medical treatment, may become better prepared to make informed choices regarding changes in health care policy.
Medical economics has been a major sociopolitical issue in the United States for the past 20 years, with concerns focused on increasing medical spending. These costs are projected to continue to rise, from 15.3% of gross domestic product in 2002 to 19.6% in 2017.1
Multiple steps have been taken to help reduce the cost of health care, many of which center on physician reimbursement. The Balanced Budget Act of 1997 worked to control Medicare spending by increasing reimbursement for clinic visits by setting reductions for procedural reimbursements. This specifically affects orthopedic surgeons, who between 1991 and 2002 experienced a 28% reduction in reimbursement, after inflation, for commonly performed orthopedic procedures, including hip and knee arthroplasty.2 Unfortunately, this system does not take into account the value of services as perceived by patients.
Total hip and knee arthroplasty (THA, TKA) are well-established surgical treatments for advanced osteoarthritis of the hip and knee, respectively. Much research has been done on patient satisfaction with these procedures and on their long-term results and cost-effectiveness. These procedures rank among the highest in patient satisfaction, and improvements in technique and technology have steadily improved long-term results. THA and TKA have proved to be cost-effective in appropriately indicated patients.
The demand for THA and TKA is projected to increase by 174% and 673%, respectively, from 2005 to 2030.3 Legislators, payers, health care providers, and patients are understandably concerned about the rising cost of health care and the implications for access to elective surgical procedures. In a recent study by Foran and colleagues,4 surveyed postoperative patients indicated that Medicare reimbursement was “much lower” for arthroplasty than it should be. In addition, they overestimated (compared with national averages) what Medicare reimburses for hip and knee arthroplasty. Many raised concerns that orthopedic surgeons might drop Medicare entirely.4
These misconceptions about reimbursement may stem partly from the inaccessibility of health care cost information. Rosenthal and colleagues5 recently queried a random selection of US hospitals and demonstrated the difficulty in obtaining THA pricing information.
In a system in which consumers and payers are often not one and the same, it is unclear if consumers understand the cost of their health care. We conducted a study to assess patients’ perceptions of the cost of total joint arthroplasty (TJA) and gain insight into their understanding of health care costs and their sense of the value of this elective surgical procedure.
Materials and Methods
After obtaining institutional review board approval and informed consent for this study, we surveyed 284 consecutive patients who underwent THA or TKA at an academic medical center. Patients had either primary or revision surgery performed (by Dr. Hallstrom or Dr. Urquhart) and were surveyed during their first (2-week) postoperative visit, between March 1, 2012 and December 20, 2012.
Surveys were labeled with patient identifiers to facilitate abstraction of data from electronic medical records. Operative reports and discharge summaries were reviewed for data that included sex, age, diagnosis, procedure, surgeon, implant, admission date, and length of stay.
The survey asked for demographic information, including level of education, insurance coverage, and annual household income, and included a question to verify the surgical procedure and a question to determine if the patient had reviewed a hospital billing statement pertaining to the patient’s admission. The survey also included these questions about reimbursement and cost:
- How much do you feel your orthopedic surgeon was reimbursed for your surgery? (EXCLUDING payments to the hospital)
- How much do you think your surgeon gets reimbursed to see you IN THE HOSPITAL after surgery?
- How much do you think your surgeon gets reimbursed per visit to see you IN CLINIC for follow-up during the first 3 months after surgery?
- How much do you think the implant used in your surgery cost?
- How much do you think the hospital was reimbursed for your surgery and admission to the hospital after surgery? (EXCLUDING payments to the surgeon)
- How much do you think it cost the hospital to provide your surgery and admission to the hospital after surgery?
Responses were limited to numeric currency format using a response area as shown in Figure 1. Overall patient satisfaction was elicited with use of a 5-point scale ranging from 1 (very unsatisfied) to 5 (very satisfied). Regarding type of implant used, patients could select from 6 prominent vendors or indicate “other” or “don’t know.” They were also asked which of several factors should primarily determine surgeon reimbursement: overall patient satisfaction, technical difficulty, amount of risk/possible harm, duration/amount of time, and rate of complications. A free-response comments section was provided at the end of the survey.
Data from the survey and the electronic medical records were collected using Research Electronic Data Capture (REDCap; Vanderbilt University, Nashville, Tennessee). Statistical analysis was performed with SAS Version 9.3 (SAS Institute, Cary, North Carolina). Data were screened before further analysis. Patients who provided nonnumeric responses in numeric response fields were excluded from further analysis. Numeric ranges were applied in subsequent analysis using the mean of the range. Implausible responses resulted in the removal of the entire encounter from subsequent analysis.
Demographic data used to define categories for further subgroup analysis are presented as percentages of the group. Medians, means, and interquartile ranges were calculated for all responses regarding reimbursement and cost. Differences in perceptions of reimbursement and cost based on subgroups, including procedure type, diagnosis, education level, and satisfaction, were calculated. Independent-samples Student t tests were used to determine the statistical significance of the differences detected.
Results
Of the 400 eligible patients seen at the first postoperative follow-up, 284 (71%) were enrolled in the study. Mean (SD) age was 62.6 (12.6) years. Of the 284 patients enrolled, 154 (54%) were female. Of the participants who reported their education and income, 125 (44%) had a bachelor’s degree or higher degree, and 68 (23.9%) reported income of more than $100,000 per year. The largest payers reported by patients were private insurance (80%) and Medicare (46%). Additional demographic details are listed in Table 1.
Of the 284 patients enrolled in the study, 159 (56%) had THA, and 88 (31%) had TKA (Table 2). Thirty-seven patients (13%) underwent revision procedures. Only 5 patients (2%) indicated they had reviewed their hospital billing statement from their most recent admission. Two hundred forty-two patients (85%) were satisfied or very satisfied with their procedure.
Regarding the implant used in their surgery, 216 patients (76%) indicated they did not know which company manufactured it. Of the 68 patients (24%) who named a manufacturer, 53 (78%) were correct in their selection (intraoperative records were checked). Patients indicated they thought the implant used in their surgery cost $6447 on average (95% CI, $5581-$7312).
On average, patients thought their surgeon was reimbursed $12,014 (95% CI, $10,845-$13,183) for their procedure, and they estimated that the hospital was reimbursed $28,392 (95% CI, $25,271-$31,512) for their perioperative care and that it cost the hospital $24,389 (95% CI, $21,612-$27,165) to provide it. Means, confidence intervals, medians, and interquartile ranges for parameters of reimbursement and cost are listed in Table 3. Seventy-one patients (25%) thought on average that the hospital took a net loss for each TJA performed, and 146 patients (51%) thought on average that the hospital generated a net profit for each TJA.
On average, patients thought surgeons were reimbursed $11,872 for a THA and $12,263 for a TKA. Patients also estimated a higher hospital cost (THA, $22,981; TKA, $26,998) and reimbursement (THA, $27,366; TKA, $30,230) after TKA than THA. These differences in perceptions of cost and reimbursement for THA and TKA appear in Table 4 and Figure 2.
Statistically significant differences were also found in perceptions of cost and reimbursement based on level of education and overall patient satisfaction. Patients with a bachelor’s degree or higher estimated physician reimbursement at $11,006, whereas patients with a lower level of education estimated reimbursement at $12,890. In addition, patients with a lower level of education gave estimates of hospital cost and reimbursement that were $7698 and $10,799 higher, respectively, than the estimates given by patients with a higher level of education (Table 5, Figure 3). Patients who were satisfied or very satisfied with their overall TJA experience estimated surgeon reimbursement at $11,673. Patients who indicated they were unsatisfied, very unsatisfied, or neutral regarding their overall experience gave a higher estimate of surgeon reimbursement: $14,317 (Table 6, Figure 4).
Because of the small number of enrolled patients who had revision surgery and the high variability in patient responses, there were no meaningful or statistically significant differences in perceptions of cost and reimbursement based on revision or primary surgery.
Patients also estimated substantial additional reimbursements to physicians for services included at no additional charge with the global surgical package. Median estimates were $300 for reimbursement to a physician making rounds in the hospital and $250 for reimbursement for an outpatient follow-up. Only 47 patients (17%) and 35 patients (12%) correctly indicated there is no additional payment for making rounds and outpatient follow-up, respectively. Estimates of these reimbursements varied by education level, procedure, and overall satisfaction (Tables 4–6).
Discussion
The sustainable growth rate (SGR) formula, part of the Balanced Budget Act of 1997, was constructed to manage health care costs in the context of overall economic growth. By 2001, Medicare health care expenditures had begun to outpace economic growth, and the SGR formula dictated a reduction in reimbursement to physicians. Each year over the past decade, Congress has passed legislation providing a temporary reprieve, staving off a drastic reduction of as much as 25% in 2010.6 Despite these adjustments, reimbursement continues to decrease because of overall inflation.
More worrisome is that “more than half of the nearly trillion dollar price tag for expanding coverage under the Affordable Care Act (ACA) will be paid by decreasing spending for the more than 46.3 million individuals covered by Medicare.”7 ACA provisions will also create an Independent Payment Advisory Board (IPAB) to oversee health care costs and reduce Medicare spending when it is expected to exceed target levels.8 As IPAB cannot recommend increasing revenues or changing benefits, and because it is initially prohibited from recommending decreasing payments to hospitals, the decreases will likely have the greatest impact on physician reimbursement.7-9
Health care policy has been a major campaign issue during recent US elections. The public and popular media remain engaged in this important discussion. Although patients, policymakers, and physicians are understandably concerned about cost and access to health care, it is unclear if patients understand the distribution of health care cost and reimbursement.
Other authors have studied patients’ perceptions of physician reimbursement for TJA. Hayden and colleagues10 surveyed 1000 residents of a Texas city. The 121 who responded to the survey thought that fair compensation for performing a TKA was $5080, on average.10 Although this was significantly higher than the actual Medicare reimbursement at the time, a later study, by Foran and colleagues,4 found patients’ estimates of both fair reimbursement and Medicare reimbursement for TJA to be even higher. Foran and colleagues4 surveyed 1120 patients who thought surgeons deserved to be paid $14,358 for THA and $13,322 for TKA, on average. These reimbursement values are nearly an order of magnitude higher than actual reimbursements. For Medicare payments, patients lowered their estimates to $8212 for THA and $7196 for TKA.4
To our knowledge, the present study is the first to use a “postconsumer” survey to assess patients’ perceptions of THA and TKA costs. Our results confirmed that patients substantially overestimated reimbursement for THA and TKA at $11,872 and $12,263, respectively, relative to the average Medicare reimbursements of $1467 and $1530, respectively.11 We also found that patients overestimated both hospital cost and reimbursement for THA at $22,981 and $27,366, respectively, relative to recently published hospital economic analyses showing THA cost and reimbursement to be $11,688 and $15,789, respectively.12 Few patients enrolled in our study demonstrated an understanding of the services included in the global surgical package. Only about 12% of patients correctly indicated there was no additional payment to the physician for initial follow-up appointments. However, patients were fairly accurate in their estimates of implant cost. On average, patients who underwent THA priced their implant at $6823, which is only about 9% higher than the reported median cost of $6072 to $6400.13,14
We also found significant differences in perceptions of cost based on level of education, joint replaced, and overall level of satisfaction. On average, patients with a bachelor’s degree or higher gave estimates of cost and reimbursement that were lower than those given by patients with a lower level of education. Estimates of physician reimbursement and hospital reimbursement and cost were higher from patients who had TKA than from patients who had THA.
Comparing perceptions of reimbursement for appendectomy and coronary artery bypass with perceptions for TJA, Foran and colleagues4 found that patients understood the relative complexity of each procedure, as evidenced by their estimates of fair reimbursement for each. However, in comparing patient estimates for the different components of cost and reimbursement for TJA, we found great variability in understanding. Patients in our study overestimated payments to the hospital by 73% but overestimated the cost of the THA implant by only 9%. However, the same patients overestimated physician reimbursement for THA by about 800%. If these patients’ estimates of reimbursement are considered surrogates for relative value, then physicians, based on actual payments, are grossly undervalued relative to implant manufacturers.
Our study had several limitations. First, the enrolled patients were all seen at one medical center, in Ann Arbor, Michigan, and our results may not be generalizable outside the region. Second, the survey respondents were postoperative patients who had an established relationship with the study’s principal investigators—a relationship that may have been a source of bias in the consideration of reimbursement as a function of value. Third, despite our efforts to carefully design a survey with open-ended responses, the order in which the survey questions were presented may have influenced patient responses. Fourth, the open-ended question design may have had an impact on responses where the correct answer would have required entering 0.00.
Despite these limitations, our study results demonstrated general public misconceptions about cost and reimbursement for common orthopedic procedures. Although more transparency in health care cost information may not immediately result in a more well-informed population,15 our patients, given the opportunity to develop an understanding of the economics of their own medical treatment, may become better prepared to make informed choices regarding changes in health care policy.
1. Kumar S, Ghildayal NS, Shah RN. Examining quality and efficiency of the U.S. healthcare system. Int J Health Care Qual Assur. 2011;24(5):366-388.
2. Hariri S, Bozic KJ, Lavernia C, Prestipino A, Rubash HE. Medicare physician reimbursement: past, present, and future. J Bone Joint Surg Am. 2007;89(11):2536-2546.
3. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007;89(4):780-785.
4. Foran JR, Sheth NP, Ward SR, et al. Patient perception of physician reimbursement in elective total hip and knee arthroplasty. J Arthroplasty. 2012;27(5):703-709.
5. Rosenthal JA, Lu X, Cram P. Availability of consumer prices from US hospitals for a common surgical procedure. JAMA Intern Med. 2013;173(6):427-432.
6. US Senate Committee on Finance. H.R. 4994: the Medicare and Medicaid Extenders Act of 2010. http://www.finance.senate.gov/legislation/details/?id=9f97aa2e-5056-a032-52d4-8db158b12b11. Accessed March 25, 2015.
7. Zinberg JM. When patients call, will physicians respond? JAMA. 2011;305(19):2011-2012.
8. Jost TS. The Independent Payment Advisory Board. N Engl J Med. 2010;363(2):103-105.
9. US Department of Health and Human Services, Centers for Medicare & Medicaid Services. Estimated financial effects of the “Patient Protection and Affordable Care Act,” as amended. 2010. http://www.cms.gov/Research-Statistics-Data-and-Systems/Research/ActuarialStudies/downloads/PPACA_2010-04-22.pdf. Accessed March 25, 2015.
10. Hayden SA, Hayden D, White LW. The U.S. public’s perceived value of the surgeon’s fee for total knee replacement. Abstract presented at: 75th Annual Meeting of the American Academy of Orthopaedic Surgeons; March 5-9, 2008; San Francisco, CA. Abstract 214.
11. Centers for Medicare & Medicaid Services. Physician Fee Schedule Search Tool. http://www.cms.gov/apps/physician-fee-schedule/search/search-criteria.aspx. Accessed March 25, 2015.
12. Rana AJ, Iorio R, Healy WL. Hospital economics of primary THA decreasing reimbursement and increasing cost, 1990 to 2008. Clin Orthop. 2011;469(2):355-361.
13. Lavernia CJ, Hernandez VH, Rossi MD. Payment analysis of total hip replacement. Curr Opin Orthop. 2007;18(1):23-27.
14. Robinson JC, Pozen A, Tseng S, Bozic KJ. Variability in costs associated with total hip and knee replacement implants. J Bone Joint Surg Am. 2012;94(18):1693-1698.
15. Smolders JM, Van Loon CJ, Rijnberg WJ, Van Susante JL. Patients poorly estimate the overall costs of a total knee arthroplasty and strongly overestimate the surgeon’s fee. Acta Orthop Belg. 2007;73(3):339-344.
1. Kumar S, Ghildayal NS, Shah RN. Examining quality and efficiency of the U.S. healthcare system. Int J Health Care Qual Assur. 2011;24(5):366-388.
2. Hariri S, Bozic KJ, Lavernia C, Prestipino A, Rubash HE. Medicare physician reimbursement: past, present, and future. J Bone Joint Surg Am. 2007;89(11):2536-2546.
3. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007;89(4):780-785.
4. Foran JR, Sheth NP, Ward SR, et al. Patient perception of physician reimbursement in elective total hip and knee arthroplasty. J Arthroplasty. 2012;27(5):703-709.
5. Rosenthal JA, Lu X, Cram P. Availability of consumer prices from US hospitals for a common surgical procedure. JAMA Intern Med. 2013;173(6):427-432.
6. US Senate Committee on Finance. H.R. 4994: the Medicare and Medicaid Extenders Act of 2010. http://www.finance.senate.gov/legislation/details/?id=9f97aa2e-5056-a032-52d4-8db158b12b11. Accessed March 25, 2015.
7. Zinberg JM. When patients call, will physicians respond? JAMA. 2011;305(19):2011-2012.
8. Jost TS. The Independent Payment Advisory Board. N Engl J Med. 2010;363(2):103-105.
9. US Department of Health and Human Services, Centers for Medicare & Medicaid Services. Estimated financial effects of the “Patient Protection and Affordable Care Act,” as amended. 2010. http://www.cms.gov/Research-Statistics-Data-and-Systems/Research/ActuarialStudies/downloads/PPACA_2010-04-22.pdf. Accessed March 25, 2015.
10. Hayden SA, Hayden D, White LW. The U.S. public’s perceived value of the surgeon’s fee for total knee replacement. Abstract presented at: 75th Annual Meeting of the American Academy of Orthopaedic Surgeons; March 5-9, 2008; San Francisco, CA. Abstract 214.
11. Centers for Medicare & Medicaid Services. Physician Fee Schedule Search Tool. http://www.cms.gov/apps/physician-fee-schedule/search/search-criteria.aspx. Accessed March 25, 2015.
12. Rana AJ, Iorio R, Healy WL. Hospital economics of primary THA decreasing reimbursement and increasing cost, 1990 to 2008. Clin Orthop. 2011;469(2):355-361.
13. Lavernia CJ, Hernandez VH, Rossi MD. Payment analysis of total hip replacement. Curr Opin Orthop. 2007;18(1):23-27.
14. Robinson JC, Pozen A, Tseng S, Bozic KJ. Variability in costs associated with total hip and knee replacement implants. J Bone Joint Surg Am. 2012;94(18):1693-1698.
15. Smolders JM, Van Loon CJ, Rijnberg WJ, Van Susante JL. Patients poorly estimate the overall costs of a total knee arthroplasty and strongly overestimate the surgeon’s fee. Acta Orthop Belg. 2007;73(3):339-344.
Polydactyly of the Hand
Polydactyly is the presence of extra digits. Its incidence is likely underestimated because many practitioners treat simple “nubbins” without referring them to orthopedic specialists.1-3 Polydactyly can be detected by ultrasound as early as 14 weeks’ gestational age, with partial autoamputation seen in most isolated polydactylies.4 The thumb, responsible for 40% of hand function, must be able to oppose the other digits with a stable pinch.5 Polydactyly encumbers this motion when the duplicated digits deviate from normal alignment. Ezaki6 noted that the anatomy is better described as “split” than “duplicated.” There are many dichotomous ways to classify polydactyly: preaxial (radial) versus postaxial (ulnar), thumb versus triphalangeal, simple versus complex (Figure 1). Mixed polydactyly is defined as the presence of preaxial and postaxial polydactyly.7 Surgical management seeks to allow normal hand function and to restore cosmesis.
Epidemiology
Sun and colleagues8 reported the overall polydactyly incidence as 2 per 1000 live births in China from 1998 to 2009, with a slight male predominance; polydactyly was also 3 times more common than syndactyly in this population. Ivy,9 in a 5-year audit of Pennsylvania Department of Health records, found polydactyly to be the fourth most common congenital anomaly after clubfoot, cleft lip/palate, and spina bifida. Thumb duplication occurs in 0.08 to 1.4 per 1000 live births and is more common in American Indians and Asians than in other races.5,10 It occurs in a male-to-female ratio of 2.5 to 1 and is most often unilateral.5 Postaxial polydactyly is predominant in black infants; it is most often inherited in an autosomal dominant fashion, if isolated, or in an autosomal recessive pattern, if syndromic.1 A prospective San Diego study of 11,161 newborns found postaxial type B polydactyly in 1 per 531 live births (1 per 143 black infants, 1 per 1339 white infants); 76% of cases were bilateral, and 86% had a positive family history.3 In patients of non-African descent, it is associated with anomalies in other organs. Central duplication is rare and often autosomal dominant.5,10
Genetics and Development
As early as 1896, the heritability of polydactyly was noted.11 As of 2010, polydactyly has been associated with 310 diseases.12 Ninety-nine genes, most involved in regulation of anterior-posterior formation of the limb bud, have been implicated.12,13
The upper limb begins to form at day 26 in utero.14 Apoptosis in the interdigital necrotic zones results in the formation of individual digits. It is presumed that, in polydactyly, the involved tissue is hypoplastic because of an abnormal interaction between mesoderm and ectoderm.5 Presence of an apical ectodermal ridge determines the formation of a limb bud, and on it the zone of polarizing activity (ZPA) dictates preaxial and postaxial alignment.14,15 The ZPA is located on the posterior zone of the developing limb bud. The levels of GLI3, a zinc finger-containing DNA-binding protein, are highest in the anterior area, and HAND2, a basic helix-loop-helix DNA-binding protein, is found in the ZPA. This polarity promotes sonic hedgehog (Shh) gene expression in the posterior region, which in turn prevents GLI3 cleavage into its repressed form. GLI3R (repressed) and GLI3A (active) concentrations are highest, therefore, in the anterior and posterior portions of the bud, respectively. The GLI3A:GLI3R ratio is responsible for the identity and number of digits in the hand (ie, the thumb develops in regions of high GLI3R). GLI and Shh mutations lead to polydactylous hands with absent thumbs (Figure 2).16
Ciliopathies have also been shown to cause postaxial polydactyly, possibly because of the role that nonmotile cilia play in hedgehog signaling.17 Mutations in Shh genomic regulators cause preaxial polydactyly.18 HoxD activates Shh in the ZPA; HoxD13 mutations are associated with synpolydactyly.16,19 In each of these mutations, Shh production is altered, and some form of polydactyly results.
Associations
Many syndromes have been associated with polydactyly. Not all polydactyly is associated with other disorders, but the more complex the polydactyly, the more likely that other anomalies are present. Every patient who presents with polydactyly should have a full history taken and a physical examination performed (Figure 3). Any patient with syndromic findings or atypical presentations (eg, triphalangism, postaxial polydactyly in a patient of non-African descent, central and index polydactyly) should be referred to a geneticist.
Classifications
The Wassel20 classification describes the anatomical presentation of thumb duplication on the basis of 70 cases in Iowa (Figures 4, 5; Table 1). Because some duplications fall outside the Wassel classification, many researchers have proposed modifications (Figure 6).21-25
The Temtamy and McKusick10 classification, which is the product of geneticists, classifies duplications by grouping genetically related presentations (Table 2). It provides the most commonly used postaxial classification, with type A being a fully developed digit and type B a rudimentary and pedunculated digit, informally referred to as a nubbin. Type B is more common than type A. Given inheritance patterns, it is assumed that type A is likely multifactorial and type B autosomal dominant.10 Thumb polydactyly inheritance is still unclear. The other types of preaxial polydactyly and high degrees of polydactyly are rare but seem to be passed on in an autosomal dominant fashion on pedigree analysis.10
The Stelling and Turek classification presents the duplication from a tissue perspective: Type I duplication is a rudimentary mass devoid of other tissue elements; type II is a subtotal duplication with some normal structures; and type III is a duplication of the entire “osteoarticular column,” including the metacarpal.1 It is interesting to note that histology of type I duplications shows neuroma-like tissue.26-28 Again, normal is a relative term because, in polydactyly, the duplications are hypoplastic and deviated, with anomalous anatomy.
The Rayan classification describes ulnar polydactyly and was derived from a case study series of 148 patients in Oklahoma (Table 3).29
There are also some complex polydactylies that are not easily classified: ulnar dimelia, cleft hand, pentadactyly, and hyperphalangism. Ulnar dimelia, also known as “mirror hand,” is typically 7 digits with no thumb, but other variations are seen. The radius is often absent, and the elbow is abnormal. There is some debate about whether it is a fusion of 2 hands. Pentadactyly, or the 5-fingered hand, appears as 5 triphalangeal digits with no thumb (Figure 7).
Isolated thumb triphalangism might appear similar to pentadactyly. Miura30,31 pointed out that the radial digit in the pentadactylous hand may be opposable (thumb-like) or nonopposable; in his studies, the patients with the opposable thumb had a metacarpal with a proximal epiphysis (Figure 8). Consequently, the triphalangeal thumb metacarpal with a distal epiphysis is true pentadactyly, whereas that with a proximal epiphysis is hyperphalangism (Figure 9). Treatment of these complex polydactylies involves the same underlying principles as for preaxial and postaxial polydactyly, albeit with additional proximal upper extremity considerations.
When to Operate (Timing)
Ezaki6 recommended surgical intervention at age 6 to 9 months, before fine motor skills have developed with the abnormal anatomy. Cortical learning occurs as the child begins prehensile activities before 6 months, but the risks of anesthesia outweigh functional benefits until the child is older. Waiting until 1 year of age is not uncommon, though surgery at an earlier age may be beneficial if the polydactyly affects hand function.32 It is not uncommon to wait with the more balanced thumb polydactylies to assess thumb function. Hypoplasia might also delay surgical intervention until there is enough tissue inventory for reconstruction. Wassel20 noted that surgical intervention ideally occurs before the supernumerary elements displace the normal elements, as tends to happen with growth. Suture ligation is an option in the neonatal unit for some pedunculated digits.33 Studies have shown satisfactory results in adults treated for polydactyly, if the patient presents later than expected.34
Surgical Considerations
Knavel recommended simple excision, stating that “ablation requires no ingenuity and creates no problems.”5 This belief, though true for some duplications, will not lead to the best outcome for more complex polydactylies. The goal of surgery is a stable and well-aligned thumb for pinch and prehensile activity, as well as a cosmetically pleasing hand. Incisions should not be made linearly along the axis of the digit, as the scar will cause deviation with growth.24
Wassel type I polydactyly might appear incidentally as a broad thumb, in which case it requires no intervention (Figure 10). However, in Wassel types I and II polydactyly with deformity, the Bilhaut-Cloquet procedure is useful for both bifid and duplicated phalanges (Figure 11).5,6,30,32,35 Collateral ligaments may need to be released in type II because of difficulty in opposing the tissue. Cosmetic results with Bilhaut-Cloquet are unpredictable. The original technique required symmetrically sized digits; results today have been improved with microtechniques and preservation of an entire nail.36 Another option is ablation of the more hypoplastic osseous element and soft-tissue augmentation of the residual digit. The theme of ablation and augmentation is seen throughout the literature for the surgical treatment of polydactyly (Figure 12).1
For type III polydactyly, the bifid proximal phalanx is narrowed by resection and realigned with osteotomy of the remaining diaphysis. Type IV polydactyly, the most common thumb duplication, often requires advancement of the abductor pollicis brevis to the base of the proximal phalanx to aid in metacarpophalangeal (MCP) stabilization, abduction, and opposition. The metacarpal head, if broad and with 2 facets, can be shaped to form a single articulating surface. The metacarpal, occasionally with the proximal phalanx, often requires realignment by closing wedge osteotomy. Last, tendons on the resected bony elements should be rebalanced on the remaining digit, and anomalous slips must be released. For instance, given a radial insertion of the long flexor tendon on the distal phalanx, the tendon should be moved centrally. A strong flexor or extensor tendon on the amputated digit should be transferred to the remaining digit.24
Types V and VI are treated similarly to type IV, with the addition of a first web space Z-plasty or web widening if there is thenar eminence contracture. Acral transposition has also been described, with transposition of the tip of the ablated digit in place of the tip of the kept digit; this technique is ideal if one digit has a more normal proximal part while the other has a more normal distal part (Figure 13).35
Type VII thumb polydactyly, the type most likely inherited and associated with other disorders, should be treated like type VI. The nail should be preserved; amputation of the distal phalanx is not advised. Resection of the delta phalanx or 1 interphalangeal (IP) joint is an option. Articular surfaces will remodel if done before the age of 1 year. If the thenar eminence is hypoplastic, then Huber transfer of the abductor digiti minimi should be considered.37 Resection of the triphalangeal thumb is also advised, even if the biphalangeal thumb is more hypoplastic, with transfer of the ligaments and tendons, as described earlier.5,6,24,30,32,35
Thumb triphalangism, if isolated, and hyperphalangism in the other digits, can be treated with resection of the delta phalanx or one of the IP joints if it is affecting function or cosmesis.1,6 Wood and Flatt23 recommended early resection of a thumb delta phalanx because of the likelihood of deviation that impedes thumb function. For children, they recommended delta phalanx resection and Kirschner wire fixation for 6 weeks; for adults, they recommended resection or fusion of the joint, with osteotomy as needed for deviation.23,24 For thumb triphalangism, multiple surgeries are the norm, as Wood24 reported in his study of 21 patients who underwent 78 operations in total.
Index polydactyly may present as a simple pedunculated skin tag, which can be simply excised, or as a more complex musculoskeletal duplication. More complex presentations can be treated with procedures similar to those used for the thumb. Typically, the additional digit is radially deviated and angulated, eventually leading to impingement of thumb pinch and the first web space. Ray amputation is also an option if no reconstructive surgery will produce the stable, sensate radial pinch that is essential to hand function.32
Ring-finger polydactyly and long-finger polydactyly are often complicated by some element of syndactyly, resulting in a relative paucity of skin (Figure 14). There is failure of both formation (hypoplasia) and differentiation (syndactyly). The hypoplasia particularly affects the function of these digits by tethering them; multiple surgeries to restore proper hand function are the norm.1 Reconstructive surgery for these digits requires preoperative tissue inventory followed by resection and augmentation; as in syndactyly, skin for coverage is at a premium. Creation of a 3-fingered hand is an option.23
Temtamy and McKusick10 type A little-finger polydactyly is treated similarly to the thumb, with the caveat that hypothenar and intrinsic muscles that insert on the resected little finger are transferred to the remaining digit. In contrast to thumb polydactyly, the extrinsic musculature tends to be in good position. Suture ligation of type B polydactyly, as described by Flatt, is likely more common than orthopedists appreciate, as pediatricians and neonatal unit practitioners commonly perform this procedure in the nursery.1-3 It has been described with 2-0 Vicryl3 (Ethicon, Somerville, New Jersey) and 4-0 silk sutures,32 with the goal of necrosis and autoamputation. Parents should be told the finger generally falls off about 10 days (range, 4-21 days) after ligation.3 Multiple authors have cited a report of exsanguination from suture ligation, but we could not locate the primary source. It is advisable to wait until a patient is 6 months of age if planning to resect the nubbin in the operating room, given the anesthesia risk and the lack of functional impairment. Katz and Linder33 indicated they remove type B polydactyly in the nursery suite used for circumcisions; they use anesthetizing cream on the skin, and sharp excision with a scalpel, followed by direct pressure and Steri-Strip (3M, St. Paul, Minnesota) application. Suture ligation is recommended only if there is a narrow, thin (<2 mm) soft-tissue stalk; any broad or bony stalk necessitates surgical removal to avoid neuroma formation and failure of autonecrosis (Figure 15).27 Other options are a single swipe of a scalpel and elliptical excision; sharp transaction of the digital nerve with subsequent retraction is advised to avoid neuroma formation.2
Barton described ulnar dimelia operations as “spare parts surgery.”1 Extra digits are ablated and a thumb created (Figure 16). The hand might have a digit in relatively good rotational position for thumbplasty, or the principles of pollicization may need to be used. If the patient is already using the hand, the surgeon should note which finger the patient uses as a thumb.24 Any accompanying wrist flexion contracture must be corrected with careful attention to musculotendinous balancing. Because the forearm and elbow, and occasionally even the more proximal limb, will be abnormal in this disorder, multiple surgeries are again the norm.1
Pentadactyly is treated like thumb hypoplasia, with first web space creation.1
Complications
In polydactyly, a reoperation rate of up to 25% has been reported, with most reoperations performed because of residual or subsequent deformity.5,30,31,38 Risk factors for reoperation are type IV thumb duplication, preoperative “zigzag” deformity, and radially deviated thumb elements at presentation.5 The delta phalanx may not show on radiographs until the patient is 18 months old, but functional deformity will worsen as long as it is present. Zigzag deformity may be due to the delta phalanx or to musculotendinous imbalance, such as a radially inserted flexor pollicis longus (FPL) or lack of stable MCP abduction. Miura31 found that careful reconstruction of the joint capsule and thenar muscles from the ablated digit to the remnant digit is the key to a successful initial surgery. Lee and colleagues39 defined zigzag deformity as more than 20° MCP and IP angulation; for cases present before surgery, they recommended FPL relocation by the pullout technique in addition to osteotomies to prevent further interphalangeal deviation (Figures 17, 18).
