Shoulder & Elbow

Scapular dislocation, which is also termed locked scapula or scapulothoracic dislocation, is an unusual condition that can be described as extrathoracic or intrathoracic dislocation, depending on the penetration of scapula into the thoracic cavity.

There have been 3 reported cases of intrathoracic scapular dislocations in the literature,^1-3all associated with a preexisting condition (eg, sternoclavicular separation, prior rib fracture, thoracotomy for a lung transplant procedure, or surgical resection of superior ribs during breast or pulmonary tumor excisions). Three published cases of intrathoracic scapular impaction involve comminuted scapular fractures with intrathoracic impaction of the inferior fragment through intercostal space.^4-6

Here we report an intrathoracic scapular dislocation that was not associated with fracture of the scapula or predisposing factors. To our knowledge, this is the first case of pure intrathoracic dislocation. The possibility of intrathoracic scapular dislocation should be considered as part of the differential diagnosis even in patients with a negative anamnesis for predisposing factors, such as lung or chest surgery. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 29-year-old woman presented to the emergency department after a motor vehicle accident. She had tenderness over the left shoulder and left elbow with decreased range of motion; however, motor and sensory examination of the wrist and fingers were normal. No distal neurovascular deficit was noted.

Physical examination revealed pain on pelvic compression. We observed an asymmetrical appearance between shoulders; the left shoulder was superior when compared with the right side (Figure 1). Palpation of the scapula aggravated the pain. The inferior angle of the left scapula was not palpable, and the medial border was palpated through the intercostal space between the third and fourth ribs.

Initial radiographs showed additional left olecranon and bilateral ramus pubis fractures. A chest radiograph showed nondisplaced fractures of the second and third ribs without any obvious hemothorax or pneumothorax. No other pathology involving the chest, such as resection of the ribs or congenital anomaly, was observed. The patient reported no history of thoracic trauma or lung surgery. There were no fractures of the scapula, humerus, or clavicles. Thoracic computed tomography was performed, and 3-dimensional (3D) reconstruction showed that the inferior angle of scapula penetrated into the thoracic cavity through the third intercostal space (Figure 2).

Given the intrathoracic scapular dislocation diagnosis, closed reduction under sedation was planned. The patient was placed in the supine position, and reduction was performed by applying pressure on the shoulder anteriorly. This maneuver increased deformity. At the same time, another physician pulled the spine of the scapula superiorly, releasing the scapula out of the thoracic cavity. When the arm was slightly lowered to neutral position, scapular deformity was no longer present (Figure 3). A shoulder sling was applied, and the patient was hospitalized for surgical fixation of pelvic and olecranon fractures. The arm was immobilized in a sling for 1 week, and shoulder exercises were started immediately afterward.

At 1-month follow-up, full shoulder range of motion was achieved, although rehabilitation for the elbow continued. Final follow-up examination at 4 months revealed no difference between shoulders, and no recurrence occurred.

Discussion

Intrathoracic scapular dislocation is a rare injury. There are only a few cases reported in the literature, and most of them are well associated with a predisposing factor. Nettrour and colleagues¹ described the first intrathoracic scapular dislocation, which occurred 6 weeks after sternoclavicular separation and fracture of a rib. In the case reports of Ward and colleagues² and Fowler and colleagues,³ the predisposing factor was resection of the ribs due to pancoast tumor and breast carcinoma, respectively. The mechanism of these dislocations depends on a weak area over the thoracic cage, creating a fulcrum point for levering the scapula into the thoracic cavity.

There are other cases of scapular dislocations that are accompanied by a comminuted fracture of scapula; a review of the literature revealed 3 cases.^4-6 In our opinion, fracture of the inferior pole of the scapula leads to injury of the soft tissues and also results in intrathoracic impaction by creating a weak area over the thoracic cavity. This mechanism can be referred to as penetration.

Our case is singular because it is the first case that is not associated with fracture of the scapula or predisposing factors. Consequently, we report the first pure intrathoracic scapular dislocation in the literature. It is important to suspect intrathoracic scapular dislocation in the case of deformity (Figure 1), even in the absence of any predisposing factors or scapular fracture.

Although plain radiographs may not be elucidative, 3D reconstruction of computed tomography (Figure 2) reveals the pathology and plays an important role in guiding treatment.

In the treatment of our patient, relying on the unique dislocation mechanism without any fracture of the scapula or ribs, we started early active shoulder movement after 1 week of immobilization in a shoulder sling, which prevented recurrence of dislocation. In addition to presenting the first pure intrathoracic scapular dislocation, this case demonstrated satisfactory clinical results with short-term immobilization and early rehabilitation.

Conclusion

Contrary to the literature, the possibility of intrathoracic scapular dislocation should be considered in the differential diagnosis even in patients with a negative anamnesis for predisposing factors, such as lung or chest surgery, and when no fractures are detected. Shoulder or thorax computed tomography, especially 3D reconstructions, are helpful in diagnosing the condition and in guiding treatment. Closed reduction under sedation followed by early rehabilitation is an appropriate treatment method, which resulted in a full return of function in 1 month in our patient.

Scapular dislocation, which is also termed locked scapula or scapulothoracic dislocation, is an unusual condition that can be described as extrathoracic or intrathoracic dislocation, depending on the penetration of scapula into the thoracic cavity.

There have been 3 reported cases of intrathoracic scapular dislocations in the literature,^1-3all associated with a preexisting condition (eg, sternoclavicular separation, prior rib fracture, thoracotomy for a lung transplant procedure, or surgical resection of superior ribs during breast or pulmonary tumor excisions). Three published cases of intrathoracic scapular impaction involve comminuted scapular fractures with intrathoracic impaction of the inferior fragment through intercostal space.^4-6

Here we report an intrathoracic scapular dislocation that was not associated with fracture of the scapula or predisposing factors. To our knowledge, this is the first case of pure intrathoracic dislocation. The possibility of intrathoracic scapular dislocation should be considered as part of the differential diagnosis even in patients with a negative anamnesis for predisposing factors, such as lung or chest surgery. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 29-year-old woman presented to the emergency department after a motor vehicle accident. She had tenderness over the left shoulder and left elbow with decreased range of motion; however, motor and sensory examination of the wrist and fingers were normal. No distal neurovascular deficit was noted.

Physical examination revealed pain on pelvic compression. We observed an asymmetrical appearance between shoulders; the left shoulder was superior when compared with the right side (Figure 1). Palpation of the scapula aggravated the pain. The inferior angle of the left scapula was not palpable, and the medial border was palpated through the intercostal space between the third and fourth ribs.

Initial radiographs showed additional left olecranon and bilateral ramus pubis fractures. A chest radiograph showed nondisplaced fractures of the second and third ribs without any obvious hemothorax or pneumothorax. No other pathology involving the chest, such as resection of the ribs or congenital anomaly, was observed. The patient reported no history of thoracic trauma or lung surgery. There were no fractures of the scapula, humerus, or clavicles. Thoracic computed tomography was performed, and 3-dimensional (3D) reconstruction showed that the inferior angle of scapula penetrated into the thoracic cavity through the third intercostal space (Figure 2).

Given the intrathoracic scapular dislocation diagnosis, closed reduction under sedation was planned. The patient was placed in the supine position, and reduction was performed by applying pressure on the shoulder anteriorly. This maneuver increased deformity. At the same time, another physician pulled the spine of the scapula superiorly, releasing the scapula out of the thoracic cavity. When the arm was slightly lowered to neutral position, scapular deformity was no longer present (Figure 3). A shoulder sling was applied, and the patient was hospitalized for surgical fixation of pelvic and olecranon fractures. The arm was immobilized in a sling for 1 week, and shoulder exercises were started immediately afterward.

At 1-month follow-up, full shoulder range of motion was achieved, although rehabilitation for the elbow continued. Final follow-up examination at 4 months revealed no difference between shoulders, and no recurrence occurred.

Discussion

Intrathoracic scapular dislocation is a rare injury. There are only a few cases reported in the literature, and most of them are well associated with a predisposing factor. Nettrour and colleagues¹ described the first intrathoracic scapular dislocation, which occurred 6 weeks after sternoclavicular separation and fracture of a rib. In the case reports of Ward and colleagues² and Fowler and colleagues,³ the predisposing factor was resection of the ribs due to pancoast tumor and breast carcinoma, respectively. The mechanism of these dislocations depends on a weak area over the thoracic cage, creating a fulcrum point for levering the scapula into the thoracic cavity.

There are other cases of scapular dislocations that are accompanied by a comminuted fracture of scapula; a review of the literature revealed 3 cases.^4-6 In our opinion, fracture of the inferior pole of the scapula leads to injury of the soft tissues and also results in intrathoracic impaction by creating a weak area over the thoracic cavity. This mechanism can be referred to as penetration.

Our case is singular because it is the first case that is not associated with fracture of the scapula or predisposing factors. Consequently, we report the first pure intrathoracic scapular dislocation in the literature. It is important to suspect intrathoracic scapular dislocation in the case of deformity (Figure 1), even in the absence of any predisposing factors or scapular fracture.

Although plain radiographs may not be elucidative, 3D reconstruction of computed tomography (Figure 2) reveals the pathology and plays an important role in guiding treatment.

In the treatment of our patient, relying on the unique dislocation mechanism without any fracture of the scapula or ribs, we started early active shoulder movement after 1 week of immobilization in a shoulder sling, which prevented recurrence of dislocation. In addition to presenting the first pure intrathoracic scapular dislocation, this case demonstrated satisfactory clinical results with short-term immobilization and early rehabilitation.

Conclusion

Contrary to the literature, the possibility of intrathoracic scapular dislocation should be considered in the differential diagnosis even in patients with a negative anamnesis for predisposing factors, such as lung or chest surgery, and when no fractures are detected. Shoulder or thorax computed tomography, especially 3D reconstructions, are helpful in diagnosing the condition and in guiding treatment. Closed reduction under sedation followed by early rehabilitation is an appropriate treatment method, which resulted in a full return of function in 1 month in our patient.

Scapular dislocation, which is also termed locked scapula or scapulothoracic dislocation, is an unusual condition that can be described as extrathoracic or intrathoracic dislocation, depending on the penetration of scapula into the thoracic cavity.

There have been 3 reported cases of intrathoracic scapular dislocations in the literature,^1-3all associated with a preexisting condition (eg, sternoclavicular separation, prior rib fracture, thoracotomy for a lung transplant procedure, or surgical resection of superior ribs during breast or pulmonary tumor excisions). Three published cases of intrathoracic scapular impaction involve comminuted scapular fractures with intrathoracic impaction of the inferior fragment through intercostal space.^4-6

Here we report an intrathoracic scapular dislocation that was not associated with fracture of the scapula or predisposing factors. To our knowledge, this is the first case of pure intrathoracic dislocation. The possibility of intrathoracic scapular dislocation should be considered as part of the differential diagnosis even in patients with a negative anamnesis for predisposing factors, such as lung or chest surgery. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 29-year-old woman presented to the emergency department after a motor vehicle accident. She had tenderness over the left shoulder and left elbow with decreased range of motion; however, motor and sensory examination of the wrist and fingers were normal. No distal neurovascular deficit was noted.

Physical examination revealed pain on pelvic compression. We observed an asymmetrical appearance between shoulders; the left shoulder was superior when compared with the right side (Figure 1). Palpation of the scapula aggravated the pain. The inferior angle of the left scapula was not palpable, and the medial border was palpated through the intercostal space between the third and fourth ribs.

Initial radiographs showed additional left olecranon and bilateral ramus pubis fractures. A chest radiograph showed nondisplaced fractures of the second and third ribs without any obvious hemothorax or pneumothorax. No other pathology involving the chest, such as resection of the ribs or congenital anomaly, was observed. The patient reported no history of thoracic trauma or lung surgery. There were no fractures of the scapula, humerus, or clavicles. Thoracic computed tomography was performed, and 3-dimensional (3D) reconstruction showed that the inferior angle of scapula penetrated into the thoracic cavity through the third intercostal space (Figure 2).

Given the intrathoracic scapular dislocation diagnosis, closed reduction under sedation was planned. The patient was placed in the supine position, and reduction was performed by applying pressure on the shoulder anteriorly. This maneuver increased deformity. At the same time, another physician pulled the spine of the scapula superiorly, releasing the scapula out of the thoracic cavity. When the arm was slightly lowered to neutral position, scapular deformity was no longer present (Figure 3). A shoulder sling was applied, and the patient was hospitalized for surgical fixation of pelvic and olecranon fractures. The arm was immobilized in a sling for 1 week, and shoulder exercises were started immediately afterward.

At 1-month follow-up, full shoulder range of motion was achieved, although rehabilitation for the elbow continued. Final follow-up examination at 4 months revealed no difference between shoulders, and no recurrence occurred.

Discussion

Intrathoracic scapular dislocation is a rare injury. There are only a few cases reported in the literature, and most of them are well associated with a predisposing factor. Nettrour and colleagues¹ described the first intrathoracic scapular dislocation, which occurred 6 weeks after sternoclavicular separation and fracture of a rib. In the case reports of Ward and colleagues² and Fowler and colleagues,³ the predisposing factor was resection of the ribs due to pancoast tumor and breast carcinoma, respectively. The mechanism of these dislocations depends on a weak area over the thoracic cage, creating a fulcrum point for levering the scapula into the thoracic cavity.

There are other cases of scapular dislocations that are accompanied by a comminuted fracture of scapula; a review of the literature revealed 3 cases.^4-6 In our opinion, fracture of the inferior pole of the scapula leads to injury of the soft tissues and also results in intrathoracic impaction by creating a weak area over the thoracic cavity. This mechanism can be referred to as penetration.

Our case is singular because it is the first case that is not associated with fracture of the scapula or predisposing factors. Consequently, we report the first pure intrathoracic scapular dislocation in the literature. It is important to suspect intrathoracic scapular dislocation in the case of deformity (Figure 1), even in the absence of any predisposing factors or scapular fracture.

Although plain radiographs may not be elucidative, 3D reconstruction of computed tomography (Figure 2) reveals the pathology and plays an important role in guiding treatment.

In the treatment of our patient, relying on the unique dislocation mechanism without any fracture of the scapula or ribs, we started early active shoulder movement after 1 week of immobilization in a shoulder sling, which prevented recurrence of dislocation. In addition to presenting the first pure intrathoracic scapular dislocation, this case demonstrated satisfactory clinical results with short-term immobilization and early rehabilitation.

Conclusion

Contrary to the literature, the possibility of intrathoracic scapular dislocation should be considered in the differential diagnosis even in patients with a negative anamnesis for predisposing factors, such as lung or chest surgery, and when no fractures are detected. Shoulder or thorax computed tomography, especially 3D reconstructions, are helpful in diagnosing the condition and in guiding treatment. Closed reduction under sedation followed by early rehabilitation is an appropriate treatment method, which resulted in a full return of function in 1 month in our patient.

The Internet is becoming a primary source for obtaining medical information. This growing trend may have serious implications for the medical field. As patients increasingly regard the Internet as an essential tool for obtaining health-related information, questions have been raised regarding the quality of medical information available on the Internet.¹ Studies have shown that health-related sites often present inaccurate, inconsistent, and outdated information that may have a negative impact on health care decisions made by patients.²

According to the US Census Bureau, 71.7% of American households report having access to the Internet.³ Of those who have access to Internet, approximately 72% have sought health information online over the last year.⁴ Among people older than age 65 years living in the United States, there has been a growing trend toward using the Internet, from 14% in 2000 to almost 60% in 2013, according to the Pew Research Internet Project.⁵ Most medical websites are viewed for information on diseases and treatment options.⁶ Since most patients want to be informed about treatment options, as well as risks and benefits for each treatment, access to credible information is essential for proper decision-making.⁷

To assess the quality of information on the Internet, we used DISCERN, a standardized questionnaire to aid consumers in judging Internet content.⁸ The DISCERN instrument, available at www.discern.org.uk, was designed by an expert group in the United Kingdom. First, an expert panel developed and tested the instrument, and then health care providers and self-help group members tested it further.^8,9 The questionnaire had been found to have good interrater reliability, regardless of use by health professionals or consumers.^8-10

More than 53,000 shoulder arthroplasties are performed in the United States annually, and the number is growing, with the main goal of pain relief from glenohumeral degenerative joint disease.^11,12 The Internet has become a quasi–second opinion for patients trying to participate in their care. Given the prevalence of shoulder-related surgeries, it is critical to analyze and become familiar with the quality of information that patients read online in order to direct them to nonbiased, all-inclusive websites. In this study, we provide a summary assessment and comparison of the quality of online information pertaining to shoulder replacement, using medical (total shoulder replacement) and nontechnical (shoulder replacement) search terms.

Methods

Websites were identified using 3 search engines (Google, Yahoo, and Bing) and 2 search terms, shoulder replacement (SR) and total shoulder arthroplasty (TSA), on January 17, 2014. These 3 search engines were used because 77% of health care–related information online searches begin through a search engine (Google, Bing, Yahoo); only 13% begin at a health care–specialized website.⁴ These search terms were used after consulting with orthopedic residents and attending physicians in a focus group regarding the terminology used with patients. The first 30 websites in each search engine were identified consecutively and evaluated for category and quality of information using the DISCERN instrument.

A total of 180 websites (90 per search term) were reviewed. Each website was evaluated independently by 3 medical students. In the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram, we recorded how websites were identified, screened, and included (Figure 1).13 Websites that were duplicated within each search term and those that were inaccessible were used to determine the total number of noncommercial versus commercial websites, but were excluded from the final analysis. The first part of the analysis involved determining the type of website (eg, commercial vs noncommercial) based upon the html endings. All .com endings were classified as commercial websites; noncommercial included .gov, .org, .edu, and .net endings. Next, each website was categorized based on the target audience. Websites were grouped into health professional–oriented information, patient-oriented, advertisement, or “other.” These classifications were based on those described in previous works.^14,15 The “other” category included images, YouTube videos, another search engine, and open forums, which were also excluded from the final analysis because they were not easily evaluable with the DISCERN instrument. Websites were considered health professional–oriented if they included journal articles, scholarly articles, and/or rehabilitation protocols. Patient-directed websites clearly stated the information was directed to patients or provided a general overview. Advertisement included sites that displayed ads or products for sale. Websites were evaluated for quality using the DISCERN instrument (Figure 2).

DISCERN has 3 subdivision scores: the reliable score (composed of the first 8 questions), the treatment options (the next 7 questions), and 1 final question that addresses the overall quality of the website and is rated independently of the first 15 questions. DISCERN uses 2 scales, a binary scale anchored on both extremes with the number 1 equaling complete absence of the criteria being measured, and the number 5 at the upper extreme, representing completeness of the quality being assessed. In between 1 and 5 is a partial ordinal scale measuring from 2 to 4, which indicates the information is present to some extent but not complete. The ordinal scale allows ranking of the criteria being assessed. Summarizing values from each of the 2 scales poses some concern: the scale is not a true binary scale because of the ordinal scale of the middle numbers (2-4), and as such, is not amenable to being an interval scale to calculate arithmetic means. To summarize the values from the 2 scales, we calculated the harmonic mean, the arithmetic mean, the geometric mean, and the median. The means were empirically compared with the median, and we used the harmonic mean to summarize scale values because it was the best approximation of the medians.