Abnormal physeal growth, joint instability, and stiffness can all occur. Stiffness is particularly difficult to treat but seldom presents a functional problem. Joint enlargement, which is not uncommon, results from either broad articular surfaces or retained cartilage from the perichondral ring after resection that later ossifies.5,38 Nubbin-type duplications may not fall off after suture ligation, necessitating further excision, and a cosmetic bump is seen after 40% of suture ligations.3 Patillo and Rayan28 and Rayan and Frey29 warned against suture ligation unless the nubbin has a small stalk because of the possibility of infection and gangrene. The excised nubbin tissue is histologically nervous, and there have been reports of painful neuromas in the remaining scar of a ligated nubbin that respond well to excision.26,27,40 It is thought that these painful lesions form because the ligature prevents the digital nerves to the vestigial digit from retracting.27 Nail deformity and IP joint stiffness are seen with the Bilhaut-Cloquet procedure, though often finger function remains satisfactory.
Conclusion
Polydactyly is a common congenital hand abnormality. Its true incidence is unknown because of inconsistent documentation. Surgeons must strive for a functional, cosmetic hand, given a diverse set of possible anomalies. Hypoplasia is the rule; tissue should be ablated and augmented as necessary. Musculotendinous insertions may need to be centralized. Patients’ family members should always be counseled that more surgery may be needed in the future, as further deformity can occur with growth. Surgically corrected thumb duplications will be stiffer, shorter, and thinner than their normal counterparts. Nail ridges are common. However, it should be noted that 88% of these patients are satisfied with their results.41 Some amount of contracture and abnormal function should be expected with index-, long-, and ring-finger duplications. The only remnant of type B postaxial duplications may be a slight discoloration or bump, though stiffness and deformity can happen with a type A deformity. A “duplicated” digit that requires surgical correction will never be completely normal, but acceptable function is routinely achievable.
1. Graham TJ, Ress AM. Finger polydactyly. Hand Clin. 1998;14(1):49-64.
2. Abzug JM, Kozin SH. Treatment of postaxial polydactyly type B. J Hand Surg Am. 2013;38(6):1223-1225.
3. Watson BT, Hennrikus WL. Postaxial type-B polydactyly—prevalence and treatment. J Bone Joint Surg Am. 1997;79(1):65-68.
4. Zimmer EZ, Bronshtein M. Fetal polydactyly diagnosis during early pregnancy: clinical applications. Am J Obstet Gynecol. 2000;183(3):755-758.
5. Cohen MS. Thumb duplication. Hand Clin. 1998;14(1):17-27.
6. Ezaki M. Radial polydactyly. Hand Clin. 1990;6(4):577-588.
7. Nathan PA, Keniston RC. Crossed polydactyly: case report and review of the literature. J Bone Joint Surg Am. 1975;57(6):847-849.
8. Sun G, Xu ZM, Liang JF, Li L, Tang DX. Twelve-year prevalence of common neonatal congenital malformations in Zhejiang Province, China. World J Pediatr. 2011;7(4):331-336.
9. Ivy RH. Congenital anomalies as recorded on birth certificates in the Division of Vital Statistics of the Pennsylvania Department of Health, for the period of 1951–1955, inclusive. Plast Reconstr Surg. 1957;20(5):400-411.
10. Temtamy SA, McKusick VA. Polydactyly as a part of syndromes. In: Bergsma D, ed. Mudge JR, Paul NW, Conde Greene S, associate eds. The Genetics of Hand Malformations. New York, NY: Liss. Birth Defects Original Article Series. 1978;14(3):364-439.
11. Gould W, Pyle L. Anomalies and Curiosities of Medicine. New York, NY: Bell; 1896.
12. Biesecker LG. Polydactyly: how many disorders and how many genes: 2010 update. Dev Dyn. 2011;250(5):931-942.
13. Grzeschik K. Human limb malformations; an approach to the molecular basis of development. Int J Dev Biol. 2001;46(7):983-991.
14. Zaleske DJ. Development of the upper limb. Hand Clin. 1985;1(3):383-390.
15. Beatty E. Upper limb tissue differentiation in the human embryo. Hand Clin. 1985;1(3):391-404.
16. Anderson E, Peluso S, Lettice LA, Hill RE. Human limb abnormalities caused by disruption of hedgehog signaling. Trends Genet. 2012;28(8):364-373.
17. Ware SM, Aygun MG, Heldebrandt F. Spectrum of clinical diseases caused by disorders of primary cilia. Proc Am Thorac Soc. 2011;8(5):444-450.
18. Lettice LA, Hill RE. Preaxial polydactyly: a model for defective long-range regulation in congenital abnormalities. Curr Opin Genet Dev. 2005;15(3):294-300.
19. Al-Qattan MA. Type II familial synpolydactyly: report on two families with an emphasis on variations of expression. Eur J Hum Genet. 2011;19(1):112-114.
20. Wassel HD. The results of surgery for polydactyly of the thumb. Clin Orthop. 1969;(64):175-193.
21. Blauth W, Olason AT. Classification of polydactyly of the hands and feet. Arch Orthop Trauma Surg. 1988;107(6):334-344.
22. Wood VE. Super digit. Hand Clin. 1990;6(4):673-684.
23. Wood VE, Flatt AE. Congenital triangular bones in the hand. J Hand Surg Am. 1977;2(3):179-193.
24. Wood VE. Polydactyly and the triphalangeal thumb. J Hand Surg Am. 1978;3(5):436-444.
25. Zuidam JM, Selles RW, Ananta M, Runia J, Hovius SER. A classification system of radial polydactyly: inclusion of triphalangeal thumb and triplication. J Hand Surg Am. 2008;33(3):373-377.
26. Leber GE, Gosain AK. Surgical excision of pedunculated supernumerary digits prevents traumatic amputation neuromas. Pediatr Dermatol. 2003;20(2):108-112.
27. Mullick S, Borschel GH. A selective approach to treatment of ulnar polydactyly: preventing painful neuroma and incomplete excision. Pediatr Dermatol. 2001;27(1):39-42.
28. Patillo D, Rayan GM. Complications of suture ligation ablation for ulnar polydactyly: a report of two cases. Hand (N Y). 2011;6(1):102-105.
29. Rayan GM, Frey B. Ulnar polydactyly. Plastic Reconstr Surg. 2001;107(6):1449-1454.
30. Miura T. Triphalangeal thumb. Plastic Reconstr Surg. 1976;58(5):587-594.
31. Miura T. Duplicated thumb. Plastic Reconstr Surg. 1982;69(3):470-481.
32. Simmons BP. Polydactyly. Hand Clin. 1985;1(3):545-566.
33. Katz K, Linder N. Postaxial type B polydactyly treated by excision in the neonatal nursery. J Pediatr Orthop. 2011;31(4):448-449.
34. Manohar A, Beard AJ. Outcome of reconstruction for duplication of the thumb in adults aged over 40. Hand Surg. 2011;16(2):207-210.
35. Watt AJ, Chung KC. Duplication. Hand Clin. 2009;25(2):215-228.
36. Tonkin MA. Thumb duplication: concepts and techniques. Clin Orthop Surg. 2012;4(1):1-17.
37. Huber E. Relief operation in the case of paralysis of the median nerve. J Hand Surg Eur. 2004;29(1):35-37.
38. Mih AD. Complications of duplicate thumb reconstruction. Hand Clin. 1998;14(1):143-149.
39. Lee CC, Park HY, Yoon JO, Lee KW. Correction of Wassel type IV thumb duplication with zigzag deformity: results of a new method of flexor pollicis longus tendon relocation. J Hand Surg Eur. 2013;38(3):272-280.
40. Hare PJ. Rudimentary polydactyly. Br J Dermatol. 1954;66(11):402-408.
41. Yen CH, Chan WL, Leung HB, Mak KH. Thumb polydactyly: clinical outcome after reconstruction. J Orthop Surg (Hong Kong). 2006;14(3):295-302.
42. Edmunds JO. A tribute to Daniel C. Riordan, MD (1917–2012). Tulane University School of Medicine, Department of Orthopaedics website. http://tulane.edu/som/departments/orthopaedics/news-and-events/danriordantribute.cfm. Accessed March 31, 2015.
43. Faust DC, Herms R. Daniel C. Riordan, MD, 1917–2012. J Hand Surg Am. 2013;38(1):202-205.
Polydactyly is the presence of extra digits. Its incidence is likely underestimated because many practitioners treat simple “nubbins” without referring them to orthopedic specialists.1-3 Polydactyly can be detected by ultrasound as early as 14 weeks’ gestational age, with partial autoamputation seen in most isolated polydactylies.4 The thumb, responsible for 40% of hand function, must be able to oppose the other digits with a stable pinch.5 Polydactyly encumbers this motion when the duplicated digits deviate from normal alignment. Ezaki6 noted that the anatomy is better described as “split” than “duplicated.” There are many dichotomous ways to classify polydactyly: preaxial (radial) versus postaxial (ulnar), thumb versus triphalangeal, simple versus complex (Figure 1). Mixed polydactyly is defined as the presence of preaxial and postaxial polydactyly.7 Surgical management seeks to allow normal hand function and to restore cosmesis.
Epidemiology
Sun and colleagues8 reported the overall polydactyly incidence as 2 per 1000 live births in China from 1998 to 2009, with a slight male predominance; polydactyly was also 3 times more common than syndactyly in this population. Ivy,9 in a 5-year audit of Pennsylvania Department of Health records, found polydactyly to be the fourth most common congenital anomaly after clubfoot, cleft lip/palate, and spina bifida. Thumb duplication occurs in 0.08 to 1.4 per 1000 live births and is more common in American Indians and Asians than in other races.5,10 It occurs in a male-to-female ratio of 2.5 to 1 and is most often unilateral.5 Postaxial polydactyly is predominant in black infants; it is most often inherited in an autosomal dominant fashion, if isolated, or in an autosomal recessive pattern, if syndromic.1 A prospective San Diego study of 11,161 newborns found postaxial type B polydactyly in 1 per 531 live births (1 per 143 black infants, 1 per 1339 white infants); 76% of cases were bilateral, and 86% had a positive family history.3 In patients of non-African descent, it is associated with anomalies in other organs. Central duplication is rare and often autosomal dominant.5,10
Genetics and Development
As early as 1896, the heritability of polydactyly was noted.11 As of 2010, polydactyly has been associated with 310 diseases.12 Ninety-nine genes, most involved in regulation of anterior-posterior formation of the limb bud, have been implicated.12,13
The upper limb begins to form at day 26 in utero.14 Apoptosis in the interdigital necrotic zones results in the formation of individual digits. It is presumed that, in polydactyly, the involved tissue is hypoplastic because of an abnormal interaction between mesoderm and ectoderm.5 Presence of an apical ectodermal ridge determines the formation of a limb bud, and on it the zone of polarizing activity (ZPA) dictates preaxial and postaxial alignment.14,15 The ZPA is located on the posterior zone of the developing limb bud. The levels of GLI3, a zinc finger-containing DNA-binding protein, are highest in the anterior area, and HAND2, a basic helix-loop-helix DNA-binding protein, is found in the ZPA. This polarity promotes sonic hedgehog (Shh) gene expression in the posterior region, which in turn prevents GLI3 cleavage into its repressed form. GLI3R (repressed) and GLI3A (active) concentrations are highest, therefore, in the anterior and posterior portions of the bud, respectively. The GLI3A:GLI3R ratio is responsible for the identity and number of digits in the hand (ie, the thumb develops in regions of high GLI3R). GLI and Shh mutations lead to polydactylous hands with absent thumbs (Figure 2).16
Ciliopathies have also been shown to cause postaxial polydactyly, possibly because of the role that nonmotile cilia play in hedgehog signaling.17 Mutations in Shh genomic regulators cause preaxial polydactyly.18 HoxD activates Shh in the ZPA; HoxD13 mutations are associated with synpolydactyly.16,19 In each of these mutations, Shh production is altered, and some form of polydactyly results.
Associations
Many syndromes have been associated with polydactyly. Not all polydactyly is associated with other disorders, but the more complex the polydactyly, the more likely that other anomalies are present. Every patient who presents with polydactyly should have a full history taken and a physical examination performed (Figure 3). Any patient with syndromic findings or atypical presentations (eg, triphalangism, postaxial polydactyly in a patient of non-African descent, central and index polydactyly) should be referred to a geneticist.
Classifications
The Wassel20 classification describes the anatomical presentation of thumb duplication on the basis of 70 cases in Iowa (Figures 4, 5; Table 1). Because some duplications fall outside the Wassel classification, many researchers have proposed modifications (Figure 6).21-25
The Temtamy and McKusick10 classification, which is the product of geneticists, classifies duplications by grouping genetically related presentations (Table 2). It provides the most commonly used postaxial classification, with type A being a fully developed digit and type B a rudimentary and pedunculated digit, informally referred to as a nubbin. Type B is more common than type A. Given inheritance patterns, it is assumed that type A is likely multifactorial and type B autosomal dominant.10 Thumb polydactyly inheritance is still unclear. The other types of preaxial polydactyly and high degrees of polydactyly are rare but seem to be passed on in an autosomal dominant fashion on pedigree analysis.10
The Stelling and Turek classification presents the duplication from a tissue perspective: Type I duplication is a rudimentary mass devoid of other tissue elements; type II is a subtotal duplication with some normal structures; and type III is a duplication of the entire “osteoarticular column,” including the metacarpal.1 It is interesting to note that histology of type I duplications shows neuroma-like tissue.26-28 Again, normal is a relative term because, in polydactyly, the duplications are hypoplastic and deviated, with anomalous anatomy.
The Rayan classification describes ulnar polydactyly and was derived from a case study series of 148 patients in Oklahoma (Table 3).29
There are also some complex polydactylies that are not easily classified: ulnar dimelia, cleft hand, pentadactyly, and hyperphalangism. Ulnar dimelia, also known as “mirror hand,” is typically 7 digits with no thumb, but other variations are seen. The radius is often absent, and the elbow is abnormal. There is some debate about whether it is a fusion of 2 hands. Pentadactyly, or the 5-fingered hand, appears as 5 triphalangeal digits with no thumb (Figure 7).
Isolated thumb triphalangism might appear similar to pentadactyly. Miura30,31 pointed out that the radial digit in the pentadactylous hand may be opposable (thumb-like) or nonopposable; in his studies, the patients with the opposable thumb had a metacarpal with a proximal epiphysis (Figure 8). Consequently, the triphalangeal thumb metacarpal with a distal epiphysis is true pentadactyly, whereas that with a proximal epiphysis is hyperphalangism (Figure 9). Treatment of these complex polydactylies involves the same underlying principles as for preaxial and postaxial polydactyly, albeit with additional proximal upper extremity considerations.
When to Operate (Timing)
Ezaki6 recommended surgical intervention at age 6 to 9 months, before fine motor skills have developed with the abnormal anatomy. Cortical learning occurs as the child begins prehensile activities before 6 months, but the risks of anesthesia outweigh functional benefits until the child is older. Waiting until 1 year of age is not uncommon, though surgery at an earlier age may be beneficial if the polydactyly affects hand function.32 It is not uncommon to wait with the more balanced thumb polydactylies to assess thumb function. Hypoplasia might also delay surgical intervention until there is enough tissue inventory for reconstruction. Wassel20 noted that surgical intervention ideally occurs before the supernumerary elements displace the normal elements, as tends to happen with growth. Suture ligation is an option in the neonatal unit for some pedunculated digits.33 Studies have shown satisfactory results in adults treated for polydactyly, if the patient presents later than expected.34
Surgical Considerations
Knavel recommended simple excision, stating that “ablation requires no ingenuity and creates no problems.”5 This belief, though true for some duplications, will not lead to the best outcome for more complex polydactylies. The goal of surgery is a stable and well-aligned thumb for pinch and prehensile activity, as well as a cosmetically pleasing hand. Incisions should not be made linearly along the axis of the digit, as the scar will cause deviation with growth.24
Wassel type I polydactyly might appear incidentally as a broad thumb, in which case it requires no intervention (Figure 10). However, in Wassel types I and II polydactyly with deformity, the Bilhaut-Cloquet procedure is useful for both bifid and duplicated phalanges (Figure 11).5,6,30,32,35 Collateral ligaments may need to be released in type II because of difficulty in opposing the tissue. Cosmetic results with Bilhaut-Cloquet are unpredictable. The original technique required symmetrically sized digits; results today have been improved with microtechniques and preservation of an entire nail.36 Another option is ablation of the more hypoplastic osseous element and soft-tissue augmentation of the residual digit. The theme of ablation and augmentation is seen throughout the literature for the surgical treatment of polydactyly (Figure 12).1
For type III polydactyly, the bifid proximal phalanx is narrowed by resection and realigned with osteotomy of the remaining diaphysis. Type IV polydactyly, the most common thumb duplication, often requires advancement of the abductor pollicis brevis to the base of the proximal phalanx to aid in metacarpophalangeal (MCP) stabilization, abduction, and opposition. The metacarpal head, if broad and with 2 facets, can be shaped to form a single articulating surface. The metacarpal, occasionally with the proximal phalanx, often requires realignment by closing wedge osteotomy. Last, tendons on the resected bony elements should be rebalanced on the remaining digit, and anomalous slips must be released. For instance, given a radial insertion of the long flexor tendon on the distal phalanx, the tendon should be moved centrally. A strong flexor or extensor tendon on the amputated digit should be transferred to the remaining digit.24
Types V and VI are treated similarly to type IV, with the addition of a first web space Z-plasty or web widening if there is thenar eminence contracture. Acral transposition has also been described, with transposition of the tip of the ablated digit in place of the tip of the kept digit; this technique is ideal if one digit has a more normal proximal part while the other has a more normal distal part (Figure 13).35
Type VII thumb polydactyly, the type most likely inherited and associated with other disorders, should be treated like type VI. The nail should be preserved; amputation of the distal phalanx is not advised. Resection of the delta phalanx or 1 interphalangeal (IP) joint is an option. Articular surfaces will remodel if done before the age of 1 year. If the thenar eminence is hypoplastic, then Huber transfer of the abductor digiti minimi should be considered.37 Resection of the triphalangeal thumb is also advised, even if the biphalangeal thumb is more hypoplastic, with transfer of the ligaments and tendons, as described earlier.5,6,24,30,32,35
Thumb triphalangism, if isolated, and hyperphalangism in the other digits, can be treated with resection of the delta phalanx or one of the IP joints if it is affecting function or cosmesis.1,6 Wood and Flatt23 recommended early resection of a thumb delta phalanx because of the likelihood of deviation that impedes thumb function. For children, they recommended delta phalanx resection and Kirschner wire fixation for 6 weeks; for adults, they recommended resection or fusion of the joint, with osteotomy as needed for deviation.23,24 For thumb triphalangism, multiple surgeries are the norm, as Wood24 reported in his study of 21 patients who underwent 78 operations in total.
Index polydactyly may present as a simple pedunculated skin tag, which can be simply excised, or as a more complex musculoskeletal duplication. More complex presentations can be treated with procedures similar to those used for the thumb. Typically, the additional digit is radially deviated and angulated, eventually leading to impingement of thumb pinch and the first web space. Ray amputation is also an option if no reconstructive surgery will produce the stable, sensate radial pinch that is essential to hand function.32
Ring-finger polydactyly and long-finger polydactyly are often complicated by some element of syndactyly, resulting in a relative paucity of skin (Figure 14). There is failure of both formation (hypoplasia) and differentiation (syndactyly). The hypoplasia particularly affects the function of these digits by tethering them; multiple surgeries to restore proper hand function are the norm.1 Reconstructive surgery for these digits requires preoperative tissue inventory followed by resection and augmentation; as in syndactyly, skin for coverage is at a premium. Creation of a 3-fingered hand is an option.23
Temtamy and McKusick10 type A little-finger polydactyly is treated similarly to the thumb, with the caveat that hypothenar and intrinsic muscles that insert on the resected little finger are transferred to the remaining digit. In contrast to thumb polydactyly, the extrinsic musculature tends to be in good position. Suture ligation of type B polydactyly, as described by Flatt, is likely more common than orthopedists appreciate, as pediatricians and neonatal unit practitioners commonly perform this procedure in the nursery.1-3 It has been described with 2-0 Vicryl3 (Ethicon, Somerville, New Jersey) and 4-0 silk sutures,32 with the goal of necrosis and autoamputation. Parents should be told the finger generally falls off about 10 days (range, 4-21 days) after ligation.3 Multiple authors have cited a report of exsanguination from suture ligation, but we could not locate the primary source. It is advisable to wait until a patient is 6 months of age if planning to resect the nubbin in the operating room, given the anesthesia risk and the lack of functional impairment. Katz and Linder33 indicated they remove type B polydactyly in the nursery suite used for circumcisions; they use anesthetizing cream on the skin, and sharp excision with a scalpel, followed by direct pressure and Steri-Strip (3M, St. Paul, Minnesota) application. Suture ligation is recommended only if there is a narrow, thin (<2 mm) soft-tissue stalk; any broad or bony stalk necessitates surgical removal to avoid neuroma formation and failure of autonecrosis (Figure 15).27 Other options are a single swipe of a scalpel and elliptical excision; sharp transaction of the digital nerve with subsequent retraction is advised to avoid neuroma formation.2
Barton described ulnar dimelia operations as “spare parts surgery.”1 Extra digits are ablated and a thumb created (Figure 16). The hand might have a digit in relatively good rotational position for thumbplasty, or the principles of pollicization may need to be used. If the patient is already using the hand, the surgeon should note which finger the patient uses as a thumb.24 Any accompanying wrist flexion contracture must be corrected with careful attention to musculotendinous balancing. Because the forearm and elbow, and occasionally even the more proximal limb, will be abnormal in this disorder, multiple surgeries are again the norm.1
Pentadactyly is treated like thumb hypoplasia, with first web space creation.1
Complications
In polydactyly, a reoperation rate of up to 25% has been reported, with most reoperations performed because of residual or subsequent deformity.5,30,31,38 Risk factors for reoperation are type IV thumb duplication, preoperative “zigzag” deformity, and radially deviated thumb elements at presentation.5 The delta phalanx may not show on radiographs until the patient is 18 months old, but functional deformity will worsen as long as it is present. Zigzag deformity may be due to the delta phalanx or to musculotendinous imbalance, such as a radially inserted flexor pollicis longus (FPL) or lack of stable MCP abduction. Miura31 found that careful reconstruction of the joint capsule and thenar muscles from the ablated digit to the remnant digit is the key to a successful initial surgery. Lee and colleagues39 defined zigzag deformity as more than 20° MCP and IP angulation; for cases present before surgery, they recommended FPL relocation by the pullout technique in addition to osteotomies to prevent further interphalangeal deviation (Figures 17, 18).
Abnormal physeal growth, joint instability, and stiffness can all occur. Stiffness is particularly difficult to treat but seldom presents a functional problem. Joint enlargement, which is not uncommon, results from either broad articular surfaces or retained cartilage from the perichondral ring after resection that later ossifies.5,38 Nubbin-type duplications may not fall off after suture ligation, necessitating further excision, and a cosmetic bump is seen after 40% of suture ligations.3 Patillo and Rayan28 and Rayan and Frey29 warned against suture ligation unless the nubbin has a small stalk because of the possibility of infection and gangrene. The excised nubbin tissue is histologically nervous, and there have been reports of painful neuromas in the remaining scar of a ligated nubbin that respond well to excision.26,27,40 It is thought that these painful lesions form because the ligature prevents the digital nerves to the vestigial digit from retracting.27 Nail deformity and IP joint stiffness are seen with the Bilhaut-Cloquet procedure, though often finger function remains satisfactory.
Conclusion
Polydactyly is a common congenital hand abnormality. Its true incidence is unknown because of inconsistent documentation. Surgeons must strive for a functional, cosmetic hand, given a diverse set of possible anomalies. Hypoplasia is the rule; tissue should be ablated and augmented as necessary. Musculotendinous insertions may need to be centralized. Patients’ family members should always be counseled that more surgery may be needed in the future, as further deformity can occur with growth. Surgically corrected thumb duplications will be stiffer, shorter, and thinner than their normal counterparts. Nail ridges are common. However, it should be noted that 88% of these patients are satisfied with their results.41 Some amount of contracture and abnormal function should be expected with index-, long-, and ring-finger duplications. The only remnant of type B postaxial duplications may be a slight discoloration or bump, though stiffness and deformity can happen with a type A deformity. A “duplicated” digit that requires surgical correction will never be completely normal, but acceptable function is routinely achievable.
Polydactyly is the presence of extra digits. Its incidence is likely underestimated because many practitioners treat simple “nubbins” without referring them to orthopedic specialists.1-3 Polydactyly can be detected by ultrasound as early as 14 weeks’ gestational age, with partial autoamputation seen in most isolated polydactylies.4 The thumb, responsible for 40% of hand function, must be able to oppose the other digits with a stable pinch.5 Polydactyly encumbers this motion when the duplicated digits deviate from normal alignment. Ezaki6 noted that the anatomy is better described as “split” than “duplicated.” There are many dichotomous ways to classify polydactyly: preaxial (radial) versus postaxial (ulnar), thumb versus triphalangeal, simple versus complex (Figure 1). Mixed polydactyly is defined as the presence of preaxial and postaxial polydactyly.7 Surgical management seeks to allow normal hand function and to restore cosmesis.
Epidemiology
Sun and colleagues8 reported the overall polydactyly incidence as 2 per 1000 live births in China from 1998 to 2009, with a slight male predominance; polydactyly was also 3 times more common than syndactyly in this population. Ivy,9 in a 5-year audit of Pennsylvania Department of Health records, found polydactyly to be the fourth most common congenital anomaly after clubfoot, cleft lip/palate, and spina bifida. Thumb duplication occurs in 0.08 to 1.4 per 1000 live births and is more common in American Indians and Asians than in other races.5,10 It occurs in a male-to-female ratio of 2.5 to 1 and is most often unilateral.5 Postaxial polydactyly is predominant in black infants; it is most often inherited in an autosomal dominant fashion, if isolated, or in an autosomal recessive pattern, if syndromic.1 A prospective San Diego study of 11,161 newborns found postaxial type B polydactyly in 1 per 531 live births (1 per 143 black infants, 1 per 1339 white infants); 76% of cases were bilateral, and 86% had a positive family history.3 In patients of non-African descent, it is associated with anomalies in other organs. Central duplication is rare and often autosomal dominant.5,10
Genetics and Development
As early as 1896, the heritability of polydactyly was noted.11 As of 2010, polydactyly has been associated with 310 diseases.12 Ninety-nine genes, most involved in regulation of anterior-posterior formation of the limb bud, have been implicated.12,13
The upper limb begins to form at day 26 in utero.14 Apoptosis in the interdigital necrotic zones results in the formation of individual digits. It is presumed that, in polydactyly, the involved tissue is hypoplastic because of an abnormal interaction between mesoderm and ectoderm.5 Presence of an apical ectodermal ridge determines the formation of a limb bud, and on it the zone of polarizing activity (ZPA) dictates preaxial and postaxial alignment.14,15 The ZPA is located on the posterior zone of the developing limb bud. The levels of GLI3, a zinc finger-containing DNA-binding protein, are highest in the anterior area, and HAND2, a basic helix-loop-helix DNA-binding protein, is found in the ZPA. This polarity promotes sonic hedgehog (Shh) gene expression in the posterior region, which in turn prevents GLI3 cleavage into its repressed form. GLI3R (repressed) and GLI3A (active) concentrations are highest, therefore, in the anterior and posterior portions of the bud, respectively. The GLI3A:GLI3R ratio is responsible for the identity and number of digits in the hand (ie, the thumb develops in regions of high GLI3R). GLI and Shh mutations lead to polydactylous hands with absent thumbs (Figure 2).16
Ciliopathies have also been shown to cause postaxial polydactyly, possibly because of the role that nonmotile cilia play in hedgehog signaling.17 Mutations in Shh genomic regulators cause preaxial polydactyly.18 HoxD activates Shh in the ZPA; HoxD13 mutations are associated with synpolydactyly.16,19 In each of these mutations, Shh production is altered, and some form of polydactyly results.
Associations
Many syndromes have been associated with polydactyly. Not all polydactyly is associated with other disorders, but the more complex the polydactyly, the more likely that other anomalies are present. Every patient who presents with polydactyly should have a full history taken and a physical examination performed (Figure 3). Any patient with syndromic findings or atypical presentations (eg, triphalangism, postaxial polydactyly in a patient of non-African descent, central and index polydactyly) should be referred to a geneticist.
Classifications
The Wassel20 classification describes the anatomical presentation of thumb duplication on the basis of 70 cases in Iowa (Figures 4, 5; Table 1). Because some duplications fall outside the Wassel classification, many researchers have proposed modifications (Figure 6).21-25
The Temtamy and McKusick10 classification, which is the product of geneticists, classifies duplications by grouping genetically related presentations (Table 2). It provides the most commonly used postaxial classification, with type A being a fully developed digit and type B a rudimentary and pedunculated digit, informally referred to as a nubbin. Type B is more common than type A. Given inheritance patterns, it is assumed that type A is likely multifactorial and type B autosomal dominant.10 Thumb polydactyly inheritance is still unclear. The other types of preaxial polydactyly and high degrees of polydactyly are rare but seem to be passed on in an autosomal dominant fashion on pedigree analysis.10
The Stelling and Turek classification presents the duplication from a tissue perspective: Type I duplication is a rudimentary mass devoid of other tissue elements; type II is a subtotal duplication with some normal structures; and type III is a duplication of the entire “osteoarticular column,” including the metacarpal.1 It is interesting to note that histology of type I duplications shows neuroma-like tissue.26-28 Again, normal is a relative term because, in polydactyly, the duplications are hypoplastic and deviated, with anomalous anatomy.
The Rayan classification describes ulnar polydactyly and was derived from a case study series of 148 patients in Oklahoma (Table 3).29
There are also some complex polydactylies that are not easily classified: ulnar dimelia, cleft hand, pentadactyly, and hyperphalangism. Ulnar dimelia, also known as “mirror hand,” is typically 7 digits with no thumb, but other variations are seen. The radius is often absent, and the elbow is abnormal. There is some debate about whether it is a fusion of 2 hands. Pentadactyly, or the 5-fingered hand, appears as 5 triphalangeal digits with no thumb (Figure 7).
Isolated thumb triphalangism might appear similar to pentadactyly. Miura30,31 pointed out that the radial digit in the pentadactylous hand may be opposable (thumb-like) or nonopposable; in his studies, the patients with the opposable thumb had a metacarpal with a proximal epiphysis (Figure 8). Consequently, the triphalangeal thumb metacarpal with a distal epiphysis is true pentadactyly, whereas that with a proximal epiphysis is hyperphalangism (Figure 9). Treatment of these complex polydactylies involves the same underlying principles as for preaxial and postaxial polydactyly, albeit with additional proximal upper extremity considerations.
When to Operate (Timing)
Ezaki6 recommended surgical intervention at age 6 to 9 months, before fine motor skills have developed with the abnormal anatomy. Cortical learning occurs as the child begins prehensile activities before 6 months, but the risks of anesthesia outweigh functional benefits until the child is older. Waiting until 1 year of age is not uncommon, though surgery at an earlier age may be beneficial if the polydactyly affects hand function.32 It is not uncommon to wait with the more balanced thumb polydactylies to assess thumb function. Hypoplasia might also delay surgical intervention until there is enough tissue inventory for reconstruction. Wassel20 noted that surgical intervention ideally occurs before the supernumerary elements displace the normal elements, as tends to happen with growth. Suture ligation is an option in the neonatal unit for some pedunculated digits.33 Studies have shown satisfactory results in adults treated for polydactyly, if the patient presents later than expected.34
Surgical Considerations
Knavel recommended simple excision, stating that “ablation requires no ingenuity and creates no problems.”5 This belief, though true for some duplications, will not lead to the best outcome for more complex polydactylies. The goal of surgery is a stable and well-aligned thumb for pinch and prehensile activity, as well as a cosmetically pleasing hand. Incisions should not be made linearly along the axis of the digit, as the scar will cause deviation with growth.24
Wassel type I polydactyly might appear incidentally as a broad thumb, in which case it requires no intervention (Figure 10). However, in Wassel types I and II polydactyly with deformity, the Bilhaut-Cloquet procedure is useful for both bifid and duplicated phalanges (Figure 11).5,6,30,32,35 Collateral ligaments may need to be released in type II because of difficulty in opposing the tissue. Cosmetic results with Bilhaut-Cloquet are unpredictable. The original technique required symmetrically sized digits; results today have been improved with microtechniques and preservation of an entire nail.36 Another option is ablation of the more hypoplastic osseous element and soft-tissue augmentation of the residual digit. The theme of ablation and augmentation is seen throughout the literature for the surgical treatment of polydactyly (Figure 12).1
For type III polydactyly, the bifid proximal phalanx is narrowed by resection and realigned with osteotomy of the remaining diaphysis. Type IV polydactyly, the most common thumb duplication, often requires advancement of the abductor pollicis brevis to the base of the proximal phalanx to aid in metacarpophalangeal (MCP) stabilization, abduction, and opposition. The metacarpal head, if broad and with 2 facets, can be shaped to form a single articulating surface. The metacarpal, occasionally with the proximal phalanx, often requires realignment by closing wedge osteotomy. Last, tendons on the resected bony elements should be rebalanced on the remaining digit, and anomalous slips must be released. For instance, given a radial insertion of the long flexor tendon on the distal phalanx, the tendon should be moved centrally. A strong flexor or extensor tendon on the amputated digit should be transferred to the remaining digit.24
Types V and VI are treated similarly to type IV, with the addition of a first web space Z-plasty or web widening if there is thenar eminence contracture. Acral transposition has also been described, with transposition of the tip of the ablated digit in place of the tip of the kept digit; this technique is ideal if one digit has a more normal proximal part while the other has a more normal distal part (Figure 13).35
Type VII thumb polydactyly, the type most likely inherited and associated with other disorders, should be treated like type VI. The nail should be preserved; amputation of the distal phalanx is not advised. Resection of the delta phalanx or 1 interphalangeal (IP) joint is an option. Articular surfaces will remodel if done before the age of 1 year. If the thenar eminence is hypoplastic, then Huber transfer of the abductor digiti minimi should be considered.37 Resection of the triphalangeal thumb is also advised, even if the biphalangeal thumb is more hypoplastic, with transfer of the ligaments and tendons, as described earlier.5,6,24,30,32,35
Thumb triphalangism, if isolated, and hyperphalangism in the other digits, can be treated with resection of the delta phalanx or one of the IP joints if it is affecting function or cosmesis.1,6 Wood and Flatt23 recommended early resection of a thumb delta phalanx because of the likelihood of deviation that impedes thumb function. For children, they recommended delta phalanx resection and Kirschner wire fixation for 6 weeks; for adults, they recommended resection or fusion of the joint, with osteotomy as needed for deviation.23,24 For thumb triphalangism, multiple surgeries are the norm, as Wood24 reported in his study of 21 patients who underwent 78 operations in total.