Results

A total of 90 websites were assessed with the search term total shoulder arthroplasty and another 90 with shoulder replacement. When 37 duplicate websites for TSA and 52 for SR were eliminated, 53 (59%) and 38 (42%) unique websites were evaluated for each search term, respectively (Figure 1). (These unique websites are included in the Appendix.) Between the 2 search terms, 20 websites were duplicated. Figure 3 shows the distribution of websites by category. Total shoulder arthroplasty provided the highest percentage of health professional–oriented information; SR had the greatest percentage of patient-oriented information. Both TSA and SR had nearly the same number of advertisements and websites labeled “other.” The percentage of noncommercial websites from each search engine is represented in Figure 4. For SR, Google had 40% (12/30) noncommercial websites compared with Yahoo at 53% (16/30) and Bing at 46% (14/30). Total shoulder arthroplasty had 43% (13/30) noncommercial websites on Google, 27% (8/30) on Yahoo, and 40% (12/30) on Bing. In total, SR had more noncommercial websites, 47% (42/90), compared with 37% (33/90) for TSA.

The mean of all 3 raters for reliablity (DISCERN questions 1-8) and treatment options (DISCERN questions 9-15) is represented in the Table. For both search terms, we found that websites identified as health professional–oriented had the highest reliable mean scores, followed by patient-oriented, and advertisement at the lowest (SR: P = .054; TSA: P = .134). For SR, treatment mean scores demonstrated similar results with health professional–oriented websites receiving the highest, followed by patient-oriented and advertisement (P = .005). However, the treatment mean scores for TSA differed with patient-oriented websites receiving higher scores than health professional–oriented websites, but this was not statistically significant (P= .407). Regarding search terms, there were no significant differences between mean reliable and treatment scores across all categories.

The average overall DISCERN score for TSA websites was 2.5 (range, 1-5), compared with 2.3 (range, 1-5) for SR websites. The overall reliable score (DISCERN questions 1-8) for TSA websites was 2.6 and 2.5 for SR websites (P < .001). For TSA websites, 38% (20/53) were classified as good, having an overall DISCERN score ≥3, versus 26% (10/38) of SR websites. The overall DISCERN score for health professional–oriented websites was 2.7, patient-oriented websites received a score of 2.6, and advertisements had the lowest score at 2.4.

Discussion

Both patients and health professionals obtain information on health care subjects through the Internet, which has become the primary resource for patients.^15,16 However, there are no strict regulations of the content being written. This creates a challenge for the typical user to find credible and evidence-based information, which is important because misleading information could cause undue anxiety, among other effects.^17,18 The aims of this study were to determine the quality of Internet information for shoulder replacement surgeries using the medical terminology total shoulder arthroplasty (TSA) and the nontechnical term shoulder replacement (SR), and to compare the results.

After analyzing the types of websites returned for both total shoulder arthroplasty and shoulder replacement (Figure 4), it was interesting to find that using nonmedical terminology as the search term provided more noncommercial websites compared with total shoulder arthroplasty. Furthermore, Yahoo provided the highest yield of noncommercial websites at 16, with Bing at 14, when using SR as the search term. We believe the increase in noncommercial websites returned for SR was greater than for TSA because SR yielded more patient-oriented websites, which usually had html endings of .edu and .org, as shown in Figure 3 (48% of SR websites offered patient-oriented information).

Although there were more noncommercial websites for SR, the majority of the DISCERN values between the 2 search terms did not differ significantly. This is a direct result of the number of sites (20) that were duplicated across both search terms. However as seen in the Table, TSA had similar reliable mean scores for advertisements and patient-oriented websites but a slightly higher reliable score for health professional–oriented websites. We correlated this with the increased number of health professional–oriented websites returned when using TSA as the search term (Figure 3). The health professional–oriented websites explained their aims and cited their sources more consistently than did patient-oriented sites and advertisements, resulting in higher reliable scores. Although patient-oriented websites frequently lacked citations, they provided information about multiple treatment options, which were more relevant to consumers. This resulted in nearly equivalent reliable scores. Treatment means for advertisements in both SR and TSA were similar. However, treatment means for professional-oriented websites in TSA were lower than those for SR because health professional–oriented websites often were only moderately relevant to consumers, with their focus usually on 1 treatment option or on rehabilitation protocols. Although the DISCERN scores were similar between the search terms, total shoulder arthroplasty provided more websites (20) classified as good—overall DISCERN score, ≥3—than SR did (10). Advertisement websites had similar overall DISCERN scores, which we anticipated because most of the advertisements were duplicated across the search terms.

Using the 2 search terms, academic websites and commercial websites, such as WebMD, consistently received higher reliable and overall DISCERN scores. Advertisement websites, which need to deliver a clear message, frequently scored high on explicitly stating their aims and relevance to consumers, but focused on their products without discussing the benefits of other treatment options. This is significant because Internet search engines, such as Google, offer sponsor links for which organizations pay to appear at the top of the search results. This creates the potential for consumers to receive biased information because most individuals only visit the top 10 websites generated by a search engine.¹⁹

We concluded that the quality of online information relating to SR and TSA was highly variable and frequently of moderate-to-poor quality, with most overall DISCERN scores <3. The quality of information found online for this study using the DISCERN instrument is consistent with those studies using DISCERN to evaluate other medical conditions (eg, bunions, chronic pain, general anesthesia, and anterior cruciate ligament reconstruction).^2,9,15,19 These studies also concluded that online information varies tremendously in quality and completeness.

This study has several limitations. Websites were searched at a single time point and, because Internet resources are frequently updated, the results of this study could vary. Furthermore, although Google, Yahoo, and Bing are 3 of the most popular search engines, these are not the only resources patients use when searching the Internet for health-related information. Other search engines, such as Pubmed.gov and MSN.com, could provide additional websites for Internet users. Lastly, although DISCERN is validated to address the quality of information available online, it does not evaluate the accuracy of the information.⁸ Our use of DISCERN involves 2 scales, a binary yes/no (ratings, 1 and 5) and an ordinal scale (ratings, 2-4). As such, a single mean summary statistic cannot be calculated.

Conclusion

The information available on the Internet pertaining to TSA and SR is highly variable and provides mostly moderate-to-poor quality information based on the DISCERN instrument. Many websites failed to describe the benefits and the risks of different treatment options, including nonoperative management. Health care professionals should be aware that patients often refer to the Internet as a primary resource for obtaining medical information. It is important to direct patients to websites that provide accurate information, because patients who educate themselves about their conditions and actively participate in decision-making may have improved health outcomes.20-22 Overall, academic websites and commercial websites, such as WebMD and OrthoInfo, generally had higher DISCERN scores when using either search term. Of major concern is the potential for misleading advertisements or incorrect information that can negatively affect health outcomes. This study found that using nonmedical terminology (SR) provided more noncommercial and patient-oriented websites, especially through Yahoo. This study highlights the need for more comprehensive online information pertaining to shoulder replacement that can better serve as a resource for Internet users.

The Internet is becoming a primary source for obtaining medical information. This growing trend may have serious implications for the medical field. As patients increasingly regard the Internet as an essential tool for obtaining health-related information, questions have been raised regarding the quality of medical information available on the Internet.¹ Studies have shown that health-related sites often present inaccurate, inconsistent, and outdated information that may have a negative impact on health care decisions made by patients.²

According to the US Census Bureau, 71.7% of American households report having access to the Internet.³ Of those who have access to Internet, approximately 72% have sought health information online over the last year.⁴ Among people older than age 65 years living in the United States, there has been a growing trend toward using the Internet, from 14% in 2000 to almost 60% in 2013, according to the Pew Research Internet Project.⁵ Most medical websites are viewed for information on diseases and treatment options.⁶ Since most patients want to be informed about treatment options, as well as risks and benefits for each treatment, access to credible information is essential for proper decision-making.⁷

To assess the quality of information on the Internet, we used DISCERN, a standardized questionnaire to aid consumers in judging Internet content.⁸ The DISCERN instrument, available at www.discern.org.uk, was designed by an expert group in the United Kingdom. First, an expert panel developed and tested the instrument, and then health care providers and self-help group members tested it further.^8,9 The questionnaire had been found to have good interrater reliability, regardless of use by health professionals or consumers.^8-10

More than 53,000 shoulder arthroplasties are performed in the United States annually, and the number is growing, with the main goal of pain relief from glenohumeral degenerative joint disease.^11,12 The Internet has become a quasi–second opinion for patients trying to participate in their care. Given the prevalence of shoulder-related surgeries, it is critical to analyze and become familiar with the quality of information that patients read online in order to direct them to nonbiased, all-inclusive websites. In this study, we provide a summary assessment and comparison of the quality of online information pertaining to shoulder replacement, using medical (total shoulder replacement) and nontechnical (shoulder replacement) search terms.

Methods

Websites were identified using 3 search engines (Google, Yahoo, and Bing) and 2 search terms, shoulder replacement (SR) and total shoulder arthroplasty (TSA), on January 17, 2014. These 3 search engines were used because 77% of health care–related information online searches begin through a search engine (Google, Bing, Yahoo); only 13% begin at a health care–specialized website.⁴ These search terms were used after consulting with orthopedic residents and attending physicians in a focus group regarding the terminology used with patients. The first 30 websites in each search engine were identified consecutively and evaluated for category and quality of information using the DISCERN instrument.

A total of 180 websites (90 per search term) were reviewed. Each website was evaluated independently by 3 medical students. In the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram, we recorded how websites were identified, screened, and included (Figure 1).13 Websites that were duplicated within each search term and those that were inaccessible were used to determine the total number of noncommercial versus commercial websites, but were excluded from the final analysis. The first part of the analysis involved determining the type of website (eg, commercial vs noncommercial) based upon the html endings. All .com endings were classified as commercial websites; noncommercial included .gov, .org, .edu, and .net endings. Next, each website was categorized based on the target audience. Websites were grouped into health professional–oriented information, patient-oriented, advertisement, or “other.” These classifications were based on those described in previous works.^14,15 The “other” category included images, YouTube videos, another search engine, and open forums, which were also excluded from the final analysis because they were not easily evaluable with the DISCERN instrument. Websites were considered health professional–oriented if they included journal articles, scholarly articles, and/or rehabilitation protocols. Patient-directed websites clearly stated the information was directed to patients or provided a general overview. Advertisement included sites that displayed ads or products for sale. Websites were evaluated for quality using the DISCERN instrument (Figure 2).

DISCERN has 3 subdivision scores: the reliable score (composed of the first 8 questions), the treatment options (the next 7 questions), and 1 final question that addresses the overall quality of the website and is rated independently of the first 15 questions. DISCERN uses 2 scales, a binary scale anchored on both extremes with the number 1 equaling complete absence of the criteria being measured, and the number 5 at the upper extreme, representing completeness of the quality being assessed. In between 1 and 5 is a partial ordinal scale measuring from 2 to 4, which indicates the information is present to some extent but not complete. The ordinal scale allows ranking of the criteria being assessed. Summarizing values from each of the 2 scales poses some concern: the scale is not a true binary scale because of the ordinal scale of the middle numbers (2-4), and as such, is not amenable to being an interval scale to calculate arithmetic means. To summarize the values from the 2 scales, we calculated the harmonic mean, the arithmetic mean, the geometric mean, and the median. The means were empirically compared with the median, and we used the harmonic mean to summarize scale values because it was the best approximation of the medians.

Results

A total of 90 websites were assessed with the search term total shoulder arthroplasty and another 90 with shoulder replacement. When 37 duplicate websites for TSA and 52 for SR were eliminated, 53 (59%) and 38 (42%) unique websites were evaluated for each search term, respectively (Figure 1). (These unique websites are included in the Appendix.) Between the 2 search terms, 20 websites were duplicated. Figure 3 shows the distribution of websites by category. Total shoulder arthroplasty provided the highest percentage of health professional–oriented information; SR had the greatest percentage of patient-oriented information. Both TSA and SR had nearly the same number of advertisements and websites labeled “other.” The percentage of noncommercial websites from each search engine is represented in Figure 4. For SR, Google had 40% (12/30) noncommercial websites compared with Yahoo at 53% (16/30) and Bing at 46% (14/30). Total shoulder arthroplasty had 43% (13/30) noncommercial websites on Google, 27% (8/30) on Yahoo, and 40% (12/30) on Bing. In total, SR had more noncommercial websites, 47% (42/90), compared with 37% (33/90) for TSA.

The mean of all 3 raters for reliablity (DISCERN questions 1-8) and treatment options (DISCERN questions 9-15) is represented in the Table. For both search terms, we found that websites identified as health professional–oriented had the highest reliable mean scores, followed by patient-oriented, and advertisement at the lowest (SR: P = .054; TSA: P = .134). For SR, treatment mean scores demonstrated similar results with health professional–oriented websites receiving the highest, followed by patient-oriented and advertisement (P = .005). However, the treatment mean scores for TSA differed with patient-oriented websites receiving higher scores than health professional–oriented websites, but this was not statistically significant (P= .407). Regarding search terms, there were no significant differences between mean reliable and treatment scores across all categories.

The average overall DISCERN score for TSA websites was 2.5 (range, 1-5), compared with 2.3 (range, 1-5) for SR websites. The overall reliable score (DISCERN questions 1-8) for TSA websites was 2.6 and 2.5 for SR websites (P < .001). For TSA websites, 38% (20/53) were classified as good, having an overall DISCERN score ≥3, versus 26% (10/38) of SR websites. The overall DISCERN score for health professional–oriented websites was 2.7, patient-oriented websites received a score of 2.6, and advertisements had the lowest score at 2.4.

Discussion

Both patients and health professionals obtain information on health care subjects through the Internet, which has become the primary resource for patients.^15,16 However, there are no strict regulations of the content being written. This creates a challenge for the typical user to find credible and evidence-based information, which is important because misleading information could cause undue anxiety, among other effects.^17,18 The aims of this study were to determine the quality of Internet information for shoulder replacement surgeries using the medical terminology total shoulder arthroplasty (TSA) and the nontechnical term shoulder replacement (SR), and to compare the results.

After analyzing the types of websites returned for both total shoulder arthroplasty and shoulder replacement (Figure 4), it was interesting to find that using nonmedical terminology as the search term provided more noncommercial websites compared with total shoulder arthroplasty. Furthermore, Yahoo provided the highest yield of noncommercial websites at 16, with Bing at 14, when using SR as the search term. We believe the increase in noncommercial websites returned for SR was greater than for TSA because SR yielded more patient-oriented websites, which usually had html endings of .edu and .org, as shown in Figure 3 (48% of SR websites offered patient-oriented information).

Although there were more noncommercial websites for SR, the majority of the DISCERN values between the 2 search terms did not differ significantly. This is a direct result of the number of sites (20) that were duplicated across both search terms. However as seen in the Table, TSA had similar reliable mean scores for advertisements and patient-oriented websites but a slightly higher reliable score for health professional–oriented websites. We correlated this with the increased number of health professional–oriented websites returned when using TSA as the search term (Figure 3). The health professional–oriented websites explained their aims and cited their sources more consistently than did patient-oriented sites and advertisements, resulting in higher reliable scores. Although patient-oriented websites frequently lacked citations, they provided information about multiple treatment options, which were more relevant to consumers. This resulted in nearly equivalent reliable scores. Treatment means for advertisements in both SR and TSA were similar. However, treatment means for professional-oriented websites in TSA were lower than those for SR because health professional–oriented websites often were only moderately relevant to consumers, with their focus usually on 1 treatment option or on rehabilitation protocols. Although the DISCERN scores were similar between the search terms, total shoulder arthroplasty provided more websites (20) classified as good—overall DISCERN score, ≥3—than SR did (10). Advertisement websites had similar overall DISCERN scores, which we anticipated because most of the advertisements were duplicated across the search terms.

Using the 2 search terms, academic websites and commercial websites, such as WebMD, consistently received higher reliable and overall DISCERN scores. Advertisement websites, which need to deliver a clear message, frequently scored high on explicitly stating their aims and relevance to consumers, but focused on their products without discussing the benefits of other treatment options. This is significant because Internet search engines, such as Google, offer sponsor links for which organizations pay to appear at the top of the search results. This creates the potential for consumers to receive biased information because most individuals only visit the top 10 websites generated by a search engine.¹⁹

We concluded that the quality of online information relating to SR and TSA was highly variable and frequently of moderate-to-poor quality, with most overall DISCERN scores <3. The quality of information found online for this study using the DISCERN instrument is consistent with those studies using DISCERN to evaluate other medical conditions (eg, bunions, chronic pain, general anesthesia, and anterior cruciate ligament reconstruction).^2,9,15,19 These studies also concluded that online information varies tremendously in quality and completeness.

This study has several limitations. Websites were searched at a single time point and, because Internet resources are frequently updated, the results of this study could vary. Furthermore, although Google, Yahoo, and Bing are 3 of the most popular search engines, these are not the only resources patients use when searching the Internet for health-related information. Other search engines, such as Pubmed.gov and MSN.com, could provide additional websites for Internet users. Lastly, although DISCERN is validated to address the quality of information available online, it does not evaluate the accuracy of the information.⁸ Our use of DISCERN involves 2 scales, a binary yes/no (ratings, 1 and 5) and an ordinal scale (ratings, 2-4). As such, a single mean summary statistic cannot be calculated.

Conclusion

The information available on the Internet pertaining to TSA and SR is highly variable and provides mostly moderate-to-poor quality information based on the DISCERN instrument. Many websites failed to describe the benefits and the risks of different treatment options, including nonoperative management. Health care professionals should be aware that patients often refer to the Internet as a primary resource for obtaining medical information. It is important to direct patients to websites that provide accurate information, because patients who educate themselves about their conditions and actively participate in decision-making may have improved health outcomes.20-22 Overall, academic websites and commercial websites, such as WebMD and OrthoInfo, generally had higher DISCERN scores when using either search term. Of major concern is the potential for misleading advertisements or incorrect information that can negatively affect health outcomes. This study found that using nonmedical terminology (SR) provided more noncommercial and patient-oriented websites, especially through Yahoo. This study highlights the need for more comprehensive online information pertaining to shoulder replacement that can better serve as a resource for Internet users.

The Internet is becoming a primary source for obtaining medical information. This growing trend may have serious implications for the medical field. As patients increasingly regard the Internet as an essential tool for obtaining health-related information, questions have been raised regarding the quality of medical information available on the Internet.¹ Studies have shown that health-related sites often present inaccurate, inconsistent, and outdated information that may have a negative impact on health care decisions made by patients.²

According to the US Census Bureau, 71.7% of American households report having access to the Internet.³ Of those who have access to Internet, approximately 72% have sought health information online over the last year.⁴ Among people older than age 65 years living in the United States, there has been a growing trend toward using the Internet, from 14% in 2000 to almost 60% in 2013, according to the Pew Research Internet Project.⁵ Most medical websites are viewed for information on diseases and treatment options.⁶ Since most patients want to be informed about treatment options, as well as risks and benefits for each treatment, access to credible information is essential for proper decision-making.⁷

To assess the quality of information on the Internet, we used DISCERN, a standardized questionnaire to aid consumers in judging Internet content.⁸ The DISCERN instrument, available at www.discern.org.uk, was designed by an expert group in the United Kingdom. First, an expert panel developed and tested the instrument, and then health care providers and self-help group members tested it further.^8,9 The questionnaire had been found to have good interrater reliability, regardless of use by health professionals or consumers.^8-10

More than 53,000 shoulder arthroplasties are performed in the United States annually, and the number is growing, with the main goal of pain relief from glenohumeral degenerative joint disease.^11,12 The Internet has become a quasi–second opinion for patients trying to participate in their care. Given the prevalence of shoulder-related surgeries, it is critical to analyze and become familiar with the quality of information that patients read online in order to direct them to nonbiased, all-inclusive websites. In this study, we provide a summary assessment and comparison of the quality of online information pertaining to shoulder replacement, using medical (total shoulder replacement) and nontechnical (shoulder replacement) search terms.