Index polydactyly may present as a simple pedunculated skin tag, which can be simply excised, or as a more complex musculoskeletal duplication. More complex presentations can be treated with procedures similar to those used for the thumb. Typically, the additional digit is radially deviated and angulated, eventually leading to impingement of thumb pinch and the first web space. Ray amputation is also an option if no reconstructive surgery will produce the stable, sensate radial pinch that is essential to hand function.32
Ring-finger polydactyly and long-finger polydactyly are often complicated by some element of syndactyly, resulting in a relative paucity of skin (Figure 14). There is failure of both formation (hypoplasia) and differentiation (syndactyly). The hypoplasia particularly affects the function of these digits by tethering them; multiple surgeries to restore proper hand function are the norm.1 Reconstructive surgery for these digits requires preoperative tissue inventory followed by resection and augmentation; as in syndactyly, skin for coverage is at a premium. Creation of a 3-fingered hand is an option.23
Temtamy and McKusick10 type A little-finger polydactyly is treated similarly to the thumb, with the caveat that hypothenar and intrinsic muscles that insert on the resected little finger are transferred to the remaining digit. In contrast to thumb polydactyly, the extrinsic musculature tends to be in good position. Suture ligation of type B polydactyly, as described by Flatt, is likely more common than orthopedists appreciate, as pediatricians and neonatal unit practitioners commonly perform this procedure in the nursery.1-3 It has been described with 2-0 Vicryl3 (Ethicon, Somerville, New Jersey) and 4-0 silk sutures,32 with the goal of necrosis and autoamputation. Parents should be told the finger generally falls off about 10 days (range, 4-21 days) after ligation.3 Multiple authors have cited a report of exsanguination from suture ligation, but we could not locate the primary source. It is advisable to wait until a patient is 6 months of age if planning to resect the nubbin in the operating room, given the anesthesia risk and the lack of functional impairment. Katz and Linder33 indicated they remove type B polydactyly in the nursery suite used for circumcisions; they use anesthetizing cream on the skin, and sharp excision with a scalpel, followed by direct pressure and Steri-Strip (3M, St. Paul, Minnesota) application. Suture ligation is recommended only if there is a narrow, thin (<2 mm) soft-tissue stalk; any broad or bony stalk necessitates surgical removal to avoid neuroma formation and failure of autonecrosis (Figure 15).27 Other options are a single swipe of a scalpel and elliptical excision; sharp transaction of the digital nerve with subsequent retraction is advised to avoid neuroma formation.2
Barton described ulnar dimelia operations as “spare parts surgery.”1 Extra digits are ablated and a thumb created (Figure 16). The hand might have a digit in relatively good rotational position for thumbplasty, or the principles of pollicization may need to be used. If the patient is already using the hand, the surgeon should note which finger the patient uses as a thumb.24 Any accompanying wrist flexion contracture must be corrected with careful attention to musculotendinous balancing. Because the forearm and elbow, and occasionally even the more proximal limb, will be abnormal in this disorder, multiple surgeries are again the norm.1
Pentadactyly is treated like thumb hypoplasia, with first web space creation.1
Complications
In polydactyly, a reoperation rate of up to 25% has been reported, with most reoperations performed because of residual or subsequent deformity.5,30,31,38 Risk factors for reoperation are type IV thumb duplication, preoperative “zigzag” deformity, and radially deviated thumb elements at presentation.5 The delta phalanx may not show on radiographs until the patient is 18 months old, but functional deformity will worsen as long as it is present. Zigzag deformity may be due to the delta phalanx or to musculotendinous imbalance, such as a radially inserted flexor pollicis longus (FPL) or lack of stable MCP abduction. Miura31 found that careful reconstruction of the joint capsule and thenar muscles from the ablated digit to the remnant digit is the key to a successful initial surgery. Lee and colleagues39 defined zigzag deformity as more than 20° MCP and IP angulation; for cases present before surgery, they recommended FPL relocation by the pullout technique in addition to osteotomies to prevent further interphalangeal deviation (Figures 17, 18).
Abnormal physeal growth, joint instability, and stiffness can all occur. Stiffness is particularly difficult to treat but seldom presents a functional problem. Joint enlargement, which is not uncommon, results from either broad articular surfaces or retained cartilage from the perichondral ring after resection that later ossifies.5,38 Nubbin-type duplications may not fall off after suture ligation, necessitating further excision, and a cosmetic bump is seen after 40% of suture ligations.3 Patillo and Rayan28 and Rayan and Frey29 warned against suture ligation unless the nubbin has a small stalk because of the possibility of infection and gangrene. The excised nubbin tissue is histologically nervous, and there have been reports of painful neuromas in the remaining scar of a ligated nubbin that respond well to excision.26,27,40 It is thought that these painful lesions form because the ligature prevents the digital nerves to the vestigial digit from retracting.27 Nail deformity and IP joint stiffness are seen with the Bilhaut-Cloquet procedure, though often finger function remains satisfactory.
Conclusion
Polydactyly is a common congenital hand abnormality. Its true incidence is unknown because of inconsistent documentation. Surgeons must strive for a functional, cosmetic hand, given a diverse set of possible anomalies. Hypoplasia is the rule; tissue should be ablated and augmented as necessary. Musculotendinous insertions may need to be centralized. Patients’ family members should always be counseled that more surgery may be needed in the future, as further deformity can occur with growth. Surgically corrected thumb duplications will be stiffer, shorter, and thinner than their normal counterparts. Nail ridges are common. However, it should be noted that 88% of these patients are satisfied with their results.41 Some amount of contracture and abnormal function should be expected with index-, long-, and ring-finger duplications. The only remnant of type B postaxial duplications may be a slight discoloration or bump, though stiffness and deformity can happen with a type A deformity. A “duplicated” digit that requires surgical correction will never be completely normal, but acceptable function is routinely achievable.
1. Graham TJ, Ress AM. Finger polydactyly. Hand Clin. 1998;14(1):49-64.
2. Abzug JM, Kozin SH. Treatment of postaxial polydactyly type B. J Hand Surg Am. 2013;38(6):1223-1225.
3. Watson BT, Hennrikus WL. Postaxial type-B polydactyly—prevalence and treatment. J Bone Joint Surg Am. 1997;79(1):65-68.
4. Zimmer EZ, Bronshtein M. Fetal polydactyly diagnosis during early pregnancy: clinical applications. Am J Obstet Gynecol. 2000;183(3):755-758.
5. Cohen MS. Thumb duplication. Hand Clin. 1998;14(1):17-27.
6. Ezaki M. Radial polydactyly. Hand Clin. 1990;6(4):577-588.
7. Nathan PA, Keniston RC. Crossed polydactyly: case report and review of the literature. J Bone Joint Surg Am. 1975;57(6):847-849.
8. Sun G, Xu ZM, Liang JF, Li L, Tang DX. Twelve-year prevalence of common neonatal congenital malformations in Zhejiang Province, China. World J Pediatr. 2011;7(4):331-336.
9. Ivy RH. Congenital anomalies as recorded on birth certificates in the Division of Vital Statistics of the Pennsylvania Department of Health, for the period of 1951–1955, inclusive. Plast Reconstr Surg. 1957;20(5):400-411.
10. Temtamy SA, McKusick VA. Polydactyly as a part of syndromes. In: Bergsma D, ed. Mudge JR, Paul NW, Conde Greene S, associate eds. The Genetics of Hand Malformations. New York, NY: Liss. Birth Defects Original Article Series. 1978;14(3):364-439.
11. Gould W, Pyle L. Anomalies and Curiosities of Medicine. New York, NY: Bell; 1896.
12. Biesecker LG. Polydactyly: how many disorders and how many genes: 2010 update. Dev Dyn. 2011;250(5):931-942.
13. Grzeschik K. Human limb malformations; an approach to the molecular basis of development. Int J Dev Biol. 2001;46(7):983-991.
14. Zaleske DJ. Development of the upper limb. Hand Clin. 1985;1(3):383-390.
15. Beatty E. Upper limb tissue differentiation in the human embryo. Hand Clin. 1985;1(3):391-404.
16. Anderson E, Peluso S, Lettice LA, Hill RE. Human limb abnormalities caused by disruption of hedgehog signaling. Trends Genet. 2012;28(8):364-373.
17. Ware SM, Aygun MG, Heldebrandt F. Spectrum of clinical diseases caused by disorders of primary cilia. Proc Am Thorac Soc. 2011;8(5):444-450.
18. Lettice LA, Hill RE. Preaxial polydactyly: a model for defective long-range regulation in congenital abnormalities. Curr Opin Genet Dev. 2005;15(3):294-300.
19. Al-Qattan MA. Type II familial synpolydactyly: report on two families with an emphasis on variations of expression. Eur J Hum Genet. 2011;19(1):112-114.
20. Wassel HD. The results of surgery for polydactyly of the thumb. Clin Orthop. 1969;(64):175-193.
21. Blauth W, Olason AT. Classification of polydactyly of the hands and feet. Arch Orthop Trauma Surg. 1988;107(6):334-344.
22. Wood VE. Super digit. Hand Clin. 1990;6(4):673-684.
23. Wood VE, Flatt AE. Congenital triangular bones in the hand. J Hand Surg Am. 1977;2(3):179-193.
24. Wood VE. Polydactyly and the triphalangeal thumb. J Hand Surg Am. 1978;3(5):436-444.
25. Zuidam JM, Selles RW, Ananta M, Runia J, Hovius SER. A classification system of radial polydactyly: inclusion of triphalangeal thumb and triplication. J Hand Surg Am. 2008;33(3):373-377.
26. Leber GE, Gosain AK. Surgical excision of pedunculated supernumerary digits prevents traumatic amputation neuromas. Pediatr Dermatol. 2003;20(2):108-112.
27. Mullick S, Borschel GH. A selective approach to treatment of ulnar polydactyly: preventing painful neuroma and incomplete excision. Pediatr Dermatol. 2001;27(1):39-42.
28. Patillo D, Rayan GM. Complications of suture ligation ablation for ulnar polydactyly: a report of two cases. Hand (N Y). 2011;6(1):102-105.
29. Rayan GM, Frey B. Ulnar polydactyly. Plastic Reconstr Surg. 2001;107(6):1449-1454.
30. Miura T. Triphalangeal thumb. Plastic Reconstr Surg. 1976;58(5):587-594.
31. Miura T. Duplicated thumb. Plastic Reconstr Surg. 1982;69(3):470-481.
32. Simmons BP. Polydactyly. Hand Clin. 1985;1(3):545-566.
33. Katz K, Linder N. Postaxial type B polydactyly treated by excision in the neonatal nursery. J Pediatr Orthop. 2011;31(4):448-449.
34. Manohar A, Beard AJ. Outcome of reconstruction for duplication of the thumb in adults aged over 40. Hand Surg. 2011;16(2):207-210.
35. Watt AJ, Chung KC. Duplication. Hand Clin. 2009;25(2):215-228.
36. Tonkin MA. Thumb duplication: concepts and techniques. Clin Orthop Surg. 2012;4(1):1-17.
37. Huber E. Relief operation in the case of paralysis of the median nerve. J Hand Surg Eur. 2004;29(1):35-37.
38. Mih AD. Complications of duplicate thumb reconstruction. Hand Clin. 1998;14(1):143-149.
39. Lee CC, Park HY, Yoon JO, Lee KW. Correction of Wassel type IV thumb duplication with zigzag deformity: results of a new method of flexor pollicis longus tendon relocation. J Hand Surg Eur. 2013;38(3):272-280.
40. Hare PJ. Rudimentary polydactyly. Br J Dermatol. 1954;66(11):402-408.
41. Yen CH, Chan WL, Leung HB, Mak KH. Thumb polydactyly: clinical outcome after reconstruction. J Orthop Surg (Hong Kong). 2006;14(3):295-302.
42. Edmunds JO. A tribute to Daniel C. Riordan, MD (1917–2012). Tulane University School of Medicine, Department of Orthopaedics website. http://tulane.edu/som/departments/orthopaedics/news-and-events/danriordantribute.cfm. Accessed March 31, 2015.
43. Faust DC, Herms R. Daniel C. Riordan, MD, 1917–2012. J Hand Surg Am. 2013;38(1):202-205.
1. Graham TJ, Ress AM. Finger polydactyly. Hand Clin. 1998;14(1):49-64.
2. Abzug JM, Kozin SH. Treatment of postaxial polydactyly type B. J Hand Surg Am. 2013;38(6):1223-1225.
3. Watson BT, Hennrikus WL. Postaxial type-B polydactyly—prevalence and treatment. J Bone Joint Surg Am. 1997;79(1):65-68.
4. Zimmer EZ, Bronshtein M. Fetal polydactyly diagnosis during early pregnancy: clinical applications. Am J Obstet Gynecol. 2000;183(3):755-758.
5. Cohen MS. Thumb duplication. Hand Clin. 1998;14(1):17-27.
6. Ezaki M. Radial polydactyly. Hand Clin. 1990;6(4):577-588.
7. Nathan PA, Keniston RC. Crossed polydactyly: case report and review of the literature. J Bone Joint Surg Am. 1975;57(6):847-849.
8. Sun G, Xu ZM, Liang JF, Li L, Tang DX. Twelve-year prevalence of common neonatal congenital malformations in Zhejiang Province, China. World J Pediatr. 2011;7(4):331-336.
9. Ivy RH. Congenital anomalies as recorded on birth certificates in the Division of Vital Statistics of the Pennsylvania Department of Health, for the period of 1951–1955, inclusive. Plast Reconstr Surg. 1957;20(5):400-411.
10. Temtamy SA, McKusick VA. Polydactyly as a part of syndromes. In: Bergsma D, ed. Mudge JR, Paul NW, Conde Greene S, associate eds. The Genetics of Hand Malformations. New York, NY: Liss. Birth Defects Original Article Series. 1978;14(3):364-439.
11. Gould W, Pyle L. Anomalies and Curiosities of Medicine. New York, NY: Bell; 1896.
12. Biesecker LG. Polydactyly: how many disorders and how many genes: 2010 update. Dev Dyn. 2011;250(5):931-942.
13. Grzeschik K. Human limb malformations; an approach to the molecular basis of development. Int J Dev Biol. 2001;46(7):983-991.
14. Zaleske DJ. Development of the upper limb. Hand Clin. 1985;1(3):383-390.
15. Beatty E. Upper limb tissue differentiation in the human embryo. Hand Clin. 1985;1(3):391-404.
16. Anderson E, Peluso S, Lettice LA, Hill RE. Human limb abnormalities caused by disruption of hedgehog signaling. Trends Genet. 2012;28(8):364-373.
17. Ware SM, Aygun MG, Heldebrandt F. Spectrum of clinical diseases caused by disorders of primary cilia. Proc Am Thorac Soc. 2011;8(5):444-450.
18. Lettice LA, Hill RE. Preaxial polydactyly: a model for defective long-range regulation in congenital abnormalities. Curr Opin Genet Dev. 2005;15(3):294-300.
19. Al-Qattan MA. Type II familial synpolydactyly: report on two families with an emphasis on variations of expression. Eur J Hum Genet. 2011;19(1):112-114.
20. Wassel HD. The results of surgery for polydactyly of the thumb. Clin Orthop. 1969;(64):175-193.
21. Blauth W, Olason AT. Classification of polydactyly of the hands and feet. Arch Orthop Trauma Surg. 1988;107(6):334-344.
22. Wood VE. Super digit. Hand Clin. 1990;6(4):673-684.
23. Wood VE, Flatt AE. Congenital triangular bones in the hand. J Hand Surg Am. 1977;2(3):179-193.
24. Wood VE. Polydactyly and the triphalangeal thumb. J Hand Surg Am. 1978;3(5):436-444.
25. Zuidam JM, Selles RW, Ananta M, Runia J, Hovius SER. A classification system of radial polydactyly: inclusion of triphalangeal thumb and triplication. J Hand Surg Am. 2008;33(3):373-377.
26. Leber GE, Gosain AK. Surgical excision of pedunculated supernumerary digits prevents traumatic amputation neuromas. Pediatr Dermatol. 2003;20(2):108-112.
27. Mullick S, Borschel GH. A selective approach to treatment of ulnar polydactyly: preventing painful neuroma and incomplete excision. Pediatr Dermatol. 2001;27(1):39-42.
28. Patillo D, Rayan GM. Complications of suture ligation ablation for ulnar polydactyly: a report of two cases. Hand (N Y). 2011;6(1):102-105.
29. Rayan GM, Frey B. Ulnar polydactyly. Plastic Reconstr Surg. 2001;107(6):1449-1454.
30. Miura T. Triphalangeal thumb. Plastic Reconstr Surg. 1976;58(5):587-594.
31. Miura T. Duplicated thumb. Plastic Reconstr Surg. 1982;69(3):470-481.
32. Simmons BP. Polydactyly. Hand Clin. 1985;1(3):545-566.
33. Katz K, Linder N. Postaxial type B polydactyly treated by excision in the neonatal nursery. J Pediatr Orthop. 2011;31(4):448-449.
34. Manohar A, Beard AJ. Outcome of reconstruction for duplication of the thumb in adults aged over 40. Hand Surg. 2011;16(2):207-210.
35. Watt AJ, Chung KC. Duplication. Hand Clin. 2009;25(2):215-228.
36. Tonkin MA. Thumb duplication: concepts and techniques. Clin Orthop Surg. 2012;4(1):1-17.
37. Huber E. Relief operation in the case of paralysis of the median nerve. J Hand Surg Eur. 2004;29(1):35-37.
38. Mih AD. Complications of duplicate thumb reconstruction. Hand Clin. 1998;14(1):143-149.
39. Lee CC, Park HY, Yoon JO, Lee KW. Correction of Wassel type IV thumb duplication with zigzag deformity: results of a new method of flexor pollicis longus tendon relocation. J Hand Surg Eur. 2013;38(3):272-280.
40. Hare PJ. Rudimentary polydactyly. Br J Dermatol. 1954;66(11):402-408.
41. Yen CH, Chan WL, Leung HB, Mak KH. Thumb polydactyly: clinical outcome after reconstruction. J Orthop Surg (Hong Kong). 2006;14(3):295-302.
42. Edmunds JO. A tribute to Daniel C. Riordan, MD (1917–2012). Tulane University School of Medicine, Department of Orthopaedics website. http://tulane.edu/som/departments/orthopaedics/news-and-events/danriordantribute.cfm. Accessed March 31, 2015.
43. Faust DC, Herms R. Daniel C. Riordan, MD, 1917–2012. J Hand Surg Am. 2013;38(1):202-205.
A Blood Test for Osteoarthritis?
The first blood test to detect rheumatoid arthritis and osteoarthritis may soon be developed, according to a study published March 19 in Scientific Reports. The research findings could potentially lead to patients being tested for rheumatoid arthritis and osteoarthritis several years before the onset of physical symptoms.
Lead researcher Dr. Naila Rabbani, Reader of Experimental Systems Biology at the University of Warwick in Coventry United Kingdom, and colleagues have identified a biomarker that is linked to both rheumatoid arthritis and osteoarthritis. While there are established tests for rheumatoid arthritis, the newly identified biomarker could lead to one that can diagnose rheumatoid arthritis and osteoarthritis.
Initially, the research's focus was on citrullinated proteins, a biomarker suspected to be present in the blood of patients with early stage rheumatoid arthritis. It had previously been established that patients with rheumatoid arthritis have citrullinated protein antibodies, but it was not believed that the same held true for people with osteoarthritis. However, investigators found that there was an increase in citrullinated protein levels in both early-stage osteoarthritis and rheumatoid arthritis.
Study authors then produced an algorithm of 3 biomarkers, plasma/serum citrullinated protein, 4-hydroxyproline, and anti-cyclic citrullinated peptide. Based on this algorithm, the researchers found that with a single test they could potentially detect and discriminate between the major types of arthritis at the early stages, before joint damage has occurred.
“Detection of early stage osteoarthritis made the study very promising and we would have been satisfied with this only, but beyond this we also found we could detect and discriminate early-stage rheumatoid arthritis and other inflammatory joint diseases at the same,” said Dr. Rabbani.
“This discovery raises the potential of a blood test that can help diagnose both rheumatoid arthritis and osteoarthritis several years before the onset of physical symptoms,” Dr. Rabbani stated.
Suggested Reading
Ahmed U, Anwar A, Savage RS, et al. Biomarkers of early stage osteoarthritis, rheumatoid arthritis and musculoskeletal health. Sci Rep. 2015 Mar 19;5:9259.
The first blood test to detect rheumatoid arthritis and osteoarthritis may soon be developed, according to a study published March 19 in Scientific Reports. The research findings could potentially lead to patients being tested for rheumatoid arthritis and osteoarthritis several years before the onset of physical symptoms.
Lead researcher Dr. Naila Rabbani, Reader of Experimental Systems Biology at the University of Warwick in Coventry United Kingdom, and colleagues have identified a biomarker that is linked to both rheumatoid arthritis and osteoarthritis. While there are established tests for rheumatoid arthritis, the newly identified biomarker could lead to one that can diagnose rheumatoid arthritis and osteoarthritis.
Initially, the research's focus was on citrullinated proteins, a biomarker suspected to be present in the blood of patients with early stage rheumatoid arthritis. It had previously been established that patients with rheumatoid arthritis have citrullinated protein antibodies, but it was not believed that the same held true for people with osteoarthritis. However, investigators found that there was an increase in citrullinated protein levels in both early-stage osteoarthritis and rheumatoid arthritis.
Study authors then produced an algorithm of 3 biomarkers, plasma/serum citrullinated protein, 4-hydroxyproline, and anti-cyclic citrullinated peptide. Based on this algorithm, the researchers found that with a single test they could potentially detect and discriminate between the major types of arthritis at the early stages, before joint damage has occurred.
“Detection of early stage osteoarthritis made the study very promising and we would have been satisfied with this only, but beyond this we also found we could detect and discriminate early-stage rheumatoid arthritis and other inflammatory joint diseases at the same,” said Dr. Rabbani.
“This discovery raises the potential of a blood test that can help diagnose both rheumatoid arthritis and osteoarthritis several years before the onset of physical symptoms,” Dr. Rabbani stated.
The first blood test to detect rheumatoid arthritis and osteoarthritis may soon be developed, according to a study published March 19 in Scientific Reports. The research findings could potentially lead to patients being tested for rheumatoid arthritis and osteoarthritis several years before the onset of physical symptoms.
Lead researcher Dr. Naila Rabbani, Reader of Experimental Systems Biology at the University of Warwick in Coventry United Kingdom, and colleagues have identified a biomarker that is linked to both rheumatoid arthritis and osteoarthritis. While there are established tests for rheumatoid arthritis, the newly identified biomarker could lead to one that can diagnose rheumatoid arthritis and osteoarthritis.
Initially, the research's focus was on citrullinated proteins, a biomarker suspected to be present in the blood of patients with early stage rheumatoid arthritis. It had previously been established that patients with rheumatoid arthritis have citrullinated protein antibodies, but it was not believed that the same held true for people with osteoarthritis. However, investigators found that there was an increase in citrullinated protein levels in both early-stage osteoarthritis and rheumatoid arthritis.
Study authors then produced an algorithm of 3 biomarkers, plasma/serum citrullinated protein, 4-hydroxyproline, and anti-cyclic citrullinated peptide. Based on this algorithm, the researchers found that with a single test they could potentially detect and discriminate between the major types of arthritis at the early stages, before joint damage has occurred.
“Detection of early stage osteoarthritis made the study very promising and we would have been satisfied with this only, but beyond this we also found we could detect and discriminate early-stage rheumatoid arthritis and other inflammatory joint diseases at the same,” said Dr. Rabbani.
“This discovery raises the potential of a blood test that can help diagnose both rheumatoid arthritis and osteoarthritis several years before the onset of physical symptoms,” Dr. Rabbani stated.
Suggested Reading
Ahmed U, Anwar A, Savage RS, et al. Biomarkers of early stage osteoarthritis, rheumatoid arthritis and musculoskeletal health. Sci Rep. 2015 Mar 19;5:9259.
Suggested Reading
Ahmed U, Anwar A, Savage RS, et al. Biomarkers of early stage osteoarthritis, rheumatoid arthritis and musculoskeletal health. Sci Rep. 2015 Mar 19;5:9259.
Twin Study Offers New Insights Into the Link Between Back Pain and Depression
Genetic factors help to explain the common association between low back pain and depression, according to a large study of twins published in the March issue of Pain.
Marina B. Pinheiro, MSc, and her research colleagues at the University of Sydney in Australia, analyzed data from the Murcia Twin Registry of nearly 2,150 Spanish twins. Questionnaire responses were assessed to determine whether participants with symptoms of depression had a higher prevalence of back pain. A series of statistical analyses were then performed to clarify genetic factors and to determine how an environment that is shared early on can contribute to the linkage between depression and back pain.
The results showed a significant association between symptoms of depression and low back pain. On the initial analysis, which considered the participants as individuals, the odds of having back pain were about 1.6 higher for those with symptoms of depression and anxiety.
For the analysis of twin pairs, which controlled for genetic and familial factors that could influence the relationship between depression and back pain, there was a 1.7 increase in odds. The association was even stronger—more than a 2.3 increase in odds of low back pain associated with depression and anxiety—on the analysis of dizygotic twins.
Upon further analysis of monozygotic twins, the association between symptoms of depression and low back pain disappeared. This suggested that the strong association found in non-identical twins resulted from the confounding effects of common genetic factors influencing both conditions.
Overall, the finding that the association between symptoms of depression and low back pain disappears after fully adjusting for genetics and familial confounders in identical twins suggests that genetics is the main confounder of the relationship between depression and back pain.
Suggested Reading
Pinheiro MB, Ferreira ML, Refshauge K, et al. Genetics and the environment affect the relationship between depression and low back pain: a co-twin control study of Spanish twins. Pain. 2015;156(3):496-503.
Genetic factors help to explain the common association between low back pain and depression, according to a large study of twins published in the March issue of Pain.
Marina B. Pinheiro, MSc, and her research colleagues at the University of Sydney in Australia, analyzed data from the Murcia Twin Registry of nearly 2,150 Spanish twins. Questionnaire responses were assessed to determine whether participants with symptoms of depression had a higher prevalence of back pain. A series of statistical analyses were then performed to clarify genetic factors and to determine how an environment that is shared early on can contribute to the linkage between depression and back pain.
The results showed a significant association between symptoms of depression and low back pain. On the initial analysis, which considered the participants as individuals, the odds of having back pain were about 1.6 higher for those with symptoms of depression and anxiety.
For the analysis of twin pairs, which controlled for genetic and familial factors that could influence the relationship between depression and back pain, there was a 1.7 increase in odds. The association was even stronger—more than a 2.3 increase in odds of low back pain associated with depression and anxiety—on the analysis of dizygotic twins.
Upon further analysis of monozygotic twins, the association between symptoms of depression and low back pain disappeared. This suggested that the strong association found in non-identical twins resulted from the confounding effects of common genetic factors influencing both conditions.
Overall, the finding that the association between symptoms of depression and low back pain disappears after fully adjusting for genetics and familial confounders in identical twins suggests that genetics is the main confounder of the relationship between depression and back pain.
Genetic factors help to explain the common association between low back pain and depression, according to a large study of twins published in the March issue of Pain.
Marina B. Pinheiro, MSc, and her research colleagues at the University of Sydney in Australia, analyzed data from the Murcia Twin Registry of nearly 2,150 Spanish twins. Questionnaire responses were assessed to determine whether participants with symptoms of depression had a higher prevalence of back pain. A series of statistical analyses were then performed to clarify genetic factors and to determine how an environment that is shared early on can contribute to the linkage between depression and back pain.
The results showed a significant association between symptoms of depression and low back pain. On the initial analysis, which considered the participants as individuals, the odds of having back pain were about 1.6 higher for those with symptoms of depression and anxiety.
For the analysis of twin pairs, which controlled for genetic and familial factors that could influence the relationship between depression and back pain, there was a 1.7 increase in odds. The association was even stronger—more than a 2.3 increase in odds of low back pain associated with depression and anxiety—on the analysis of dizygotic twins.
Upon further analysis of monozygotic twins, the association between symptoms of depression and low back pain disappeared. This suggested that the strong association found in non-identical twins resulted from the confounding effects of common genetic factors influencing both conditions.
Overall, the finding that the association between symptoms of depression and low back pain disappears after fully adjusting for genetics and familial confounders in identical twins suggests that genetics is the main confounder of the relationship between depression and back pain.
Suggested Reading
Pinheiro MB, Ferreira ML, Refshauge K, et al. Genetics and the environment affect the relationship between depression and low back pain: a co-twin control study of Spanish twins. Pain. 2015;156(3):496-503.
Suggested Reading
Pinheiro MB, Ferreira ML, Refshauge K, et al. Genetics and the environment affect the relationship between depression and low back pain: a co-twin control study of Spanish twins. Pain. 2015;156(3):496-503.
Common OTC Analgesic Proven Inefficacious for Treating Low Back Pain
Paracetamol (acetaminophen) is ineffective for the treatment of spinal pain and provides negligible benefits for low back pain or osteoarthritis of the hip or knee, its usage also may affect the liver, according to a study published March 31 in BMJ.
Lead study author Gustavo Machado, a PhD student from The George Institute for Global Health at the University of Sydney in Australia, and his research colleagues conducted a systematic review and meta-analysis to examine the efficacy and safety of paracetamol for lower back pain and osteoarthritis of the hip or knee. The reduction of pain intensity, improvement of disability, quality of life, safety, and patient adherence were analyzed in this trial.
The study included 13 randomized controlled trials that examined the effects of paracetamol use compared with placebo. Ten trials included 3,541 patients and evaluated the use of paracetamol for osteoarthritis of the hip or knee, and 3 trials included 1,825 patients that were evaluated for the use of paracetamol for lower back pain.
Among the study’s findings:
• For lower back pain, paracetamol had no effect and did not reduce disability or improve quality of life compared with placebo.
• Paracetamol use for osteoarthritis was shown to increase the likelihood of receiving abnormal results on liver function tests by almost 4 times compared with placebo.
• For osteoarthritis, the researchers found small, but not clinically important benefits in the reduction of pain and disability compared with placebo.
“This latest research, the most comprehensive systematic review of its kind, reaffirms this with an even larger, global patient base, and has for the first time also established that the effects of paracetamol for knee and hip osteoarthritis are too small to be of clinical importance,” Mr. Machado stated.
The study also found that adverse side effects varied across all of the trials. But no differences were found in the number of patients using paracetamol reporting these effects or being withdrawn from studies because of adverse events compared with those using a placebo. The adherence to treatment schedule rates was similar among patients taking paracetamol compared with those taking placebo.
“Use of paracetamol for low back pain or osteoarthritis was also shown to be associated with higher risk of liver toxicity in patients," Mr. Machado said. “Patients were nearly 4 times more likely to have abnormal results on liver function tests compared to those taking placebo pills.”
“World-wide, paracetamol is the most widely used over-the counter medicine for musculoskeletal conditions, so it is important to reconsider treatment recommendations given this new evidence,” stated Mr. Machado.
Suggested Reading
Machado GC, Maher CG, Ferreira PH, et al. Efficacy and safety of paracetamol for spinal pain and osteoarthritis: systematic review and meta-analysis of randomised placebo controlled trials. BMJ. 2015 Mar 31;350:h1225.
Paracetamol (acetaminophen) is ineffective for the treatment of spinal pain and provides negligible benefits for low back pain or osteoarthritis of the hip or knee, its usage also may affect the liver, according to a study published March 31 in BMJ.