Methods

Websites were identified using 3 search engines (Google, Yahoo, and Bing) and 2 search terms, shoulder replacement (SR) and total shoulder arthroplasty (TSA), on January 17, 2014. These 3 search engines were used because 77% of health care–related information online searches begin through a search engine (Google, Bing, Yahoo); only 13% begin at a health care–specialized website.⁴ These search terms were used after consulting with orthopedic residents and attending physicians in a focus group regarding the terminology used with patients. The first 30 websites in each search engine were identified consecutively and evaluated for category and quality of information using the DISCERN instrument.

A total of 180 websites (90 per search term) were reviewed. Each website was evaluated independently by 3 medical students. In the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram, we recorded how websites were identified, screened, and included (Figure 1).13 Websites that were duplicated within each search term and those that were inaccessible were used to determine the total number of noncommercial versus commercial websites, but were excluded from the final analysis. The first part of the analysis involved determining the type of website (eg, commercial vs noncommercial) based upon the html endings. All .com endings were classified as commercial websites; noncommercial included .gov, .org, .edu, and .net endings. Next, each website was categorized based on the target audience. Websites were grouped into health professional–oriented information, patient-oriented, advertisement, or “other.” These classifications were based on those described in previous works.^14,15 The “other” category included images, YouTube videos, another search engine, and open forums, which were also excluded from the final analysis because they were not easily evaluable with the DISCERN instrument. Websites were considered health professional–oriented if they included journal articles, scholarly articles, and/or rehabilitation protocols. Patient-directed websites clearly stated the information was directed to patients or provided a general overview. Advertisement included sites that displayed ads or products for sale. Websites were evaluated for quality using the DISCERN instrument (Figure 2).

DISCERN has 3 subdivision scores: the reliable score (composed of the first 8 questions), the treatment options (the next 7 questions), and 1 final question that addresses the overall quality of the website and is rated independently of the first 15 questions. DISCERN uses 2 scales, a binary scale anchored on both extremes with the number 1 equaling complete absence of the criteria being measured, and the number 5 at the upper extreme, representing completeness of the quality being assessed. In between 1 and 5 is a partial ordinal scale measuring from 2 to 4, which indicates the information is present to some extent but not complete. The ordinal scale allows ranking of the criteria being assessed. Summarizing values from each of the 2 scales poses some concern: the scale is not a true binary scale because of the ordinal scale of the middle numbers (2-4), and as such, is not amenable to being an interval scale to calculate arithmetic means. To summarize the values from the 2 scales, we calculated the harmonic mean, the arithmetic mean, the geometric mean, and the median. The means were empirically compared with the median, and we used the harmonic mean to summarize scale values because it was the best approximation of the medians.

Results

A total of 90 websites were assessed with the search term total shoulder arthroplasty and another 90 with shoulder replacement. When 37 duplicate websites for TSA and 52 for SR were eliminated, 53 (59%) and 38 (42%) unique websites were evaluated for each search term, respectively (Figure 1). (These unique websites are included in the Appendix.) Between the 2 search terms, 20 websites were duplicated. Figure 3 shows the distribution of websites by category. Total shoulder arthroplasty provided the highest percentage of health professional–oriented information; SR had the greatest percentage of patient-oriented information. Both TSA and SR had nearly the same number of advertisements and websites labeled “other.” The percentage of noncommercial websites from each search engine is represented in Figure 4. For SR, Google had 40% (12/30) noncommercial websites compared with Yahoo at 53% (16/30) and Bing at 46% (14/30). Total shoulder arthroplasty had 43% (13/30) noncommercial websites on Google, 27% (8/30) on Yahoo, and 40% (12/30) on Bing. In total, SR had more noncommercial websites, 47% (42/90), compared with 37% (33/90) for TSA.

The mean of all 3 raters for reliablity (DISCERN questions 1-8) and treatment options (DISCERN questions 9-15) is represented in the Table. For both search terms, we found that websites identified as health professional–oriented had the highest reliable mean scores, followed by patient-oriented, and advertisement at the lowest (SR: P = .054; TSA: P = .134). For SR, treatment mean scores demonstrated similar results with health professional–oriented websites receiving the highest, followed by patient-oriented and advertisement (P = .005). However, the treatment mean scores for TSA differed with patient-oriented websites receiving higher scores than health professional–oriented websites, but this was not statistically significant (P= .407). Regarding search terms, there were no significant differences between mean reliable and treatment scores across all categories.

The average overall DISCERN score for TSA websites was 2.5 (range, 1-5), compared with 2.3 (range, 1-5) for SR websites. The overall reliable score (DISCERN questions 1-8) for TSA websites was 2.6 and 2.5 for SR websites (P < .001). For TSA websites, 38% (20/53) were classified as good, having an overall DISCERN score ≥3, versus 26% (10/38) of SR websites. The overall DISCERN score for health professional–oriented websites was 2.7, patient-oriented websites received a score of 2.6, and advertisements had the lowest score at 2.4.

Discussion

Both patients and health professionals obtain information on health care subjects through the Internet, which has become the primary resource for patients.^15,16 However, there are no strict regulations of the content being written. This creates a challenge for the typical user to find credible and evidence-based information, which is important because misleading information could cause undue anxiety, among other effects.^17,18 The aims of this study were to determine the quality of Internet information for shoulder replacement surgeries using the medical terminology total shoulder arthroplasty (TSA) and the nontechnical term shoulder replacement (SR), and to compare the results.

After analyzing the types of websites returned for both total shoulder arthroplasty and shoulder replacement (Figure 4), it was interesting to find that using nonmedical terminology as the search term provided more noncommercial websites compared with total shoulder arthroplasty. Furthermore, Yahoo provided the highest yield of noncommercial websites at 16, with Bing at 14, when using SR as the search term. We believe the increase in noncommercial websites returned for SR was greater than for TSA because SR yielded more patient-oriented websites, which usually had html endings of .edu and .org, as shown in Figure 3 (48% of SR websites offered patient-oriented information).

Although there were more noncommercial websites for SR, the majority of the DISCERN values between the 2 search terms did not differ significantly. This is a direct result of the number of sites (20) that were duplicated across both search terms. However as seen in the Table, TSA had similar reliable mean scores for advertisements and patient-oriented websites but a slightly higher reliable score for health professional–oriented websites. We correlated this with the increased number of health professional–oriented websites returned when using TSA as the search term (Figure 3). The health professional–oriented websites explained their aims and cited their sources more consistently than did patient-oriented sites and advertisements, resulting in higher reliable scores. Although patient-oriented websites frequently lacked citations, they provided information about multiple treatment options, which were more relevant to consumers. This resulted in nearly equivalent reliable scores. Treatment means for advertisements in both SR and TSA were similar. However, treatment means for professional-oriented websites in TSA were lower than those for SR because health professional–oriented websites often were only moderately relevant to consumers, with their focus usually on 1 treatment option or on rehabilitation protocols. Although the DISCERN scores were similar between the search terms, total shoulder arthroplasty provided more websites (20) classified as good—overall DISCERN score, ≥3—than SR did (10). Advertisement websites had similar overall DISCERN scores, which we anticipated because most of the advertisements were duplicated across the search terms.

Using the 2 search terms, academic websites and commercial websites, such as WebMD, consistently received higher reliable and overall DISCERN scores. Advertisement websites, which need to deliver a clear message, frequently scored high on explicitly stating their aims and relevance to consumers, but focused on their products without discussing the benefits of other treatment options. This is significant because Internet search engines, such as Google, offer sponsor links for which organizations pay to appear at the top of the search results. This creates the potential for consumers to receive biased information because most individuals only visit the top 10 websites generated by a search engine.¹⁹

We concluded that the quality of online information relating to SR and TSA was highly variable and frequently of moderate-to-poor quality, with most overall DISCERN scores <3. The quality of information found online for this study using the DISCERN instrument is consistent with those studies using DISCERN to evaluate other medical conditions (eg, bunions, chronic pain, general anesthesia, and anterior cruciate ligament reconstruction).^2,9,15,19 These studies also concluded that online information varies tremendously in quality and completeness.

This study has several limitations. Websites were searched at a single time point and, because Internet resources are frequently updated, the results of this study could vary. Furthermore, although Google, Yahoo, and Bing are 3 of the most popular search engines, these are not the only resources patients use when searching the Internet for health-related information. Other search engines, such as Pubmed.gov and MSN.com, could provide additional websites for Internet users. Lastly, although DISCERN is validated to address the quality of information available online, it does not evaluate the accuracy of the information.⁸ Our use of DISCERN involves 2 scales, a binary yes/no (ratings, 1 and 5) and an ordinal scale (ratings, 2-4). As such, a single mean summary statistic cannot be calculated.

Conclusion

The information available on the Internet pertaining to TSA and SR is highly variable and provides mostly moderate-to-poor quality information based on the DISCERN instrument. Many websites failed to describe the benefits and the risks of different treatment options, including nonoperative management. Health care professionals should be aware that patients often refer to the Internet as a primary resource for obtaining medical information. It is important to direct patients to websites that provide accurate information, because patients who educate themselves about their conditions and actively participate in decision-making may have improved health outcomes.20-22 Overall, academic websites and commercial websites, such as WebMD and OrthoInfo, generally had higher DISCERN scores when using either search term. Of major concern is the potential for misleading advertisements or incorrect information that can negatively affect health outcomes. This study found that using nonmedical terminology (SR) provided more noncommercial and patient-oriented websites, especially through Yahoo. This study highlights the need for more comprehensive online information pertaining to shoulder replacement that can better serve as a resource for Internet users.

Musculoskeletal disorders, the leading cause of disability in the United States,¹ account for more than half of all persons reporting missing a workday because of a medical condition.² Shoulder disorders in particular play a significant role in the burden of musculoskeletal disorders and cost of care. In 2008, 18.9 million adults (8.2% of the US adult population) reported chronic shoulder pain.¹ Among shoulder disorders, rotator cuff pathology is the most common cause of shoulder-related disability found by orthopedic surgeons.³ Rotator cuff surgery (RCS) is one of the most commonly performed orthopedic surgical procedures, and surgery volume is on the rise. One study found a 141% increase in rotator cuff repairs between the years 1996 (~41 per 100,000 population) and 2006 (~98 per 100,000 population).⁴

US health care costs are also increasing. In 2011, $2.7 trillion was spent on health care, representing 17.9% of the national gross domestic product (GDP). According to projections, costs will rise to $4.6 trillion by 2020.5 In particular, as patients continue to live longer and remain more active into their later years, the costs of treating and managing musculoskeletal disorders become more important from a public policy standpoint. In 2006, the cost of treating musculoskeletal disorders alone was $576 billion, representing 4.5% of that year’s GDP.²

Paramount in this era of rising costs is the idea of maximizing the value of health care dollars. Health care economists Porter and Teisberg⁶ defined value as patient health outcomes achieved per dollar of cost expended in a care cycle (diagnosis, treatment, ongoing management) for a particular disease or disorder. For proper management of value, outcomes and costs for an entire cycle of care must be determined. From a practical standpoint, this first requires determining the true cost of a care cycle—dollars spent on personnel, equipment, materials, and other resources required to deliver a particular service—rather than the amount charged or reimbursed for providing the service in question.⁷

Kaplan and Anderson^8,9 described the TDABC (time-driven activity-based costing) algorithm for calculating the cost of delivering a service based on 2 parameters: unit cost of a particular resource, and time required to supply it. These parameters apply to material costs and labor costs. In the medical setting, the TDABC algorithm can be applied by defining a care delivery value chain for each aspect of patient care and then multiplying incremental cost per unit time by time required to deliver that resource (Figure 1). Tabulating the overall unit cost for each resource then yields the overall cost of the care cycle. Clinical outcomes data can then be determined and used to calculate overall value for the patient care cycle.

In the study reported here, we used the TDABC algorithm to calculate the direct financial costs of surgical treatment of rotator cuff tears confirmed by magnetic resonance imaging (MRI) in an academic medical center.

Methods

Per our institution’s Office for the Protection of Research Subjects, institutional review board (IRB) approval is required only for projects using “human subjects” as defined by federal policy. In the present study, no private information could be identified, and all data were obtained from hospital billing records without intervention or interaction with individual patients. Accordingly, IRB approval was deemed unnecessary for our economic cost analysis.

Billing records of a single academic fellowship-trained sports surgeon were reviewed to identify patients who underwent primary repair of an MRI-confirmed rotator cuff tear between April 1, 2009, and July 31, 2012. Patients who had undergone prior shoulder surgery of any type were excluded from the study. Operative reports were reviewed, and exact surgical procedures performed were noted. The operating surgeon selected the specific repair techniques, including single- or double-row repair, with emphasis on restoring footprint coverage and avoiding overtensioning.

All surgeries were performed in an outpatient surgical center owned and operated by the surgeon’s home university. Surgeries were performed by the attending physician assisted by a senior orthopedic resident. The RCS care cycle was divided into 3 phases (Figure 2):

1. Preoperative. Patient’s interaction with receptionist in surgery center, time with preoperative nurse and circulating nurse in preoperative area, resident check-in time, and time placing preoperative nerve block and consumable materials used during block placement.

2. Operative. Time in operating room with surgical team for RCS, consumable materials used during surgery (eg, anchors, shavers, drapes), anesthetic medications, shoulder abduction pillow placed on completion of surgery, and cost of instrument processing.

3. Postoperative. Time in postoperative recovery area with recovery room nursing staff.

Time in each portion of the care cycle was directly observed and tabulated by hospital volunteers in the surgery center. Institutional billing data were used to identify material resources consumed, and the actual cost paid by the hospital for these resources was obtained from internal records. Mean hourly salary data and standard benefit rates were obtained for surgery center staff. Attending physician salary was extrapolated from published mean market salary data for academic physicians and mean hours worked,^10,11 and resident physician costs were tabulated from publically available institutional payroll data and average resident work hours at our institution. These cost data and times were then used to tabulate total cost for the RCS care cycle using the TDABC algorithm.

Results

We identified 28 shoulders in 26 patients (mean age, 54.5 years) who met the inclusion criteria. Of these 28 shoulders, 18 (64.3%) had an isolated supraspinatus tear, 8 (28.6%) had combined supraspinatus and infraspinatus tears, 1 (3.6%) had combined supraspinatus and subscapularis tears, and 1 (3.6%) had an isolated infraspinatus tear. Demographic data are listed in Table 1.

All patients received an interscalene nerve block in the preoperative area before being brought into the operating room. In our analysis, we included nerve block supply costs and the anesthesiologist’s mean time placing the nerve block.

In all cases, primary rotator cuff repair was performed with suture anchors (Parcus Medical) with the patient in the lateral decubitus position. In 13 (46%) of the 28 shoulders, this repair was described as “complex,” requiring double-row technique. Subacromial decompression and bursectomy were performed in addition to the rotator cuff repair. Labral débridement was performed in 23 patients, synovectomy in 10, biceps tenodesis with anchor (Smith & Nephew) in 1, and biceps tenotomy in 1. Mean time in operating room was 148 minutes; mean time in postoperative recovery unit was 105 minutes.

Directly observing the care cycle, hospital volunteers found that patients spent a mean of 15 minutes with the receptionist when they arrived in the outpatient surgical center, 25 minutes with nurses for check-in in the preoperative holding area, and 10 minutes with the anesthesiology resident and 15 minutes with the orthopedic surgery resident for preoperative evaluation and paperwork. Mean nerve block time was 20 minutes. Mean electrocardiogram (ECG) time (12 patients) was 15 minutes. The surgical technician spent a mean time of 20 minutes setting up the operating room before the patient was brought in and 15 minutes cleaning up after the patient was transferred to the recovery room. Costs of postoperative care in the recovery room were based on a 2:1 patient-to-nurse ratio, as is the standard practice in our outpatient surgery center.

Using the times mentioned and our hospital’s salary data—including standard hospital benefits rates of 33.5% for nonphysicians and 17.65% for physicians—we determined, using the TDABC algorithm, a direct cost of $5904.21 for this process cycle, excluding hospital overhead and indirect costs. Table 2 provides the overall cost breakdown. Compared with the direct economic cost, the mean hospital charge to insurers for the procedure was $31,459.35. Mean reimbursement from insurers was $9679.08.

Overall attending and resident physician costs were $1077.75, which consisted of $623.66 for the surgeon and $454.09 for the anesthesiologist (included placement of nerve block and administration of anesthesia during surgery). Preoperative bloodwork was obtained in 23 cases, adding a mean cost of $111.04 after adjusting for standard hospital markup. Preoperative ECG was performed in 12 cases, for an added mean cost of $7.30 based on the TDABC algorithm.

We also broke down costs by care cycle phase. The preoperative phase, excluding the preoperative laboratory studies and ECGs (not performed in all cases), cost $134.34 (2.3% of total costs); the operative phase cost $5718.01 (96.8% of total costs); and the postoperative phase cost $51.86 (0.9% of total costs). Within the operative phase, the cost of consumables (specifically, suture anchors) was the main cost driver. Mean anchor cost per case was $3432.67. “Complex” tears involving a double-row repair averaged $4570.25 in anchor cost per patient, as compared with $2522.60 in anchor costs for simple repairs.

Discussion

US health care costs continue to increase unsustainably, with rising pressure on hospitals and providers to deliver the highest value for each health care dollar. The present study is the first to calculate (using the TDABC algorithm) the direct economic cost ($5904.21) of the entire RCS care cycle at a university-based outpatient surgery center. Rent, utility costs, administrative costs, overhead, and other indirect costs at the surgery center were not included in this cost analysis, as they would be incurred irrespective of type of surgery performed. As such, our data isolate the procedure-specific costs of rotator cuff repair in order to provide a more meaningful comparison for other institutions, where indirect costs may be different.

In the literature, rigorous economic analysis of shoulder pathology is sparse. Kuye and colleagues¹² systematically reviewed economic evaluations in shoulder surgery for the period 1980–2010 and noted more than 50% of the papers were published between 2005 and 2010.¹² They also noted the poor quality of these studies and concluded more rigorous economic evaluations are needed to help justify the rising costs of shoulder-related treatments.

Several studies have directly evaluated costs associated with RCS. Cordasco and colleagues¹³ detailed the success of open rotator cuff repair as an outpatient procedure—noting its 43% cost savings ($4300 for outpatient vs $7500 for inpatient) and high patient satisfaction—using hospital charge data for operating room time, supplies, instruments, and postoperative slings. Churchill and Ghorai¹⁴ evaluated costs of mini-open and arthroscopic rotator cuff repairs in a statewide database and estimated the arthroscopic repair cost at $8985, compared with $7841 for the mini-open repair. They used reported hospital charge data, which were not itemized and did not include physician professional fees. Adla and colleagues,¹⁵ in a similar analysis of open versus arthroscopic cuff repair, estimated direct material costs of $1609.50 (arthroscopic) and $360.75 (open); these figures were converted from 2005 UK currency using the exchange rate cited in their paper. Salaries of surgeon, anesthesiologist, and other operating room personnel were said to be included in the operating room cost, but the authors’ paper did not include these data.