Lead study author Gustavo Machado, a PhD student from The George Institute for Global Health at the University of Sydney in Australia, and his research colleagues conducted a systematic review and meta-analysis to examine the efficacy and safety of paracetamol for lower back pain and osteoarthritis of the hip or knee. The reduction of pain intensity, improvement of disability, quality of life, safety, and patient adherence were analyzed in this trial.
The study included 13 randomized controlled trials that examined the effects of paracetamol use compared with placebo. Ten trials included 3,541 patients and evaluated the use of paracetamol for osteoarthritis of the hip or knee, and 3 trials included 1,825 patients that were evaluated for the use of paracetamol for lower back pain.
Among the study’s findings:
• For lower back pain, paracetamol had no effect and did not reduce disability or improve quality of life compared with placebo.
• Paracetamol use for osteoarthritis was shown to increase the likelihood of receiving abnormal results on liver function tests by almost 4 times compared with placebo.
• For osteoarthritis, the researchers found small, but not clinically important benefits in the reduction of pain and disability compared with placebo.
“This latest research, the most comprehensive systematic review of its kind, reaffirms this with an even larger, global patient base, and has for the first time also established that the effects of paracetamol for knee and hip osteoarthritis are too small to be of clinical importance,” Mr. Machado stated.
The study also found that adverse side effects varied across all of the trials. But no differences were found in the number of patients using paracetamol reporting these effects or being withdrawn from studies because of adverse events compared with those using a placebo. The adherence to treatment schedule rates was similar among patients taking paracetamol compared with those taking placebo.
“Use of paracetamol for low back pain or osteoarthritis was also shown to be associated with higher risk of liver toxicity in patients," Mr. Machado said. “Patients were nearly 4 times more likely to have abnormal results on liver function tests compared to those taking placebo pills.”
“World-wide, paracetamol is the most widely used over-the counter medicine for musculoskeletal conditions, so it is important to reconsider treatment recommendations given this new evidence,” stated Mr. Machado.
Paracetamol (acetaminophen) is ineffective for the treatment of spinal pain and provides negligible benefits for low back pain or osteoarthritis of the hip or knee, its usage also may affect the liver, according to a study published March 31 in BMJ.
Lead study author Gustavo Machado, a PhD student from The George Institute for Global Health at the University of Sydney in Australia, and his research colleagues conducted a systematic review and meta-analysis to examine the efficacy and safety of paracetamol for lower back pain and osteoarthritis of the hip or knee. The reduction of pain intensity, improvement of disability, quality of life, safety, and patient adherence were analyzed in this trial.
The study included 13 randomized controlled trials that examined the effects of paracetamol use compared with placebo. Ten trials included 3,541 patients and evaluated the use of paracetamol for osteoarthritis of the hip or knee, and 3 trials included 1,825 patients that were evaluated for the use of paracetamol for lower back pain.
Among the study’s findings:
• For lower back pain, paracetamol had no effect and did not reduce disability or improve quality of life compared with placebo.
• Paracetamol use for osteoarthritis was shown to increase the likelihood of receiving abnormal results on liver function tests by almost 4 times compared with placebo.
• For osteoarthritis, the researchers found small, but not clinically important benefits in the reduction of pain and disability compared with placebo.
“This latest research, the most comprehensive systematic review of its kind, reaffirms this with an even larger, global patient base, and has for the first time also established that the effects of paracetamol for knee and hip osteoarthritis are too small to be of clinical importance,” Mr. Machado stated.
The study also found that adverse side effects varied across all of the trials. But no differences were found in the number of patients using paracetamol reporting these effects or being withdrawn from studies because of adverse events compared with those using a placebo. The adherence to treatment schedule rates was similar among patients taking paracetamol compared with those taking placebo.
“Use of paracetamol for low back pain or osteoarthritis was also shown to be associated with higher risk of liver toxicity in patients," Mr. Machado said. “Patients were nearly 4 times more likely to have abnormal results on liver function tests compared to those taking placebo pills.”
“World-wide, paracetamol is the most widely used over-the counter medicine for musculoskeletal conditions, so it is important to reconsider treatment recommendations given this new evidence,” stated Mr. Machado.
Suggested Reading
Machado GC, Maher CG, Ferreira PH, et al. Efficacy and safety of paracetamol for spinal pain and osteoarthritis: systematic review and meta-analysis of randomised placebo controlled trials. BMJ. 2015 Mar 31;350:h1225.
Suggested Reading
Machado GC, Maher CG, Ferreira PH, et al. Efficacy and safety of paracetamol for spinal pain and osteoarthritis: systematic review and meta-analysis of randomised placebo controlled trials. BMJ. 2015 Mar 31;350:h1225.
Total Hip Arthroplasty After Contralateral Hip Disarticulation: A Challenging “Simple Primary”
Patients with lower limb amputation have a high incidence of hip and knee osteoarthritis (OA) in the residual limb as well as the contralateral limb. A radical surgery, hip disarticulation is generally performed in younger patients after malignancy or trauma. Compliance is poor with existing prostheses, resulting in increased dependency on and use of the remaining sound limb.
In this case report, a crutch-walking 51-year-old woman presented with severe left hip arthritis 25 years after a right hip disarticulation. She underwent total hip arthroplasty (THA), a challenging procedure in a person without a contralateral hip joint. The many complex technical considerations associated with her THA included precise perioperative planning, the selection of appropriate prostheses and bearing surfaces, and the preoperative and intraoperative assessment of limb length and offset. The patient provided written informed consent for print and electronic publication of this case report.
Case Report
A 51-year-old woman presented to our service with a 3-year history of debilitating left hip pain. Twenty-five years earlier, she had been diagnosed with synovial sarcoma of the right knee and underwent limb-sparing surgery, followed by a true hip disarticulation performed for local recurrence. After her surgery, she declined the use of a prosthesis and mobilized with the use of 2 crutches. She has remained otherwise healthy and active, and runs her own business, which involves some lifting and carrying of objects. During the 3 years prior to presentation, she developed progressively debilitating left hip and groin pain, which radiated to the medial aspect of her left knee. Her mobilization distance had reduced to a few hundred meters, and she experienced significant night pain, and start-up pain. Activity modification, weight loss, and nonsteroidal anti-inflammatory medication afforded no relief. She denied any back pain or radicular symptoms.
Clinical examination showed a well-healed scar and pristine stump under her right hemipelvis. Passive range of movement of her left hip was painful for all movements, reduced at flexion (90º) and internal (10º) and external rotation (5º). Examination of her left knee was normal, with a full range of movement and no joint-line tenderness. A high body mass index (>30) was noted. Radiographic imaging confirmed significant OA of the hip joint (Figure 1). Informed consent was obtained for THA. The implants were selected—an uncemented collared Corail Stem (DePuy, Warsaw, Indiana) with a stainless steel dual mobility (DM) Novae SunFit acetabular cup (Serf, Decines, France), with bearing components of ceramic on polyethylene. A preoperative computed tomography (CT) scan of the left hip was performed (Figure 2) to aid templating, which was accomplished using plain films and CT images, with reference to the proximal femur for deciding level of neck cut, planning stem size, and optimizing length and offset, while determining cup size, depth, inclination, and height for the acetabular component.
Prior to surgery, the patient was positioned in the lateral decubitus position, using folded pillows under the medial aspect of her left proximal and distal thigh in lieu of her amputated limb. Pillows were secured to the table with elastic bandage tape. Standard pubic symphysis, lumbosacral, and midthoracic padded bolsters stabilized the pelvis in the normal fashion, with additional elastic bandage tape to further secure the pelvis brim to the table and reduce intraoperative motion. A posterior approach was used. A capsulotomy was performed with the hip in extension and slight abduction, with meticulous preservation of the capsule as the guide for the patient’s native length and offset. Reaming of the acetabulum was line to line, with insertion of an uncemented DM metal-back press-fit hydroxyapatite-coated shell placed in a standard fashion parallel with the transverse acetabular ligament, as described by Archbold and colleagues.1 The femur was sequentially reamed with broaches until press fit was achieved, and a calcar reamer was used to optimize interface with the collared implant. The surgeon’s standard 4 clinical tests were performed with trial implants after reduction to gauge hip tension, length, and offset. These tests are positive shuck test with hip and knee extension, lack of shuck in hip extension with knee flexion, lack of kick sign in hip extension and knee flexion, and palpation of gluteus medius belly to determine tension. Finally, with the hip returned to the extended and slightly abducted position, the capsule was tested for length and tension. The definitive stem implant was inserted, final testing with trial heads was repeated prior to definitive neck length and head selection, and final reduction was performed. A layered closure was performed, after generous washout. Pillows were taped together and positioned from the bed railing across the midline of the bed to prevent abduction, in the fashion of an abduction pillow.
The patient was mobilized the day after surgery and permitted full weight-bearing. Recovery was uneventful, and the patient returned to work within 6 weeks of surgery after her scheduled appointment and radiographic examination (Figure 3). Ongoing regular clinical and radiologic surveillance are planned.
Discussion
Hip and knee OA in the residual limb is more common for amputees than for the general population.2,3 THA for OA in amputees has been reported after below-knee amputation in both the ipsilateral and the contralateral hip.4 A true hip disarticulation is a rarely performed radical surgical procedure, involving the removal of the entire femur, and is most often related to surgical oncologic treatment or combat-related injuries, both being more common in younger people. Like many patients who have had a hip disarticulation,5 our patient declined a prosthesis, finding the design cosmetically unappealing and uncomfortable, in favor of crutch-walking. This accelerated wear of the remaining hip, and is a sobering reminder of the high demand on the bearing surfaces of the implants after her procedure.
The implants chosen for this procedure are critical. We use implants which are proven and reliable. Our institution uses the Corail Stem, an uncemented collared stem with an Orthopaedic Data Evaluation Panel (ODEP) 10A rating,6 widely used for THA.7 For the acetabulum, we chose the Novae SunFit, a modern version based on Bousquet’s 1976 DM design. The DM cup is a tripolar cup with a fixed porous-coated or cemented metal cup, which articulates with a large mobile polyethylene liner. A standard head in either metal or ceramic is inserted into this liner. The articulation between the head and the liner is constrained, while the articulation between the liner and the metal cup is unconstrained. This interposition of a mobile insert increases the effective head diameter, and the favorable head-neck ratio allows increased range of motion while avoiding early femoral neck impingement with a fixed liner or metal cup. A growing body of evidence indicates that DM cups reduce dislocation rates in primary and revision total knee arthroplasty and, when used with prudence, in selected tumor cases.8 A study of 1905 hips, using second-generation DM cups, reported cumulative survival rate of 98.6% at 12.2 years,9 with favorable outcomes compared with standard prostheses in the medium term for younger patients,10 and in the longer term,11 without increasing polyethylene wear.12
We use DM cups for 2 patient cohorts: first, for all patients older than 75 years because, in this age group, the risk of dislocation is higher than the risk of revision for wear-induced lysis; and second, in younger patients with any neuromuscular, cognitive, or mechanical risk factors that would excessively increase the risk of dislocation. This reflects the balance of risks in arthroplasty, with the ever-present trade-off between polyethylene-induced osteolysis and stability. Dislocation of the remaining sound limb for this young, active, agile patient would be a catastrophic complication. Given our patient’s risk factors for dislocation—female, an amputee with a high risk of falling, high body mass index, and lack of a contralateral limb to restrict adduction—the balance of risks favored hip stability over wear. We chose, therefore, a DM cup, using a ceramic-head-on-polyethylene-insert surface-bearing combination.
CT scanning is routinely performed in our institution to optimize preoperative templating. The preoperative CT images enable accurate planning, notably for the extramedullary reconstruction,13 and are used in addition to acetates and standard radiographs. This encourages preservation of acetabular bone stock by selecting the smallest suitable cup, reduces the risk of femoral fracture by giving an accurate prediction of the stem size, and ensures accuracy of restoring the patient’s offset and length. Although limb-length discrepancy was not an issue for this patient with a single sound limb, the sequalae of excessively increasing offset or length (eg, gluteus medius tendinopathy and trochanteric bursitis) would arguably be more debilitating than for someone who could offload weight to the “good hip.” For these reasons, marrying the preoperative templating with on-table testing with trial prostheses and restoring the native capsular tension is vital.
The importance of on-table positioning for proximal amputees undergoing hip arthroplasty has been highlighted.14 Lacking the normal bony constraints increases the risk of intraoperative on-table movement, which, in turn, risks reducing the accuracy of implant positioning. Crude limb-length checking using the contralateral knee is not possible. In addition, the lack of a contralateral hip joint causes a degree of compensatory pelvic tilt, which raises the option of increasing the coverage to compensate for obligate adduction during single-leg, crutch-walking gait. Lacking established guidelines to accommodate these variables, we inserted the cup in a standard fashion, at 45º, referencing acetabular version using the transverse acetabular ligament,1 and used the smallest stable cup after line-to-line reaming.
This case of THA in a young, crutch-walking patient with a contralateral true hip disarticulation highlights the importance of meticulous preoperative planning, implant selection appropriate for the patient in question, perioperative positioning, and the technical and operative challenges of restoring the patient’s normal hip architecture.
1. Archbold HA, Mockford B, Molloy D, McConway J, Ogonda L, Beverland D. The transverse acetabular ligament: an aid to orientation of the acetabular component during primary total hip replacement: a preliminary study of 1000 cases investigating postoperative stability. J Bone Joint Surg Br. 2006;88(7):883-886.
2. Kulkarni J, Adams J, Thomas E, Silman A. Association between amputation, arthritis and osteopenia in British male war veterans with major lower limb amputations. Clin Rehabil. 1998;12(4):348-353.
3. Struyf PA, van Heugten CM, Hitters MW, Smeets RJ. The prevalence of osteoarthritis of the intact hip and knee among traumatic leg amputees. Arch Phys Med Rehabil. 2009;90(3):440-446.
4. Nejat EJ, Meyer A, Sánchez PM, Schaefer SH, Westrich GH. Total hip arthroplasty and rehabilitation in ambulatory lower extremity amputees--a case series. Iowa Orthop J. 2005;25:38-41.
5. Zaffer SM, Braddom RL, Conti A, Goff J, Bokma D. Total hip disarticulation prosthesis with suction socket: report of two cases. Am J Phys Med Rehabil. 1999;78(2):160-162.
6. Lewis P. ODEP [Orthopaedic Data Evaluation Panel]. NHS Supply Chain website. http://www.supplychain.nhs.uk/odep. Accessed April 2, 2015.
7. National Joint Registry for England and Wales. 8th Annual Report, 2011. National Joint Registry website. www.njrcentre.org.uk/NjrCentre/Portals/0/Documents/NJR%208th%20Annual%20Report%202011.pdf. Accessed April 2, 2015.
8. Grazioli A, Ek ET, Rüdiger HA. Biomechanical concept and clinical outcome of dual mobility cups. Int Orthop. 2012;36(12):2411-2418.
9. Massin P, Orain V, Philippot R, Farizon F, Fessy MH. Fixation failures of dual mobility cups: a mid-term study of 2601 hip replacements. Clin Orthop. 2012;470(7):1932-1940.
10. Epinette JA, Béracassat R, Tracol P, Pagazani G, Vandenbussche E. Are modern dual mobility cups a valuable option in reducing instability after primary hip arthroplasty, even in younger patients? J Arthroplasty. 2014;29(6):1323-1328.
11. Philippot R, Meucci JF, Boyer B, Farizon F. Modern dual-mobility cup implanted with an uncemented stem: about 100 cases with 12-year follow-up. Surg Technol Int. 2013;23:208-212.
12. Prudhon JL, Ferreira A, Verdier R. Dual mobility cup: dislocation rate and survivorship at ten years of follow-up. Int Orthop. 2013;37(12):2345-2350.
13. Sariali E, Mouttet A, Pasquier G, Durante E, Catone Y. Accuracy of reconstruction of the hip using computerised three-dimensional pre-operative planning and a cementless modular neck. J Bone Joint Surg Br. 2009;91(13):333-340.
14. Bong MR, Kaplan KM, Jaffe WL. Total hip arthroplasty in a patient with contralateral hemipelvectomy. J Arthroplasty. 2006;21(5):762-764.
Patients with lower limb amputation have a high incidence of hip and knee osteoarthritis (OA) in the residual limb as well as the contralateral limb. A radical surgery, hip disarticulation is generally performed in younger patients after malignancy or trauma. Compliance is poor with existing prostheses, resulting in increased dependency on and use of the remaining sound limb.
In this case report, a crutch-walking 51-year-old woman presented with severe left hip arthritis 25 years after a right hip disarticulation. She underwent total hip arthroplasty (THA), a challenging procedure in a person without a contralateral hip joint. The many complex technical considerations associated with her THA included precise perioperative planning, the selection of appropriate prostheses and bearing surfaces, and the preoperative and intraoperative assessment of limb length and offset. The patient provided written informed consent for print and electronic publication of this case report.
Case Report
A 51-year-old woman presented to our service with a 3-year history of debilitating left hip pain. Twenty-five years earlier, she had been diagnosed with synovial sarcoma of the right knee and underwent limb-sparing surgery, followed by a true hip disarticulation performed for local recurrence. After her surgery, she declined the use of a prosthesis and mobilized with the use of 2 crutches. She has remained otherwise healthy and active, and runs her own business, which involves some lifting and carrying of objects. During the 3 years prior to presentation, she developed progressively debilitating left hip and groin pain, which radiated to the medial aspect of her left knee. Her mobilization distance had reduced to a few hundred meters, and she experienced significant night pain, and start-up pain. Activity modification, weight loss, and nonsteroidal anti-inflammatory medication afforded no relief. She denied any back pain or radicular symptoms.
Clinical examination showed a well-healed scar and pristine stump under her right hemipelvis. Passive range of movement of her left hip was painful for all movements, reduced at flexion (90º) and internal (10º) and external rotation (5º). Examination of her left knee was normal, with a full range of movement and no joint-line tenderness. A high body mass index (>30) was noted. Radiographic imaging confirmed significant OA of the hip joint (Figure 1). Informed consent was obtained for THA. The implants were selected—an uncemented collared Corail Stem (DePuy, Warsaw, Indiana) with a stainless steel dual mobility (DM) Novae SunFit acetabular cup (Serf, Decines, France), with bearing components of ceramic on polyethylene. A preoperative computed tomography (CT) scan of the left hip was performed (Figure 2) to aid templating, which was accomplished using plain films and CT images, with reference to the proximal femur for deciding level of neck cut, planning stem size, and optimizing length and offset, while determining cup size, depth, inclination, and height for the acetabular component.
Prior to surgery, the patient was positioned in the lateral decubitus position, using folded pillows under the medial aspect of her left proximal and distal thigh in lieu of her amputated limb. Pillows were secured to the table with elastic bandage tape. Standard pubic symphysis, lumbosacral, and midthoracic padded bolsters stabilized the pelvis in the normal fashion, with additional elastic bandage tape to further secure the pelvis brim to the table and reduce intraoperative motion. A posterior approach was used. A capsulotomy was performed with the hip in extension and slight abduction, with meticulous preservation of the capsule as the guide for the patient’s native length and offset. Reaming of the acetabulum was line to line, with insertion of an uncemented DM metal-back press-fit hydroxyapatite-coated shell placed in a standard fashion parallel with the transverse acetabular ligament, as described by Archbold and colleagues.1 The femur was sequentially reamed with broaches until press fit was achieved, and a calcar reamer was used to optimize interface with the collared implant. The surgeon’s standard 4 clinical tests were performed with trial implants after reduction to gauge hip tension, length, and offset. These tests are positive shuck test with hip and knee extension, lack of shuck in hip extension with knee flexion, lack of kick sign in hip extension and knee flexion, and palpation of gluteus medius belly to determine tension. Finally, with the hip returned to the extended and slightly abducted position, the capsule was tested for length and tension. The definitive stem implant was inserted, final testing with trial heads was repeated prior to definitive neck length and head selection, and final reduction was performed. A layered closure was performed, after generous washout. Pillows were taped together and positioned from the bed railing across the midline of the bed to prevent abduction, in the fashion of an abduction pillow.
The patient was mobilized the day after surgery and permitted full weight-bearing. Recovery was uneventful, and the patient returned to work within 6 weeks of surgery after her scheduled appointment and radiographic examination (Figure 3). Ongoing regular clinical and radiologic surveillance are planned.
Discussion
Hip and knee OA in the residual limb is more common for amputees than for the general population.2,3 THA for OA in amputees has been reported after below-knee amputation in both the ipsilateral and the contralateral hip.4 A true hip disarticulation is a rarely performed radical surgical procedure, involving the removal of the entire femur, and is most often related to surgical oncologic treatment or combat-related injuries, both being more common in younger people. Like many patients who have had a hip disarticulation,5 our patient declined a prosthesis, finding the design cosmetically unappealing and uncomfortable, in favor of crutch-walking. This accelerated wear of the remaining hip, and is a sobering reminder of the high demand on the bearing surfaces of the implants after her procedure.
The implants chosen for this procedure are critical. We use implants which are proven and reliable. Our institution uses the Corail Stem, an uncemented collared stem with an Orthopaedic Data Evaluation Panel (ODEP) 10A rating,6 widely used for THA.7 For the acetabulum, we chose the Novae SunFit, a modern version based on Bousquet’s 1976 DM design. The DM cup is a tripolar cup with a fixed porous-coated or cemented metal cup, which articulates with a large mobile polyethylene liner. A standard head in either metal or ceramic is inserted into this liner. The articulation between the head and the liner is constrained, while the articulation between the liner and the metal cup is unconstrained. This interposition of a mobile insert increases the effective head diameter, and the favorable head-neck ratio allows increased range of motion while avoiding early femoral neck impingement with a fixed liner or metal cup. A growing body of evidence indicates that DM cups reduce dislocation rates in primary and revision total knee arthroplasty and, when used with prudence, in selected tumor cases.8 A study of 1905 hips, using second-generation DM cups, reported cumulative survival rate of 98.6% at 12.2 years,9 with favorable outcomes compared with standard prostheses in the medium term for younger patients,10 and in the longer term,11 without increasing polyethylene wear.12
We use DM cups for 2 patient cohorts: first, for all patients older than 75 years because, in this age group, the risk of dislocation is higher than the risk of revision for wear-induced lysis; and second, in younger patients with any neuromuscular, cognitive, or mechanical risk factors that would excessively increase the risk of dislocation. This reflects the balance of risks in arthroplasty, with the ever-present trade-off between polyethylene-induced osteolysis and stability. Dislocation of the remaining sound limb for this young, active, agile patient would be a catastrophic complication. Given our patient’s risk factors for dislocation—female, an amputee with a high risk of falling, high body mass index, and lack of a contralateral limb to restrict adduction—the balance of risks favored hip stability over wear. We chose, therefore, a DM cup, using a ceramic-head-on-polyethylene-insert surface-bearing combination.
CT scanning is routinely performed in our institution to optimize preoperative templating. The preoperative CT images enable accurate planning, notably for the extramedullary reconstruction,13 and are used in addition to acetates and standard radiographs. This encourages preservation of acetabular bone stock by selecting the smallest suitable cup, reduces the risk of femoral fracture by giving an accurate prediction of the stem size, and ensures accuracy of restoring the patient’s offset and length. Although limb-length discrepancy was not an issue for this patient with a single sound limb, the sequalae of excessively increasing offset or length (eg, gluteus medius tendinopathy and trochanteric bursitis) would arguably be more debilitating than for someone who could offload weight to the “good hip.” For these reasons, marrying the preoperative templating with on-table testing with trial prostheses and restoring the native capsular tension is vital.
The importance of on-table positioning for proximal amputees undergoing hip arthroplasty has been highlighted.14 Lacking the normal bony constraints increases the risk of intraoperative on-table movement, which, in turn, risks reducing the accuracy of implant positioning. Crude limb-length checking using the contralateral knee is not possible. In addition, the lack of a contralateral hip joint causes a degree of compensatory pelvic tilt, which raises the option of increasing the coverage to compensate for obligate adduction during single-leg, crutch-walking gait. Lacking established guidelines to accommodate these variables, we inserted the cup in a standard fashion, at 45º, referencing acetabular version using the transverse acetabular ligament,1 and used the smallest stable cup after line-to-line reaming.
This case of THA in a young, crutch-walking patient with a contralateral true hip disarticulation highlights the importance of meticulous preoperative planning, implant selection appropriate for the patient in question, perioperative positioning, and the technical and operative challenges of restoring the patient’s normal hip architecture.
Patients with lower limb amputation have a high incidence of hip and knee osteoarthritis (OA) in the residual limb as well as the contralateral limb. A radical surgery, hip disarticulation is generally performed in younger patients after malignancy or trauma. Compliance is poor with existing prostheses, resulting in increased dependency on and use of the remaining sound limb.
In this case report, a crutch-walking 51-year-old woman presented with severe left hip arthritis 25 years after a right hip disarticulation. She underwent total hip arthroplasty (THA), a challenging procedure in a person without a contralateral hip joint. The many complex technical considerations associated with her THA included precise perioperative planning, the selection of appropriate prostheses and bearing surfaces, and the preoperative and intraoperative assessment of limb length and offset. The patient provided written informed consent for print and electronic publication of this case report.
Case Report
A 51-year-old woman presented to our service with a 3-year history of debilitating left hip pain. Twenty-five years earlier, she had been diagnosed with synovial sarcoma of the right knee and underwent limb-sparing surgery, followed by a true hip disarticulation performed for local recurrence. After her surgery, she declined the use of a prosthesis and mobilized with the use of 2 crutches. She has remained otherwise healthy and active, and runs her own business, which involves some lifting and carrying of objects. During the 3 years prior to presentation, she developed progressively debilitating left hip and groin pain, which radiated to the medial aspect of her left knee. Her mobilization distance had reduced to a few hundred meters, and she experienced significant night pain, and start-up pain. Activity modification, weight loss, and nonsteroidal anti-inflammatory medication afforded no relief. She denied any back pain or radicular symptoms.
Clinical examination showed a well-healed scar and pristine stump under her right hemipelvis. Passive range of movement of her left hip was painful for all movements, reduced at flexion (90º) and internal (10º) and external rotation (5º). Examination of her left knee was normal, with a full range of movement and no joint-line tenderness. A high body mass index (>30) was noted. Radiographic imaging confirmed significant OA of the hip joint (Figure 1). Informed consent was obtained for THA. The implants were selected—an uncemented collared Corail Stem (DePuy, Warsaw, Indiana) with a stainless steel dual mobility (DM) Novae SunFit acetabular cup (Serf, Decines, France), with bearing components of ceramic on polyethylene. A preoperative computed tomography (CT) scan of the left hip was performed (Figure 2) to aid templating, which was accomplished using plain films and CT images, with reference to the proximal femur for deciding level of neck cut, planning stem size, and optimizing length and offset, while determining cup size, depth, inclination, and height for the acetabular component.
Prior to surgery, the patient was positioned in the lateral decubitus position, using folded pillows under the medial aspect of her left proximal and distal thigh in lieu of her amputated limb. Pillows were secured to the table with elastic bandage tape. Standard pubic symphysis, lumbosacral, and midthoracic padded bolsters stabilized the pelvis in the normal fashion, with additional elastic bandage tape to further secure the pelvis brim to the table and reduce intraoperative motion. A posterior approach was used. A capsulotomy was performed with the hip in extension and slight abduction, with meticulous preservation of the capsule as the guide for the patient’s native length and offset. Reaming of the acetabulum was line to line, with insertion of an uncemented DM metal-back press-fit hydroxyapatite-coated shell placed in a standard fashion parallel with the transverse acetabular ligament, as described by Archbold and colleagues.1 The femur was sequentially reamed with broaches until press fit was achieved, and a calcar reamer was used to optimize interface with the collared implant. The surgeon’s standard 4 clinical tests were performed with trial implants after reduction to gauge hip tension, length, and offset. These tests are positive shuck test with hip and knee extension, lack of shuck in hip extension with knee flexion, lack of kick sign in hip extension and knee flexion, and palpation of gluteus medius belly to determine tension. Finally, with the hip returned to the extended and slightly abducted position, the capsule was tested for length and tension. The definitive stem implant was inserted, final testing with trial heads was repeated prior to definitive neck length and head selection, and final reduction was performed. A layered closure was performed, after generous washout. Pillows were taped together and positioned from the bed railing across the midline of the bed to prevent abduction, in the fashion of an abduction pillow.
The patient was mobilized the day after surgery and permitted full weight-bearing. Recovery was uneventful, and the patient returned to work within 6 weeks of surgery after her scheduled appointment and radiographic examination (Figure 3). Ongoing regular clinical and radiologic surveillance are planned.
Discussion
Hip and knee OA in the residual limb is more common for amputees than for the general population.2,3 THA for OA in amputees has been reported after below-knee amputation in both the ipsilateral and the contralateral hip.4 A true hip disarticulation is a rarely performed radical surgical procedure, involving the removal of the entire femur, and is most often related to surgical oncologic treatment or combat-related injuries, both being more common in younger people. Like many patients who have had a hip disarticulation,5 our patient declined a prosthesis, finding the design cosmetically unappealing and uncomfortable, in favor of crutch-walking. This accelerated wear of the remaining hip, and is a sobering reminder of the high demand on the bearing surfaces of the implants after her procedure.
The implants chosen for this procedure are critical. We use implants which are proven and reliable. Our institution uses the Corail Stem, an uncemented collared stem with an Orthopaedic Data Evaluation Panel (ODEP) 10A rating,6 widely used for THA.7 For the acetabulum, we chose the Novae SunFit, a modern version based on Bousquet’s 1976 DM design. The DM cup is a tripolar cup with a fixed porous-coated or cemented metal cup, which articulates with a large mobile polyethylene liner. A standard head in either metal or ceramic is inserted into this liner. The articulation between the head and the liner is constrained, while the articulation between the liner and the metal cup is unconstrained. This interposition of a mobile insert increases the effective head diameter, and the favorable head-neck ratio allows increased range of motion while avoiding early femoral neck impingement with a fixed liner or metal cup. A growing body of evidence indicates that DM cups reduce dislocation rates in primary and revision total knee arthroplasty and, when used with prudence, in selected tumor cases.8 A study of 1905 hips, using second-generation DM cups, reported cumulative survival rate of 98.6% at 12.2 years,9 with favorable outcomes compared with standard prostheses in the medium term for younger patients,10 and in the longer term,11 without increasing polyethylene wear.12
We use DM cups for 2 patient cohorts: first, for all patients older than 75 years because, in this age group, the risk of dislocation is higher than the risk of revision for wear-induced lysis; and second, in younger patients with any neuromuscular, cognitive, or mechanical risk factors that would excessively increase the risk of dislocation. This reflects the balance of risks in arthroplasty, with the ever-present trade-off between polyethylene-induced osteolysis and stability. Dislocation of the remaining sound limb for this young, active, agile patient would be a catastrophic complication. Given our patient’s risk factors for dislocation—female, an amputee with a high risk of falling, high body mass index, and lack of a contralateral limb to restrict adduction—the balance of risks favored hip stability over wear. We chose, therefore, a DM cup, using a ceramic-head-on-polyethylene-insert surface-bearing combination.
CT scanning is routinely performed in our institution to optimize preoperative templating. The preoperative CT images enable accurate planning, notably for the extramedullary reconstruction,13 and are used in addition to acetates and standard radiographs. This encourages preservation of acetabular bone stock by selecting the smallest suitable cup, reduces the risk of femoral fracture by giving an accurate prediction of the stem size, and ensures accuracy of restoring the patient’s offset and length. Although limb-length discrepancy was not an issue for this patient with a single sound limb, the sequalae of excessively increasing offset or length (eg, gluteus medius tendinopathy and trochanteric bursitis) would arguably be more debilitating than for someone who could offload weight to the “good hip.” For these reasons, marrying the preoperative templating with on-table testing with trial prostheses and restoring the native capsular tension is vital.
The importance of on-table positioning for proximal amputees undergoing hip arthroplasty has been highlighted.14 Lacking the normal bony constraints increases the risk of intraoperative on-table movement, which, in turn, risks reducing the accuracy of implant positioning. Crude limb-length checking using the contralateral knee is not possible. In addition, the lack of a contralateral hip joint causes a degree of compensatory pelvic tilt, which raises the option of increasing the coverage to compensate for obligate adduction during single-leg, crutch-walking gait. Lacking established guidelines to accommodate these variables, we inserted the cup in a standard fashion, at 45º, referencing acetabular version using the transverse acetabular ligament,1 and used the smallest stable cup after line-to-line reaming.
This case of THA in a young, crutch-walking patient with a contralateral true hip disarticulation highlights the importance of meticulous preoperative planning, implant selection appropriate for the patient in question, perioperative positioning, and the technical and operative challenges of restoring the patient’s normal hip architecture.
1. Archbold HA, Mockford B, Molloy D, McConway J, Ogonda L, Beverland D. The transverse acetabular ligament: an aid to orientation of the acetabular component during primary total hip replacement: a preliminary study of 1000 cases investigating postoperative stability. J Bone Joint Surg Br. 2006;88(7):883-886.