Two studies directly estimated the costs of arthroscopic rotator cuff repair. Hearnden and Tennent¹⁶ calculated the cost of RCS at their UK institution to be £2672, which included cost of operating room consumable materials, medication, and salaries of operating room personnel, including surgeon and anesthesiologist. Using online currency conversion from 2008 exchange rates and adjusting for inflation gave a corresponding US cost of $5449.63.¹⁷ Vitale and colleagues¹⁸ prospectively calculated costs of arthroscopic rotator cuff repair over a 1-year period using a cost-to-charge ratio from tabulated inpatient charges, procedure charges, and physician fees and payments abstracted from medical records, hospital billing, and administrative databases. Mean total cost for this cycle was $10,605.20, which included several costs (physical therapy, radiologist fees) not included in the present study. These studies, though more comprehensive than prior work, did not capture the entire cycle of surgical care.

Our study was designed to provide initial data on the direct costs of arthroscopic repair of the rotator cuff for the entire process cycle. Our overall cost estimate of $5904.21 differs significantly from prior work—not unexpected given the completely different cost methodology used.

Our study had several limitations. First, it was a single-surgeon evaluation, and a number of operating room variables (eg, use of adjunct instrumentation such as radiofrequency probes, differences in draping preferences) as well as surgeon volume in performing rotator cuff repairs might have substantially affected the reproducibility and generalizability of our data. Similarly, the large number of adjunctive procedures (eg, subacromial decompression, labral débridement) performed in conjunction with the rotator cuff repairs added operative time and therefore increased overall cost. Double-row repairs added operative time and increased the cost of consumable materials as well. Differences in surgeon preference for suture anchors may also be important, as anchors are a major cost driver and can vary significantly between vendors and institutions. Tear-related variables (eg, tear size, tear chronicity, degree of fatty cuff degeneration) were not controlled for and might have significantly affected operative time and associated cost. Resident involvement in the surgical procedure and anesthesia process in an academic setting prolongs surgical time and thus directly impacts costs.

In addition, we used the patient’s time in the operating room as a proxy for actual surgical time, as this was the only reliable and reproducible data point available in our electronic medical record. As such, an unquantifiable amount of surgeon time may have been overallocated to our cost estimate for time spent inducing anesthesia, positioning, helping take the patient off the operating table, and so on. However, as typical surgeon practice is to be involved in these tasks in the operating room, the possible overestimate of surgeon cost is likely minimal.

Our salary data for the TDABC algorithm were based on national averages for work hours and gross income for physicians and on hospital-based wage structure and may not be generalizable to other institutions. There may also be regional differences in work hours and salaries, which in turn would factor into a different per-minute cost for surgeon and anesthesiologist, depending on the exact geographic area where the surgery is performed. Costs may be higher at institutions that use certified nurse anesthetists rather than resident physicians because of the salary differences between these practitioners.

Moreover, the time that patients spend in the holding area—waiting to go into surgery and, after surgery, waiting for their ride home, for their prescriptions to be ready, and so forth—is an important variable to consider from a cost standpoint. However, as this time varied significantly and involved minimal contact with hospital personnel, we excluded its associated costs from our analysis. Similarly, and as already noted, hospital overhead and other indirect costs were excluded from analysis as well.

Conclusion

Using the TDABC algorithm, we found a direct economic cost of $5904.21 for RCS at our academic outpatient surgical center, with anchor cost the main cost driver. Judicious use of consumable resources is a key focus for cost containment in arthroscopic shoulder surgery, particularly with respect to implantable suture anchors. However, in the setting of more complex tears that require multiple anchors in a double-row repair construct, our pilot data may be useful to hospitals and surgery centers negotiating procedural reimbursement for the increased cost of complex repairs. Use of the TDABC algorithm for RCS and other procedures may also help in identifying opportunities to deliver more cost-effective health care.

Musculoskeletal disorders, the leading cause of disability in the United States,¹ account for more than half of all persons reporting missing a workday because of a medical condition.² Shoulder disorders in particular play a significant role in the burden of musculoskeletal disorders and cost of care. In 2008, 18.9 million adults (8.2% of the US adult population) reported chronic shoulder pain.¹ Among shoulder disorders, rotator cuff pathology is the most common cause of shoulder-related disability found by orthopedic surgeons.³ Rotator cuff surgery (RCS) is one of the most commonly performed orthopedic surgical procedures, and surgery volume is on the rise. One study found a 141% increase in rotator cuff repairs between the years 1996 (~41 per 100,000 population) and 2006 (~98 per 100,000 population).⁴

US health care costs are also increasing. In 2011, $2.7 trillion was spent on health care, representing 17.9% of the national gross domestic product (GDP). According to projections, costs will rise to $4.6 trillion by 2020.5 In particular, as patients continue to live longer and remain more active into their later years, the costs of treating and managing musculoskeletal disorders become more important from a public policy standpoint. In 2006, the cost of treating musculoskeletal disorders alone was $576 billion, representing 4.5% of that year’s GDP.²

Paramount in this era of rising costs is the idea of maximizing the value of health care dollars. Health care economists Porter and Teisberg⁶ defined value as patient health outcomes achieved per dollar of cost expended in a care cycle (diagnosis, treatment, ongoing management) for a particular disease or disorder. For proper management of value, outcomes and costs for an entire cycle of care must be determined. From a practical standpoint, this first requires determining the true cost of a care cycle—dollars spent on personnel, equipment, materials, and other resources required to deliver a particular service—rather than the amount charged or reimbursed for providing the service in question.⁷

Kaplan and Anderson^8,9 described the TDABC (time-driven activity-based costing) algorithm for calculating the cost of delivering a service based on 2 parameters: unit cost of a particular resource, and time required to supply it. These parameters apply to material costs and labor costs. In the medical setting, the TDABC algorithm can be applied by defining a care delivery value chain for each aspect of patient care and then multiplying incremental cost per unit time by time required to deliver that resource (Figure 1). Tabulating the overall unit cost for each resource then yields the overall cost of the care cycle. Clinical outcomes data can then be determined and used to calculate overall value for the patient care cycle.

In the study reported here, we used the TDABC algorithm to calculate the direct financial costs of surgical treatment of rotator cuff tears confirmed by magnetic resonance imaging (MRI) in an academic medical center.

Methods

Per our institution’s Office for the Protection of Research Subjects, institutional review board (IRB) approval is required only for projects using “human subjects” as defined by federal policy. In the present study, no private information could be identified, and all data were obtained from hospital billing records without intervention or interaction with individual patients. Accordingly, IRB approval was deemed unnecessary for our economic cost analysis.

Billing records of a single academic fellowship-trained sports surgeon were reviewed to identify patients who underwent primary repair of an MRI-confirmed rotator cuff tear between April 1, 2009, and July 31, 2012. Patients who had undergone prior shoulder surgery of any type were excluded from the study. Operative reports were reviewed, and exact surgical procedures performed were noted. The operating surgeon selected the specific repair techniques, including single- or double-row repair, with emphasis on restoring footprint coverage and avoiding overtensioning.

All surgeries were performed in an outpatient surgical center owned and operated by the surgeon’s home university. Surgeries were performed by the attending physician assisted by a senior orthopedic resident. The RCS care cycle was divided into 3 phases (Figure 2):

1. Preoperative. Patient’s interaction with receptionist in surgery center, time with preoperative nurse and circulating nurse in preoperative area, resident check-in time, and time placing preoperative nerve block and consumable materials used during block placement.

2. Operative. Time in operating room with surgical team for RCS, consumable materials used during surgery (eg, anchors, shavers, drapes), anesthetic medications, shoulder abduction pillow placed on completion of surgery, and cost of instrument processing.

3. Postoperative. Time in postoperative recovery area with recovery room nursing staff.

Time in each portion of the care cycle was directly observed and tabulated by hospital volunteers in the surgery center. Institutional billing data were used to identify material resources consumed, and the actual cost paid by the hospital for these resources was obtained from internal records. Mean hourly salary data and standard benefit rates were obtained for surgery center staff. Attending physician salary was extrapolated from published mean market salary data for academic physicians and mean hours worked,^10,11 and resident physician costs were tabulated from publically available institutional payroll data and average resident work hours at our institution. These cost data and times were then used to tabulate total cost for the RCS care cycle using the TDABC algorithm.

Results

We identified 28 shoulders in 26 patients (mean age, 54.5 years) who met the inclusion criteria. Of these 28 shoulders, 18 (64.3%) had an isolated supraspinatus tear, 8 (28.6%) had combined supraspinatus and infraspinatus tears, 1 (3.6%) had combined supraspinatus and subscapularis tears, and 1 (3.6%) had an isolated infraspinatus tear. Demographic data are listed in Table 1.

All patients received an interscalene nerve block in the preoperative area before being brought into the operating room. In our analysis, we included nerve block supply costs and the anesthesiologist’s mean time placing the nerve block.

In all cases, primary rotator cuff repair was performed with suture anchors (Parcus Medical) with the patient in the lateral decubitus position. In 13 (46%) of the 28 shoulders, this repair was described as “complex,” requiring double-row technique. Subacromial decompression and bursectomy were performed in addition to the rotator cuff repair. Labral débridement was performed in 23 patients, synovectomy in 10, biceps tenodesis with anchor (Smith & Nephew) in 1, and biceps tenotomy in 1. Mean time in operating room was 148 minutes; mean time in postoperative recovery unit was 105 minutes.

Directly observing the care cycle, hospital volunteers found that patients spent a mean of 15 minutes with the receptionist when they arrived in the outpatient surgical center, 25 minutes with nurses for check-in in the preoperative holding area, and 10 minutes with the anesthesiology resident and 15 minutes with the orthopedic surgery resident for preoperative evaluation and paperwork. Mean nerve block time was 20 minutes. Mean electrocardiogram (ECG) time (12 patients) was 15 minutes. The surgical technician spent a mean time of 20 minutes setting up the operating room before the patient was brought in and 15 minutes cleaning up after the patient was transferred to the recovery room. Costs of postoperative care in the recovery room were based on a 2:1 patient-to-nurse ratio, as is the standard practice in our outpatient surgery center.

Using the times mentioned and our hospital’s salary data—including standard hospital benefits rates of 33.5% for nonphysicians and 17.65% for physicians—we determined, using the TDABC algorithm, a direct cost of $5904.21 for this process cycle, excluding hospital overhead and indirect costs. Table 2 provides the overall cost breakdown. Compared with the direct economic cost, the mean hospital charge to insurers for the procedure was $31,459.35. Mean reimbursement from insurers was $9679.08.

Overall attending and resident physician costs were $1077.75, which consisted of $623.66 for the surgeon and $454.09 for the anesthesiologist (included placement of nerve block and administration of anesthesia during surgery). Preoperative bloodwork was obtained in 23 cases, adding a mean cost of $111.04 after adjusting for standard hospital markup. Preoperative ECG was performed in 12 cases, for an added mean cost of $7.30 based on the TDABC algorithm.

We also broke down costs by care cycle phase. The preoperative phase, excluding the preoperative laboratory studies and ECGs (not performed in all cases), cost $134.34 (2.3% of total costs); the operative phase cost $5718.01 (96.8% of total costs); and the postoperative phase cost $51.86 (0.9% of total costs). Within the operative phase, the cost of consumables (specifically, suture anchors) was the main cost driver. Mean anchor cost per case was $3432.67. “Complex” tears involving a double-row repair averaged $4570.25 in anchor cost per patient, as compared with $2522.60 in anchor costs for simple repairs.

Discussion

US health care costs continue to increase unsustainably, with rising pressure on hospitals and providers to deliver the highest value for each health care dollar. The present study is the first to calculate (using the TDABC algorithm) the direct economic cost ($5904.21) of the entire RCS care cycle at a university-based outpatient surgery center. Rent, utility costs, administrative costs, overhead, and other indirect costs at the surgery center were not included in this cost analysis, as they would be incurred irrespective of type of surgery performed. As such, our data isolate the procedure-specific costs of rotator cuff repair in order to provide a more meaningful comparison for other institutions, where indirect costs may be different.

In the literature, rigorous economic analysis of shoulder pathology is sparse. Kuye and colleagues¹² systematically reviewed economic evaluations in shoulder surgery for the period 1980–2010 and noted more than 50% of the papers were published between 2005 and 2010.¹² They also noted the poor quality of these studies and concluded more rigorous economic evaluations are needed to help justify the rising costs of shoulder-related treatments.

Several studies have directly evaluated costs associated with RCS. Cordasco and colleagues¹³ detailed the success of open rotator cuff repair as an outpatient procedure—noting its 43% cost savings ($4300 for outpatient vs $7500 for inpatient) and high patient satisfaction—using hospital charge data for operating room time, supplies, instruments, and postoperative slings. Churchill and Ghorai¹⁴ evaluated costs of mini-open and arthroscopic rotator cuff repairs in a statewide database and estimated the arthroscopic repair cost at $8985, compared with $7841 for the mini-open repair. They used reported hospital charge data, which were not itemized and did not include physician professional fees. Adla and colleagues,¹⁵ in a similar analysis of open versus arthroscopic cuff repair, estimated direct material costs of $1609.50 (arthroscopic) and $360.75 (open); these figures were converted from 2005 UK currency using the exchange rate cited in their paper. Salaries of surgeon, anesthesiologist, and other operating room personnel were said to be included in the operating room cost, but the authors’ paper did not include these data.

Two studies directly estimated the costs of arthroscopic rotator cuff repair. Hearnden and Tennent¹⁶ calculated the cost of RCS at their UK institution to be £2672, which included cost of operating room consumable materials, medication, and salaries of operating room personnel, including surgeon and anesthesiologist. Using online currency conversion from 2008 exchange rates and adjusting for inflation gave a corresponding US cost of $5449.63.¹⁷ Vitale and colleagues¹⁸ prospectively calculated costs of arthroscopic rotator cuff repair over a 1-year period using a cost-to-charge ratio from tabulated inpatient charges, procedure charges, and physician fees and payments abstracted from medical records, hospital billing, and administrative databases. Mean total cost for this cycle was $10,605.20, which included several costs (physical therapy, radiologist fees) not included in the present study. These studies, though more comprehensive than prior work, did not capture the entire cycle of surgical care.

Our study was designed to provide initial data on the direct costs of arthroscopic repair of the rotator cuff for the entire process cycle. Our overall cost estimate of $5904.21 differs significantly from prior work—not unexpected given the completely different cost methodology used.

Our study had several limitations. First, it was a single-surgeon evaluation, and a number of operating room variables (eg, use of adjunct instrumentation such as radiofrequency probes, differences in draping preferences) as well as surgeon volume in performing rotator cuff repairs might have substantially affected the reproducibility and generalizability of our data. Similarly, the large number of adjunctive procedures (eg, subacromial decompression, labral débridement) performed in conjunction with the rotator cuff repairs added operative time and therefore increased overall cost. Double-row repairs added operative time and increased the cost of consumable materials as well. Differences in surgeon preference for suture anchors may also be important, as anchors are a major cost driver and can vary significantly between vendors and institutions. Tear-related variables (eg, tear size, tear chronicity, degree of fatty cuff degeneration) were not controlled for and might have significantly affected operative time and associated cost. Resident involvement in the surgical procedure and anesthesia process in an academic setting prolongs surgical time and thus directly impacts costs.

In addition, we used the patient’s time in the operating room as a proxy for actual surgical time, as this was the only reliable and reproducible data point available in our electronic medical record. As such, an unquantifiable amount of surgeon time may have been overallocated to our cost estimate for time spent inducing anesthesia, positioning, helping take the patient off the operating table, and so on. However, as typical surgeon practice is to be involved in these tasks in the operating room, the possible overestimate of surgeon cost is likely minimal.

Our salary data for the TDABC algorithm were based on national averages for work hours and gross income for physicians and on hospital-based wage structure and may not be generalizable to other institutions. There may also be regional differences in work hours and salaries, which in turn would factor into a different per-minute cost for surgeon and anesthesiologist, depending on the exact geographic area where the surgery is performed. Costs may be higher at institutions that use certified nurse anesthetists rather than resident physicians because of the salary differences between these practitioners.

Moreover, the time that patients spend in the holding area—waiting to go into surgery and, after surgery, waiting for their ride home, for their prescriptions to be ready, and so forth—is an important variable to consider from a cost standpoint. However, as this time varied significantly and involved minimal contact with hospital personnel, we excluded its associated costs from our analysis. Similarly, and as already noted, hospital overhead and other indirect costs were excluded from analysis as well.

Conclusion

Using the TDABC algorithm, we found a direct economic cost of $5904.21 for RCS at our academic outpatient surgical center, with anchor cost the main cost driver. Judicious use of consumable resources is a key focus for cost containment in arthroscopic shoulder surgery, particularly with respect to implantable suture anchors. However, in the setting of more complex tears that require multiple anchors in a double-row repair construct, our pilot data may be useful to hospitals and surgery centers negotiating procedural reimbursement for the increased cost of complex repairs. Use of the TDABC algorithm for RCS and other procedures may also help in identifying opportunities to deliver more cost-effective health care.

Musculoskeletal disorders, the leading cause of disability in the United States,¹ account for more than half of all persons reporting missing a workday because of a medical condition.² Shoulder disorders in particular play a significant role in the burden of musculoskeletal disorders and cost of care. In 2008, 18.9 million adults (8.2% of the US adult population) reported chronic shoulder pain.¹ Among shoulder disorders, rotator cuff pathology is the most common cause of shoulder-related disability found by orthopedic surgeons.³ Rotator cuff surgery (RCS) is one of the most commonly performed orthopedic surgical procedures, and surgery volume is on the rise. One study found a 141% increase in rotator cuff repairs between the years 1996 (~41 per 100,000 population) and 2006 (~98 per 100,000 population).⁴

US health care costs are also increasing. In 2011, $2.7 trillion was spent on health care, representing 17.9% of the national gross domestic product (GDP). According to projections, costs will rise to $4.6 trillion by 2020.5 In particular, as patients continue to live longer and remain more active into their later years, the costs of treating and managing musculoskeletal disorders become more important from a public policy standpoint. In 2006, the cost of treating musculoskeletal disorders alone was $576 billion, representing 4.5% of that year’s GDP.²

Paramount in this era of rising costs is the idea of maximizing the value of health care dollars. Health care economists Porter and Teisberg⁶ defined value as patient health outcomes achieved per dollar of cost expended in a care cycle (diagnosis, treatment, ongoing management) for a particular disease or disorder. For proper management of value, outcomes and costs for an entire cycle of care must be determined. From a practical standpoint, this first requires determining the true cost of a care cycle—dollars spent on personnel, equipment, materials, and other resources required to deliver a particular service—rather than the amount charged or reimbursed for providing the service in question.⁷

Kaplan and Anderson^8,9 described the TDABC (time-driven activity-based costing) algorithm for calculating the cost of delivering a service based on 2 parameters: unit cost of a particular resource, and time required to supply it. These parameters apply to material costs and labor costs. In the medical setting, the TDABC algorithm can be applied by defining a care delivery value chain for each aspect of patient care and then multiplying incremental cost per unit time by time required to deliver that resource (Figure 1). Tabulating the overall unit cost for each resource then yields the overall cost of the care cycle. Clinical outcomes data can then be determined and used to calculate overall value for the patient care cycle.

In the study reported here, we used the TDABC algorithm to calculate the direct financial costs of surgical treatment of rotator cuff tears confirmed by magnetic resonance imaging (MRI) in an academic medical center.

Methods

Per our institution’s Office for the Protection of Research Subjects, institutional review board (IRB) approval is required only for projects using “human subjects” as defined by federal policy. In the present study, no private information could be identified, and all data were obtained from hospital billing records without intervention or interaction with individual patients. Accordingly, IRB approval was deemed unnecessary for our economic cost analysis.