2. Kulkarni J, Adams J, Thomas E, Silman A. Association between amputation, arthritis and osteopenia in British male war veterans with major lower limb amputations. Clin Rehabil. 1998;12(4):348-353.
3. Struyf PA, van Heugten CM, Hitters MW, Smeets RJ. The prevalence of osteoarthritis of the intact hip and knee among traumatic leg amputees. Arch Phys Med Rehabil. 2009;90(3):440-446.
4. Nejat EJ, Meyer A, Sánchez PM, Schaefer SH, Westrich GH. Total hip arthroplasty and rehabilitation in ambulatory lower extremity amputees--a case series. Iowa Orthop J. 2005;25:38-41.
5. Zaffer SM, Braddom RL, Conti A, Goff J, Bokma D. Total hip disarticulation prosthesis with suction socket: report of two cases. Am J Phys Med Rehabil. 1999;78(2):160-162.
6. Lewis P. ODEP [Orthopaedic Data Evaluation Panel]. NHS Supply Chain website. http://www.supplychain.nhs.uk/odep. Accessed April 2, 2015.
7. National Joint Registry for England and Wales. 8th Annual Report, 2011. National Joint Registry website. www.njrcentre.org.uk/NjrCentre/Portals/0/Documents/NJR%208th%20Annual%20Report%202011.pdf. Accessed April 2, 2015.
8. Grazioli A, Ek ET, Rüdiger HA. Biomechanical concept and clinical outcome of dual mobility cups. Int Orthop. 2012;36(12):2411-2418.
9. Massin P, Orain V, Philippot R, Farizon F, Fessy MH. Fixation failures of dual mobility cups: a mid-term study of 2601 hip replacements. Clin Orthop. 2012;470(7):1932-1940.
10. Epinette JA, Béracassat R, Tracol P, Pagazani G, Vandenbussche E. Are modern dual mobility cups a valuable option in reducing instability after primary hip arthroplasty, even in younger patients? J Arthroplasty. 2014;29(6):1323-1328.
11. Philippot R, Meucci JF, Boyer B, Farizon F. Modern dual-mobility cup implanted with an uncemented stem: about 100 cases with 12-year follow-up. Surg Technol Int. 2013;23:208-212.
12. Prudhon JL, Ferreira A, Verdier R. Dual mobility cup: dislocation rate and survivorship at ten years of follow-up. Int Orthop. 2013;37(12):2345-2350.
13. Sariali E, Mouttet A, Pasquier G, Durante E, Catone Y. Accuracy of reconstruction of the hip using computerised three-dimensional pre-operative planning and a cementless modular neck. J Bone Joint Surg Br. 2009;91(13):333-340.
14. Bong MR, Kaplan KM, Jaffe WL. Total hip arthroplasty in a patient with contralateral hemipelvectomy. J Arthroplasty. 2006;21(5):762-764.
1. Archbold HA, Mockford B, Molloy D, McConway J, Ogonda L, Beverland D. The transverse acetabular ligament: an aid to orientation of the acetabular component during primary total hip replacement: a preliminary study of 1000 cases investigating postoperative stability. J Bone Joint Surg Br. 2006;88(7):883-886.
2. Kulkarni J, Adams J, Thomas E, Silman A. Association between amputation, arthritis and osteopenia in British male war veterans with major lower limb amputations. Clin Rehabil. 1998;12(4):348-353.
3. Struyf PA, van Heugten CM, Hitters MW, Smeets RJ. The prevalence of osteoarthritis of the intact hip and knee among traumatic leg amputees. Arch Phys Med Rehabil. 2009;90(3):440-446.
4. Nejat EJ, Meyer A, Sánchez PM, Schaefer SH, Westrich GH. Total hip arthroplasty and rehabilitation in ambulatory lower extremity amputees--a case series. Iowa Orthop J. 2005;25:38-41.
5. Zaffer SM, Braddom RL, Conti A, Goff J, Bokma D. Total hip disarticulation prosthesis with suction socket: report of two cases. Am J Phys Med Rehabil. 1999;78(2):160-162.
6. Lewis P. ODEP [Orthopaedic Data Evaluation Panel]. NHS Supply Chain website. http://www.supplychain.nhs.uk/odep. Accessed April 2, 2015.
7. National Joint Registry for England and Wales. 8th Annual Report, 2011. National Joint Registry website. www.njrcentre.org.uk/NjrCentre/Portals/0/Documents/NJR%208th%20Annual%20Report%202011.pdf. Accessed April 2, 2015.
8. Grazioli A, Ek ET, Rüdiger HA. Biomechanical concept and clinical outcome of dual mobility cups. Int Orthop. 2012;36(12):2411-2418.
9. Massin P, Orain V, Philippot R, Farizon F, Fessy MH. Fixation failures of dual mobility cups: a mid-term study of 2601 hip replacements. Clin Orthop. 2012;470(7):1932-1940.
10. Epinette JA, Béracassat R, Tracol P, Pagazani G, Vandenbussche E. Are modern dual mobility cups a valuable option in reducing instability after primary hip arthroplasty, even in younger patients? J Arthroplasty. 2014;29(6):1323-1328.
11. Philippot R, Meucci JF, Boyer B, Farizon F. Modern dual-mobility cup implanted with an uncemented stem: about 100 cases with 12-year follow-up. Surg Technol Int. 2013;23:208-212.
12. Prudhon JL, Ferreira A, Verdier R. Dual mobility cup: dislocation rate and survivorship at ten years of follow-up. Int Orthop. 2013;37(12):2345-2350.
13. Sariali E, Mouttet A, Pasquier G, Durante E, Catone Y. Accuracy of reconstruction of the hip using computerised three-dimensional pre-operative planning and a cementless modular neck. J Bone Joint Surg Br. 2009;91(13):333-340.
14. Bong MR, Kaplan KM, Jaffe WL. Total hip arthroplasty in a patient with contralateral hemipelvectomy. J Arthroplasty. 2006;21(5):762-764.
Operative Intervention for Geriatric Hip Fracture: Does Type of Surgery Affect Hospital Length of Stay?
Hip fractures, the most severe and costly fall-related fractures, account for 350,000 hospital admissions per year.1 The majority of hip fractures result from low-impact falls, typically in patients over age 60 years. In fact, the increase in hip fracture with age is nearly exponential.2,3 With the predicted aging of our population, hip fractures will continue to increase in volume. Between 2000 and 2050, the elderly US population will increase by 135%,4 proportionately increasing the number of projected hip fractures. Considering that hip fractures account for 72% of total costs in terms of orthopedic fracture care in the elderly, the dramatic rise in hip fractures is of great concern for future costs of health care delivery in this field.5-7
In an effort to move toward a value-based system in which costs are reduced while quality of care is maintained, Medicare recently unveiled a new bundled payment system of reimbursement. Through this system, hospitals will be reimbursed for treatment provided to Medicare beneficiaries based on the expected costs of care, instead of through the traditional fee-for-service model. Given this development, orthopedic surgeons will need to develop interventions that reduce costs while maintaining quality of care after hip fracture surgery.
One of the most significant ramifications of a value-based system is that reimbursement for hip fractures may be standardized based on a single diagnosis regardless of the actual costs associated with treatment.8 In hip fracture cases, however, a wide range of factors, including degree of communition of the bone, presence of medical comorbidities,9 and amount of soft-tissue injury, can dramatically increase recovery time. In fact, one of the most important determinants of treatment costs related to hospital length of stay (LOS) is whether the fracture is a femoral neck or intertrochanteric fracture.10,11 Type of fracture is a significant determinant of surgical options, and these can dramatically change patient outcomes and costs of surgical care.12-16 In addition, hospital recovery time or LOS can vary widely based on type of surgery. As hospitalization costs account for 44% of the direct medical costs for hip fractures,17 differences in LOS can have major financial implications in a value-based system of reimbursement in which all forms of hip fracture are reimbursed a standard amount.
We conducted a study to analyze differences in hospital LOS for different forms of hip fracture repair to determine the potential financial repercussions of a bundled payment model of reimbursement. By performing a retrospective chart review at a large, level I trauma center, we were able to compare LOS and associated costs for total hip arthroplasty (THA), hemiarthroplasty (HA), cephalomedullary nailing (CMN), open reduction and internal fixation (ORIF), and closed reduction and percutaneous pinning (CRPP).
Materials and Methods
After receiving institutional review board approval for this study, we retrospectively reviewed all hip fracture cases treated at a level I trauma center between January 2000 and December 2009. Current Procedural Terminology (CPT) codes were searched for cases of low-energy falls that caused hip fractures that were resolved with THA, HA, CMN, ORIF, or CRPP. Patients who underwent HA or THA were grouped for analysis. Patients who were over age 60 years and had acetabular, proximal femoral, trochanteric, or femoral neck fractures were included in our search. Patients who had incomplete medical records or did not meet the age criterion were excluded from analysis.
We reviewed patient charts in our institutional electronic medical records database to collect these data: date of birth, age, sex, date of admission, date of discharge, American Society of Anesthesiologists (ASA) Physical Status score, complications, height, weight, start and stop times of procedure, whether or not the procedure was an emergent procedure, days from admission to surgery, 90-day readmissions, days from surgery to discharge, and general category of operation. We also recorded individual comorbidities, including prior myocardial infarction, dysrhythmia, atrial fibrillation, congestive heart failure, heart block, cerebrovascular disease, chronic obstructive pulmonary disease, emphysema, current smoking status, smoking history, renal disease, dialysis, cancer, and diabetes. Duration of surgery was calculated from recorded start and stop times. Body mass index was calculated using height and weight recorded during initial stay. LOS was recorded as the difference between the admission and discharge dates.
Mean total cost to the hospital ($4530/d patient was hospitalized) was obtained from the institution’s financial services. All fractional LOS values were rounded to the nearest whole number and multiplied by the per diem cost. Student t test was used to compare mean LOS and costs of HA/THA with those of all the other procedures. Additional tests were run to analyze differences in LOS and type of surgeries performed throughout the 9-year period. A multivariate regression model controlling for ASA score, body mass index, age, sex, and comorbidities was developed to analyze differences in LOS and costs for patients who underwent HA/THA versus CMN, ORIF, and CRPP. Significance was set at P = .05.
Results
Our search identified 720 patients who were over age 60 years and underwent operative fixation for hip fracture at our level I trauma center between 2000 and 2009. Of these 720 patients, 105 who had incomplete charts or did not meet the age criteria were excluded, leaving 615 patients (with complete records of isolated low-energy hip fractures) for analysis.
Table 1 lists the demographics of our patient population. The majority of patients had undergone ORIF (30.24%) or HA/THA (45.69%). CRPP was the least common procedure (9.92%) after CMN (14.15%). Mean age was 78.4 years; the majority of patients were between 75 and 89 years of age. Mean hospital LOS was 6.91 days. The majority of patients (n = 414; 67.32%) were female. ASA scores had a narrow distribution, with most patients assigned a score of 3. The readmission rate was significantly higher for HA/THA (39.1%) than for ORIF (28.5%; P = .02) and CRPP (24.6%; P = .04).
Table 2 lists mean LOS and associated costs for each procedure compared with HA/THA. Mean LOS for all patients was 6.91 days, with associated hospitalization costs of $30,011.25. Patients who underwent HA/THA had the longest mean LOS (7.43 days) and highest mean hospitalization costs ($33,657.90). In comparison, patients who underwent ORIF had a mean LOS of 6.59 days with $29,852.70 in costs (P = .04). CRPP also had a significantly (P < .003) shorter LOS (5.59 days) and lower costs ($25,322.70). Although CMN had a mean LOS of 6.89 days and $31,211.70 in costs, the difference in LOS was not significantly different from that of HA/THA. The proportion of surgeries that were HA/THA, CMN, ORIF, and CRPP did not change significantly through the 9-year period (P = .19). Similarly, mean LOS did not change significantly for any of the types of surgery through this period (Table 3).
Figure 1 provides the distribution of LOS for all 4 procedures. The interquartile range (IQR) for patients who underwent HA/THA was 4 to 9 days (median, 6 days). Patients who underwent CMN also had a median LOS of 6 days and an IQR of 4 to 8 days. Both ORIF (IQR, 4-8 days) and CRPP (IQR, 3-6 days) were associated with a median LOS of 5 days.
Figure 2 shows mean hospitalization costs based on type of procedure. HA/THA had the highest mean cost, $33,657.90, or $8335.20 more than CRPP ($25,322.70). Patients who underwent CMN had a mean cost of $31,211.70, versus $29,852.70 for patients who underwent ORIF.
Table 4 summarizes the multivariate analysis results. After ASA score, sex, age, and comorbidities were controlled for, there was an overall significant relationship involving surgical treatment, LOS, and associated hospitalization costs for HA/THA, ORIF, and CRPP. Compared with HA/THA, ORIF had $3805.20 less in costs (P = .042) and 0.84 fewer hospital days. Patients who underwent CRPP were hospitalized for significantly fewer days (1.63) and associated costs ($7383.90) (P = .0076). There was no significant difference in LOS and costs between HA/THA and CMN. Of the controlled variables, only ASA score (P < .001) and male sex (P = .001) were significantly associated with changes in LOS and costs. There was no significant association with comorbidities, LOS, or costs.
Discussion
In this study of surgical intervention in patients with hip fractures, we determined that HA/THA was associated with significantly increased hospital LOS and costs than ORIF and CRPP. Although arthroplasty had an increased mean LOS compared with CMN, the difference was not statistically significant. In addition to type of procedure, both male sex (P = .001) and preoperative ASA score (P < .001) were significant predictors of LOS and costs. These findings are supported by other studies in which preoperative functioning was found to be a strong predictor of increased LOS and costs among hip fracture patients,18 most likely because of increased risk for complications.19
Although our study was the first to directly compare LOS and costs for HA/THA and CMN, other investigators have analyzed the effect of surgical complications on LOS for patients treated with THA, HA, and CMN. In a study on the effects of surgical complications on LOS after hip fracture surgery, Foss and colleagues17 reported that the proportion of CMN patients (31%) with complications was larger than that of HA patients (19%) and THA patients (0%). They also reported that surgical complications were associated with significantly increased LOS during primary admission. Similarly, Edwards and colleagues20 found that the infection risk was higher with CMN (3.1%) than with THA (0%) and HA (0%-2.3%) and that infections were associated with increased LOS (P > .001). However, further statistical analysis revealed that the odds of developing an infection were not significantly higher with CMN than with other studies.20 Similarly, other studies have reported low rates of complications, including nonunion, with CMN.21,22 In our study, we found no significant difference in LOS and costs for CMN and HA/THA after controlling for ASA score, which is known to be associated with a higher risk for complications.18,19
The largest difference in LOS and costs after controlling for potential confounding variables was between HA/THA and CRPP ($7383.90). To our knowledge, only one study has performed a comparative analysis of LOS for CRPP and other surgical treatments for hip fractures. For femoral neck fractures treated between 1990 and 1994, Fekete and colleagues23 found that LOS was 14.9 days for ORIF cases and 12.1 days for CRPP cases—a difference of 2.8 days. In comparison, we found a 1-day difference in mean LOS between ORIF cases (6.59 days) and CRPP cases (5.59 days).
Other studies of LOS and associated costs over a 2-year period have found that ORIF is overall more costly than HA/THA. For example, Keating and colleagues13 compared total costs of care, including LOS, for healthy older patients with displaced intracapsular hip fractures treated with ORIF, bipolar HA, or THA. Although ORIF was initially less costly than HA/THA, overall ORIF costs over 2 years were significantly higher because of readmissions, which increased overall LOS. Similarly, in cases of displaced femoral fractures, Iorio and colleagues15 found that LOS was 6.4 days for ORIF, 4.9 days for unipolar HA, 6.2 days for bipolar HA, and 5.5 days for cemented and hybrid THA. However, when overall projected costs were estimated, including the costs of rehabilitation and of (probable) revision arthroplasty, ORIF was estimated to cost more over a 2-year period because of the need for additional care and in-patient stays. In contrast, we found that hospitalization costs were $3805.20 lower for ORIF than for HA/THA, even after adjusting for comorbidities, and that ORIF had a lower overall readmission rate. Early discharge of patients who are at risk for subsequent complications may have played a significant role in increasing readmission rates for arthroplasty patients. These findings indicate the complexities involved in a bundled payment system of reimbursement, in which a single payment for both initial stay and related readmissions will force orthopedists to consider long-term hospitalization costs when deciding on length of postoperative care and the most cost-effective surgical treatment.
One of the limitations of this study is its retrospective design. Although selection of our sample from a single level I trauma center reduced differences in cost and patient care protocols between institutions, it also reduced the generalizability of our actual costs. In addition, for some patients, LOS may have increased because of delays in surgery or discharge, lack of operating room availability, or need for further medical clearance for additional procedures. Day of admission could also have significantly affected LOS. However, the effects of these confounding factors were reduced because of the large sample analyzed. As stated earlier, overall LOS depends on both initial in-patient stays and readmissions. Therefore, long-term prospective studies that compare LOS and associated costs for patients with hip fractures treated with ORIF, CRPP, HA/THA, and CMN are needed.
Conclusion
It has been recently suggested that hip fracture repair be included in the National Pilot Program on Payment Bundling, which will potentially reimburse orthopedic surgeons a standardized amount for hip fracture surgery regardless of actual treatment costs.8 In this model, it will be essential to understand how type of fracture and surgical procedure can influence LOS and therefore hip fracture treatment costs. We found that, based on these factors, mean LOS ranged from 5.59 to 7.43 days, which translates to a cost range of $25,322.70 to $33,657.90. Before a standardized bundled payment system is implemented, further studies are needed to identify other factors that can significantly affect the cost of hip fracture repair.
1. American Academy of Orthopaedic Surgeons. Burden of Musculoskeletal Diseases in the United States: Prevalence, Societal and Economic Cost. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2008.
2. Samelson EJ, Zhang Y, Kiel DP, Hannan MT, Felson DT. Effect of birth cohort on risk of hip fracture: age-specific incidence rates in the Framingham study. Am J Public Health. 2002;92(5):858-862.
3. Scott JC. Osteoporosis and hip fractures. Rheum Dis Clin North Am. 1990;16(3):717-740.
4. Wiener JM, Tilly J. Population ageing in the United States of America: implications for public programmes. Int J Epidemiol. 2002;31(4):776-781.
5. Burge R, Dawson-Hughes B, Solomon DH, Wong JB, King A, Tosteson A. Incidence and economic burden of osteoporosis-related fractures in the United States, 2005–2025. J Bone Miner Res. 2007;22(3):465-475.
6. Burge RT, King AB, Balda E, Worley D. Methodology for estimating current and future burden of osteoporosis in state populations: application to Florida in 2000 through 2025. Value Health. 2003;6(5):574-583.
7. Tosteson AN, Burge RT, Marshall DA, Lindsay R. Therapies for treatment of osteoporosis in US women: cost-effectiveness and budget impact considerations. Am J Manag Care. 2008;14(9):605-615.
8. Sood N, Huckfeldt PJ, Escarce JJ, Grabowski DC, Newhouse JP. Medicare’s bundled payment pilot for acute and postacute care: analysis and recommendations on where to begin. Health Aff. 2011;30(9):1708-1717.
9. Shah A, Eissler J, Radomisli T. Algorithms for the treatment of femoral neck fractures. Clin Orthop. 2002;(399):28-34.
10. Sund R, Riihimäki J, Mäkelä M, et al. Modeling the length of the care episode after hip fracture: does the type of fracture matter? Scand J Surg. 2009;98(3):169-174.
11. Fox KM, Magaziner J, Hebel JR, Kenzora JE, Kashner TM. Intertrochanteric versus femoral neck hip fractures: differential characteristics, treatment, and sequelae. J Gerontol A Biol Sci Med Sci. 1999;54(12):M635-M640.
12. Carroll C, Stevenson M, Scope A, Evans P, Buckley S. Hemiarthroplasty and total hip arthroplasty for treating primary intracapsular fracture of the hip: a systematic review and cost-effectiveness analysis. Health Technol Assess. 2011;15(36):1-74.
13. Keating JF, Grant A, Masson M, Scott NW, Forbes JF. Randomized comparison of reduction and fixation, bipolar hemiarthroplasty, and total hip arthroplasty. Treatment of displaced intracapsular hip fractures in healthy older patients. J Bone Joint Surg Am. 2006;88(2):249-260.
14. Rogmark C, Carlsson A, Johnell O, Sembo I. Costs of internal fixation and arthroplasty for displaced femoral neck fractures: a randomized study of 68 patients. Acta Orthop Scand. 2003;74(3):293-298.
15. Iorio R, Healy WL, Lemos DW, Appleby D, Lucchesi CA, Saleh KJ. Displaced femoral neck fractures in the elderly: outcomes and cost effectiveness. Clin Orthop. 2001;(383):229-242.
16. Slover J, Hoffman MV, Malchau H, Tosteson AN, Koval KJ. A cost-effectiveness analysis of the arthroplasty options for displaced femoral neck fractures in the active, healthy, elderly population. J Arthroplasty. 2009;24(6):854-860.
17. Foss NB, Palm H, Krasheninnikoff M, Kehlet H, Gebuhr P. Impact of surgical complications on length of stay after hip fracture surgery. Injury. 2007;38(7):780-784.
18. Garcia AE, Bonnaig JV, Yoneda ZT. Patient variables which may predict length of stay and hospital costs in elderly patients with hip fracture. J Orthop Trauma. 2012;26(11):620-623.
19. Donegan DJ, Gay AN, Baldwin K, Morales EE, Esterhai JL Jr, Mehta S. Use of medical comorbidities to predict complications after hip fracture surgery in the elderly. J Bone Joint Surg Am. 2010;92(4):807-813.
20. Edwards C, Counsell A, Boulton C, Moran CG. Early infection after hip fracture surgery: risk factors, costs and outcome. J Bone Joint Surg Br. 2008;90(6):770-777.
21. Jain P, Maini L, Mishra P, Upadhyay A, Agarwal A. Cephalomedullary interlocked nail for ipsilateral hip and femoral shaft fractures. Injury. 2004;35(10):1031-1038.
22. Matre K, Havelin LI, Gjertsen JE, Espehaug B, Fevang JM. Intramedullary nails result in more reoperations than sliding hip screws in two-part intertrochanteric fractures. Clin Orthop. 2013;471(4):1379-1386.
23. Fekete K, Manninger J, Kazár G, Cserháti P, Bosch U. Percutaneous internal fixation of femoral neck fractures with cannulated screws and a small tension band plate. Orthop Traumatol. 2000;8(4):250-263.
Hip fractures, the most severe and costly fall-related fractures, account for 350,000 hospital admissions per year.1 The majority of hip fractures result from low-impact falls, typically in patients over age 60 years. In fact, the increase in hip fracture with age is nearly exponential.2,3 With the predicted aging of our population, hip fractures will continue to increase in volume. Between 2000 and 2050, the elderly US population will increase by 135%,4 proportionately increasing the number of projected hip fractures. Considering that hip fractures account for 72% of total costs in terms of orthopedic fracture care in the elderly, the dramatic rise in hip fractures is of great concern for future costs of health care delivery in this field.5-7
In an effort to move toward a value-based system in which costs are reduced while quality of care is maintained, Medicare recently unveiled a new bundled payment system of reimbursement. Through this system, hospitals will be reimbursed for treatment provided to Medicare beneficiaries based on the expected costs of care, instead of through the traditional fee-for-service model. Given this development, orthopedic surgeons will need to develop interventions that reduce costs while maintaining quality of care after hip fracture surgery.
One of the most significant ramifications of a value-based system is that reimbursement for hip fractures may be standardized based on a single diagnosis regardless of the actual costs associated with treatment.8 In hip fracture cases, however, a wide range of factors, including degree of communition of the bone, presence of medical comorbidities,9 and amount of soft-tissue injury, can dramatically increase recovery time. In fact, one of the most important determinants of treatment costs related to hospital length of stay (LOS) is whether the fracture is a femoral neck or intertrochanteric fracture.10,11 Type of fracture is a significant determinant of surgical options, and these can dramatically change patient outcomes and costs of surgical care.12-16 In addition, hospital recovery time or LOS can vary widely based on type of surgery. As hospitalization costs account for 44% of the direct medical costs for hip fractures,17 differences in LOS can have major financial implications in a value-based system of reimbursement in which all forms of hip fracture are reimbursed a standard amount.
We conducted a study to analyze differences in hospital LOS for different forms of hip fracture repair to determine the potential financial repercussions of a bundled payment model of reimbursement. By performing a retrospective chart review at a large, level I trauma center, we were able to compare LOS and associated costs for total hip arthroplasty (THA), hemiarthroplasty (HA), cephalomedullary nailing (CMN), open reduction and internal fixation (ORIF), and closed reduction and percutaneous pinning (CRPP).
Materials and Methods
After receiving institutional review board approval for this study, we retrospectively reviewed all hip fracture cases treated at a level I trauma center between January 2000 and December 2009. Current Procedural Terminology (CPT) codes were searched for cases of low-energy falls that caused hip fractures that were resolved with THA, HA, CMN, ORIF, or CRPP. Patients who underwent HA or THA were grouped for analysis. Patients who were over age 60 years and had acetabular, proximal femoral, trochanteric, or femoral neck fractures were included in our search. Patients who had incomplete medical records or did not meet the age criterion were excluded from analysis.
We reviewed patient charts in our institutional electronic medical records database to collect these data: date of birth, age, sex, date of admission, date of discharge, American Society of Anesthesiologists (ASA) Physical Status score, complications, height, weight, start and stop times of procedure, whether or not the procedure was an emergent procedure, days from admission to surgery, 90-day readmissions, days from surgery to discharge, and general category of operation. We also recorded individual comorbidities, including prior myocardial infarction, dysrhythmia, atrial fibrillation, congestive heart failure, heart block, cerebrovascular disease, chronic obstructive pulmonary disease, emphysema, current smoking status, smoking history, renal disease, dialysis, cancer, and diabetes. Duration of surgery was calculated from recorded start and stop times. Body mass index was calculated using height and weight recorded during initial stay. LOS was recorded as the difference between the admission and discharge dates.
Mean total cost to the hospital ($4530/d patient was hospitalized) was obtained from the institution’s financial services. All fractional LOS values were rounded to the nearest whole number and multiplied by the per diem cost. Student t test was used to compare mean LOS and costs of HA/THA with those of all the other procedures. Additional tests were run to analyze differences in LOS and type of surgeries performed throughout the 9-year period. A multivariate regression model controlling for ASA score, body mass index, age, sex, and comorbidities was developed to analyze differences in LOS and costs for patients who underwent HA/THA versus CMN, ORIF, and CRPP. Significance was set at P = .05.
Results
Our search identified 720 patients who were over age 60 years and underwent operative fixation for hip fracture at our level I trauma center between 2000 and 2009. Of these 720 patients, 105 who had incomplete charts or did not meet the age criteria were excluded, leaving 615 patients (with complete records of isolated low-energy hip fractures) for analysis.
Table 1 lists the demographics of our patient population. The majority of patients had undergone ORIF (30.24%) or HA/THA (45.69%). CRPP was the least common procedure (9.92%) after CMN (14.15%). Mean age was 78.4 years; the majority of patients were between 75 and 89 years of age. Mean hospital LOS was 6.91 days. The majority of patients (n = 414; 67.32%) were female. ASA scores had a narrow distribution, with most patients assigned a score of 3. The readmission rate was significantly higher for HA/THA (39.1%) than for ORIF (28.5%; P = .02) and CRPP (24.6%; P = .04).
Table 2 lists mean LOS and associated costs for each procedure compared with HA/THA. Mean LOS for all patients was 6.91 days, with associated hospitalization costs of $30,011.25. Patients who underwent HA/THA had the longest mean LOS (7.43 days) and highest mean hospitalization costs ($33,657.90). In comparison, patients who underwent ORIF had a mean LOS of 6.59 days with $29,852.70 in costs (P = .04). CRPP also had a significantly (P < .003) shorter LOS (5.59 days) and lower costs ($25,322.70). Although CMN had a mean LOS of 6.89 days and $31,211.70 in costs, the difference in LOS was not significantly different from that of HA/THA. The proportion of surgeries that were HA/THA, CMN, ORIF, and CRPP did not change significantly through the 9-year period (P = .19). Similarly, mean LOS did not change significantly for any of the types of surgery through this period (Table 3).
Figure 1 provides the distribution of LOS for all 4 procedures. The interquartile range (IQR) for patients who underwent HA/THA was 4 to 9 days (median, 6 days). Patients who underwent CMN also had a median LOS of 6 days and an IQR of 4 to 8 days. Both ORIF (IQR, 4-8 days) and CRPP (IQR, 3-6 days) were associated with a median LOS of 5 days.
Figure 2 shows mean hospitalization costs based on type of procedure. HA/THA had the highest mean cost, $33,657.90, or $8335.20 more than CRPP ($25,322.70). Patients who underwent CMN had a mean cost of $31,211.70, versus $29,852.70 for patients who underwent ORIF.
Table 4 summarizes the multivariate analysis results. After ASA score, sex, age, and comorbidities were controlled for, there was an overall significant relationship involving surgical treatment, LOS, and associated hospitalization costs for HA/THA, ORIF, and CRPP. Compared with HA/THA, ORIF had $3805.20 less in costs (P = .042) and 0.84 fewer hospital days. Patients who underwent CRPP were hospitalized for significantly fewer days (1.63) and associated costs ($7383.90) (P = .0076). There was no significant difference in LOS and costs between HA/THA and CMN. Of the controlled variables, only ASA score (P < .001) and male sex (P = .001) were significantly associated with changes in LOS and costs. There was no significant association with comorbidities, LOS, or costs.
Discussion
In this study of surgical intervention in patients with hip fractures, we determined that HA/THA was associated with significantly increased hospital LOS and costs than ORIF and CRPP. Although arthroplasty had an increased mean LOS compared with CMN, the difference was not statistically significant. In addition to type of procedure, both male sex (P = .001) and preoperative ASA score (P < .001) were significant predictors of LOS and costs. These findings are supported by other studies in which preoperative functioning was found to be a strong predictor of increased LOS and costs among hip fracture patients,18 most likely because of increased risk for complications.19
Although our study was the first to directly compare LOS and costs for HA/THA and CMN, other investigators have analyzed the effect of surgical complications on LOS for patients treated with THA, HA, and CMN. In a study on the effects of surgical complications on LOS after hip fracture surgery, Foss and colleagues17 reported that the proportion of CMN patients (31%) with complications was larger than that of HA patients (19%) and THA patients (0%). They also reported that surgical complications were associated with significantly increased LOS during primary admission. Similarly, Edwards and colleagues20 found that the infection risk was higher with CMN (3.1%) than with THA (0%) and HA (0%-2.3%) and that infections were associated with increased LOS (P > .001). However, further statistical analysis revealed that the odds of developing an infection were not significantly higher with CMN than with other studies.20 Similarly, other studies have reported low rates of complications, including nonunion, with CMN.21,22 In our study, we found no significant difference in LOS and costs for CMN and HA/THA after controlling for ASA score, which is known to be associated with a higher risk for complications.18,19
The largest difference in LOS and costs after controlling for potential confounding variables was between HA/THA and CRPP ($7383.90). To our knowledge, only one study has performed a comparative analysis of LOS for CRPP and other surgical treatments for hip fractures. For femoral neck fractures treated between 1990 and 1994, Fekete and colleagues23 found that LOS was 14.9 days for ORIF cases and 12.1 days for CRPP cases—a difference of 2.8 days. In comparison, we found a 1-day difference in mean LOS between ORIF cases (6.59 days) and CRPP cases (5.59 days).
Other studies of LOS and associated costs over a 2-year period have found that ORIF is overall more costly than HA/THA. For example, Keating and colleagues13 compared total costs of care, including LOS, for healthy older patients with displaced intracapsular hip fractures treated with ORIF, bipolar HA, or THA. Although ORIF was initially less costly than HA/THA, overall ORIF costs over 2 years were significantly higher because of readmissions, which increased overall LOS. Similarly, in cases of displaced femoral fractures, Iorio and colleagues15 found that LOS was 6.4 days for ORIF, 4.9 days for unipolar HA, 6.2 days for bipolar HA, and 5.5 days for cemented and hybrid THA. However, when overall projected costs were estimated, including the costs of rehabilitation and of (probable) revision arthroplasty, ORIF was estimated to cost more over a 2-year period because of the need for additional care and in-patient stays. In contrast, we found that hospitalization costs were $3805.20 lower for ORIF than for HA/THA, even after adjusting for comorbidities, and that ORIF had a lower overall readmission rate. Early discharge of patients who are at risk for subsequent complications may have played a significant role in increasing readmission rates for arthroplasty patients. These findings indicate the complexities involved in a bundled payment system of reimbursement, in which a single payment for both initial stay and related readmissions will force orthopedists to consider long-term hospitalization costs when deciding on length of postoperative care and the most cost-effective surgical treatment.
One of the limitations of this study is its retrospective design. Although selection of our sample from a single level I trauma center reduced differences in cost and patient care protocols between institutions, it also reduced the generalizability of our actual costs. In addition, for some patients, LOS may have increased because of delays in surgery or discharge, lack of operating room availability, or need for further medical clearance for additional procedures. Day of admission could also have significantly affected LOS. However, the effects of these confounding factors were reduced because of the large sample analyzed. As stated earlier, overall LOS depends on both initial in-patient stays and readmissions. Therefore, long-term prospective studies that compare LOS and associated costs for patients with hip fractures treated with ORIF, CRPP, HA/THA, and CMN are needed.
Conclusion
It has been recently suggested that hip fracture repair be included in the National Pilot Program on Payment Bundling, which will potentially reimburse orthopedic surgeons a standardized amount for hip fracture surgery regardless of actual treatment costs.8 In this model, it will be essential to understand how type of fracture and surgical procedure can influence LOS and therefore hip fracture treatment costs. We found that, based on these factors, mean LOS ranged from 5.59 to 7.43 days, which translates to a cost range of $25,322.70 to $33,657.90. Before a standardized bundled payment system is implemented, further studies are needed to identify other factors that can significantly affect the cost of hip fracture repair.
Hip fractures, the most severe and costly fall-related fractures, account for 350,000 hospital admissions per year.1 The majority of hip fractures result from low-impact falls, typically in patients over age 60 years. In fact, the increase in hip fracture with age is nearly exponential.2,3 With the predicted aging of our population, hip fractures will continue to increase in volume. Between 2000 and 2050, the elderly US population will increase by 135%,4 proportionately increasing the number of projected hip fractures. Considering that hip fractures account for 72% of total costs in terms of orthopedic fracture care in the elderly, the dramatic rise in hip fractures is of great concern for future costs of health care delivery in this field.5-7
In an effort to move toward a value-based system in which costs are reduced while quality of care is maintained, Medicare recently unveiled a new bundled payment system of reimbursement. Through this system, hospitals will be reimbursed for treatment provided to Medicare beneficiaries based on the expected costs of care, instead of through the traditional fee-for-service model. Given this development, orthopedic surgeons will need to develop interventions that reduce costs while maintaining quality of care after hip fracture surgery.
One of the most significant ramifications of a value-based system is that reimbursement for hip fractures may be standardized based on a single diagnosis regardless of the actual costs associated with treatment.8 In hip fracture cases, however, a wide range of factors, including degree of communition of the bone, presence of medical comorbidities,9 and amount of soft-tissue injury, can dramatically increase recovery time. In fact, one of the most important determinants of treatment costs related to hospital length of stay (LOS) is whether the fracture is a femoral neck or intertrochanteric fracture.10,11 Type of fracture is a significant determinant of surgical options, and these can dramatically change patient outcomes and costs of surgical care.12-16 In addition, hospital recovery time or LOS can vary widely based on type of surgery. As hospitalization costs account for 44% of the direct medical costs for hip fractures,17 differences in LOS can have major financial implications in a value-based system of reimbursement in which all forms of hip fracture are reimbursed a standard amount.
We conducted a study to analyze differences in hospital LOS for different forms of hip fracture repair to determine the potential financial repercussions of a bundled payment model of reimbursement. By performing a retrospective chart review at a large, level I trauma center, we were able to compare LOS and associated costs for total hip arthroplasty (THA), hemiarthroplasty (HA), cephalomedullary nailing (CMN), open reduction and internal fixation (ORIF), and closed reduction and percutaneous pinning (CRPP).
Materials and Methods
After receiving institutional review board approval for this study, we retrospectively reviewed all hip fracture cases treated at a level I trauma center between January 2000 and December 2009. Current Procedural Terminology (CPT) codes were searched for cases of low-energy falls that caused hip fractures that were resolved with THA, HA, CMN, ORIF, or CRPP. Patients who underwent HA or THA were grouped for analysis. Patients who were over age 60 years and had acetabular, proximal femoral, trochanteric, or femoral neck fractures were included in our search. Patients who had incomplete medical records or did not meet the age criterion were excluded from analysis.
We reviewed patient charts in our institutional electronic medical records database to collect these data: date of birth, age, sex, date of admission, date of discharge, American Society of Anesthesiologists (ASA) Physical Status score, complications, height, weight, start and stop times of procedure, whether or not the procedure was an emergent procedure, days from admission to surgery, 90-day readmissions, days from surgery to discharge, and general category of operation. We also recorded individual comorbidities, including prior myocardial infarction, dysrhythmia, atrial fibrillation, congestive heart failure, heart block, cerebrovascular disease, chronic obstructive pulmonary disease, emphysema, current smoking status, smoking history, renal disease, dialysis, cancer, and diabetes. Duration of surgery was calculated from recorded start and stop times. Body mass index was calculated using height and weight recorded during initial stay. LOS was recorded as the difference between the admission and discharge dates.
Mean total cost to the hospital ($4530/d patient was hospitalized) was obtained from the institution’s financial services. All fractional LOS values were rounded to the nearest whole number and multiplied by the per diem cost. Student t test was used to compare mean LOS and costs of HA/THA with those of all the other procedures. Additional tests were run to analyze differences in LOS and type of surgeries performed throughout the 9-year period. A multivariate regression model controlling for ASA score, body mass index, age, sex, and comorbidities was developed to analyze differences in LOS and costs for patients who underwent HA/THA versus CMN, ORIF, and CRPP. Significance was set at P = .05.
Results
Our search identified 720 patients who were over age 60 years and underwent operative fixation for hip fracture at our level I trauma center between 2000 and 2009. Of these 720 patients, 105 who had incomplete charts or did not meet the age criteria were excluded, leaving 615 patients (with complete records of isolated low-energy hip fractures) for analysis.
Table 1 lists the demographics of our patient population. The majority of patients had undergone ORIF (30.24%) or HA/THA (45.69%). CRPP was the least common procedure (9.92%) after CMN (14.15%). Mean age was 78.4 years; the majority of patients were between 75 and 89 years of age. Mean hospital LOS was 6.91 days. The majority of patients (n = 414; 67.32%) were female. ASA scores had a narrow distribution, with most patients assigned a score of 3. The readmission rate was significantly higher for HA/THA (39.1%) than for ORIF (28.5%; P = .02) and CRPP (24.6%; P = .04).
Table 2 lists mean LOS and associated costs for each procedure compared with HA/THA. Mean LOS for all patients was 6.91 days, with associated hospitalization costs of $30,011.25. Patients who underwent HA/THA had the longest mean LOS (7.43 days) and highest mean hospitalization costs ($33,657.90). In comparison, patients who underwent ORIF had a mean LOS of 6.59 days with $29,852.70 in costs (P = .04). CRPP also had a significantly (P < .003) shorter LOS (5.59 days) and lower costs ($25,322.70). Although CMN had a mean LOS of 6.89 days and $31,211.70 in costs, the difference in LOS was not significantly different from that of HA/THA. The proportion of surgeries that were HA/THA, CMN, ORIF, and CRPP did not change significantly through the 9-year period (P = .19). Similarly, mean LOS did not change significantly for any of the types of surgery through this period (Table 3).
Figure 1 provides the distribution of LOS for all 4 procedures. The interquartile range (IQR) for patients who underwent HA/THA was 4 to 9 days (median, 6 days). Patients who underwent CMN also had a median LOS of 6 days and an IQR of 4 to 8 days. Both ORIF (IQR, 4-8 days) and CRPP (IQR, 3-6 days) were associated with a median LOS of 5 days.
Figure 2 shows mean hospitalization costs based on type of procedure. HA/THA had the highest mean cost, $33,657.90, or $8335.20 more than CRPP ($25,322.70). Patients who underwent CMN had a mean cost of $31,211.70, versus $29,852.70 for patients who underwent ORIF.
Table 4 summarizes the multivariate analysis results. After ASA score, sex, age, and comorbidities were controlled for, there was an overall significant relationship involving surgical treatment, LOS, and associated hospitalization costs for HA/THA, ORIF, and CRPP. Compared with HA/THA, ORIF had $3805.20 less in costs (P = .042) and 0.84 fewer hospital days. Patients who underwent CRPP were hospitalized for significantly fewer days (1.63) and associated costs ($7383.90) (P = .0076). There was no significant difference in LOS and costs between HA/THA and CMN. Of the controlled variables, only ASA score (P < .001) and male sex (P = .001) were significantly associated with changes in LOS and costs. There was no significant association with comorbidities, LOS, or costs.
Discussion
In this study of surgical intervention in patients with hip fractures, we determined that HA/THA was associated with significantly increased hospital LOS and costs than ORIF and CRPP. Although arthroplasty had an increased mean LOS compared with CMN, the difference was not statistically significant. In addition to type of procedure, both male sex (P = .001) and preoperative ASA score (P < .001) were significant predictors of LOS and costs. These findings are supported by other studies in which preoperative functioning was found to be a strong predictor of increased LOS and costs among hip fracture patients,18 most likely because of increased risk for complications.19
Although our study was the first to directly compare LOS and costs for HA/THA and CMN, other investigators have analyzed the effect of surgical complications on LOS for patients treated with THA, HA, and CMN. In a study on the effects of surgical complications on LOS after hip fracture surgery, Foss and colleagues17 reported that the proportion of CMN patients (31%) with complications was larger than that of HA patients (19%) and THA patients (0%). They also reported that surgical complications were associated with significantly increased LOS during primary admission. Similarly, Edwards and colleagues20 found that the infection risk was higher with CMN (3.1%) than with THA (0%) and HA (0%-2.3%) and that infections were associated with increased LOS (P > .001). However, further statistical analysis revealed that the odds of developing an infection were not significantly higher with CMN than with other studies.20 Similarly, other studies have reported low rates of complications, including nonunion, with CMN.21,22 In our study, we found no significant difference in LOS and costs for CMN and HA/THA after controlling for ASA score, which is known to be associated with a higher risk for complications.18,19
The largest difference in LOS and costs after controlling for potential confounding variables was between HA/THA and CRPP ($7383.90). To our knowledge, only one study has performed a comparative analysis of LOS for CRPP and other surgical treatments for hip fractures. For femoral neck fractures treated between 1990 and 1994, Fekete and colleagues23 found that LOS was 14.9 days for ORIF cases and 12.1 days for CRPP cases—a difference of 2.8 days. In comparison, we found a 1-day difference in mean LOS between ORIF cases (6.59 days) and CRPP cases (5.59 days).
Other studies of LOS and associated costs over a 2-year period have found that ORIF is overall more costly than HA/THA. For example, Keating and colleagues13 compared total costs of care, including LOS, for healthy older patients with displaced intracapsular hip fractures treated with ORIF, bipolar HA, or THA. Although ORIF was initially less costly than HA/THA, overall ORIF costs over 2 years were significantly higher because of readmissions, which increased overall LOS. Similarly, in cases of displaced femoral fractures, Iorio and colleagues15 found that LOS was 6.4 days for ORIF, 4.9 days for unipolar HA, 6.2 days for bipolar HA, and 5.5 days for cemented and hybrid THA. However, when overall projected costs were estimated, including the costs of rehabilitation and of (probable) revision arthroplasty, ORIF was estimated to cost more over a 2-year period because of the need for additional care and in-patient stays. In contrast, we found that hospitalization costs were $3805.20 lower for ORIF than for HA/THA, even after adjusting for comorbidities, and that ORIF had a lower overall readmission rate. Early discharge of patients who are at risk for subsequent complications may have played a significant role in increasing readmission rates for arthroplasty patients. These findings indicate the complexities involved in a bundled payment system of reimbursement, in which a single payment for both initial stay and related readmissions will force orthopedists to consider long-term hospitalization costs when deciding on length of postoperative care and the most cost-effective surgical treatment.
One of the limitations of this study is its retrospective design. Although selection of our sample from a single level I trauma center reduced differences in cost and patient care protocols between institutions, it also reduced the generalizability of our actual costs. In addition, for some patients, LOS may have increased because of delays in surgery or discharge, lack of operating room availability, or need for further medical clearance for additional procedures. Day of admission could also have significantly affected LOS. However, the effects of these confounding factors were reduced because of the large sample analyzed. As stated earlier, overall LOS depends on both initial in-patient stays and readmissions. Therefore, long-term prospective studies that compare LOS and associated costs for patients with hip fractures treated with ORIF, CRPP, HA/THA, and CMN are needed.
Conclusion
It has been recently suggested that hip fracture repair be included in the National Pilot Program on Payment Bundling, which will potentially reimburse orthopedic surgeons a standardized amount for hip fracture surgery regardless of actual treatment costs.8 In this model, it will be essential to understand how type of fracture and surgical procedure can influence LOS and therefore hip fracture treatment costs. We found that, based on these factors, mean LOS ranged from 5.59 to 7.43 days, which translates to a cost range of $25,322.70 to $33,657.90. Before a standardized bundled payment system is implemented, further studies are needed to identify other factors that can significantly affect the cost of hip fracture repair.
1. American Academy of Orthopaedic Surgeons. Burden of Musculoskeletal Diseases in the United States: Prevalence, Societal and Economic Cost. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2008.
2. Samelson EJ, Zhang Y, Kiel DP, Hannan MT, Felson DT. Effect of birth cohort on risk of hip fracture: age-specific incidence rates in the Framingham study. Am J Public Health. 2002;92(5):858-862.
3. Scott JC. Osteoporosis and hip fractures. Rheum Dis Clin North Am. 1990;16(3):717-740.
4. Wiener JM, Tilly J. Population ageing in the United States of America: implications for public programmes. Int J Epidemiol. 2002;31(4):776-781.
5. Burge R, Dawson-Hughes B, Solomon DH, Wong JB, King A, Tosteson A. Incidence and economic burden of osteoporosis-related fractures in the United States, 2005–2025. J Bone Miner Res. 2007;22(3):465-475.
6. Burge RT, King AB, Balda E, Worley D. Methodology for estimating current and future burden of osteoporosis in state populations: application to Florida in 2000 through 2025. Value Health. 2003;6(5):574-583.
7. Tosteson AN, Burge RT, Marshall DA, Lindsay R. Therapies for treatment of osteoporosis in US women: cost-effectiveness and budget impact considerations. Am J Manag Care. 2008;14(9):605-615.
8. Sood N, Huckfeldt PJ, Escarce JJ, Grabowski DC, Newhouse JP. Medicare’s bundled payment pilot for acute and postacute care: analysis and recommendations on where to begin. Health Aff. 2011;30(9):1708-1717.
9. Shah A, Eissler J, Radomisli T. Algorithms for the treatment of femoral neck fractures. Clin Orthop. 2002;(399):28-34.
10. Sund R, Riihimäki J, Mäkelä M, et al. Modeling the length of the care episode after hip fracture: does the type of fracture matter? Scand J Surg. 2009;98(3):169-174.
11. Fox KM, Magaziner J, Hebel JR, Kenzora JE, Kashner TM. Intertrochanteric versus femoral neck hip fractures: differential characteristics, treatment, and sequelae. J Gerontol A Biol Sci Med Sci. 1999;54(12):M635-M640.
12. Carroll C, Stevenson M, Scope A, Evans P, Buckley S. Hemiarthroplasty and total hip arthroplasty for treating primary intracapsular fracture of the hip: a systematic review and cost-effectiveness analysis. Health Technol Assess. 2011;15(36):1-74.
13. Keating JF, Grant A, Masson M, Scott NW, Forbes JF. Randomized comparison of reduction and fixation, bipolar hemiarthroplasty, and total hip arthroplasty. Treatment of displaced intracapsular hip fractures in healthy older patients. J Bone Joint Surg Am. 2006;88(2):249-260.
14. Rogmark C, Carlsson A, Johnell O, Sembo I. Costs of internal fixation and arthroplasty for displaced femoral neck fractures: a randomized study of 68 patients. Acta Orthop Scand. 2003;74(3):293-298.
15. Iorio R, Healy WL, Lemos DW, Appleby D, Lucchesi CA, Saleh KJ. Displaced femoral neck fractures in the elderly: outcomes and cost effectiveness. Clin Orthop. 2001;(383):229-242.
16. Slover J, Hoffman MV, Malchau H, Tosteson AN, Koval KJ. A cost-effectiveness analysis of the arthroplasty options for displaced femoral neck fractures in the active, healthy, elderly population. J Arthroplasty. 2009;24(6):854-860.
17. Foss NB, Palm H, Krasheninnikoff M, Kehlet H, Gebuhr P. Impact of surgical complications on length of stay after hip fracture surgery. Injury. 2007;38(7):780-784.
18. Garcia AE, Bonnaig JV, Yoneda ZT. Patient variables which may predict length of stay and hospital costs in elderly patients with hip fracture. J Orthop Trauma. 2012;26(11):620-623.
19. Donegan DJ, Gay AN, Baldwin K, Morales EE, Esterhai JL Jr, Mehta S. Use of medical comorbidities to predict complications after hip fracture surgery in the elderly. J Bone Joint Surg Am. 2010;92(4):807-813.
20. Edwards C, Counsell A, Boulton C, Moran CG. Early infection after hip fracture surgery: risk factors, costs and outcome. J Bone Joint Surg Br. 2008;90(6):770-777.
21. Jain P, Maini L, Mishra P, Upadhyay A, Agarwal A. Cephalomedullary interlocked nail for ipsilateral hip and femoral shaft fractures. Injury. 2004;35(10):1031-1038.
22. Matre K, Havelin LI, Gjertsen JE, Espehaug B, Fevang JM. Intramedullary nails result in more reoperations than sliding hip screws in two-part intertrochanteric fractures. Clin Orthop. 2013;471(4):1379-1386.
23. Fekete K, Manninger J, Kazár G, Cserháti P, Bosch U. Percutaneous internal fixation of femoral neck fractures with cannulated screws and a small tension band plate. Orthop Traumatol. 2000;8(4):250-263.
1. American Academy of Orthopaedic Surgeons. Burden of Musculoskeletal Diseases in the United States: Prevalence, Societal and Economic Cost. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2008.
2. Samelson EJ, Zhang Y, Kiel DP, Hannan MT, Felson DT. Effect of birth cohort on risk of hip fracture: age-specific incidence rates in the Framingham study. Am J Public Health. 2002;92(5):858-862.
3. Scott JC. Osteoporosis and hip fractures. Rheum Dis Clin North Am. 1990;16(3):717-740.
4. Wiener JM, Tilly J. Population ageing in the United States of America: implications for public programmes. Int J Epidemiol. 2002;31(4):776-781.
5. Burge R, Dawson-Hughes B, Solomon DH, Wong JB, King A, Tosteson A. Incidence and economic burden of osteoporosis-related fractures in the United States, 2005–2025. J Bone Miner Res. 2007;22(3):465-475.
6. Burge RT, King AB, Balda E, Worley D. Methodology for estimating current and future burden of osteoporosis in state populations: application to Florida in 2000 through 2025. Value Health. 2003;6(5):574-583.
7. Tosteson AN, Burge RT, Marshall DA, Lindsay R. Therapies for treatment of osteoporosis in US women: cost-effectiveness and budget impact considerations. Am J Manag Care. 2008;14(9):605-615.
8. Sood N, Huckfeldt PJ, Escarce JJ, Grabowski DC, Newhouse JP. Medicare’s bundled payment pilot for acute and postacute care: analysis and recommendations on where to begin. Health Aff. 2011;30(9):1708-1717.
9. Shah A, Eissler J, Radomisli T. Algorithms for the treatment of femoral neck fractures. Clin Orthop. 2002;(399):28-34.
10. Sund R, Riihimäki J, Mäkelä M, et al. Modeling the length of the care episode after hip fracture: does the type of fracture matter? Scand J Surg. 2009;98(3):169-174.
11. Fox KM, Magaziner J, Hebel JR, Kenzora JE, Kashner TM. Intertrochanteric versus femoral neck hip fractures: differential characteristics, treatment, and sequelae. J Gerontol A Biol Sci Med Sci. 1999;54(12):M635-M640.
12. Carroll C, Stevenson M, Scope A, Evans P, Buckley S. Hemiarthroplasty and total hip arthroplasty for treating primary intracapsular fracture of the hip: a systematic review and cost-effectiveness analysis. Health Technol Assess. 2011;15(36):1-74.
13. Keating JF, Grant A, Masson M, Scott NW, Forbes JF. Randomized comparison of reduction and fixation, bipolar hemiarthroplasty, and total hip arthroplasty. Treatment of displaced intracapsular hip fractures in healthy older patients. J Bone Joint Surg Am. 2006;88(2):249-260.
14. Rogmark C, Carlsson A, Johnell O, Sembo I. Costs of internal fixation and arthroplasty for displaced femoral neck fractures: a randomized study of 68 patients. Acta Orthop Scand. 2003;74(3):293-298.
15. Iorio R, Healy WL, Lemos DW, Appleby D, Lucchesi CA, Saleh KJ. Displaced femoral neck fractures in the elderly: outcomes and cost effectiveness. Clin Orthop. 2001;(383):229-242.
16. Slover J, Hoffman MV, Malchau H, Tosteson AN, Koval KJ. A cost-effectiveness analysis of the arthroplasty options for displaced femoral neck fractures in the active, healthy, elderly population. J Arthroplasty. 2009;24(6):854-860.
17. Foss NB, Palm H, Krasheninnikoff M, Kehlet H, Gebuhr P. Impact of surgical complications on length of stay after hip fracture surgery. Injury. 2007;38(7):780-784.
18. Garcia AE, Bonnaig JV, Yoneda ZT. Patient variables which may predict length of stay and hospital costs in elderly patients with hip fracture. J Orthop Trauma. 2012;26(11):620-623.
19. Donegan DJ, Gay AN, Baldwin K, Morales EE, Esterhai JL Jr, Mehta S. Use of medical comorbidities to predict complications after hip fracture surgery in the elderly. J Bone Joint Surg Am. 2010;92(4):807-813.
20. Edwards C, Counsell A, Boulton C, Moran CG. Early infection after hip fracture surgery: risk factors, costs and outcome. J Bone Joint Surg Br. 2008;90(6):770-777.
21. Jain P, Maini L, Mishra P, Upadhyay A, Agarwal A. Cephalomedullary interlocked nail for ipsilateral hip and femoral shaft fractures. Injury. 2004;35(10):1031-1038.
22. Matre K, Havelin LI, Gjertsen JE, Espehaug B, Fevang JM. Intramedullary nails result in more reoperations than sliding hip screws in two-part intertrochanteric fractures. Clin Orthop. 2013;471(4):1379-1386.
23. Fekete K, Manninger J, Kazár G, Cserháti P, Bosch U. Percutaneous internal fixation of femoral neck fractures with cannulated screws and a small tension band plate. Orthop Traumatol. 2000;8(4):250-263.
Long-Term Outcomes of Allograft Reconstruction of the Anterior Cruciate Ligament
Injuries of the anterior cruciate ligament (ACL) are common. Good to excellent long-term results are generally expected in more than 90% of ACL reconstructions.1,2 Although our knowledge of the biomechanics, kinematics, and long-term outcomes of ACL reconstruction is extensive, the ideal graft choice for ACL reconstruction is still up for debate.
Historically, both quadruple-stranded hamstring tendon and bone–patellar tendon–bone (BPTB) autografts have been the most popular graft options for operative reconstruction of the ACL.3 Recently, allograft tissues have become increasingly popular as a graft source. Proponents of allograft ACL reconstruction have cited several advantages over autograft reconstruction, including decreased donor-site morbidity, shorter operative times, and quicker postoperative recovery.4-7 Nevertheless, some authors have recently reported higher rates of both reoperation and graft failure after allograft ACL reconstruction.4,8-11 The 2 senior surgeons in the Sports Medicine Section of the Department of Orthopedic Surgery at the University of Arizona College of Medicine had not recognized such high failure and revision rates in their own clinical practices.
To evaluate the long-term outcomes of allograft ACL reconstruction, we retrospectively reviewed the cases of all patients who underwent allograft or autograft ACL reconstruction by 2 senior surgeons at a single institution over an 8-year period. We hypothesized that the reoperation and revision surgery rates for allograft ACL reconstruction would not be higher than those reported for autograft reconstruction. We also hypothesized that allograft ACL reconstruction failure rates would not be higher for patients younger than 25 years than for patients who are older and less active.
Materials and Methods
This study was approved by the Institutional Review Board at the University of Arizona College of Medicine. We retrospectively reviewed the cases of all patients who underwent primary endoscopic ACL reconstruction at the University of Arizona College of Medicine over an 8-year period (2000–2008). All ACL reconstructions were performed by 2 senior, fellowship-trained sports medicine specialists, including Dr. William A. Grana. Patients were identified from the Current Procedural Terminology (CPT) code for ACL reconstruction. Both autograft and allograft reconstructions were included in the study. Patients undergoing revision ACL reconstruction and patients with multi-ligamentous knee injuries were excluded. All available medical records were reviewed for patient demographics and any concomitant knee pathology. We included patients of all activity levels, patients with acute ACL tears, and patients with chronically ACL-deficient knees. We identified a separate cohort of Division I varsity athletes from the University of Arizona for evaluation. These patients were identified from the injury surveillance system in the athletic training facility of the University of Arizona.
ACL reconstructions at our institution during this 8-year period were performed with both allograft and autograft soft tissue. Allograft tendons were most commonly used. Tibialis anterior allograft was used in the majority of those knees. Tibialis posterior and semitendinosus allografts were used in a small subset of patients. Autograft reconstruction was performed with quadruple-stranded semitendinosus and gracilis tendons. We reviewed operative reports to determine type of graft used for reconstruction.
Patients were assessed clinically by telephone interview and/or mailed survey. They were specifically asked whether there had been any postoperative complications. We reviewed all operative and postoperative follow-up notes for postoperative complications. Objective clinical assessment involved use of the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, the Tegner-Lysholm Knee Scoring Scale, and the Tegner Activity Scale.
Operative Technique
A standard, transtibial arthroscopically assisted ACL reconstruction was performed in all patients. For autograft reconstruction patients, both the semitendinosus and gracilis tendons were harvested through a small anteromedial incision and prepared to form a quadruple-stranded graft. All allograft tendons were obtained from the Musculoskeletal Transplant Foundation (MTF). Tibialis anterior and tibialis posterior allografts were folded in half to form a double-stranded graft. Alternatively, 2 semitendinosus allografts were prepared in the same fashion as that described for autograft hamstring tendons. The tibial tunnel was placed into the center of the ACL tibial footprint. With use of a transtibial approach, an endoscopic offset guide was used to place the femoral tunnel at the 10- and 2-o’clock positions in the right and left knees, respectively. In almost all cases, the graft was secured on the femoral side with a cortical fixation button. Tibial fixation was obtained with a bioabsorbable interference screw.
After ACL reconstruction, each patient participated in the standard accelerated rehabilitation outlined by Shelbourne and Gray.12 Guided rehabilitation was instituted within 1 week after surgery under the guidance of a physical therapist. Range-of-motion exercises and closed-chain strengthening exercises were begun at this time. The protocol emphasized early return of full terminal extension and normalization of gait patterns. Patients were allowed to return to play only after meeting specific criteria, about 6 months after surgery. Many athletes in our Division I university population are allowed to return to play 5 to 6 months after surgery, after meeting return-to-play criteria.
Statistical Analysis
We used Minitab 14 (Minitab, State College, Pennsylvania) to perform all statistical analyses, unpaired Student t tests to compare IKDC and Tegner-Lysholm results between allograft and autograft groups, and χ2 tests to compare revision and reoperation rates between groups. Significance was set at P = .05.
Results
We identified 362 patients who underwent ACL reconstructions at our institution between 2000 and 2008. Of these patients, 302 met the study inclusion criteria. One-hundred twenty-three (40.7%) of the 302 were available for follow-up by telephone interview and/or mailed questionnaire. This follow-up group consisted of 67 males and 56 females. Mean age at surgery was 29 years (range, 17-53 years). Mean follow-up was 50.3 months (range, 11-111 months). Of the 123 patients, 99 underwent allograft ACL reconstruction, and 24 underwent autograft ACL reconstruction. Seventeen (17%) of the 99 allograft cases required additional surgery (Table 1). The reoperation rate for patients under age 25 years (30.8%) was higher than the rate for patients older than 25 years (Table 2). Regarding patients who underwent additional surgeries, mean scores were lower with allograft (Tegner-Lysholm, 59; IKDC, 54) than with autograft (Tegner-Lysholm, 83; IKDC, 79) (Ps = .0025 and .006, respectively).
Revision rates were 10.1% (allograft group) and 4.2% (autograft group) (Table 1). This difference was not statistically significant (P = .18). In the allograft group, the revision rate was higher for patients younger than 25 years (20.5%) than for patients older than 25 years (3.3%) (Table 2). In comparison, in the autograft group, the revision rate was only 4% for patients younger than 25 years. For younger patients, the higher rate of revision with allograft (vs autograft) was statistically significant (P = .038). For older patients, allograft and autograft revision rates did not differ significantly (P = .19). No patient younger than 25 years required revision reconstruction after autograft ACL reconstruction.
IKDC and Tegner-Lysholm outcome scores for allograft and autograft groups are shown in Table 3. In patients 25 years or younger, IKDC scores were 75.18 after allograft reconstruction and 85.34 after autograft reconstruction—a significant difference (P = .045). In addition, Tegner-Lysholm scores were significantly higher after autograft reconstruction (91.58) than allograft reconstruction (78.19) in these younger patients (P = .003) (Table 3). IKDC and Tegner-Lysholm scores were not significantly different for older patients (Ps = .241 and .211, respectively).
The study also included a subset of 19 primary ACL reconstructions (13 allograft, 6 autograft) performed on Division I athletes from the University of Arizona. (Nineteen [91%] of the 21 athletes in our Division I cohort were available for follow-up.) All these patients were younger than 25 years. All autograft reconstructions were performed with quadruple-stranded gracilis and semitendinosus tendons. ACL graft failure occurred in 8 (62%) of the 13 allograft cases; there were no failures in the autograft group (Table 4). One of the 5 allograft cases that did not fail required multiple surgical débridement procedures for infection, but the graft was ultimately retained. There were no infections among the 6 autograft cases.
Discussion
The ideal graft for ACL reconstruction is still a matter of intense debate. There are many graft options for ACL reconstruction. Both BPTB and hamstring autografts are associated with various graft-specific comorbidities. Anterior knee pain, knee extensor weakness, extension loss, patella fracture, patellofemoral crepitance, and infrapatellar nerve injury have been described with BPTB autografts.13-17 In a meta-analysis of 11 studies comparing BPTB autografts with hamstring autograft, Goldblatt and colleagues17 found more extension loss, kneeling pain, and patellofemoral crepitance in the BPTP group.
Knee flexion weakness, knee flexion loss, increased knee laxity, and saphenous nerve injury have all been described with use of hamstring autografts.16-19 Goldblatt and colleagues17 demonstrated a significant flexion loss in the hamstring group in their meta-analysis as well as increased laxity with both the Lachman test and the pivot shift test. They also found that the hamstring autograft group exhibited side-to-side differences of more than 3 mm on KT-1000 testing when compared with the BPTB autograft group.
Proposed advantages of allograft reconstruction include elimination of donor-site morbidity and/or pain from a less invasive procedure, faster initial recovery, more sizing options, and shorter operative times.4-7 In a 5-year follow-up of patients who had ACL reconstruction with either Achilles allograft or BPTB autograft, Poehling and colleagues7 demonstrated overall similar long-term outcomes between the groups. However, the allograft patients reported less pain 1 and 6 weeks after surgery; better function 1 week, 3 months, and 1 year after surgery; and fewer activity limitations throughout the follow-up period. Lamblin and colleagues20 also found no difference between nonirradiated allograft and autograft tissue in ACL reconstruction in a 2013 meta-analysis of ACL studies published over a 32-year period.
Despite the proposed advantages of allograft ACL reconstruction, several recent studies have demonstrated poorer outcomes in both younger patients and more active patients after allograft reconstruction.8-11,21 In a 2007 meta-analysis, Prodromos and colleagues11 compared a series of allograft reconstructions with previously published data sets of both BPTB and hamstring autografts. They found that allograft reconstructions had significantly lower stability rates than autograft reconstructions. In a case–control study by Borchers and colleagues,10 21 patients with ACL graft failure were identified over a 2-year period, and surgical outcomes were compared with those of 42 age- and sex-matched controls. The authors found higher activity level and allograft use to be risk factors for subsequent graft failure after ACL reconstruction. More important, they showed a multiplicative interaction between higher activity level after ACL reconstruction and allograft use—an interaction that greatly increased the odds for ACL graft failure. Last, in a retrospective review, Singhal and colleagues8 evaluated the outcomes of ACL reconstruction using tibialis anterior tendon allograft and reported a 23.1% revision rate. In addition, 37.7% of patients required repeat surgery. The failure/reoperation rate was 55% for patients 25 years or younger and 24% for patients older than 25 years. The authors recommended not using tibialis anterior allografts in patients 25 years or younger and in patients who frequently engage in level I ACL-dependent sports.
The poor outcomes reported by Singhal and colleagues8 may be related to use of irradiated soft-tissue allografts. In a comparison of nonirradiated BPTB allograft and BPTB autograft in patients 25 years or younger, Barber and colleagues22 found equivalent outcomes at 2-year follow-up. They actually found a higher rate of failure for autograft reconstruction (9.4%) than allograft reconstruction (7.1%). A potential critique of their study is the significant difference between the patient groups’ mean ages: 18.6 years (autograft) versus 20.1 years (allograft). Despite this selection bias, Barber and colleagues22 argued that nonirradiated BPTB allograft is equivalent to BPTB autograft for ACL reconstruction.