Billing records of a single academic fellowship-trained sports surgeon were reviewed to identify patients who underwent primary repair of an MRI-confirmed rotator cuff tear between April 1, 2009, and July 31, 2012. Patients who had undergone prior shoulder surgery of any type were excluded from the study. Operative reports were reviewed, and exact surgical procedures performed were noted. The operating surgeon selected the specific repair techniques, including single- or double-row repair, with emphasis on restoring footprint coverage and avoiding overtensioning.

All surgeries were performed in an outpatient surgical center owned and operated by the surgeon’s home university. Surgeries were performed by the attending physician assisted by a senior orthopedic resident. The RCS care cycle was divided into 3 phases (Figure 2):

1. Preoperative. Patient’s interaction with receptionist in surgery center, time with preoperative nurse and circulating nurse in preoperative area, resident check-in time, and time placing preoperative nerve block and consumable materials used during block placement.

2. Operative. Time in operating room with surgical team for RCS, consumable materials used during surgery (eg, anchors, shavers, drapes), anesthetic medications, shoulder abduction pillow placed on completion of surgery, and cost of instrument processing.

3. Postoperative. Time in postoperative recovery area with recovery room nursing staff.

Time in each portion of the care cycle was directly observed and tabulated by hospital volunteers in the surgery center. Institutional billing data were used to identify material resources consumed, and the actual cost paid by the hospital for these resources was obtained from internal records. Mean hourly salary data and standard benefit rates were obtained for surgery center staff. Attending physician salary was extrapolated from published mean market salary data for academic physicians and mean hours worked,^10,11 and resident physician costs were tabulated from publically available institutional payroll data and average resident work hours at our institution. These cost data and times were then used to tabulate total cost for the RCS care cycle using the TDABC algorithm.

Results

We identified 28 shoulders in 26 patients (mean age, 54.5 years) who met the inclusion criteria. Of these 28 shoulders, 18 (64.3%) had an isolated supraspinatus tear, 8 (28.6%) had combined supraspinatus and infraspinatus tears, 1 (3.6%) had combined supraspinatus and subscapularis tears, and 1 (3.6%) had an isolated infraspinatus tear. Demographic data are listed in Table 1.

All patients received an interscalene nerve block in the preoperative area before being brought into the operating room. In our analysis, we included nerve block supply costs and the anesthesiologist’s mean time placing the nerve block.

In all cases, primary rotator cuff repair was performed with suture anchors (Parcus Medical) with the patient in the lateral decubitus position. In 13 (46%) of the 28 shoulders, this repair was described as “complex,” requiring double-row technique. Subacromial decompression and bursectomy were performed in addition to the rotator cuff repair. Labral débridement was performed in 23 patients, synovectomy in 10, biceps tenodesis with anchor (Smith & Nephew) in 1, and biceps tenotomy in 1. Mean time in operating room was 148 minutes; mean time in postoperative recovery unit was 105 minutes.

Directly observing the care cycle, hospital volunteers found that patients spent a mean of 15 minutes with the receptionist when they arrived in the outpatient surgical center, 25 minutes with nurses for check-in in the preoperative holding area, and 10 minutes with the anesthesiology resident and 15 minutes with the orthopedic surgery resident for preoperative evaluation and paperwork. Mean nerve block time was 20 minutes. Mean electrocardiogram (ECG) time (12 patients) was 15 minutes. The surgical technician spent a mean time of 20 minutes setting up the operating room before the patient was brought in and 15 minutes cleaning up after the patient was transferred to the recovery room. Costs of postoperative care in the recovery room were based on a 2:1 patient-to-nurse ratio, as is the standard practice in our outpatient surgery center.

Using the times mentioned and our hospital’s salary data—including standard hospital benefits rates of 33.5% for nonphysicians and 17.65% for physicians—we determined, using the TDABC algorithm, a direct cost of $5904.21 for this process cycle, excluding hospital overhead and indirect costs. Table 2 provides the overall cost breakdown. Compared with the direct economic cost, the mean hospital charge to insurers for the procedure was $31,459.35. Mean reimbursement from insurers was $9679.08.

Overall attending and resident physician costs were $1077.75, which consisted of $623.66 for the surgeon and $454.09 for the anesthesiologist (included placement of nerve block and administration of anesthesia during surgery). Preoperative bloodwork was obtained in 23 cases, adding a mean cost of $111.04 after adjusting for standard hospital markup. Preoperative ECG was performed in 12 cases, for an added mean cost of $7.30 based on the TDABC algorithm.

We also broke down costs by care cycle phase. The preoperative phase, excluding the preoperative laboratory studies and ECGs (not performed in all cases), cost $134.34 (2.3% of total costs); the operative phase cost $5718.01 (96.8% of total costs); and the postoperative phase cost $51.86 (0.9% of total costs). Within the operative phase, the cost of consumables (specifically, suture anchors) was the main cost driver. Mean anchor cost per case was $3432.67. “Complex” tears involving a double-row repair averaged $4570.25 in anchor cost per patient, as compared with $2522.60 in anchor costs for simple repairs.

Discussion

US health care costs continue to increase unsustainably, with rising pressure on hospitals and providers to deliver the highest value for each health care dollar. The present study is the first to calculate (using the TDABC algorithm) the direct economic cost ($5904.21) of the entire RCS care cycle at a university-based outpatient surgery center. Rent, utility costs, administrative costs, overhead, and other indirect costs at the surgery center were not included in this cost analysis, as they would be incurred irrespective of type of surgery performed. As such, our data isolate the procedure-specific costs of rotator cuff repair in order to provide a more meaningful comparison for other institutions, where indirect costs may be different.

In the literature, rigorous economic analysis of shoulder pathology is sparse. Kuye and colleagues¹² systematically reviewed economic evaluations in shoulder surgery for the period 1980–2010 and noted more than 50% of the papers were published between 2005 and 2010.¹² They also noted the poor quality of these studies and concluded more rigorous economic evaluations are needed to help justify the rising costs of shoulder-related treatments.

Several studies have directly evaluated costs associated with RCS. Cordasco and colleagues¹³ detailed the success of open rotator cuff repair as an outpatient procedure—noting its 43% cost savings ($4300 for outpatient vs $7500 for inpatient) and high patient satisfaction—using hospital charge data for operating room time, supplies, instruments, and postoperative slings. Churchill and Ghorai¹⁴ evaluated costs of mini-open and arthroscopic rotator cuff repairs in a statewide database and estimated the arthroscopic repair cost at $8985, compared with $7841 for the mini-open repair. They used reported hospital charge data, which were not itemized and did not include physician professional fees. Adla and colleagues,¹⁵ in a similar analysis of open versus arthroscopic cuff repair, estimated direct material costs of $1609.50 (arthroscopic) and $360.75 (open); these figures were converted from 2005 UK currency using the exchange rate cited in their paper. Salaries of surgeon, anesthesiologist, and other operating room personnel were said to be included in the operating room cost, but the authors’ paper did not include these data.

Two studies directly estimated the costs of arthroscopic rotator cuff repair. Hearnden and Tennent¹⁶ calculated the cost of RCS at their UK institution to be £2672, which included cost of operating room consumable materials, medication, and salaries of operating room personnel, including surgeon and anesthesiologist. Using online currency conversion from 2008 exchange rates and adjusting for inflation gave a corresponding US cost of $5449.63.¹⁷ Vitale and colleagues¹⁸ prospectively calculated costs of arthroscopic rotator cuff repair over a 1-year period using a cost-to-charge ratio from tabulated inpatient charges, procedure charges, and physician fees and payments abstracted from medical records, hospital billing, and administrative databases. Mean total cost for this cycle was $10,605.20, which included several costs (physical therapy, radiologist fees) not included in the present study. These studies, though more comprehensive than prior work, did not capture the entire cycle of surgical care.

Our study was designed to provide initial data on the direct costs of arthroscopic repair of the rotator cuff for the entire process cycle. Our overall cost estimate of $5904.21 differs significantly from prior work—not unexpected given the completely different cost methodology used.

Our study had several limitations. First, it was a single-surgeon evaluation, and a number of operating room variables (eg, use of adjunct instrumentation such as radiofrequency probes, differences in draping preferences) as well as surgeon volume in performing rotator cuff repairs might have substantially affected the reproducibility and generalizability of our data. Similarly, the large number of adjunctive procedures (eg, subacromial decompression, labral débridement) performed in conjunction with the rotator cuff repairs added operative time and therefore increased overall cost. Double-row repairs added operative time and increased the cost of consumable materials as well. Differences in surgeon preference for suture anchors may also be important, as anchors are a major cost driver and can vary significantly between vendors and institutions. Tear-related variables (eg, tear size, tear chronicity, degree of fatty cuff degeneration) were not controlled for and might have significantly affected operative time and associated cost. Resident involvement in the surgical procedure and anesthesia process in an academic setting prolongs surgical time and thus directly impacts costs.

In addition, we used the patient’s time in the operating room as a proxy for actual surgical time, as this was the only reliable and reproducible data point available in our electronic medical record. As such, an unquantifiable amount of surgeon time may have been overallocated to our cost estimate for time spent inducing anesthesia, positioning, helping take the patient off the operating table, and so on. However, as typical surgeon practice is to be involved in these tasks in the operating room, the possible overestimate of surgeon cost is likely minimal.

Our salary data for the TDABC algorithm were based on national averages for work hours and gross income for physicians and on hospital-based wage structure and may not be generalizable to other institutions. There may also be regional differences in work hours and salaries, which in turn would factor into a different per-minute cost for surgeon and anesthesiologist, depending on the exact geographic area where the surgery is performed. Costs may be higher at institutions that use certified nurse anesthetists rather than resident physicians because of the salary differences between these practitioners.

Moreover, the time that patients spend in the holding area—waiting to go into surgery and, after surgery, waiting for their ride home, for their prescriptions to be ready, and so forth—is an important variable to consider from a cost standpoint. However, as this time varied significantly and involved minimal contact with hospital personnel, we excluded its associated costs from our analysis. Similarly, and as already noted, hospital overhead and other indirect costs were excluded from analysis as well.

Conclusion

Using the TDABC algorithm, we found a direct economic cost of $5904.21 for RCS at our academic outpatient surgical center, with anchor cost the main cost driver. Judicious use of consumable resources is a key focus for cost containment in arthroscopic shoulder surgery, particularly with respect to implantable suture anchors. However, in the setting of more complex tears that require multiple anchors in a double-row repair construct, our pilot data may be useful to hospitals and surgery centers negotiating procedural reimbursement for the increased cost of complex repairs. Use of the TDABC algorithm for RCS and other procedures may also help in identifying opportunities to deliver more cost-effective health care.

Isolated brachialis muscle atrophy has been rarely reported. Among the few cases in the literature, 1 was attributed to a presumed compartment syndrome,1 1 to a displaced clavicle fracture,2 and 3 to neuralgic amyotrophy.3,4 We present a case of isolated brachialis muscle atrophy of unknown etiology, the presentation of which is consistent with neuralgic amyotrophy, also known as Parsonage-Turner syndrome or brachial plexitis. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old right-handed highway worker presented for evaluation of right-arm muscle atrophy. One year earlier, while lifting heavy bags at work, he felt a painful strain in his right arm, although there was no bruising or swelling. Approximately 4 weeks after this incident, he developed right shoulder pain and began to notice a slight decrease in the muscle mass of his right anterior arm. On evaluation at an outside facility, the physician noted some brachialis muscle atrophy. His shoulder pain was attributed to acromioclavicular joint problems. After an initial trial of physical therapy that did not alleviate this joint pain, an acromioclavicular joint resection was performed, and his pain improved. The brachialis muscle atrophy continued to progress, however. Over the course of the next 6 months, the patient noticed a continually decreasing muscle mass in his right arm, as well as arm fatigue with routine recreational activities. On follow-up, again at an outside institution, the treating physicians noted continued atrophy of the distal arm corresponding to the region of the brachialis musculature. Magnetic resonance imaging showed continuity of the brachialis muscle and tendon, with muscle atrophy. The patient was able to return to work, although with a subjective decrease in right elbow flexion strength.

On presentation at our institution, the patient complained of right arm weakness with heavy use but did not have pain or sensory complaints. His medical history was otherwise unremarkable. Physical examination revealed obvious wasting of the right brachialis muscle, most notable on the lateral aspect of the distal arm (Figures 1, 2A, 2B). His biceps muscle was functioning with full strength and had a normal bulk. He had a normal range of active and passive motion, including full extension and flexion of both elbows, as well as complete pronosupination of the forearms. There was no focal tenderness. Manual muscle testing of both upper extremities was completely normal except for 4/5 flexion strength of the right elbow. Neurovascular examination also revealed normal findings, including intact sensation over the radiolateral forearm. A second magnetic resonance image showed that the brachialis muscle had completely atrophied. Because the clinical examination and imaging studies both indicated isolated brachialis atrophy without deficit elsewhere along the musculocutaneous nerve, electromyography was not performed. The patient was fully functional and working at his usual occupation, and no further intervention was recommended.

Discussion

Isolated wasting of the brachialis muscle is extremely rare with few reports in the literature. Farmer and colleagues¹ reported a case of brachialis atrophy that was presumed to have resulted from exercise-induced chronic compartment syndrome. In that case, the patient developed a prodrome of arm pain followed by brachialis muscle atrophy. This patient was treated with oral anti-inflammatory agents with improvement in pain but without recovery of the brachialis muscle. While this case was attributed to compartment syndrome, it is likely that it represented neuralgic amyotrophy because there was no evidence of elbow flexion contracture, which would have accompanied true necrosis of the brachialis muscle as seen in compartment syndrome. However, acute compartment syndrome of the brachialis muscle after minor trauma has been reported.⁵ In that case, full-scale compartment syndrome was treated with rapid fasciotomy, with complete recovery of the brachialis.

Isolated brachialis atrophy has also been described in the setting of a displaced midshaft clavicle fracture in an elite athlete.² Two fracture fragments were thought to have injured the brachial plexus, separately causing brachialis atrophy and altered sensation over the clavicular head of the deltoid muscle. Atrophy remained 1 year after injury.

Although it had been occasionally reported, the first large series of patients with sporadic neuralgic amyotrophy in the upper extremity was reported by Parsonage and Turner⁶ in 1948. They described 136 patients who developed flaccid paralysis and atrophy of various muscles of the shoulder girdle and/or upper extremity. This was generally preceded by acute pain in the shoulder girdle, often associated with antecedent viral infection, stress, illness, or other precipitating factors.

To our knowledge, there have been 3 other reported cases of neuralgic amyotrophy of the brachialis muscle. Watson and colleagues³ presented 2 patients with nonspecific, neurogenic shoulder pain after which an indolent, progressive atrophy of the brachialis muscle ensued.³ Van Tongel and colleagues⁴ described a more traditional case of Parsonage-Turner syndrome, with bilateral wasting of the shoulder girdle that also exhibited unilateral brachialis atrophy without affecting other muscles in the arm.⁴ Our case, with shoulder pain followed by muscle atrophy, fits the pattern of neuralgic amyotrophy.

Others have similarly described isolated wasting of 1 muscle with the sparing of other muscles with a common innervation. Isolated atrophy of the extensor or flexor pollicis longus has been reported as variants of either posterior or anterior interosseous neuropathy, respectively.^7,8 Nerve fibers in the brachial plexus destined to innervate muscles supplied by the anterior interosseous nerve may be the cause of the motor deficit in cases of anterior interosseous nerve palsy, which seem to be associated with brachial plexitis.⁹

We present a case of isolated brachialis muscle atrophy after a minor trauma that may have resulted from Parsonage-Turner syndrome or a variant of brachial plexitis. The constellation of shoulder and arm pain, with subsequent muscle atrophy, makes this diagnosis likely.

Isolated brachialis muscle atrophy has been rarely reported. Among the few cases in the literature, 1 was attributed to a presumed compartment syndrome,1 1 to a displaced clavicle fracture,2 and 3 to neuralgic amyotrophy.3,4 We present a case of isolated brachialis muscle atrophy of unknown etiology, the presentation of which is consistent with neuralgic amyotrophy, also known as Parsonage-Turner syndrome or brachial plexitis. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old right-handed highway worker presented for evaluation of right-arm muscle atrophy. One year earlier, while lifting heavy bags at work, he felt a painful strain in his right arm, although there was no bruising or swelling. Approximately 4 weeks after this incident, he developed right shoulder pain and began to notice a slight decrease in the muscle mass of his right anterior arm. On evaluation at an outside facility, the physician noted some brachialis muscle atrophy. His shoulder pain was attributed to acromioclavicular joint problems. After an initial trial of physical therapy that did not alleviate this joint pain, an acromioclavicular joint resection was performed, and his pain improved. The brachialis muscle atrophy continued to progress, however. Over the course of the next 6 months, the patient noticed a continually decreasing muscle mass in his right arm, as well as arm fatigue with routine recreational activities. On follow-up, again at an outside institution, the treating physicians noted continued atrophy of the distal arm corresponding to the region of the brachialis musculature. Magnetic resonance imaging showed continuity of the brachialis muscle and tendon, with muscle atrophy. The patient was able to return to work, although with a subjective decrease in right elbow flexion strength.

On presentation at our institution, the patient complained of right arm weakness with heavy use but did not have pain or sensory complaints. His medical history was otherwise unremarkable. Physical examination revealed obvious wasting of the right brachialis muscle, most notable on the lateral aspect of the distal arm (Figures 1, 2A, 2B). His biceps muscle was functioning with full strength and had a normal bulk. He had a normal range of active and passive motion, including full extension and flexion of both elbows, as well as complete pronosupination of the forearms. There was no focal tenderness. Manual muscle testing of both upper extremities was completely normal except for 4/5 flexion strength of the right elbow. Neurovascular examination also revealed normal findings, including intact sensation over the radiolateral forearm. A second magnetic resonance image showed that the brachialis muscle had completely atrophied. Because the clinical examination and imaging studies both indicated isolated brachialis atrophy without deficit elsewhere along the musculocutaneous nerve, electromyography was not performed. The patient was fully functional and working at his usual occupation, and no further intervention was recommended.

Discussion

Isolated wasting of the brachialis muscle is extremely rare with few reports in the literature. Farmer and colleagues¹ reported a case of brachialis atrophy that was presumed to have resulted from exercise-induced chronic compartment syndrome. In that case, the patient developed a prodrome of arm pain followed by brachialis muscle atrophy. This patient was treated with oral anti-inflammatory agents with improvement in pain but without recovery of the brachialis muscle. While this case was attributed to compartment syndrome, it is likely that it represented neuralgic amyotrophy because there was no evidence of elbow flexion contracture, which would have accompanied true necrosis of the brachialis muscle as seen in compartment syndrome. However, acute compartment syndrome of the brachialis muscle after minor trauma has been reported.⁵ In that case, full-scale compartment syndrome was treated with rapid fasciotomy, with complete recovery of the brachialis.

Isolated brachialis atrophy has also been described in the setting of a displaced midshaft clavicle fracture in an elite athlete.² Two fracture fragments were thought to have injured the brachial plexus, separately causing brachialis atrophy and altered sensation over the clavicular head of the deltoid muscle. Atrophy remained 1 year after injury.

Although it had been occasionally reported, the first large series of patients with sporadic neuralgic amyotrophy in the upper extremity was reported by Parsonage and Turner⁶ in 1948. They described 136 patients who developed flaccid paralysis and atrophy of various muscles of the shoulder girdle and/or upper extremity. This was generally preceded by acute pain in the shoulder girdle, often associated with antecedent viral infection, stress, illness, or other precipitating factors.