Our study is one of the largest allograft studies with a comparison group. The principal findings of this study demonstrate that overall reoperation and revision rates after irradiated soft-tissue allograft ACL reconstruction are higher than those historically quoted for autograft ACL reconstruction. Specifically, allograft patients younger than 25 years had a reoperation rate of 30.8% and a revision rate of 20.5%. (Allograft patients older than 25 years had lower rates of reoperation, 8.3%, and revision, 3.3%.) After revision surgery, autograft patients’ subjective outcomes (IKDC and Tegner-Lysholm scores) were significantly improved compared with those of allograft patients (Ps = .0017 and .0031, respectively). Most compelling, however, is the unexpected and quite concerning 62% failure rate in our high-level Division I intercollegiate athletes.
There are multiple hypotheses regarding the higher failure rates of allograft tissues versus autograft tissues in ACL reconstruction. Processing methods, exposure to ionizing radiation, and the incorporation/ligamentization process have all been cited as possible reasons for allograft failure. All the allograft tendons used in the present study were obtained from MTF, which uses a proprietary “aseptic” processing system that includes washing in buffered saline impregnated with antibiotics (imipenem/cilastatin, amphotericin B, gentamicin) followed by final rinsing in phosphate-buffered saline. The majority of grafts are subjected to low-level irradiation (<2 Mrad/20 kGy) based on the outcomes of MTF’s stringent donor-selection process. Although the washing process has not been shown to alter the structural integrity of donor grafts, multiple studies have outlined the detrimental effects of higher levels of gamma radiation on allograft tissues. Although lower levels are effective against potential bacterial contaminants, a radiation level of 4 Mrad is necessary to kill the human immunodeficiency virus (HIV). Thus, a dose of 4 Mrad or higher is needed to truly “sterilize” a graft. This higher dose is an issue, as it has been known for some time that higher levels of ionizing radiation can have adverse effects on the biomechanical strength of soft-tissue allografts. In fact, ionizing radiation has dose-dependent effects.23-26 Schwartz and colleagues27 showed in a caprine model that radiation exposure at 4 Mrad significantly decreased the biomechanical strength of ACL allografts at 6 months. Balsly and colleagues28 found in a biomechanical study that radiation doses of 18 to 22 Mrad did not significantly affect the mechanical integrity of soft-tissue allografts. Conversely, in an in vivo study, Rappe and colleagues29 showed that Achilles allografts irradiated at a dose of 2.0 to 2.5 Mrad had a failure rate (33%) much higher than that of nonirradiated allografts (2.4%). The radiation dose used by MTF is less than 2 Mrad. Although more than needed to kill bacterial contaminants, this dose is considered by MTF to be below the threshold for biomechanical alterations. Only a minority of grafts is treated without irradiation.
It is possible that any level of radiation affects ligamentization of allograft tissues. Multiple studies have outlined the ligamentization process of autograft tendons in vivo. Patellar tendon autografts undergo central degeneration 2 to 6 weeks after reconstruction, but, by 6 to 12 months, these tendons have structural properties similar to those of the native ACL.30-34 Findings are similar for hamstring autografts.35,36 Goradia and colleagues36 found that, by 52 weeks, semitendinosus autografts transform into a histologic structure similar to that of the normal ACL. Remodeling of allograft tendons has been described as occurring at a much slower rate.27,37-40 Bhatia and colleagues37 demonstrated faster remodeling in autograft tissues versus allograft tissues at early time points in an in vivo rabbit model. Ultimately, differences in graft incorporation and ligamentization may be a primary factor in the higher failure rates of allograft ACL reconstruction. Current rehabilitation protocols may not take into account the longer ligamentization process for allograft tissues. These protocols are largely based on our current understanding of the ligamentization process after autograft reconstruction. It is possible that the rehabilitation program and return-to-play schedule for allograft reconstruction need to be altered to help avoid higher failure rates. The return-to-play protocol at the authors’ institution scheduled most varsity athletes to return to play 6 months after surgery. In some cases, the timetable was shortened, and some athletes were returned to play 5 months after surgery, after meeting all return-to-play criteria. Based on the findings of the present study, this return-to-play schedule may be much too aggressive for high-level athletes after allograft reconstruction. It is possible these allografts have not reached “maturity,” as their autograft counterparts have, and thus are not ready for unrestricted return to play.
Our study had multiple strengths. All reconstructions were performed by 2 senior surgeons with extensive clinical experience. The autograft and allograft reconstructions used the same techniques and rehabilitation protocols. This is one of the largest studies of outcomes of allograft ACL reconstruction and one of the largest studies that used a comparison group of autograft reconstructions. Having a comparison group effectively allowed us to contrast the differences between allograft and autograft tissues. Last, this study evaluated a subgroup of high-level NCAA Division I athletes. Follow-up in the overall study was 40.7%, but follow-up in this subgroup was 91%. The very high follow-up rate in the university population helped us validate the overall results of the study. Study results reinforced the fact that irradiated soft-tissue allograft may not be indicated for ACL reconstruction in a younger, more active patient population and led to a change in approach to ACL reconstruction for Division I intercollegiate athletes at the University of Arizona. Allograft ACL reconstruction is no longer recommended for the intercollegiate athletes at the University of Arizona.
Our study had its limitations. First, it had the inherent biases of a retrospective study. Second, many patients were lost to follow-up. We contacted and surveyed 40.7% of the patients who met the inclusion criteria. We tried reaching them in multiple ways—through US mail, all listed phone numbers, family members, and so forth. Tucson, Arizona is a college town and has a larger transient population, which may have added to the difficulty in contacting patients.
Conclusion
Given the high rates of reoperation and revision surgery with allograft reconstruction in younger patients in this study, we recommend against routine use of irradiated soft-tissue allograft tissue for ACL reconstruction in patients 25 years or younger. In our clinical practices, we prefer using autograft tissue for ACL reconstruction in younger, more active individuals. Irradiated soft-tissue allograft ACL reconstruction is a viable option in the older, less active patient population. Although the overall reoperation rate in this cohort study is acceptable, the revision rate for patients younger than 25 years is concerning and should be taken into account when considering use of irradiated soft-tissue allograft for ACL reconstruction in these younger patients.
1. Schepsis AA, Busconi BD. Sports Medicine. Philadelphia, PA: Lippincott Williams & Wilkins; 2006.
2. Campbell WC, Canale ST, Beaty JH. Campbell’s Operative Orthopaedics. 11th ed. Philadelphia, PA: Mosby/Elsevier; 2008.
3. Sherman OH, Banffy MB. Anterior cruciate ligament reconstruction: which graft is best? Arthroscopy. 2004;20(9):974-980.
4. Lee JH, Bae DK, Song SJ, Cho SM, Yoon KH. Comparison of clinical results and second-look arthroscopy findings after arthroscopic anterior cruciate ligament reconstruction using 3 different types of grafts. Arthroscopy. 2010;26(1):41-49.
5. Sun K, Tian SQ, Zhang JH, Xia CS, Zhang CL, Yu TB. Anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft versus allograft. Arthroscopy. 2009;25(7):750-759.
6. Kuhn MA, Ross G. Allografts in the treatment of anterior cruciate ligament injuries. Sports Med Arthrosc Rev. 2007;15(3):133-138.
7. Poehling GG, Curl WW, Lee CA, et al. Analysis of outcomes of anterior cruciate ligament repair with 5-year follow-up: allograft versus autograft. Arthroscopy. 2005;21(7):774-785.
8. Singhal MC, Gardiner JR, Johnson DL. Failure of primary anterior cruciate ligament surgery using anterior tibialis allograft. Arthroscopy. 2007;23(5):469-475.
9. Barrett GR, Luber K, Replogle WH, Manley JL. Allograft anterior cruciate ligament reconstruction in the young, active patient: Tegner activity level and failure rate. Arthroscopy. 2010;26(12):1593-1601.
10. Borchers JR, Pedroza A, Kaeding C. Activity level and graft type as risk factors for anterior cruciate ligament graft failure: a case–control study. Am J Sports Med. 2009;37(12):2362-2367.
11. Prodromos C, Joyce B, Shi K. A meta-analysis of stability of autografts compared to allografts after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2007;15(7):851-856.
12. Shelbourne KD, Gray T. Anterior cruciate ligament reconstruction with autogenous patellar tendon graft followed by accelerated rehabilitation. A two- to nine-year followup. Am J Sports Med. 1997;25(6):786-795.
13. Rosenberg TD, Franklin JL, Baldwin GN, Nelson KA. Extensor mechanism function after patellar tendon graft harvest for anterior cruciate ligament reconstruction. Am J Sports Med. 1992;20(5):519-525.
14. Piva SR, Childs JD, Klucinec BM, Irrgang JJ, Almeida GJ, Fitzgerald GK. Patella fracture during rehabilitation after bone–patellar tendon–bone anterior cruciate ligament reconstruction: 2 case reports. J Orthop Sports Phys Ther. 2009;39(4):278-286.
15. Lee GH, McCulloch P, Cole BJ, Bush-Joseph CA, Bach BR Jr. The incidence of acute patellar tendon harvest complications for anterior cruciate ligament reconstruction. Arthroscopy. 2008;24(2):162-166.
16. Kartus J, Movin T, Karlsson J. Donor-site morbidity and anterior knee problems after anterior cruciate ligament reconstruction using autografts. Arthroscopy. 2001;17(9):971-980.
17. Goldblatt JP, Fitzsimmons SE, Balk E, Richmond JC. Reconstruction of the anterior cruciate ligament: meta-analysis of patellar tendon versus hamstring tendon autograft. Arthroscopy. 2005;21(7):791-803.
18. Freedman KB, D’Amato MJ, Nedeff DD, Kaz A, Bach BR Jr. Arthroscopic anterior cruciate ligament reconstruction: a metaanalysis comparing patellar tendon and hamstring tendon autografts. Am J Sports Med. 2003;31(1):2-11.
19. Yunes M, Richmond JC, Engels EA, Pinczewski LA. Patellar versus hamstring tendons in anterior cruciate ligament reconstruction: a meta-analysis. Arthroscopy. 2001;17(3):248-257.
20. Lamblin CJ, Waterman BR, Lubowitz JH. Anterior cruciate ligament reconstruction with autografts compared with non-irradiated, non-chemically treated allografts. Arthroscopy. 2013;29(6):1113-1122.
21. Pallis M, Svoboda SJ, Cameron KL, Owens BD. Survival comparison of allograft and autograft anterior cruciate ligament reconstruction at the United States Military Academy. Am J Sports Med. 2012;40(6):1242-1246.
22. Barber FA, Cowden CH 3rd, Sanders EJ. Revision rates after anterior cruciate ligament reconstruction using bone–patellar tendon–bone allograft or autograft in a population 25 years old and younger. Arthroscopy. 2014;30(4):483-491.
23. Salehpour A, Butler DL, Proch FS, et al. Dose-dependent response of gamma irradiation on mechanical properties and related biochemical composition of goat bone–patellar tendon–bone allografts. J Orthop Res. 1995;13(6):898-906.
24. Gibbons MJ, Butler DL, Grood ES, Bylski-Austrow DI, Levy MS, Noyes FR. Effects of gamma irradiation on the initial mechanical and material properties of goat bone–patellar tendon–bone allografts. J Orthop Res. 1991;9(2):209-218.
25. Fideler BM, Vangsness CT Jr, Lu B, Orlando C, Moore T. Gamma irradiation: effects on biomechanical properties of human bone–patellar tendon–bone allografts. Am J Sports Med. 1995;23(5):643-646.
26. De Deyne P, Haut RC. Some effects of gamma irradiation on patellar tendon allografts. Connect Tissue Res. 1991;27(1):51-62.
27. Schwartz HE, Matava MJ, Proch FS, et al. The effect of gamma irradiation on anterior cruciate ligament allograft biomechanical and biochemical properties in the caprine model at time zero and at 6 months after surgery. Am J Sports Med. 2006;34(11):1747-1755.
28. Balsly CR, Cotter AT, Williams LA, Gaskins BD, Moore MA, Wolfinbarger L Jr. Effect of low dose and moderate dose gamma irradiation on the mechanical properties of bone and soft tissue allografts. Cell Tissue Bank. 2008;9(4):289-298.
29. Rappe M, Horodyski M, Meister K, Indelicato PA. Nonirradiated versus irradiated Achilles allograft: in vivo failure comparison. Am J Sports Med. 2007;35(10):1653-1658.
30. Amiel D, Kleiner JB, Akeson WH. The natural history of the anterior cruciate ligament autograft of patellar tendon origin. Am J Sports Med. 1986;14(6):449-462.
31. Amiel D, Kleiner JB, Roux RD, Harwood FL, Akeson WH. The phenomenon of “ligamentization”: anterior cruciate ligament reconstruction with autogenous patellar tendon. J Orthop Res. 1986;4(2):162-172.
32. Arnoczky SP, Tarvin GB, Marshall JL. Anterior cruciate ligament replacement using patellar tendon. An evaluation of graft revascularization in the dog. J Bone Joint Surg Am. 1982;64(2):217-224.
33. Ballock RT, Woo SL, Lyon RM, Hollis JM, Akeson WH. Use of patellar tendon autograft for anterior cruciate ligament reconstruction in the rabbit: a long-term histologic and biomechanical study. J Orthop Res. 1989;7(4):474-485.
34. Clancy WG Jr, Narechania RG, Rosenberg TD, Gmeiner JG, Wisnefske DD, Lange TA. Anterior and posterior cruciate ligament reconstruction in rhesus monkeys. J Bone Joint Surg Am. 1981;63(8):1270-1284.
35. Blickenstaff KR, Grana WA, Egle D. Analysis of a semitendinosus autograft in a rabbit model. Am J Sports Med. 1997;25(4):554-559.
36. Goradia VK, Rochat MC, Kida M, Grana WA. Natural history of a hamstring tendon autograft used for anterior cruciate ligament reconstruction in a sheep model. Am J Sports Med. 2000;28(1):40-46.
37. Bhatia S, Bell R, Frank RM, et al. Bony incorporation of soft tissue anterior cruciate ligament grafts in an animal model: autograft versus allograft with low-dose gamma irradiation. Am J Sports Med. 2012;40(8):1789-1798.
38. Jackson DW, Grood ES, Goldstein JD, et al. A comparison of patellar tendon autograft and allograft used for anterior cruciate ligament reconstruction in the goat model. Am J Sports Med. 1993;21(2):176-185.
39. Goertzen MJ, Clahsen H, Schulitz KP. Anterior cruciate ligament reconstruction using cryopreserved irradiated bone-ACL-bone-allograft transplants. Knee Surg Sports Traumatol Arthrosc. 1994;2(3):150-157.
40. Mae T, Shino K, Maeda A, Toritsuka Y, Horibe S, Ochi T. Effect of gamma irradiation on remodeling process of tendon allograft. Clin Orthop. 2003;(414):305-314.
Injuries of the anterior cruciate ligament (ACL) are common. Good to excellent long-term results are generally expected in more than 90% of ACL reconstructions.1,2 Although our knowledge of the biomechanics, kinematics, and long-term outcomes of ACL reconstruction is extensive, the ideal graft choice for ACL reconstruction is still up for debate.
Historically, both quadruple-stranded hamstring tendon and bone–patellar tendon–bone (BPTB) autografts have been the most popular graft options for operative reconstruction of the ACL.3 Recently, allograft tissues have become increasingly popular as a graft source. Proponents of allograft ACL reconstruction have cited several advantages over autograft reconstruction, including decreased donor-site morbidity, shorter operative times, and quicker postoperative recovery.4-7 Nevertheless, some authors have recently reported higher rates of both reoperation and graft failure after allograft ACL reconstruction.4,8-11 The 2 senior surgeons in the Sports Medicine Section of the Department of Orthopedic Surgery at the University of Arizona College of Medicine had not recognized such high failure and revision rates in their own clinical practices.
To evaluate the long-term outcomes of allograft ACL reconstruction, we retrospectively reviewed the cases of all patients who underwent allograft or autograft ACL reconstruction by 2 senior surgeons at a single institution over an 8-year period. We hypothesized that the reoperation and revision surgery rates for allograft ACL reconstruction would not be higher than those reported for autograft reconstruction. We also hypothesized that allograft ACL reconstruction failure rates would not be higher for patients younger than 25 years than for patients who are older and less active.
Materials and Methods
This study was approved by the Institutional Review Board at the University of Arizona College of Medicine. We retrospectively reviewed the cases of all patients who underwent primary endoscopic ACL reconstruction at the University of Arizona College of Medicine over an 8-year period (2000–2008). All ACL reconstructions were performed by 2 senior, fellowship-trained sports medicine specialists, including Dr. William A. Grana. Patients were identified from the Current Procedural Terminology (CPT) code for ACL reconstruction. Both autograft and allograft reconstructions were included in the study. Patients undergoing revision ACL reconstruction and patients with multi-ligamentous knee injuries were excluded. All available medical records were reviewed for patient demographics and any concomitant knee pathology. We included patients of all activity levels, patients with acute ACL tears, and patients with chronically ACL-deficient knees. We identified a separate cohort of Division I varsity athletes from the University of Arizona for evaluation. These patients were identified from the injury surveillance system in the athletic training facility of the University of Arizona.
ACL reconstructions at our institution during this 8-year period were performed with both allograft and autograft soft tissue. Allograft tendons were most commonly used. Tibialis anterior allograft was used in the majority of those knees. Tibialis posterior and semitendinosus allografts were used in a small subset of patients. Autograft reconstruction was performed with quadruple-stranded semitendinosus and gracilis tendons. We reviewed operative reports to determine type of graft used for reconstruction.
Patients were assessed clinically by telephone interview and/or mailed survey. They were specifically asked whether there had been any postoperative complications. We reviewed all operative and postoperative follow-up notes for postoperative complications. Objective clinical assessment involved use of the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, the Tegner-Lysholm Knee Scoring Scale, and the Tegner Activity Scale.
Operative Technique
A standard, transtibial arthroscopically assisted ACL reconstruction was performed in all patients. For autograft reconstruction patients, both the semitendinosus and gracilis tendons were harvested through a small anteromedial incision and prepared to form a quadruple-stranded graft. All allograft tendons were obtained from the Musculoskeletal Transplant Foundation (MTF). Tibialis anterior and tibialis posterior allografts were folded in half to form a double-stranded graft. Alternatively, 2 semitendinosus allografts were prepared in the same fashion as that described for autograft hamstring tendons. The tibial tunnel was placed into the center of the ACL tibial footprint. With use of a transtibial approach, an endoscopic offset guide was used to place the femoral tunnel at the 10- and 2-o’clock positions in the right and left knees, respectively. In almost all cases, the graft was secured on the femoral side with a cortical fixation button. Tibial fixation was obtained with a bioabsorbable interference screw.
After ACL reconstruction, each patient participated in the standard accelerated rehabilitation outlined by Shelbourne and Gray.12 Guided rehabilitation was instituted within 1 week after surgery under the guidance of a physical therapist. Range-of-motion exercises and closed-chain strengthening exercises were begun at this time. The protocol emphasized early return of full terminal extension and normalization of gait patterns. Patients were allowed to return to play only after meeting specific criteria, about 6 months after surgery. Many athletes in our Division I university population are allowed to return to play 5 to 6 months after surgery, after meeting return-to-play criteria.
Statistical Analysis
We used Minitab 14 (Minitab, State College, Pennsylvania) to perform all statistical analyses, unpaired Student t tests to compare IKDC and Tegner-Lysholm results between allograft and autograft groups, and χ2 tests to compare revision and reoperation rates between groups. Significance was set at P = .05.
Results
We identified 362 patients who underwent ACL reconstructions at our institution between 2000 and 2008. Of these patients, 302 met the study inclusion criteria. One-hundred twenty-three (40.7%) of the 302 were available for follow-up by telephone interview and/or mailed questionnaire. This follow-up group consisted of 67 males and 56 females. Mean age at surgery was 29 years (range, 17-53 years). Mean follow-up was 50.3 months (range, 11-111 months). Of the 123 patients, 99 underwent allograft ACL reconstruction, and 24 underwent autograft ACL reconstruction. Seventeen (17%) of the 99 allograft cases required additional surgery (Table 1). The reoperation rate for patients under age 25 years (30.8%) was higher than the rate for patients older than 25 years (Table 2). Regarding patients who underwent additional surgeries, mean scores were lower with allograft (Tegner-Lysholm, 59; IKDC, 54) than with autograft (Tegner-Lysholm, 83; IKDC, 79) (Ps = .0025 and .006, respectively).
Revision rates were 10.1% (allograft group) and 4.2% (autograft group) (Table 1). This difference was not statistically significant (P = .18). In the allograft group, the revision rate was higher for patients younger than 25 years (20.5%) than for patients older than 25 years (3.3%) (Table 2). In comparison, in the autograft group, the revision rate was only 4% for patients younger than 25 years. For younger patients, the higher rate of revision with allograft (vs autograft) was statistically significant (P = .038). For older patients, allograft and autograft revision rates did not differ significantly (P = .19). No patient younger than 25 years required revision reconstruction after autograft ACL reconstruction.
IKDC and Tegner-Lysholm outcome scores for allograft and autograft groups are shown in Table 3. In patients 25 years or younger, IKDC scores were 75.18 after allograft reconstruction and 85.34 after autograft reconstruction—a significant difference (P = .045). In addition, Tegner-Lysholm scores were significantly higher after autograft reconstruction (91.58) than allograft reconstruction (78.19) in these younger patients (P = .003) (Table 3). IKDC and Tegner-Lysholm scores were not significantly different for older patients (Ps = .241 and .211, respectively).
The study also included a subset of 19 primary ACL reconstructions (13 allograft, 6 autograft) performed on Division I athletes from the University of Arizona. (Nineteen [91%] of the 21 athletes in our Division I cohort were available for follow-up.) All these patients were younger than 25 years. All autograft reconstructions were performed with quadruple-stranded gracilis and semitendinosus tendons. ACL graft failure occurred in 8 (62%) of the 13 allograft cases; there were no failures in the autograft group (Table 4). One of the 5 allograft cases that did not fail required multiple surgical débridement procedures for infection, but the graft was ultimately retained. There were no infections among the 6 autograft cases.
Discussion
The ideal graft for ACL reconstruction is still a matter of intense debate. There are many graft options for ACL reconstruction. Both BPTB and hamstring autografts are associated with various graft-specific comorbidities. Anterior knee pain, knee extensor weakness, extension loss, patella fracture, patellofemoral crepitance, and infrapatellar nerve injury have been described with BPTB autografts.13-17 In a meta-analysis of 11 studies comparing BPTB autografts with hamstring autograft, Goldblatt and colleagues17 found more extension loss, kneeling pain, and patellofemoral crepitance in the BPTP group.
Knee flexion weakness, knee flexion loss, increased knee laxity, and saphenous nerve injury have all been described with use of hamstring autografts.16-19 Goldblatt and colleagues17 demonstrated a significant flexion loss in the hamstring group in their meta-analysis as well as increased laxity with both the Lachman test and the pivot shift test. They also found that the hamstring autograft group exhibited side-to-side differences of more than 3 mm on KT-1000 testing when compared with the BPTB autograft group.
Proposed advantages of allograft reconstruction include elimination of donor-site morbidity and/or pain from a less invasive procedure, faster initial recovery, more sizing options, and shorter operative times.4-7 In a 5-year follow-up of patients who had ACL reconstruction with either Achilles allograft or BPTB autograft, Poehling and colleagues7 demonstrated overall similar long-term outcomes between the groups. However, the allograft patients reported less pain 1 and 6 weeks after surgery; better function 1 week, 3 months, and 1 year after surgery; and fewer activity limitations throughout the follow-up period. Lamblin and colleagues20 also found no difference between nonirradiated allograft and autograft tissue in ACL reconstruction in a 2013 meta-analysis of ACL studies published over a 32-year period.
Despite the proposed advantages of allograft ACL reconstruction, several recent studies have demonstrated poorer outcomes in both younger patients and more active patients after allograft reconstruction.8-11,21 In a 2007 meta-analysis, Prodromos and colleagues11 compared a series of allograft reconstructions with previously published data sets of both BPTB and hamstring autografts. They found that allograft reconstructions had significantly lower stability rates than autograft reconstructions. In a case–control study by Borchers and colleagues,10 21 patients with ACL graft failure were identified over a 2-year period, and surgical outcomes were compared with those of 42 age- and sex-matched controls. The authors found higher activity level and allograft use to be risk factors for subsequent graft failure after ACL reconstruction. More important, they showed a multiplicative interaction between higher activity level after ACL reconstruction and allograft use—an interaction that greatly increased the odds for ACL graft failure. Last, in a retrospective review, Singhal and colleagues8 evaluated the outcomes of ACL reconstruction using tibialis anterior tendon allograft and reported a 23.1% revision rate. In addition, 37.7% of patients required repeat surgery. The failure/reoperation rate was 55% for patients 25 years or younger and 24% for patients older than 25 years. The authors recommended not using tibialis anterior allografts in patients 25 years or younger and in patients who frequently engage in level I ACL-dependent sports.
The poor outcomes reported by Singhal and colleagues8 may be related to use of irradiated soft-tissue allografts. In a comparison of nonirradiated BPTB allograft and BPTB autograft in patients 25 years or younger, Barber and colleagues22 found equivalent outcomes at 2-year follow-up. They actually found a higher rate of failure for autograft reconstruction (9.4%) than allograft reconstruction (7.1%). A potential critique of their study is the significant difference between the patient groups’ mean ages: 18.6 years (autograft) versus 20.1 years (allograft). Despite this selection bias, Barber and colleagues22 argued that nonirradiated BPTB allograft is equivalent to BPTB autograft for ACL reconstruction.
Our study is one of the largest allograft studies with a comparison group. The principal findings of this study demonstrate that overall reoperation and revision rates after irradiated soft-tissue allograft ACL reconstruction are higher than those historically quoted for autograft ACL reconstruction. Specifically, allograft patients younger than 25 years had a reoperation rate of 30.8% and a revision rate of 20.5%. (Allograft patients older than 25 years had lower rates of reoperation, 8.3%, and revision, 3.3%.) After revision surgery, autograft patients’ subjective outcomes (IKDC and Tegner-Lysholm scores) were significantly improved compared with those of allograft patients (Ps = .0017 and .0031, respectively). Most compelling, however, is the unexpected and quite concerning 62% failure rate in our high-level Division I intercollegiate athletes.
There are multiple hypotheses regarding the higher failure rates of allograft tissues versus autograft tissues in ACL reconstruction. Processing methods, exposure to ionizing radiation, and the incorporation/ligamentization process have all been cited as possible reasons for allograft failure. All the allograft tendons used in the present study were obtained from MTF, which uses a proprietary “aseptic” processing system that includes washing in buffered saline impregnated with antibiotics (imipenem/cilastatin, amphotericin B, gentamicin) followed by final rinsing in phosphate-buffered saline. The majority of grafts are subjected to low-level irradiation (<2 Mrad/20 kGy) based on the outcomes of MTF’s stringent donor-selection process. Although the washing process has not been shown to alter the structural integrity of donor grafts, multiple studies have outlined the detrimental effects of higher levels of gamma radiation on allograft tissues. Although lower levels are effective against potential bacterial contaminants, a radiation level of 4 Mrad is necessary to kill the human immunodeficiency virus (HIV). Thus, a dose of 4 Mrad or higher is needed to truly “sterilize” a graft. This higher dose is an issue, as it has been known for some time that higher levels of ionizing radiation can have adverse effects on the biomechanical strength of soft-tissue allografts. In fact, ionizing radiation has dose-dependent effects.23-26 Schwartz and colleagues27 showed in a caprine model that radiation exposure at 4 Mrad significantly decreased the biomechanical strength of ACL allografts at 6 months. Balsly and colleagues28 found in a biomechanical study that radiation doses of 18 to 22 Mrad did not significantly affect the mechanical integrity of soft-tissue allografts. Conversely, in an in vivo study, Rappe and colleagues29 showed that Achilles allografts irradiated at a dose of 2.0 to 2.5 Mrad had a failure rate (33%) much higher than that of nonirradiated allografts (2.4%). The radiation dose used by MTF is less than 2 Mrad. Although more than needed to kill bacterial contaminants, this dose is considered by MTF to be below the threshold for biomechanical alterations. Only a minority of grafts is treated without irradiation.
It is possible that any level of radiation affects ligamentization of allograft tissues. Multiple studies have outlined the ligamentization process of autograft tendons in vivo. Patellar tendon autografts undergo central degeneration 2 to 6 weeks after reconstruction, but, by 6 to 12 months, these tendons have structural properties similar to those of the native ACL.30-34 Findings are similar for hamstring autografts.35,36 Goradia and colleagues36 found that, by 52 weeks, semitendinosus autografts transform into a histologic structure similar to that of the normal ACL. Remodeling of allograft tendons has been described as occurring at a much slower rate.27,37-40 Bhatia and colleagues37 demonstrated faster remodeling in autograft tissues versus allograft tissues at early time points in an in vivo rabbit model. Ultimately, differences in graft incorporation and ligamentization may be a primary factor in the higher failure rates of allograft ACL reconstruction. Current rehabilitation protocols may not take into account the longer ligamentization process for allograft tissues. These protocols are largely based on our current understanding of the ligamentization process after autograft reconstruction. It is possible that the rehabilitation program and return-to-play schedule for allograft reconstruction need to be altered to help avoid higher failure rates. The return-to-play protocol at the authors’ institution scheduled most varsity athletes to return to play 6 months after surgery. In some cases, the timetable was shortened, and some athletes were returned to play 5 months after surgery, after meeting all return-to-play criteria. Based on the findings of the present study, this return-to-play schedule may be much too aggressive for high-level athletes after allograft reconstruction. It is possible these allografts have not reached “maturity,” as their autograft counterparts have, and thus are not ready for unrestricted return to play.
Our study had multiple strengths. All reconstructions were performed by 2 senior surgeons with extensive clinical experience. The autograft and allograft reconstructions used the same techniques and rehabilitation protocols. This is one of the largest studies of outcomes of allograft ACL reconstruction and one of the largest studies that used a comparison group of autograft reconstructions. Having a comparison group effectively allowed us to contrast the differences between allograft and autograft tissues. Last, this study evaluated a subgroup of high-level NCAA Division I athletes. Follow-up in the overall study was 40.7%, but follow-up in this subgroup was 91%. The very high follow-up rate in the university population helped us validate the overall results of the study. Study results reinforced the fact that irradiated soft-tissue allograft may not be indicated for ACL reconstruction in a younger, more active patient population and led to a change in approach to ACL reconstruction for Division I intercollegiate athletes at the University of Arizona. Allograft ACL reconstruction is no longer recommended for the intercollegiate athletes at the University of Arizona.
Our study had its limitations. First, it had the inherent biases of a retrospective study. Second, many patients were lost to follow-up. We contacted and surveyed 40.7% of the patients who met the inclusion criteria. We tried reaching them in multiple ways—through US mail, all listed phone numbers, family members, and so forth. Tucson, Arizona is a college town and has a larger transient population, which may have added to the difficulty in contacting patients.
Conclusion
Given the high rates of reoperation and revision surgery with allograft reconstruction in younger patients in this study, we recommend against routine use of irradiated soft-tissue allograft tissue for ACL reconstruction in patients 25 years or younger. In our clinical practices, we prefer using autograft tissue for ACL reconstruction in younger, more active individuals. Irradiated soft-tissue allograft ACL reconstruction is a viable option in the older, less active patient population. Although the overall reoperation rate in this cohort study is acceptable, the revision rate for patients younger than 25 years is concerning and should be taken into account when considering use of irradiated soft-tissue allograft for ACL reconstruction in these younger patients.
Injuries of the anterior cruciate ligament (ACL) are common. Good to excellent long-term results are generally expected in more than 90% of ACL reconstructions.1,2 Although our knowledge of the biomechanics, kinematics, and long-term outcomes of ACL reconstruction is extensive, the ideal graft choice for ACL reconstruction is still up for debate.
Historically, both quadruple-stranded hamstring tendon and bone–patellar tendon–bone (BPTB) autografts have been the most popular graft options for operative reconstruction of the ACL.3 Recently, allograft tissues have become increasingly popular as a graft source. Proponents of allograft ACL reconstruction have cited several advantages over autograft reconstruction, including decreased donor-site morbidity, shorter operative times, and quicker postoperative recovery.4-7 Nevertheless, some authors have recently reported higher rates of both reoperation and graft failure after allograft ACL reconstruction.4,8-11 The 2 senior surgeons in the Sports Medicine Section of the Department of Orthopedic Surgery at the University of Arizona College of Medicine had not recognized such high failure and revision rates in their own clinical practices.
To evaluate the long-term outcomes of allograft ACL reconstruction, we retrospectively reviewed the cases of all patients who underwent allograft or autograft ACL reconstruction by 2 senior surgeons at a single institution over an 8-year period. We hypothesized that the reoperation and revision surgery rates for allograft ACL reconstruction would not be higher than those reported for autograft reconstruction. We also hypothesized that allograft ACL reconstruction failure rates would not be higher for patients younger than 25 years than for patients who are older and less active.
Materials and Methods
This study was approved by the Institutional Review Board at the University of Arizona College of Medicine. We retrospectively reviewed the cases of all patients who underwent primary endoscopic ACL reconstruction at the University of Arizona College of Medicine over an 8-year period (2000–2008). All ACL reconstructions were performed by 2 senior, fellowship-trained sports medicine specialists, including Dr. William A. Grana. Patients were identified from the Current Procedural Terminology (CPT) code for ACL reconstruction. Both autograft and allograft reconstructions were included in the study. Patients undergoing revision ACL reconstruction and patients with multi-ligamentous knee injuries were excluded. All available medical records were reviewed for patient demographics and any concomitant knee pathology. We included patients of all activity levels, patients with acute ACL tears, and patients with chronically ACL-deficient knees. We identified a separate cohort of Division I varsity athletes from the University of Arizona for evaluation. These patients were identified from the injury surveillance system in the athletic training facility of the University of Arizona.
ACL reconstructions at our institution during this 8-year period were performed with both allograft and autograft soft tissue. Allograft tendons were most commonly used. Tibialis anterior allograft was used in the majority of those knees. Tibialis posterior and semitendinosus allografts were used in a small subset of patients. Autograft reconstruction was performed with quadruple-stranded semitendinosus and gracilis tendons. We reviewed operative reports to determine type of graft used for reconstruction.
Patients were assessed clinically by telephone interview and/or mailed survey. They were specifically asked whether there had been any postoperative complications. We reviewed all operative and postoperative follow-up notes for postoperative complications. Objective clinical assessment involved use of the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, the Tegner-Lysholm Knee Scoring Scale, and the Tegner Activity Scale.
Operative Technique
A standard, transtibial arthroscopically assisted ACL reconstruction was performed in all patients. For autograft reconstruction patients, both the semitendinosus and gracilis tendons were harvested through a small anteromedial incision and prepared to form a quadruple-stranded graft. All allograft tendons were obtained from the Musculoskeletal Transplant Foundation (MTF). Tibialis anterior and tibialis posterior allografts were folded in half to form a double-stranded graft. Alternatively, 2 semitendinosus allografts were prepared in the same fashion as that described for autograft hamstring tendons. The tibial tunnel was placed into the center of the ACL tibial footprint. With use of a transtibial approach, an endoscopic offset guide was used to place the femoral tunnel at the 10- and 2-o’clock positions in the right and left knees, respectively. In almost all cases, the graft was secured on the femoral side with a cortical fixation button. Tibial fixation was obtained with a bioabsorbable interference screw.
After ACL reconstruction, each patient participated in the standard accelerated rehabilitation outlined by Shelbourne and Gray.12 Guided rehabilitation was instituted within 1 week after surgery under the guidance of a physical therapist. Range-of-motion exercises and closed-chain strengthening exercises were begun at this time. The protocol emphasized early return of full terminal extension and normalization of gait patterns. Patients were allowed to return to play only after meeting specific criteria, about 6 months after surgery. Many athletes in our Division I university population are allowed to return to play 5 to 6 months after surgery, after meeting return-to-play criteria.
Statistical Analysis
We used Minitab 14 (Minitab, State College, Pennsylvania) to perform all statistical analyses, unpaired Student t tests to compare IKDC and Tegner-Lysholm results between allograft and autograft groups, and χ2 tests to compare revision and reoperation rates between groups. Significance was set at P = .05.
Results
We identified 362 patients who underwent ACL reconstructions at our institution between 2000 and 2008. Of these patients, 302 met the study inclusion criteria. One-hundred twenty-three (40.7%) of the 302 were available for follow-up by telephone interview and/or mailed questionnaire. This follow-up group consisted of 67 males and 56 females. Mean age at surgery was 29 years (range, 17-53 years). Mean follow-up was 50.3 months (range, 11-111 months). Of the 123 patients, 99 underwent allograft ACL reconstruction, and 24 underwent autograft ACL reconstruction. Seventeen (17%) of the 99 allograft cases required additional surgery (Table 1). The reoperation rate for patients under age 25 years (30.8%) was higher than the rate for patients older than 25 years (Table 2). Regarding patients who underwent additional surgeries, mean scores were lower with allograft (Tegner-Lysholm, 59; IKDC, 54) than with autograft (Tegner-Lysholm, 83; IKDC, 79) (Ps = .0025 and .006, respectively).
Revision rates were 10.1% (allograft group) and 4.2% (autograft group) (Table 1). This difference was not statistically significant (P = .18). In the allograft group, the revision rate was higher for patients younger than 25 years (20.5%) than for patients older than 25 years (3.3%) (Table 2). In comparison, in the autograft group, the revision rate was only 4% for patients younger than 25 years. For younger patients, the higher rate of revision with allograft (vs autograft) was statistically significant (P = .038). For older patients, allograft and autograft revision rates did not differ significantly (P = .19). No patient younger than 25 years required revision reconstruction after autograft ACL reconstruction.
IKDC and Tegner-Lysholm outcome scores for allograft and autograft groups are shown in Table 3. In patients 25 years or younger, IKDC scores were 75.18 after allograft reconstruction and 85.34 after autograft reconstruction—a significant difference (P = .045). In addition, Tegner-Lysholm scores were significantly higher after autograft reconstruction (91.58) than allograft reconstruction (78.19) in these younger patients (P = .003) (Table 3). IKDC and Tegner-Lysholm scores were not significantly different for older patients (Ps = .241 and .211, respectively).
The study also included a subset of 19 primary ACL reconstructions (13 allograft, 6 autograft) performed on Division I athletes from the University of Arizona. (Nineteen [91%] of the 21 athletes in our Division I cohort were available for follow-up.) All these patients were younger than 25 years. All autograft reconstructions were performed with quadruple-stranded gracilis and semitendinosus tendons. ACL graft failure occurred in 8 (62%) of the 13 allograft cases; there were no failures in the autograft group (Table 4). One of the 5 allograft cases that did not fail required multiple surgical débridement procedures for infection, but the graft was ultimately retained. There were no infections among the 6 autograft cases.
Discussion
The ideal graft for ACL reconstruction is still a matter of intense debate. There are many graft options for ACL reconstruction. Both BPTB and hamstring autografts are associated with various graft-specific comorbidities. Anterior knee pain, knee extensor weakness, extension loss, patella fracture, patellofemoral crepitance, and infrapatellar nerve injury have been described with BPTB autografts.13-17 In a meta-analysis of 11 studies comparing BPTB autografts with hamstring autograft, Goldblatt and colleagues17 found more extension loss, kneeling pain, and patellofemoral crepitance in the BPTP group.
Knee flexion weakness, knee flexion loss, increased knee laxity, and saphenous nerve injury have all been described with use of hamstring autografts.16-19 Goldblatt and colleagues17 demonstrated a significant flexion loss in the hamstring group in their meta-analysis as well as increased laxity with both the Lachman test and the pivot shift test. They also found that the hamstring autograft group exhibited side-to-side differences of more than 3 mm on KT-1000 testing when compared with the BPTB autograft group.
Proposed advantages of allograft reconstruction include elimination of donor-site morbidity and/or pain from a less invasive procedure, faster initial recovery, more sizing options, and shorter operative times.4-7 In a 5-year follow-up of patients who had ACL reconstruction with either Achilles allograft or BPTB autograft, Poehling and colleagues7 demonstrated overall similar long-term outcomes between the groups. However, the allograft patients reported less pain 1 and 6 weeks after surgery; better function 1 week, 3 months, and 1 year after surgery; and fewer activity limitations throughout the follow-up period. Lamblin and colleagues20 also found no difference between nonirradiated allograft and autograft tissue in ACL reconstruction in a 2013 meta-analysis of ACL studies published over a 32-year period.
Despite the proposed advantages of allograft ACL reconstruction, several recent studies have demonstrated poorer outcomes in both younger patients and more active patients after allograft reconstruction.8-11,21 In a 2007 meta-analysis, Prodromos and colleagues11 compared a series of allograft reconstructions with previously published data sets of both BPTB and hamstring autografts. They found that allograft reconstructions had significantly lower stability rates than autograft reconstructions. In a case–control study by Borchers and colleagues,10 21 patients with ACL graft failure were identified over a 2-year period, and surgical outcomes were compared with those of 42 age- and sex-matched controls. The authors found higher activity level and allograft use to be risk factors for subsequent graft failure after ACL reconstruction. More important, they showed a multiplicative interaction between higher activity level after ACL reconstruction and allograft use—an interaction that greatly increased the odds for ACL graft failure. Last, in a retrospective review, Singhal and colleagues8 evaluated the outcomes of ACL reconstruction using tibialis anterior tendon allograft and reported a 23.1% revision rate. In addition, 37.7% of patients required repeat surgery. The failure/reoperation rate was 55% for patients 25 years or younger and 24% for patients older than 25 years. The authors recommended not using tibialis anterior allografts in patients 25 years or younger and in patients who frequently engage in level I ACL-dependent sports.
The poor outcomes reported by Singhal and colleagues8 may be related to use of irradiated soft-tissue allografts. In a comparison of nonirradiated BPTB allograft and BPTB autograft in patients 25 years or younger, Barber and colleagues22 found equivalent outcomes at 2-year follow-up. They actually found a higher rate of failure for autograft reconstruction (9.4%) than allograft reconstruction (7.1%). A potential critique of their study is the significant difference between the patient groups’ mean ages: 18.6 years (autograft) versus 20.1 years (allograft). Despite this selection bias, Barber and colleagues22 argued that nonirradiated BPTB allograft is equivalent to BPTB autograft for ACL reconstruction.
Our study is one of the largest allograft studies with a comparison group. The principal findings of this study demonstrate that overall reoperation and revision rates after irradiated soft-tissue allograft ACL reconstruction are higher than those historically quoted for autograft ACL reconstruction. Specifically, allograft patients younger than 25 years had a reoperation rate of 30.8% and a revision rate of 20.5%. (Allograft patients older than 25 years had lower rates of reoperation, 8.3%, and revision, 3.3%.) After revision surgery, autograft patients’ subjective outcomes (IKDC and Tegner-Lysholm scores) were significantly improved compared with those of allograft patients (Ps = .0017 and .0031, respectively). Most compelling, however, is the unexpected and quite concerning 62% failure rate in our high-level Division I intercollegiate athletes.
There are multiple hypotheses regarding the higher failure rates of allograft tissues versus autograft tissues in ACL reconstruction. Processing methods, exposure to ionizing radiation, and the incorporation/ligamentization process have all been cited as possible reasons for allograft failure. All the allograft tendons used in the present study were obtained from MTF, which uses a proprietary “aseptic” processing system that includes washing in buffered saline impregnated with antibiotics (imipenem/cilastatin, amphotericin B, gentamicin) followed by final rinsing in phosphate-buffered saline. The majority of grafts are subjected to low-level irradiation (<2 Mrad/20 kGy) based on the outcomes of MTF’s stringent donor-selection process. Although the washing process has not been shown to alter the structural integrity of donor grafts, multiple studies have outlined the detrimental effects of higher levels of gamma radiation on allograft tissues. Although lower levels are effective against potential bacterial contaminants, a radiation level of 4 Mrad is necessary to kill the human immunodeficiency virus (HIV). Thus, a dose of 4 Mrad or higher is needed to truly “sterilize” a graft. This higher dose is an issue, as it has been known for some time that higher levels of ionizing radiation can have adverse effects on the biomechanical strength of soft-tissue allografts. In fact, ionizing radiation has dose-dependent effects.23-26 Schwartz and colleagues27 showed in a caprine model that radiation exposure at 4 Mrad significantly decreased the biomechanical strength of ACL allografts at 6 months. Balsly and colleagues28 found in a biomechanical study that radiation doses of 18 to 22 Mrad did not significantly affect the mechanical integrity of soft-tissue allografts. Conversely, in an in vivo study, Rappe and colleagues29 showed that Achilles allografts irradiated at a dose of 2.0 to 2.5 Mrad had a failure rate (33%) much higher than that of nonirradiated allografts (2.4%). The radiation dose used by MTF is less than 2 Mrad. Although more than needed to kill bacterial contaminants, this dose is considered by MTF to be below the threshold for biomechanical alterations. Only a minority of grafts is treated without irradiation.
It is possible that any level of radiation affects ligamentization of allograft tissues. Multiple studies have outlined the ligamentization process of autograft tendons in vivo. Patellar tendon autografts undergo central degeneration 2 to 6 weeks after reconstruction, but, by 6 to 12 months, these tendons have structural properties similar to those of the native ACL.30-34 Findings are similar for hamstring autografts.35,36 Goradia and colleagues36 found that, by 52 weeks, semitendinosus autografts transform into a histologic structure similar to that of the normal ACL. Remodeling of allograft tendons has been described as occurring at a much slower rate.27,37-40 Bhatia and colleagues37 demonstrated faster remodeling in autograft tissues versus allograft tissues at early time points in an in vivo rabbit model. Ultimately, differences in graft incorporation and ligamentization may be a primary factor in the higher failure rates of allograft ACL reconstruction. Current rehabilitation protocols may not take into account the longer ligamentization process for allograft tissues. These protocols are largely based on our current understanding of the ligamentization process after autograft reconstruction. It is possible that the rehabilitation program and return-to-play schedule for allograft reconstruction need to be altered to help avoid higher failure rates. The return-to-play protocol at the authors’ institution scheduled most varsity athletes to return to play 6 months after surgery. In some cases, the timetable was shortened, and some athletes were returned to play 5 months after surgery, after meeting all return-to-play criteria. Based on the findings of the present study, this return-to-play schedule may be much too aggressive for high-level athletes after allograft reconstruction. It is possible these allografts have not reached “maturity,” as their autograft counterparts have, and thus are not ready for unrestricted return to play.
Our study had multiple strengths. All reconstructions were performed by 2 senior surgeons with extensive clinical experience. The autograft and allograft reconstructions used the same techniques and rehabilitation protocols. This is one of the largest studies of outcomes of allograft ACL reconstruction and one of the largest studies that used a comparison group of autograft reconstructions. Having a comparison group effectively allowed us to contrast the differences between allograft and autograft tissues. Last, this study evaluated a subgroup of high-level NCAA Division I athletes. Follow-up in the overall study was 40.7%, but follow-up in this subgroup was 91%. The very high follow-up rate in the university population helped us validate the overall results of the study. Study results reinforced the fact that irradiated soft-tissue allograft may not be indicated for ACL reconstruction in a younger, more active patient population and led to a change in approach to ACL reconstruction for Division I intercollegiate athletes at the University of Arizona. Allograft ACL reconstruction is no longer recommended for the intercollegiate athletes at the University of Arizona.
Our study had its limitations. First, it had the inherent biases of a retrospective study. Second, many patients were lost to follow-up. We contacted and surveyed 40.7% of the patients who met the inclusion criteria. We tried reaching them in multiple ways—through US mail, all listed phone numbers, family members, and so forth. Tucson, Arizona is a college town and has a larger transient population, which may have added to the difficulty in contacting patients.
Conclusion
Given the high rates of reoperation and revision surgery with allograft reconstruction in younger patients in this study, we recommend against routine use of irradiated soft-tissue allograft tissue for ACL reconstruction in patients 25 years or younger. In our clinical practices, we prefer using autograft tissue for ACL reconstruction in younger, more active individuals. Irradiated soft-tissue allograft ACL reconstruction is a viable option in the older, less active patient population. Although the overall reoperation rate in this cohort study is acceptable, the revision rate for patients younger than 25 years is concerning and should be taken into account when considering use of irradiated soft-tissue allograft for ACL reconstruction in these younger patients.
1. Schepsis AA, Busconi BD. Sports Medicine. Philadelphia, PA: Lippincott Williams & Wilkins; 2006.
2. Campbell WC, Canale ST, Beaty JH. Campbell’s Operative Orthopaedics. 11th ed. Philadelphia, PA: Mosby/Elsevier; 2008.
3. Sherman OH, Banffy MB. Anterior cruciate ligament reconstruction: which graft is best? Arthroscopy. 2004;20(9):974-980.
4. Lee JH, Bae DK, Song SJ, Cho SM, Yoon KH. Comparison of clinical results and second-look arthroscopy findings after arthroscopic anterior cruciate ligament reconstruction using 3 different types of grafts. Arthroscopy. 2010;26(1):41-49.
5. Sun K, Tian SQ, Zhang JH, Xia CS, Zhang CL, Yu TB. Anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft versus allograft. Arthroscopy. 2009;25(7):750-759.
6. Kuhn MA, Ross G. Allografts in the treatment of anterior cruciate ligament injuries. Sports Med Arthrosc Rev. 2007;15(3):133-138.
7. Poehling GG, Curl WW, Lee CA, et al. Analysis of outcomes of anterior cruciate ligament repair with 5-year follow-up: allograft versus autograft. Arthroscopy. 2005;21(7):774-785.
8. Singhal MC, Gardiner JR, Johnson DL. Failure of primary anterior cruciate ligament surgery using anterior tibialis allograft. Arthroscopy. 2007;23(5):469-475.
9. Barrett GR, Luber K, Replogle WH, Manley JL. Allograft anterior cruciate ligament reconstruction in the young, active patient: Tegner activity level and failure rate. Arthroscopy. 2010;26(12):1593-1601.
10. Borchers JR, Pedroza A, Kaeding C. Activity level and graft type as risk factors for anterior cruciate ligament graft failure: a case–control study. Am J Sports Med. 2009;37(12):2362-2367.
11. Prodromos C, Joyce B, Shi K. A meta-analysis of stability of autografts compared to allografts after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2007;15(7):851-856.
12. Shelbourne KD, Gray T. Anterior cruciate ligament reconstruction with autogenous patellar tendon graft followed by accelerated rehabilitation. A two- to nine-year followup. Am J Sports Med. 1997;25(6):786-795.
13. Rosenberg TD, Franklin JL, Baldwin GN, Nelson KA. Extensor mechanism function after patellar tendon graft harvest for anterior cruciate ligament reconstruction. Am J Sports Med. 1992;20(5):519-525.
14. Piva SR, Childs JD, Klucinec BM, Irrgang JJ, Almeida GJ, Fitzgerald GK. Patella fracture during rehabilitation after bone–patellar tendon–bone anterior cruciate ligament reconstruction: 2 case reports. J Orthop Sports Phys Ther. 2009;39(4):278-286.
15. Lee GH, McCulloch P, Cole BJ, Bush-Joseph CA, Bach BR Jr. The incidence of acute patellar tendon harvest complications for anterior cruciate ligament reconstruction. Arthroscopy. 2008;24(2):162-166.
16. Kartus J, Movin T, Karlsson J. Donor-site morbidity and anterior knee problems after anterior cruciate ligament reconstruction using autografts. Arthroscopy. 2001;17(9):971-980.
17. Goldblatt JP, Fitzsimmons SE, Balk E, Richmond JC. Reconstruction of the anterior cruciate ligament: meta-analysis of patellar tendon versus hamstring tendon autograft. Arthroscopy. 2005;21(7):791-803.
18. Freedman KB, D’Amato MJ, Nedeff DD, Kaz A, Bach BR Jr. Arthroscopic anterior cruciate ligament reconstruction: a metaanalysis comparing patellar tendon and hamstring tendon autografts. Am J Sports Med. 2003;31(1):2-11.
19. Yunes M, Richmond JC, Engels EA, Pinczewski LA. Patellar versus hamstring tendons in anterior cruciate ligament reconstruction: a meta-analysis. Arthroscopy. 2001;17(3):248-257.
20. Lamblin CJ, Waterman BR, Lubowitz JH. Anterior cruciate ligament reconstruction with autografts compared with non-irradiated, non-chemically treated allografts. Arthroscopy. 2013;29(6):1113-1122.
21. Pallis M, Svoboda SJ, Cameron KL, Owens BD. Survival comparison of allograft and autograft anterior cruciate ligament reconstruction at the United States Military Academy. Am J Sports Med. 2012;40(6):1242-1246.
22. Barber FA, Cowden CH 3rd, Sanders EJ. Revision rates after anterior cruciate ligament reconstruction using bone–patellar tendon–bone allograft or autograft in a population 25 years old and younger. Arthroscopy. 2014;30(4):483-491.
23. Salehpour A, Butler DL, Proch FS, et al. Dose-dependent response of gamma irradiation on mechanical properties and related biochemical composition of goat bone–patellar tendon–bone allografts. J Orthop Res. 1995;13(6):898-906.
24. Gibbons MJ, Butler DL, Grood ES, Bylski-Austrow DI, Levy MS, Noyes FR. Effects of gamma irradiation on the initial mechanical and material properties of goat bone–patellar tendon–bone allografts. J Orthop Res. 1991;9(2):209-218.
25. Fideler BM, Vangsness CT Jr, Lu B, Orlando C, Moore T. Gamma irradiation: effects on biomechanical properties of human bone–patellar tendon–bone allografts. Am J Sports Med. 1995;23(5):643-646.
26. De Deyne P, Haut RC. Some effects of gamma irradiation on patellar tendon allografts. Connect Tissue Res. 1991;27(1):51-62.
27. Schwartz HE, Matava MJ, Proch FS, et al. The effect of gamma irradiation on anterior cruciate ligament allograft biomechanical and biochemical properties in the caprine model at time zero and at 6 months after surgery. Am J Sports Med. 2006;34(11):1747-1755.
28. Balsly CR, Cotter AT, Williams LA, Gaskins BD, Moore MA, Wolfinbarger L Jr. Effect of low dose and moderate dose gamma irradiation on the mechanical properties of bone and soft tissue allografts. Cell Tissue Bank. 2008;9(4):289-298.
29. Rappe M, Horodyski M, Meister K, Indelicato PA. Nonirradiated versus irradiated Achilles allograft: in vivo failure comparison. Am J Sports Med. 2007;35(10):1653-1658.
30. Amiel D, Kleiner JB, Akeson WH. The natural history of the anterior cruciate ligament autograft of patellar tendon origin. Am J Sports Med. 1986;14(6):449-462.
31. Amiel D, Kleiner JB, Roux RD, Harwood FL, Akeson WH. The phenomenon of “ligamentization”: anterior cruciate ligament reconstruction with autogenous patellar tendon. J Orthop Res. 1986;4(2):162-172.
32. Arnoczky SP, Tarvin GB, Marshall JL. Anterior cruciate ligament replacement using patellar tendon. An evaluation of graft revascularization in the dog. J Bone Joint Surg Am. 1982;64(2):217-224.
33. Ballock RT, Woo SL, Lyon RM, Hollis JM, Akeson WH. Use of patellar tendon autograft for anterior cruciate ligament reconstruction in the rabbit: a long-term histologic and biomechanical study. J Orthop Res. 1989;7(4):474-485.
34. Clancy WG Jr, Narechania RG, Rosenberg TD, Gmeiner JG, Wisnefske DD, Lange TA. Anterior and posterior cruciate ligament reconstruction in rhesus monkeys. J Bone Joint Surg Am. 1981;63(8):1270-1284.
35. Blickenstaff KR, Grana WA, Egle D. Analysis of a semitendinosus autograft in a rabbit model. Am J Sports Med. 1997;25(4):554-559.
36. Goradia VK, Rochat MC, Kida M, Grana WA. Natural history of a hamstring tendon autograft used for anterior cruciate ligament reconstruction in a sheep model. Am J Sports Med. 2000;28(1):40-46.
37. Bhatia S, Bell R, Frank RM, et al. Bony incorporation of soft tissue anterior cruciate ligament grafts in an animal model: autograft versus allograft with low-dose gamma irradiation. Am J Sports Med. 2012;40(8):1789-1798.
38. Jackson DW, Grood ES, Goldstein JD, et al. A comparison of patellar tendon autograft and allograft used for anterior cruciate ligament reconstruction in the goat model. Am J Sports Med. 1993;21(2):176-185.
39. Goertzen MJ, Clahsen H, Schulitz KP. Anterior cruciate ligament reconstruction using cryopreserved irradiated bone-ACL-bone-allograft transplants. Knee Surg Sports Traumatol Arthrosc. 1994;2(3):150-157.
40. Mae T, Shino K, Maeda A, Toritsuka Y, Horibe S, Ochi T. Effect of gamma irradiation on remodeling process of tendon allograft. Clin Orthop. 2003;(414):305-314.
1. Schepsis AA, Busconi BD. Sports Medicine. Philadelphia, PA: Lippincott Williams & Wilkins; 2006.
2. Campbell WC, Canale ST, Beaty JH. Campbell’s Operative Orthopaedics. 11th ed. Philadelphia, PA: Mosby/Elsevier; 2008.
3. Sherman OH, Banffy MB. Anterior cruciate ligament reconstruction: which graft is best? Arthroscopy. 2004;20(9):974-980.
4. Lee JH, Bae DK, Song SJ, Cho SM, Yoon KH. Comparison of clinical results and second-look arthroscopy findings after arthroscopic anterior cruciate ligament reconstruction using 3 different types of grafts. Arthroscopy. 2010;26(1):41-49.
5. Sun K, Tian SQ, Zhang JH, Xia CS, Zhang CL, Yu TB. Anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft versus allograft. Arthroscopy. 2009;25(7):750-759.
6. Kuhn MA, Ross G. Allografts in the treatment of anterior cruciate ligament injuries. Sports Med Arthrosc Rev. 2007;15(3):133-138.
7. Poehling GG, Curl WW, Lee CA, et al. Analysis of outcomes of anterior cruciate ligament repair with 5-year follow-up: allograft versus autograft. Arthroscopy. 2005;21(7):774-785.
8. Singhal MC, Gardiner JR, Johnson DL. Failure of primary anterior cruciate ligament surgery using anterior tibialis allograft. Arthroscopy. 2007;23(5):469-475.
9. Barrett GR, Luber K, Replogle WH, Manley JL. Allograft anterior cruciate ligament reconstruction in the young, active patient: Tegner activity level and failure rate. Arthroscopy. 2010;26(12):1593-1601.
10. Borchers JR, Pedroza A, Kaeding C. Activity level and graft type as risk factors for anterior cruciate ligament graft failure: a case–control study. Am J Sports Med. 2009;37(12):2362-2367.
11. Prodromos C, Joyce B, Shi K. A meta-analysis of stability of autografts compared to allografts after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2007;15(7):851-856.
12. Shelbourne KD, Gray T. Anterior cruciate ligament reconstruction with autogenous patellar tendon graft followed by accelerated rehabilitation. A two- to nine-year followup. Am J Sports Med. 1997;25(6):786-795.
13. Rosenberg TD, Franklin JL, Baldwin GN, Nelson KA. Extensor mechanism function after patellar tendon graft harvest for anterior cruciate ligament reconstruction. Am J Sports Med. 1992;20(5):519-525.
14. Piva SR, Childs JD, Klucinec BM, Irrgang JJ, Almeida GJ, Fitzgerald GK. Patella fracture during rehabilitation after bone–patellar tendon–bone anterior cruciate ligament reconstruction: 2 case reports. J Orthop Sports Phys Ther. 2009;39(4):278-286.
15. Lee GH, McCulloch P, Cole BJ, Bush-Joseph CA, Bach BR Jr. The incidence of acute patellar tendon harvest complications for anterior cruciate ligament reconstruction. Arthroscopy. 2008;24(2):162-166.
16. Kartus J, Movin T, Karlsson J. Donor-site morbidity and anterior knee problems after anterior cruciate ligament reconstruction using autografts. Arthroscopy. 2001;17(9):971-980.
17. Goldblatt JP, Fitzsimmons SE, Balk E, Richmond JC. Reconstruction of the anterior cruciate ligament: meta-analysis of patellar tendon versus hamstring tendon autograft. Arthroscopy. 2005;21(7):791-803.
18. Freedman KB, D’Amato MJ, Nedeff DD, Kaz A, Bach BR Jr. Arthroscopic anterior cruciate ligament reconstruction: a metaanalysis comparing patellar tendon and hamstring tendon autografts. Am J Sports Med. 2003;31(1):2-11.
19. Yunes M, Richmond JC, Engels EA, Pinczewski LA. Patellar versus hamstring tendons in anterior cruciate ligament reconstruction: a meta-analysis. Arthroscopy. 2001;17(3):248-257.
20. Lamblin CJ, Waterman BR, Lubowitz JH. Anterior cruciate ligament reconstruction with autografts compared with non-irradiated, non-chemically treated allografts. Arthroscopy. 2013;29(6):1113-1122.
21. Pallis M, Svoboda SJ, Cameron KL, Owens BD. Survival comparison of allograft and autograft anterior cruciate ligament reconstruction at the United States Military Academy. Am J Sports Med. 2012;40(6):1242-1246.
22. Barber FA, Cowden CH 3rd, Sanders EJ. Revision rates after anterior cruciate ligament reconstruction using bone–patellar tendon–bone allograft or autograft in a population 25 years old and younger. Arthroscopy. 2014;30(4):483-491.
23. Salehpour A, Butler DL, Proch FS, et al. Dose-dependent response of gamma irradiation on mechanical properties and related biochemical composition of goat bone–patellar tendon–bone allografts. J Orthop Res. 1995;13(6):898-906.
24. Gibbons MJ, Butler DL, Grood ES, Bylski-Austrow DI, Levy MS, Noyes FR. Effects of gamma irradiation on the initial mechanical and material properties of goat bone–patellar tendon–bone allografts. J Orthop Res. 1991;9(2):209-218.
25. Fideler BM, Vangsness CT Jr, Lu B, Orlando C, Moore T. Gamma irradiation: effects on biomechanical properties of human bone–patellar tendon–bone allografts. Am J Sports Med. 1995;23(5):643-646.
26. De Deyne P, Haut RC. Some effects of gamma irradiation on patellar tendon allografts. Connect Tissue Res. 1991;27(1):51-62.
27. Schwartz HE, Matava MJ, Proch FS, et al. The effect of gamma irradiation on anterior cruciate ligament allograft biomechanical and biochemical properties in the caprine model at time zero and at 6 months after surgery. Am J Sports Med. 2006;34(11):1747-1755.
28. Balsly CR, Cotter AT, Williams LA, Gaskins BD, Moore MA, Wolfinbarger L Jr. Effect of low dose and moderate dose gamma irradiation on the mechanical properties of bone and soft tissue allografts. Cell Tissue Bank. 2008;9(4):289-298.
29. Rappe M, Horodyski M, Meister K, Indelicato PA. Nonirradiated versus irradiated Achilles allograft: in vivo failure comparison. Am J Sports Med. 2007;35(10):1653-1658.
30. Amiel D, Kleiner JB, Akeson WH. The natural history of the anterior cruciate ligament autograft of patellar tendon origin. Am J Sports Med. 1986;14(6):449-462.
31. Amiel D, Kleiner JB, Roux RD, Harwood FL, Akeson WH. The phenomenon of “ligamentization”: anterior cruciate ligament reconstruction with autogenous patellar tendon. J Orthop Res. 1986;4(2):162-172.
32. Arnoczky SP, Tarvin GB, Marshall JL. Anterior cruciate ligament replacement using patellar tendon. An evaluation of graft revascularization in the dog. J Bone Joint Surg Am. 1982;64(2):217-224.
33. Ballock RT, Woo SL, Lyon RM, Hollis JM, Akeson WH. Use of patellar tendon autograft for anterior cruciate ligament reconstruction in the rabbit: a long-term histologic and biomechanical study. J Orthop Res. 1989;7(4):474-485.
34. Clancy WG Jr, Narechania RG, Rosenberg TD, Gmeiner JG, Wisnefske DD, Lange TA. Anterior and posterior cruciate ligament reconstruction in rhesus monkeys. J Bone Joint Surg Am. 1981;63(8):1270-1284.
35. Blickenstaff KR, Grana WA, Egle D. Analysis of a semitendinosus autograft in a rabbit model. Am J Sports Med. 1997;25(4):554-559.
36. Goradia VK, Rochat MC, Kida M, Grana WA. Natural history of a hamstring tendon autograft used for anterior cruciate ligament reconstruction in a sheep model. Am J Sports Med. 2000;28(1):40-46.
37. Bhatia S, Bell R, Frank RM, et al. Bony incorporation of soft tissue anterior cruciate ligament grafts in an animal model: autograft versus allograft with low-dose gamma irradiation. Am J Sports Med. 2012;40(8):1789-1798.
38. Jackson DW, Grood ES, Goldstein JD, et al. A comparison of patellar tendon autograft and allograft used for anterior cruciate ligament reconstruction in the goat model. Am J Sports Med. 1993;21(2):176-185.
39. Goertzen MJ, Clahsen H, Schulitz KP. Anterior cruciate ligament reconstruction using cryopreserved irradiated bone-ACL-bone-allograft transplants. Knee Surg Sports Traumatol Arthrosc. 1994;2(3):150-157.
40. Mae T, Shino K, Maeda A, Toritsuka Y, Horibe S, Ochi T. Effect of gamma irradiation on remodeling process of tendon allograft. Clin Orthop. 2003;(414):305-314.