To our knowledge, there have been 3 other reported cases of neuralgic amyotrophy of the brachialis muscle. Watson and colleagues³ presented 2 patients with nonspecific, neurogenic shoulder pain after which an indolent, progressive atrophy of the brachialis muscle ensued.³ Van Tongel and colleagues⁴ described a more traditional case of Parsonage-Turner syndrome, with bilateral wasting of the shoulder girdle that also exhibited unilateral brachialis atrophy without affecting other muscles in the arm.⁴ Our case, with shoulder pain followed by muscle atrophy, fits the pattern of neuralgic amyotrophy.

Others have similarly described isolated wasting of 1 muscle with the sparing of other muscles with a common innervation. Isolated atrophy of the extensor or flexor pollicis longus has been reported as variants of either posterior or anterior interosseous neuropathy, respectively.^7,8 Nerve fibers in the brachial plexus destined to innervate muscles supplied by the anterior interosseous nerve may be the cause of the motor deficit in cases of anterior interosseous nerve palsy, which seem to be associated with brachial plexitis.⁹

We present a case of isolated brachialis muscle atrophy after a minor trauma that may have resulted from Parsonage-Turner syndrome or a variant of brachial plexitis. The constellation of shoulder and arm pain, with subsequent muscle atrophy, makes this diagnosis likely.

Isolated brachialis muscle atrophy has been rarely reported. Among the few cases in the literature, 1 was attributed to a presumed compartment syndrome,1 1 to a displaced clavicle fracture,2 and 3 to neuralgic amyotrophy.3,4 We present a case of isolated brachialis muscle atrophy of unknown etiology, the presentation of which is consistent with neuralgic amyotrophy, also known as Parsonage-Turner syndrome or brachial plexitis. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old right-handed highway worker presented for evaluation of right-arm muscle atrophy. One year earlier, while lifting heavy bags at work, he felt a painful strain in his right arm, although there was no bruising or swelling. Approximately 4 weeks after this incident, he developed right shoulder pain and began to notice a slight decrease in the muscle mass of his right anterior arm. On evaluation at an outside facility, the physician noted some brachialis muscle atrophy. His shoulder pain was attributed to acromioclavicular joint problems. After an initial trial of physical therapy that did not alleviate this joint pain, an acromioclavicular joint resection was performed, and his pain improved. The brachialis muscle atrophy continued to progress, however. Over the course of the next 6 months, the patient noticed a continually decreasing muscle mass in his right arm, as well as arm fatigue with routine recreational activities. On follow-up, again at an outside institution, the treating physicians noted continued atrophy of the distal arm corresponding to the region of the brachialis musculature. Magnetic resonance imaging showed continuity of the brachialis muscle and tendon, with muscle atrophy. The patient was able to return to work, although with a subjective decrease in right elbow flexion strength.

On presentation at our institution, the patient complained of right arm weakness with heavy use but did not have pain or sensory complaints. His medical history was otherwise unremarkable. Physical examination revealed obvious wasting of the right brachialis muscle, most notable on the lateral aspect of the distal arm (Figures 1, 2A, 2B). His biceps muscle was functioning with full strength and had a normal bulk. He had a normal range of active and passive motion, including full extension and flexion of both elbows, as well as complete pronosupination of the forearms. There was no focal tenderness. Manual muscle testing of both upper extremities was completely normal except for 4/5 flexion strength of the right elbow. Neurovascular examination also revealed normal findings, including intact sensation over the radiolateral forearm. A second magnetic resonance image showed that the brachialis muscle had completely atrophied. Because the clinical examination and imaging studies both indicated isolated brachialis atrophy without deficit elsewhere along the musculocutaneous nerve, electromyography was not performed. The patient was fully functional and working at his usual occupation, and no further intervention was recommended.

Discussion

Isolated wasting of the brachialis muscle is extremely rare with few reports in the literature. Farmer and colleagues¹ reported a case of brachialis atrophy that was presumed to have resulted from exercise-induced chronic compartment syndrome. In that case, the patient developed a prodrome of arm pain followed by brachialis muscle atrophy. This patient was treated with oral anti-inflammatory agents with improvement in pain but without recovery of the brachialis muscle. While this case was attributed to compartment syndrome, it is likely that it represented neuralgic amyotrophy because there was no evidence of elbow flexion contracture, which would have accompanied true necrosis of the brachialis muscle as seen in compartment syndrome. However, acute compartment syndrome of the brachialis muscle after minor trauma has been reported.⁵ In that case, full-scale compartment syndrome was treated with rapid fasciotomy, with complete recovery of the brachialis.

Isolated brachialis atrophy has also been described in the setting of a displaced midshaft clavicle fracture in an elite athlete.² Two fracture fragments were thought to have injured the brachial plexus, separately causing brachialis atrophy and altered sensation over the clavicular head of the deltoid muscle. Atrophy remained 1 year after injury.

Although it had been occasionally reported, the first large series of patients with sporadic neuralgic amyotrophy in the upper extremity was reported by Parsonage and Turner⁶ in 1948. They described 136 patients who developed flaccid paralysis and atrophy of various muscles of the shoulder girdle and/or upper extremity. This was generally preceded by acute pain in the shoulder girdle, often associated with antecedent viral infection, stress, illness, or other precipitating factors.

To our knowledge, there have been 3 other reported cases of neuralgic amyotrophy of the brachialis muscle. Watson and colleagues³ presented 2 patients with nonspecific, neurogenic shoulder pain after which an indolent, progressive atrophy of the brachialis muscle ensued.³ Van Tongel and colleagues⁴ described a more traditional case of Parsonage-Turner syndrome, with bilateral wasting of the shoulder girdle that also exhibited unilateral brachialis atrophy without affecting other muscles in the arm.⁴ Our case, with shoulder pain followed by muscle atrophy, fits the pattern of neuralgic amyotrophy.

Others have similarly described isolated wasting of 1 muscle with the sparing of other muscles with a common innervation. Isolated atrophy of the extensor or flexor pollicis longus has been reported as variants of either posterior or anterior interosseous neuropathy, respectively.^7,8 Nerve fibers in the brachial plexus destined to innervate muscles supplied by the anterior interosseous nerve may be the cause of the motor deficit in cases of anterior interosseous nerve palsy, which seem to be associated with brachial plexitis.⁹

We present a case of isolated brachialis muscle atrophy after a minor trauma that may have resulted from Parsonage-Turner syndrome or a variant of brachial plexitis. The constellation of shoulder and arm pain, with subsequent muscle atrophy, makes this diagnosis likely.

Elbow epicondylitis is a painful condition caused by overuse and development of tendon degeneration. It is one of the most common elbow problems in adults, occurring both laterally and medially. “Tennis elbow” or lateral epicondylitis is diagnosed 7 to 10 times more often than the medial form, “golfer’s elbow.”¹ Although these injuries are often associated with racquet sports, activities such as bowling and weightlifting and the professions of carpentry, plumbing, and meat-cutting have been described as causes.^2,3

Elbow epicondylitis is thought to be the result of multiple microtraumatic events that cause disruption of the internal structure of the tendon and degeneration of the cells and matrix.⁴ Lesions caused by chronic overuse are now commonly called tendinosis and are not considered inflammatory in nature. Although the term tendinitis is used frequently and indiscriminately, histopathologic studies have shown that specimens of tendon obtained from areas of chronic overuse do not contain large numbers of macrophages, lymphocytes, or neutrophils.⁵ Rather, tendinosis appears to be a degenerative process that is characterized by the presence of dense populations of fibroblasts, vascular hyperplasia, and disorganized collagen. This constellation of findings has been termed by some authors as angiofibroblastic hyperplasia.⁶

Conservative care for the treatment of chronic tendinosis has been well described and is often successful. Treatment consists of rest, ice, compression, and elevation in the acute phase. This can be followed with bracing, activity modification, physical therapy, oral nonsteroidal anti-inflammatory drugs, topical applications, and injections of cortisone or platelet-rich plasma. When conservative treatment fails, surgical intervention may be considered. Procedures for the treatment of lateral epicondylitis include open débridement and release, arthroscopic débridement, percutaneous release, and radiofrequency (RF) coblation. The goals of operative treatment are to resect pathological material, to stimulate neovascularization by producing focused local bleeding, and to create a healthy scar while doing the least possible structural damage to surrounding tissues.⁴

The efficacy of a bipolar RF-based approach for using microtenotomy was first recognized when researchers studied the effects of transmyocardial revascularization for treating congestive heart failure.⁷ The use of RF- and laser-based transmyocardial revascularization initiated an angiogenic response in degenerated (ischemic) heart tissue. This success led to investigating the use of a RF-based approach for performing microtenotomy. Preclinical studies demonstrated that RF-based microtenotomy was effective for stimulating an angiogenic-healing response in tendon tissue.⁸ Histologic evaluation of treated tendons showed an early inflammatory response, with new blood-vessel formation by 28 days. In 2005, short-term results of this technique were published.⁹ This preliminary prospective case series showed that the treatment was safe and effectively improved or eliminated clinical symptoms.⁹ In the present midterm study, we hypothesized that pain scores would improve after RF microtenotomy and that these favorable results would continue to be observed over a longer term postoperatively.

Materials and Methods

Patients

This was a prospective, nonrandomized, single-center clinical study. After receiving institutional review board approval, patients who were 18 to 65 years of age with a diagnosis of tendinosis were approached for enrollment. For inclusion, patients had to be symptomatic for at least 6 months and had to have failed extensive conservative treatments. Nonoperative treatment included activity modification, enrollment in a facility- or home-based exercise program, bracing, oral nonsteroidal anti-inflammatory medication, and cortisone injection. Candidates with diabetes, confirmed or suspected pregnancy, surgery in the same tendon, implanted hardware adjacent to the target treatment region, or who were receiving care under workers’ compensation or had litigation-related injury were excluded. A single clinician performed a thorough medical history and clinical evaluation. The clinical follow-up and data collection were performed by an independent medical technician.

Clinical Outcomes

Pain status was assessed by using a visual analog scale (VAS). Postoperative clinical assessment was conducted within the first 2 days; at 7 to 10 days; at 4 to 6 weeks; and at 3, 6, 12, and 24 months, up to 9 years postoperatively. The VAS scales were completed annually up to 9 years after the procedure.

The percent improvement of VAS score was calculated. This value represented the difference between the patient’s preoperative and most recent VAS assessments. Failure of the procedure was defined as less than 50% improvement of the VAS score.

The RF-Based Microtenotomy Device

The Topaz Microdebrider (ArthroCare), connected to a System 2000 generator at setting 4 (175 V-RMS), was used to perform the RF-based microtenotomy. The device uses a controlled plasma-mediated RF-based process (coblation). Radiofrequency energy is used to excite the electrolytes in a conductive medium, such as a saline solution, to create precisely focused plasma. The energized particles in the plasma have sufficient energy to break molecular bonds,^10,11 excising or dissolving (ie, ablating) soft tissue at relatively low temperatures (typically, 40°-70° C).^12,13 The diameter of the active tip of the Topaz device is 0.8 mm.

Surgical Procedure

The senior author performed the majority of procedures in this study. Near the end of the series, the senior author’s associate also performed procedures. The symptomatic area of the tendon was identified and marked while the patient was alert. After the patient was positioned appropriately, light sedation was administered. A tourniquet was placed over the treatment limb and inflated to 250 mm Hg. A small incision, approximately 3 cm in length, was made over the marked treatment site to expose the involved tendon. After initiating sterile isotonic saline flow of 1 drop every 1 to 2 seconds from a line connected to the RF system, the tip of the device was placed on the tendon perpendicular to its surface (Figure 1). Using a light touch, it was activated for 500 milliseconds using a timer accessory for the control box. Five to 8 grams of pressure were applied with the device to penetrate the tendon and achieve successful ablation. The RF applications were performed at 5-mm intervals, to create a grid-like pattern on and throughout the symptomatic tendon area. The tendon was perforated to a depth of several millimeters on every second or third application throughout the treatment grid. After treatment of the symptomatic area, the wound was irrigated with copious amounts of normal saline solution and closed with interrupted nylon suture. Local anesthetic was injected only in the skin and in subcutaneous tissue. Standard wound dressings were applied. In the immediate postoperative period, the patient was advised to begin gentle active and passive range-of-motion exercises. Each patient was evaluated at 1 week postoperatively. At 6 weeks, patients were permitted to increase the intensity of their activities. Return to sports and heavy lifting was allowed once the patient was asymptomatic and had achieved full strength and range of motion; this typically occurred at 6 to 9 weeks after surgery.

Statistical Analysis

Normally distributed data were described using standard parametric statistics (ie, mean and standard deviation); non-normally distributed data were characterized using nonparametric descriptors (ie, median and quartiles). Statistical evaluation of improvement in pain status was performed by calculating 99% confidence intervals and using the Student t test for change between subsequent time points. Use of confidence intervals provides a descriptive analysis of the observed treatment effect, while permitting determination of statistical relevance. In all statistical testing, confidence bounds not including 0 were considered statistically significant. Probability of P ≤ .01 for committing type I experiment-wise error (rejecting a true null hypothesis) was selected for all statistical testing because of our lack of a control group, small sample size, and evaluation of multiple postoperative time points.

Results

Eighty consecutive patients with tendinosis of the elbow were included in this study. Sixty-nine patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The average age of the patients (33 women, 47 men) was 50 years. The duration of follow-up evaluation ranged from 6 months to 9 years (mean, 2.5 years; median, 2 years). The Table presents the VAS improvement for these patients after the RF microtenotomy.

Within the lateral epicondylitis group, 91% (63/69) of the patients reported a successful outcome. The postoperative VAS improved to 1.3 from 6.9, which demonstrated an 81% improvement. Of the 6 patients that did not improve, 2 underwent repeat surgery.

Among the patients treated for medial epicondylitis, 91% (10/11) reported improvement in symptoms. The postoperative VAS improved to 1.3 from 6.1, a 79% improvement. One patient did not improve and did not undergo repeat surgery.

Discussion

For the treatment of medial and lateral elbow epicondylitis, RF microtenotomy is successful in 91% of patients. Symptomatic improvement was observed up to 9 years postoperatively. During this study, no complications were recorded; 7 treatment failures occurred. When compared with other techniques, the results with RF microtenotomy are equivalent or better.

In a retrospective study, Szabo and colleagues¹⁴ compared open, arthroscopic, and percutaneous release for lateral elbow tendinosis. They found the 3 methods to be highly effective for the treatment of tendinosis with no significant difference between them. Resection of the epicondyle and transfer of the anconeus muscle was found to be effective (94%) in a retrospective study by Almquist and colleagues.¹⁵ Dunn and coauthors¹⁶ reported a 97% success rate at 10 to 14 years postoperatively with a mini-open technique. Rubenthaler and colleagues¹⁷ showed 88% effectiveness for the open technique and 93% for the arthroscopic technique. With arthroscopic release of the extensor carpi radialis brevis tendon, Lattermann and coauthors¹⁸ reported clinical improvement in 94% of patients. In a study by Rose and colleagues,¹⁹ denervation of the lateral epicondyle was effective in relieving pain in 80% of patients who had had a positive response to a local anesthetic block. In a recently published study by Koh and coauthors,²⁰ 19 of 20 patients experienced a favorable outcome after treatment with ultrasonic microresection.

Regardless of surgical methods and their reported success rate, complications are associated with elbow surgery. Postoperative problems may include restricted function, elbow instability, persistent muscle weakness, and painful neuroma of the posterior cutaneous nerve.^10,21,22 The recent introduction of arthroscopic release offers the potential for less morbidity and enables visualization of the elbow joint. However, disadvantages of the arthroscopic approach include violation of the joint for extra-articular pathology, increased operative time and cost, and neurovascular complications. Additionally, it is possible that the entire spectrum of extra-articular tendinosis cannot be effectively identified arthroscopically.²³ In a prospective, randomized study, Meknas and colleagues²⁴ compared RF microtenotomy with extensor tendon release and repair. They showed that patients treated with RF-microtenotomy experienced earlier pain relief and improved grip strength over the release group.

Different proposed mechanisms of action have been described to explain the favorable effects of the RF-based microtenotomy procedure, such as induced healing by an angiogenic response in the tendon tissue. In an animal study, Harwood and colleagues⁸ showed that low-dose RF-based plasma microtenotomy has the ability to stimulate angiogenic growth factors in tendons, such as α_v integrin and vascular endothelial growth factor. These factors have been shown to be associated with healing.⁸ Early inflammatory response with new-vessel formation after 28 days was found in another animal study using the same method.²⁵ Evaluation of RF-based methods in a prospective controlled laboratory study using a rabbit-tendon model showed histologic evidence of early inflammation with development of neovasculature after treatment.⁸ A later histologic study using an aged Achilles rabbit tendon model was performed to evaluate the effect of RF-based plasma microtenotomy on collagen remodeling.²⁵ The degenerated tendon showed gaps, few normal crimpings, and a lack of reflectivity under polarized light. At 9 days after treatment, the treated tendon showed localized irregular crimpings, and, at 30 days, it showed regular crimping, tightly dense collagen fibers, and hypercellularity with good reflectivity. This was similar in appearance to a normal nondegenerated tendon (Figures 2A-2D). The RF-treated tendon also demonstrated an increase in production of insulin-like growth factor-1, β-fibroblast growth factor-1, α_v integrin, and vascular endothelial growth factor.

Pathologic nerve ingrowth or nerve irritation in the tendon substance has been considered a possible cause of the pain experienced with tendinosis. Radiofrequency treatment has been shown to induce acute degeneration and ablation of sensory nerve fibers.²⁶ These degenerated nerve fibers were observed to regenerate at 90 days after treatment.²⁷ These findings provide potential evidence for early pain relief that is maintained long term as the nerves regenerate.

This midterm follow-up of patients with elbow epicondylitis has shown that RF-based microtenotomy can produce successful, durable results. Microtenotomy is a technically simple procedure to perform and is associated with a rapid and uncomplicated recovery. It is safe and can effectively eliminate or markedly reduce clinical symptoms.

Limitations

Lateral epicondylitis has been described as a self-limited disease, with resolution of symptoms at 12 to 18 months with conservative treatment. This perspective challenges the indication of any proposed surgical treatment for the condition. Although the results of this research demonstrated the benefits of RF microtenotomy, there are inherent limitations of the study design. The study lacks a control group, and randomization would improve the strength of the study. Additional outcome measures, such as Disabilities of the Arm, Shoulder, and Hand score, and grip strength could complement pain scores to provide more data. These data were collected in a preliminary study.⁹ Postoperative histologic analysis of treated human tissue would be ideal, but ethical considerations limit study to animal models. An additional limitation is potential examiner bias. Data collection was performed by an independent medical technician; a third-party blinded evaluation could have been performed, but this was not feasible in a clinical setting.

Conclusion

Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed 9 years after surgery.

Elbow epicondylitis is a painful condition caused by overuse and development of tendon degeneration. It is one of the most common elbow problems in adults, occurring both laterally and medially. “Tennis elbow” or lateral epicondylitis is diagnosed 7 to 10 times more often than the medial form, “golfer’s elbow.”¹ Although these injuries are often associated with racquet sports, activities such as bowling and weightlifting and the professions of carpentry, plumbing, and meat-cutting have been described as causes.^2,3

Elbow epicondylitis is thought to be the result of multiple microtraumatic events that cause disruption of the internal structure of the tendon and degeneration of the cells and matrix.⁴ Lesions caused by chronic overuse are now commonly called tendinosis and are not considered inflammatory in nature. Although the term tendinitis is used frequently and indiscriminately, histopathologic studies have shown that specimens of tendon obtained from areas of chronic overuse do not contain large numbers of macrophages, lymphocytes, or neutrophils.⁵ Rather, tendinosis appears to be a degenerative process that is characterized by the presence of dense populations of fibroblasts, vascular hyperplasia, and disorganized collagen. This constellation of findings has been termed by some authors as angiofibroblastic hyperplasia.⁶

Conservative care for the treatment of chronic tendinosis has been well described and is often successful. Treatment consists of rest, ice, compression, and elevation in the acute phase. This can be followed with bracing, activity modification, physical therapy, oral nonsteroidal anti-inflammatory drugs, topical applications, and injections of cortisone or platelet-rich plasma. When conservative treatment fails, surgical intervention may be considered. Procedures for the treatment of lateral epicondylitis include open débridement and release, arthroscopic débridement, percutaneous release, and radiofrequency (RF) coblation. The goals of operative treatment are to resect pathological material, to stimulate neovascularization by producing focused local bleeding, and to create a healthy scar while doing the least possible structural damage to surrounding tissues.⁴

The efficacy of a bipolar RF-based approach for using microtenotomy was first recognized when researchers studied the effects of transmyocardial revascularization for treating congestive heart failure.⁷ The use of RF- and laser-based transmyocardial revascularization initiated an angiogenic response in degenerated (ischemic) heart tissue. This success led to investigating the use of a RF-based approach for performing microtenotomy. Preclinical studies demonstrated that RF-based microtenotomy was effective for stimulating an angiogenic-healing response in tendon tissue.⁸ Histologic evaluation of treated tendons showed an early inflammatory response, with new blood-vessel formation by 28 days. In 2005, short-term results of this technique were published.⁹ This preliminary prospective case series showed that the treatment was safe and effectively improved or eliminated clinical symptoms.⁹ In the present midterm study, we hypothesized that pain scores would improve after RF microtenotomy and that these favorable results would continue to be observed over a longer term postoperatively.

Materials and Methods

Patients

This was a prospective, nonrandomized, single-center clinical study. After receiving institutional review board approval, patients who were 18 to 65 years of age with a diagnosis of tendinosis were approached for enrollment. For inclusion, patients had to be symptomatic for at least 6 months and had to have failed extensive conservative treatments. Nonoperative treatment included activity modification, enrollment in a facility- or home-based exercise program, bracing, oral nonsteroidal anti-inflammatory medication, and cortisone injection. Candidates with diabetes, confirmed or suspected pregnancy, surgery in the same tendon, implanted hardware adjacent to the target treatment region, or who were receiving care under workers’ compensation or had litigation-related injury were excluded. A single clinician performed a thorough medical history and clinical evaluation. The clinical follow-up and data collection were performed by an independent medical technician.

Clinical Outcomes

Pain status was assessed by using a visual analog scale (VAS). Postoperative clinical assessment was conducted within the first 2 days; at 7 to 10 days; at 4 to 6 weeks; and at 3, 6, 12, and 24 months, up to 9 years postoperatively. The VAS scales were completed annually up to 9 years after the procedure.

The percent improvement of VAS score was calculated. This value represented the difference between the patient’s preoperative and most recent VAS assessments. Failure of the procedure was defined as less than 50% improvement of the VAS score.

The RF-Based Microtenotomy Device

The Topaz Microdebrider (ArthroCare), connected to a System 2000 generator at setting 4 (175 V-RMS), was used to perform the RF-based microtenotomy. The device uses a controlled plasma-mediated RF-based process (coblation). Radiofrequency energy is used to excite the electrolytes in a conductive medium, such as a saline solution, to create precisely focused plasma. The energized particles in the plasma have sufficient energy to break molecular bonds,^10,11 excising or dissolving (ie, ablating) soft tissue at relatively low temperatures (typically, 40°-70° C).^12,13 The diameter of the active tip of the Topaz device is 0.8 mm.

Surgical Procedure

The senior author performed the majority of procedures in this study. Near the end of the series, the senior author’s associate also performed procedures. The symptomatic area of the tendon was identified and marked while the patient was alert. After the patient was positioned appropriately, light sedation was administered. A tourniquet was placed over the treatment limb and inflated to 250 mm Hg. A small incision, approximately 3 cm in length, was made over the marked treatment site to expose the involved tendon. After initiating sterile isotonic saline flow of 1 drop every 1 to 2 seconds from a line connected to the RF system, the tip of the device was placed on the tendon perpendicular to its surface (Figure 1). Using a light touch, it was activated for 500 milliseconds using a timer accessory for the control box. Five to 8 grams of pressure were applied with the device to penetrate the tendon and achieve successful ablation. The RF applications were performed at 5-mm intervals, to create a grid-like pattern on and throughout the symptomatic tendon area. The tendon was perforated to a depth of several millimeters on every second or third application throughout the treatment grid. After treatment of the symptomatic area, the wound was irrigated with copious amounts of normal saline solution and closed with interrupted nylon suture. Local anesthetic was injected only in the skin and in subcutaneous tissue. Standard wound dressings were applied. In the immediate postoperative period, the patient was advised to begin gentle active and passive range-of-motion exercises. Each patient was evaluated at 1 week postoperatively. At 6 weeks, patients were permitted to increase the intensity of their activities. Return to sports and heavy lifting was allowed once the patient was asymptomatic and had achieved full strength and range of motion; this typically occurred at 6 to 9 weeks after surgery.

Statistical Analysis

Normally distributed data were described using standard parametric statistics (ie, mean and standard deviation); non-normally distributed data were characterized using nonparametric descriptors (ie, median and quartiles). Statistical evaluation of improvement in pain status was performed by calculating 99% confidence intervals and using the Student t test for change between subsequent time points. Use of confidence intervals provides a descriptive analysis of the observed treatment effect, while permitting determination of statistical relevance. In all statistical testing, confidence bounds not including 0 were considered statistically significant. Probability of P ≤ .01 for committing type I experiment-wise error (rejecting a true null hypothesis) was selected for all statistical testing because of our lack of a control group, small sample size, and evaluation of multiple postoperative time points.

Results

Eighty consecutive patients with tendinosis of the elbow were included in this study. Sixty-nine patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The average age of the patients (33 women, 47 men) was 50 years. The duration of follow-up evaluation ranged from 6 months to 9 years (mean, 2.5 years; median, 2 years). The Table presents the VAS improvement for these patients after the RF microtenotomy.

Within the lateral epicondylitis group, 91% (63/69) of the patients reported a successful outcome. The postoperative VAS improved to 1.3 from 6.9, which demonstrated an 81% improvement. Of the 6 patients that did not improve, 2 underwent repeat surgery.

Among the patients treated for medial epicondylitis, 91% (10/11) reported improvement in symptoms. The postoperative VAS improved to 1.3 from 6.1, a 79% improvement. One patient did not improve and did not undergo repeat surgery.

Discussion

For the treatment of medial and lateral elbow epicondylitis, RF microtenotomy is successful in 91% of patients. Symptomatic improvement was observed up to 9 years postoperatively. During this study, no complications were recorded; 7 treatment failures occurred. When compared with other techniques, the results with RF microtenotomy are equivalent or better.

In a retrospective study, Szabo and colleagues¹⁴ compared open, arthroscopic, and percutaneous release for lateral elbow tendinosis. They found the 3 methods to be highly effective for the treatment of tendinosis with no significant difference between them. Resection of the epicondyle and transfer of the anconeus muscle was found to be effective (94%) in a retrospective study by Almquist and colleagues.¹⁵ Dunn and coauthors¹⁶ reported a 97% success rate at 10 to 14 years postoperatively with a mini-open technique. Rubenthaler and colleagues¹⁷ showed 88% effectiveness for the open technique and 93% for the arthroscopic technique. With arthroscopic release of the extensor carpi radialis brevis tendon, Lattermann and coauthors¹⁸ reported clinical improvement in 94% of patients. In a study by Rose and colleagues,¹⁹ denervation of the lateral epicondyle was effective in relieving pain in 80% of patients who had had a positive response to a local anesthetic block. In a recently published study by Koh and coauthors,²⁰ 19 of 20 patients experienced a favorable outcome after treatment with ultrasonic microresection.

Regardless of surgical methods and their reported success rate, complications are associated with elbow surgery. Postoperative problems may include restricted function, elbow instability, persistent muscle weakness, and painful neuroma of the posterior cutaneous nerve.^10,21,22 The recent introduction of arthroscopic release offers the potential for less morbidity and enables visualization of the elbow joint. However, disadvantages of the arthroscopic approach include violation of the joint for extra-articular pathology, increased operative time and cost, and neurovascular complications. Additionally, it is possible that the entire spectrum of extra-articular tendinosis cannot be effectively identified arthroscopically.²³ In a prospective, randomized study, Meknas and colleagues²⁴ compared RF microtenotomy with extensor tendon release and repair. They showed that patients treated with RF-microtenotomy experienced earlier pain relief and improved grip strength over the release group.

Different proposed mechanisms of action have been described to explain the favorable effects of the RF-based microtenotomy procedure, such as induced healing by an angiogenic response in the tendon tissue. In an animal study, Harwood and colleagues⁸ showed that low-dose RF-based plasma microtenotomy has the ability to stimulate angiogenic growth factors in tendons, such as α_v integrin and vascular endothelial growth factor. These factors have been shown to be associated with healing.⁸ Early inflammatory response with new-vessel formation after 28 days was found in another animal study using the same method.²⁵ Evaluation of RF-based methods in a prospective controlled laboratory study using a rabbit-tendon model showed histologic evidence of early inflammation with development of neovasculature after treatment.⁸ A later histologic study using an aged Achilles rabbit tendon model was performed to evaluate the effect of RF-based plasma microtenotomy on collagen remodeling.²⁵ The degenerated tendon showed gaps, few normal crimpings, and a lack of reflectivity under polarized light. At 9 days after treatment, the treated tendon showed localized irregular crimpings, and, at 30 days, it showed regular crimping, tightly dense collagen fibers, and hypercellularity with good reflectivity. This was similar in appearance to a normal nondegenerated tendon (Figures 2A-2D). The RF-treated tendon also demonstrated an increase in production of insulin-like growth factor-1, β-fibroblast growth factor-1, α_v integrin, and vascular endothelial growth factor.

Pathologic nerve ingrowth or nerve irritation in the tendon substance has been considered a possible cause of the pain experienced with tendinosis. Radiofrequency treatment has been shown to induce acute degeneration and ablation of sensory nerve fibers.²⁶ These degenerated nerve fibers were observed to regenerate at 90 days after treatment.²⁷ These findings provide potential evidence for early pain relief that is maintained long term as the nerves regenerate.

This midterm follow-up of patients with elbow epicondylitis has shown that RF-based microtenotomy can produce successful, durable results. Microtenotomy is a technically simple procedure to perform and is associated with a rapid and uncomplicated recovery. It is safe and can effectively eliminate or markedly reduce clinical symptoms.

Limitations

Lateral epicondylitis has been described as a self-limited disease, with resolution of symptoms at 12 to 18 months with conservative treatment. This perspective challenges the indication of any proposed surgical treatment for the condition. Although the results of this research demonstrated the benefits of RF microtenotomy, there are inherent limitations of the study design. The study lacks a control group, and randomization would improve the strength of the study. Additional outcome measures, such as Disabilities of the Arm, Shoulder, and Hand score, and grip strength could complement pain scores to provide more data. These data were collected in a preliminary study.⁹ Postoperative histologic analysis of treated human tissue would be ideal, but ethical considerations limit study to animal models. An additional limitation is potential examiner bias. Data collection was performed by an independent medical technician; a third-party blinded evaluation could have been performed, but this was not feasible in a clinical setting.

Conclusion

Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed 9 years after surgery.

Elbow epicondylitis is a painful condition caused by overuse and development of tendon degeneration. It is one of the most common elbow problems in adults, occurring both laterally and medially. “Tennis elbow” or lateral epicondylitis is diagnosed 7 to 10 times more often than the medial form, “golfer’s elbow.”¹ Although these injuries are often associated with racquet sports, activities such as bowling and weightlifting and the professions of carpentry, plumbing, and meat-cutting have been described as causes.^2,3

Elbow epicondylitis is thought to be the result of multiple microtraumatic events that cause disruption of the internal structure of the tendon and degeneration of the cells and matrix.⁴ Lesions caused by chronic overuse are now commonly called tendinosis and are not considered inflammatory in nature. Although the term tendinitis is used frequently and indiscriminately, histopathologic studies have shown that specimens of tendon obtained from areas of chronic overuse do not contain large numbers of macrophages, lymphocytes, or neutrophils.⁵ Rather, tendinosis appears to be a degenerative process that is characterized by the presence of dense populations of fibroblasts, vascular hyperplasia, and disorganized collagen. This constellation of findings has been termed by some authors as angiofibroblastic hyperplasia.⁶

Conservative care for the treatment of chronic tendinosis has been well described and is often successful. Treatment consists of rest, ice, compression, and elevation in the acute phase. This can be followed with bracing, activity modification, physical therapy, oral nonsteroidal anti-inflammatory drugs, topical applications, and injections of cortisone or platelet-rich plasma. When conservative treatment fails, surgical intervention may be considered. Procedures for the treatment of lateral epicondylitis include open débridement and release, arthroscopic débridement, percutaneous release, and radiofrequency (RF) coblation. The goals of operative treatment are to resect pathological material, to stimulate neovascularization by producing focused local bleeding, and to create a healthy scar while doing the least possible structural damage to surrounding tissues.⁴

The efficacy of a bipolar RF-based approach for using microtenotomy was first recognized when researchers studied the effects of transmyocardial revascularization for treating congestive heart failure.⁷ The use of RF- and laser-based transmyocardial revascularization initiated an angiogenic response in degenerated (ischemic) heart tissue. This success led to investigating the use of a RF-based approach for performing microtenotomy. Preclinical studies demonstrated that RF-based microtenotomy was effective for stimulating an angiogenic-healing response in tendon tissue.⁸ Histologic evaluation of treated tendons showed an early inflammatory response, with new blood-vessel formation by 28 days. In 2005, short-term results of this technique were published.⁹ This preliminary prospective case series showed that the treatment was safe and effectively improved or eliminated clinical symptoms.⁹ In the present midterm study, we hypothesized that pain scores would improve after RF microtenotomy and that these favorable results would continue to be observed over a longer term postoperatively.

Materials and Methods

Patients

This was a prospective, nonrandomized, single-center clinical study. After receiving institutional review board approval, patients who were 18 to 65 years of age with a diagnosis of tendinosis were approached for enrollment. For inclusion, patients had to be symptomatic for at least 6 months and had to have failed extensive conservative treatments. Nonoperative treatment included activity modification, enrollment in a facility- or home-based exercise program, bracing, oral nonsteroidal anti-inflammatory medication, and cortisone injection. Candidates with diabetes, confirmed or suspected pregnancy, surgery in the same tendon, implanted hardware adjacent to the target treatment region, or who were receiving care under workers’ compensation or had litigation-related injury were excluded. A single clinician performed a thorough medical history and clinical evaluation. The clinical follow-up and data collection were performed by an independent medical technician.

Clinical Outcomes

Pain status was assessed by using a visual analog scale (VAS). Postoperative clinical assessment was conducted within the first 2 days; at 7 to 10 days; at 4 to 6 weeks; and at 3, 6, 12, and 24 months, up to 9 years postoperatively. The VAS scales were completed annually up to 9 years after the procedure.

The percent improvement of VAS score was calculated. This value represented the difference between the patient’s preoperative and most recent VAS assessments. Failure of the procedure was defined as less than 50% improvement of the VAS score.

The RF-Based Microtenotomy Device

The Topaz Microdebrider (ArthroCare), connected to a System 2000 generator at setting 4 (175 V-RMS), was used to perform the RF-based microtenotomy. The device uses a controlled plasma-mediated RF-based process (coblation). Radiofrequency energy is used to excite the electrolytes in a conductive medium, such as a saline solution, to create precisely focused plasma. The energized particles in the plasma have sufficient energy to break molecular bonds,^10,11 excising or dissolving (ie, ablating) soft tissue at relatively low temperatures (typically, 40°-70° C).^12,13 The diameter of the active tip of the Topaz device is 0.8 mm.

Surgical Procedure

The senior author performed the majority of procedures in this study. Near the end of the series, the senior author’s associate also performed procedures. The symptomatic area of the tendon was identified and marked while the patient was alert. After the patient was positioned appropriately, light sedation was administered. A tourniquet was placed over the treatment limb and inflated to 250 mm Hg. A small incision, approximately 3 cm in length, was made over the marked treatment site to expose the involved tendon. After initiating sterile isotonic saline flow of 1 drop every 1 to 2 seconds from a line connected to the RF system, the tip of the device was placed on the tendon perpendicular to its surface (Figure 1). Using a light touch, it was activated for 500 milliseconds using a timer accessory for the control box. Five to 8 grams of pressure were applied with the device to penetrate the tendon and achieve successful ablation. The RF applications were performed at 5-mm intervals, to create a grid-like pattern on and throughout the symptomatic tendon area. The tendon was perforated to a depth of several millimeters on every second or third application throughout the treatment grid. After treatment of the symptomatic area, the wound was irrigated with copious amounts of normal saline solution and closed with interrupted nylon suture. Local anesthetic was injected only in the skin and in subcutaneous tissue. Standard wound dressings were applied. In the immediate postoperative period, the patient was advised to begin gentle active and passive range-of-motion exercises. Each patient was evaluated at 1 week postoperatively. At 6 weeks, patients were permitted to increase the intensity of their activities. Return to sports and heavy lifting was allowed once the patient was asymptomatic and had achieved full strength and range of motion; this typically occurred at 6 to 9 weeks after surgery.

Statistical Analysis

Normally distributed data were described using standard parametric statistics (ie, mean and standard deviation); non-normally distributed data were characterized using nonparametric descriptors (ie, median and quartiles). Statistical evaluation of improvement in pain status was performed by calculating 99% confidence intervals and using the Student t test for change between subsequent time points. Use of confidence intervals provides a descriptive analysis of the observed treatment effect, while permitting determination of statistical relevance. In all statistical testing, confidence bounds not including 0 were considered statistically significant. Probability of P ≤ .01 for committing type I experiment-wise error (rejecting a true null hypothesis) was selected for all statistical testing because of our lack of a control group, small sample size, and evaluation of multiple postoperative time points.

Results

Eighty consecutive patients with tendinosis of the elbow were included in this study. Sixty-nine patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The average age of the patients (33 women, 47 men) was 50 years. The duration of follow-up evaluation ranged from 6 months to 9 years (mean, 2.5 years; median, 2 years). The Table presents the VAS improvement for these patients after the RF microtenotomy.

Within the lateral epicondylitis group, 91% (63/69) of the patients reported a successful outcome. The postoperative VAS improved to 1.3 from 6.9, which demonstrated an 81% improvement. Of the 6 patients that did not improve, 2 underwent repeat surgery.

Among the patients treated for medial epicondylitis, 91% (10/11) reported improvement in symptoms. The postoperative VAS improved to 1.3 from 6.1, a 79% improvement. One patient did not improve and did not undergo repeat surgery.

Discussion

For the treatment of medial and lateral elbow epicondylitis, RF microtenotomy is successful in 91% of patients. Symptomatic improvement was observed up to 9 years postoperatively. During this study, no complications were recorded; 7 treatment failures occurred. When compared with other techniques, the results with RF microtenotomy are equivalent or better.

In a retrospective study, Szabo and colleagues¹⁴ compared open, arthroscopic, and percutaneous release for lateral elbow tendinosis. They found the 3 methods to be highly effective for the treatment of tendinosis with no significant difference between them. Resection of the epicondyle and transfer of the anconeus muscle was found to be effective (94%) in a retrospective study by Almquist and colleagues.¹⁵ Dunn and coauthors¹⁶ reported a 97% success rate at 10 to 14 years postoperatively with a mini-open technique. Rubenthaler and colleagues¹⁷ showed 88% effectiveness for the open technique and 93% for the arthroscopic technique. With arthroscopic release of the extensor carpi radialis brevis tendon, Lattermann and coauthors¹⁸ reported clinical improvement in 94% of patients. In a study by Rose and colleagues,¹⁹ denervation of the lateral epicondyle was effective in relieving pain in 80% of patients who had had a positive response to a local anesthetic block. In a recently published study by Koh and coauthors,²⁰ 19 of 20 patients experienced a favorable outcome after treatment with ultrasonic microresection.

Regardless of surgical methods and their reported success rate, complications are associated with elbow surgery. Postoperative problems may include restricted function, elbow instability, persistent muscle weakness, and painful neuroma of the posterior cutaneous nerve.^10,21,22 The recent introduction of arthroscopic release offers the potential for less morbidity and enables visualization of the elbow joint. However, disadvantages of the arthroscopic approach include violation of the joint for extra-articular pathology, increased operative time and cost, and neurovascular complications. Additionally, it is possible that the entire spectrum of extra-articular tendinosis cannot be effectively identified arthroscopically.²³ In a prospective, randomized study, Meknas and colleagues²⁴ compared RF microtenotomy with extensor tendon release and repair. They showed that patients treated with RF-microtenotomy experienced earlier pain relief and improved grip strength over the release group.

Different proposed mechanisms of action have been described to explain the favorable effects of the RF-based microtenotomy procedure, such as induced healing by an angiogenic response in the tendon tissue. In an animal study, Harwood and colleagues⁸ showed that low-dose RF-based plasma microtenotomy has the ability to stimulate angiogenic growth factors in tendons, such as α_v integrin and vascular endothelial growth factor. These factors have been shown to be associated with healing.⁸ Early inflammatory response with new-vessel formation after 28 days was found in another animal study using the same method.²⁵ Evaluation of RF-based methods in a prospective controlled laboratory study using a rabbit-tendon model showed histologic evidence of early inflammation with development of neovasculature after treatment.⁸ A later histologic study using an aged Achilles rabbit tendon model was performed to evaluate the effect of RF-based plasma microtenotomy on collagen remodeling.²⁵ The degenerated tendon showed gaps, few normal crimpings, and a lack of reflectivity under polarized light. At 9 days after treatment, the treated tendon showed localized irregular crimpings, and, at 30 days, it showed regular crimping, tightly dense collagen fibers, and hypercellularity with good reflectivity. This was similar in appearance to a normal nondegenerated tendon (Figures 2A-2D). The RF-treated tendon also demonstrated an increase in production of insulin-like growth factor-1, β-fibroblast growth factor-1, α_v integrin, and vascular endothelial growth factor.

Pathologic nerve ingrowth or nerve irritation in the tendon substance has been considered a possible cause of the pain experienced with tendinosis. Radiofrequency treatment has been shown to induce acute degeneration and ablation of sensory nerve fibers.²⁶ These degenerated nerve fibers were observed to regenerate at 90 days after treatment.²⁷ These findings provide potential evidence for early pain relief that is maintained long term as the nerves regenerate.

This midterm follow-up of patients with elbow epicondylitis has shown that RF-based microtenotomy can produce successful, durable results. Microtenotomy is a technically simple procedure to perform and is associated with a rapid and uncomplicated recovery. It is safe and can effectively eliminate or markedly reduce clinical symptoms.

Limitations

Lateral epicondylitis has been described as a self-limited disease, with resolution of symptoms at 12 to 18 months with conservative treatment. This perspective challenges the indication of any proposed surgical treatment for the condition. Although the results of this research demonstrated the benefits of RF microtenotomy, there are inherent limitations of the study design. The study lacks a control group, and randomization would improve the strength of the study. Additional outcome measures, such as Disabilities of the Arm, Shoulder, and Hand score, and grip strength could complement pain scores to provide more data. These data were collected in a preliminary study.⁹ Postoperative histologic analysis of treated human tissue would be ideal, but ethical considerations limit study to animal models. An additional limitation is potential examiner bias. Data collection was performed by an independent medical technician; a third-party blinded evaluation could have been performed, but this was not feasible in a clinical setting.

Conclusion

Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed 9 years after surgery.

 Compartment syndrome (CS) is one of the true orthopedic emergencies. Identifying the high-risk patient, making a prompt diagnosis, and initiating effective treatment are the crucial steps in avoiding a poor outcome. A physician’s inability to communicate with young children can interfere with diagnosing CS in a timely fashion. Many young patients in hospitals are admitted to pediatric floors where routine orthopedic care is not the norm and staff are unfamiliar with the signs and symptoms of evolving CS. As orthopedic surgeons are often involved in caring for these patients, they should be aware of the aspects of CS that are unique to children and should be able to identify patients who are at risk and would benefit from close monitoring. In addition, given the consequences of late diagnosis, early diagnosis is important from a medicolegal standpoint. Only 44% of cases of adult and pediatric CS are decided in favor of treating physicians, compared with 75% of cases in other orthopedic malpractice claims.1,2

Risk Factors for Posttraumatic Compartment Syndrome

Supracondylar Humeral Fracture

CS is a well-described complication of this injury. CS develops in 0.1% to 0.3% of children who present with supracondylar humeral fracture.^3,4 Casted elbow flexion beyond 90° and concomitant vascular injury put these children at increased risk for CS. Mubarak and Carroll⁵ reported 9 cases of CS in the volar compartment of the forearm after an extension-type supracondylar humeral fracture and attributed 8 of them to elbow flexion beyond 90° after closed reduction. In 29 children with supracondylar humeral fracture,Battaglia and colleagues³ found the highest compartment pressure in the deep volar compartment, especially near the fracture site, as well as a significant increase in pressure with the elbow flexed beyond 90°.

In a study of children with supracondylar humeral fracture, Choi and colleagues⁶ found 2 cases of CS among 9 patients who presented with a pulseless, poorly perfused hand and no cases of CS among 24 patients who presented with a pulseless but well-perfused hand.

Studies have found that a treatment delay of 8 to 12 hours did not increase the rate of CS in Gartland type 2 and type 3 fractures.^7-10 The investigators in these studies did not recommend delaying treatment of patients with neurologic deficit and absent radial pulse. Ramachandran and colleagues4 reported 11 cases of CS in patients with low-energy supracondylar humeral fracture and intact radial pulse at presentation. The patients who developed CS presented with severe swelling, and their mean treatment delay was 22 hours (range, 6-64 hours). Given the data, we do not recommend delayed treatment for children with supracondylar humeral fracture and neurologic deficit or absent pulse. We do recommend close inpatient preoperative monitoring of patients with severe swelling.

CS after supracondylar humeral fracture is mostly seen in the volar compartment of the forearm, but it has also been reported in the mobile wad, the anterior arm compartment, and the posterior arm compartment.^11,12

Floating Elbow

CS has been reported in children with ipsilateral humeral and forearm fractures. Blakemore and colleagues¹³ reported a 33% rate of CS in children with displaced distal humeral and forearm fractures. A retrospective review of 16 cases of floating elbow treated at Boston Children’s Hospital found CS in 2 patients and incipient CS in 4 of 10 patients with forearm fractures treated with closed reduction and plaster casting. There were no signs of CS in 6 patients with distal humeral and forearm fractures stabilized with Kirschner wires.¹⁴ Given the data, we do not recommend circumferential casting for forearm fractures in children with floating elbow.

Forearm Fracture

Haasbeek and Cole¹⁵ reported CS in 5 (11%) of 46 children with open forearm fracture. Yuan and colleagues¹⁶ reported CS in 3 (6%) of 50 open forearm fractures and 3 of 30 closed fractures treated with closed reduction and intramedullary nailing. They found increased risk for CS in patients with longer operative time, indicating prolonged closed manipulation of these fractures as a risk factor for CS. They did not find any cases of CS among 205 forearm fractures treated with closed reduction and casting.

Flynn and colleagues17 reported CS in 2 of 30 patients treated with intramedullary nailing within 24 hours of injury and in 0 of 73 patients treated after 24 hours.

Blackman and colleagues¹⁸ reported CS in 3 (7.7%) of 39 open forearm fractures and 0 of 74 closed fractures treated operatively. In their series, a small incision was made to facilitate reduction in 38 (51.4%) of 74 closed fractures to decrease closed manipulation and operative time. The rate of CS after intramedullary nailing of closed forearm fractures was lower in this series than in similar reports in the literature.

Reported data indicate increased risk for CS in children with open forearm fractures and fractures treated with closed reduction and intramedullary nailing, especially performed within 24 hours of injury, and prolonged closed manipulation performed during surgery. We recommend close monitoring of all children with operatively treated forearm fractures and, in particular, children with the risk factors mentioned.

Femoral Fracture

Although CS after femoral shaft fractures is not common, CS has been reported after 90/90 spica casting of femoral shaft fractures in children. Mubarak and colleagues19 reported on 9 children who developed calf CS after treatment of femoral shaft fracture in 90/90 spica casts. The technique used in 7 of the 9 reported cases involved initial application of a short leg cast and then traction applied to the leg—believed to cause impinging of the cast on the posterior compartment of the leg. The authors recommended an alternative method of applying spica casts, which is beyond the scope of this review.

Tibial Fracture

Children with tibial fracture, especially a fracture sustained in a motor vehicle accident, are at risk for CS. Hope and Cole²⁰ found CS in 4 (4%) of 92 children with open tibial fracture.

Children with tibial tubercle fracture are at increased risk for CS because of concomitant vascular injury. Pandya and colleagues²¹ reported CS or vascular compromise in 4 of 40 patients with tibial tubercle fracture. We recommend close monitoring for signs of impending CS in children who present with high-energy tibial shaft fracture and tibial tubercle fracture.

Flynn and colleagues²² reported outcomes of 43 cases of acute CS of the leg in children treated at 2 pediatric trauma centers. Mean time from injury to fasciotomy was 20.5 hours (range, 3.9-118 hours). Functional outcome was excellent at time of follow-up; 41 of 43 cases had no sequelae, and the 2 patients who lost function underwent fasciotomy more than 80 hours after injury. Despite the long interval between injury and surgery, excellent results were achieved with fasciotomy, suggesting an increased potential for recovery in the pediatric population.

Mubarak²³ reported on 6 cases of distal tibial physis fracture in patients who presented with severe pain and swelling of the ankle, hyposthesia of the first web space, weakness of the extensor hallucis longus and extensor digitorum communis, and pain on passive flexion of the toes. In all these patients, intramuscular pressure was more than 40 mm Hg beneath the extensor retinaculum and less than 20 mm Hg in the anterior compartment. All patients experienced prompt relief of pain and improved sensation and strength within 24 hours after release of the superior extensor retinaculum and fracture stabilization.

Miscellaneous and Nontraumatic Causes of Compartment Syndrome

Neonatal CS is very rare, and diagnosis is often missed. Neonatal CS is thought to be caused by a combination of low neonatal blood pressure and birth trauma.²⁴ Ragland and colleagues²⁵ reported on 24 cases of neonatal CS; in only 1 case was the diagnosis made within 24 hours.They described a “sentinel skin lesion” on the forearm of each patient as the sign of neonatal CS. Late diagnosis results in contracture and growth arrest of the involved extremity. In their series, only 1 patient underwent fasciotomy within 24 hours, and it resulted in a good functional outcome. High clinical suspicion is the key to early diagnosis and treatment of this rare pathology.

Medical problems that cause intracompartmental bleeding (hepatic failure, renal failure, leukemia, hemophilia) have been cited as causing CS.^26-28 CS may be the first symptom of occult hemophilia²⁹ Correction of the coagulation defect may take priority over surgical treatment in these cases, though the decision should be made on a case-by-case basis.²⁶

CS in children can also be caused by snakebites. Shaw and Hosalkar³⁰ reported on successful use of antivenin in preventing the need for surgical treatment in 16 of 19 patients with rattlesnake bites. Two patients had limited surgical débridement, and 1 underwent fasciotomy for CS. The authors recommended using antivenin to prevent CS in children with snakebites.³⁰

Prasarn and colleagues² reported on 12 cases of upper extremity CS in children in the absence of fractures. Of the 12 patients, 10 were managed in an intensive care unit and had an obtunded sensorium. Etiology in 7 (58%) of the 12 cases was iatrogenic (intravenous infiltration, retained phlebotomy tourniquet). In this series, 4 amputations were performed on affected extremities.

Diagnosis

Identification of evolving CS in a child is difficult because of the child’s limited ability to communicate and anxiety about being examined by a stranger. Orthopedists are trained to look for the 5 Ps (pain, paresthesia, paralysis, pallor, pulselessness) associated with CS. Examining an anxious, frightened young child is difficult, and documenting the degree of pain is not practical in a child who may not be able or willing to communicate effectively.

In a series of 33 children with CS, Bae and colleagues³¹ found that the 5 Ps were relatively unreliable in making a timely diagnosis. The authors also found that increased analgesic use was documented a mean of 7.3 hours before a change in vascular status and that it was a more sensitive indicator of CS in children. The resulting recommendation is that children at risk for CS be closely monitored for the 3 As (increasing analgesic requirement, anxiety, agitation).³²

Regional anesthesia is used to control postoperative pain in adults and children.^33,34 Injudicious use may mask the primary symptom (pain) of CS.^32,35-38 Use of regional anesthesia in patients at high risk for CS is highly discouraged.

Although CS is a clinical diagnosis, compartment pressure measurements can be useful in making decisions in certain clinical scenarios. In an obtunded child or in a child with severe mental and communication disability, such a measurement can help confirm or rule out the diagnosis.

Normal compartment pressures are higher in children than in adults. Staudt and colleagues³⁹ compared pressures in 4 lower leg compartments of 20 healthy children and 20 healthy adults. Mean pressure varied from 13.3 mm Hg to 16.6 mm Hg in children and from 5.2 mm Hg to 9.7 mm Hg in adults—indicating higher normal pressure in lower leg compartments in children.

Compartment pressures were reported highest within 5 cm of the fracture site.⁴⁰ When clinically indicated, they should be measured in that area in an injured extremity. The pressure threshold that requires fasciotomy is debatable. Intracompartmental pressures of 30 to 45 mm Hg, or measurements less than 30 mm Hg of diastolic blood pressure (pressure change = diastolic blood pressure – compartment pressure), have been recommended as cutoffs by some authors.^41-44 As resting normal compartment pressures are higher in children, these cutoffs cannot be used as reliably in children as in adults. Direct measurement of intracompartmental pressure is invasive and can be difficult in an agitated, awake child. The potential utility of near-infrared spectroscopy in the diagnosis of increased compartment pressure has been reported.^45,46 This method uses differential light absorption properties of oxygenated hemoglobin to measure tissue ischemia—similar to the method used in pulse oximetry. Compared with pulse oximetry, near-infrared spectroscopy can sample deeper tissue (3 cm below skin level). Shuler and colleagues⁴⁵ reported near-infrared spectroscopy findings for 14 adults with acute CS. Lower tissue oxygenation levels correlated with increased intracompartmental pressures, but the authors could not define a cutoff for which near-infrared spectroscopy measurements would indicate significant tissue ischemia. Use of this method in diagnosing CS in children was described in a case report.⁴⁶

CS remains a clinical diagnosis. Informing family and staff about the signs and symptoms of this syndrome and closely monitoring analgesic use in these patients are crucial. Compartment pressure measurements can be used when the diagnosis is unclear, particularly in noncommunicative patients, but these values should be interpreted with caution.

Treatment

Once CS is diagnosed, emergent fasciotomy and decompression are indicated. Surgeons planning fasciotomy should be aware of the definitive treatment of the CS etiology. Treatment of clotting deficiency in cases caused by excessive bleeding, fracture fixation, and vascular repair may be indicated during fasciotomy and decompression.

Summary

Increased need for analgesics is often the first sign of CS in children and should be considered the sentinel alarm for ongoing tissue necrosis. CS remains a clinical diagnosis, and compartment pressure should be measured only as a confirmatory test in noncommunicative patients or when the diagnosis is unclear. Children with supracondylar humeral fractures, forearm fractures, tibial fractures, and medical risk factors for coagulopathy are at increased risk and should be monitored closely. When the diagnosis is made promptly and the condition is treated with fasciotomy, good long-term clinical results can be expected.

 Compartment syndrome (CS) is one of the true orthopedic emergencies. Identifying the high-risk patient, making a prompt diagnosis, and initiating effective treatment are the crucial steps in avoiding a poor outcome. A physician’s inability to communicate with young children can interfere with diagnosing CS in a timely fashion. Many young patients in hospitals are admitted to pediatric floors where routine orthopedic care is not the norm and staff are unfamiliar with the signs and symptoms of evolving CS. As orthopedic surgeons are often involved in caring for these patients, they should be aware of the aspects of CS that are unique to children and should be able to identify patients who are at risk and would benefit from close monitoring. In addition, given the consequences of late diagnosis, early diagnosis is important from a medicolegal standpoint. Only 44% of cases of adult and pediatric CS are decided in favor of treating physicians, compared with 75% of cases in other orthopedic malpractice claims.1,2

Risk Factors for Posttraumatic Compartment Syndrome

Supracondylar Humeral Fracture

CS is a well-described complication of this injury. CS develops in 0.1% to 0.3% of children who present with supracondylar humeral fracture.^3,4 Casted elbow flexion beyond 90° and concomitant vascular injury put these children at increased risk for CS. Mubarak and Carroll⁵ reported 9 cases of CS in the volar compartment of the forearm after an extension-type supracondylar humeral fracture and attributed 8 of them to elbow flexion beyond 90° after closed reduction. In 29 children with supracondylar humeral fracture,Battaglia and colleagues³ found the highest compartment pressure in the deep volar compartment, especially near the fracture site, as well as a significant increase in pressure with the elbow flexed beyond 90°.

In a study of children with supracondylar humeral fracture, Choi and colleagues⁶ found 2 cases of CS among 9 patients who presented with a pulseless, poorly perfused hand and no cases of CS among 24 patients who presented with a pulseless but well-perfused hand.

Studies have found that a treatment delay of 8 to 12 hours did not increase the rate of CS in Gartland type 2 and type 3 fractures.^7-10 The investigators in these studies did not recommend delaying treatment of patients with neurologic deficit and absent radial pulse. Ramachandran and colleagues4 reported 11 cases of CS in patients with low-energy supracondylar humeral fracture and intact radial pulse at presentation. The patients who developed CS presented with severe swelling, and their mean treatment delay was 22 hours (range, 6-64 hours). Given the data, we do not recommend delayed treatment for children with supracondylar humeral fracture and neurologic deficit or absent pulse. We do recommend close inpatient preoperative monitoring of patients with severe swelling.

CS after supracondylar humeral fracture is mostly seen in the volar compartment of the forearm, but it has also been reported in the mobile wad, the anterior arm compartment, and the posterior arm compartment.^11,12

Floating Elbow

CS has been reported in children with ipsilateral humeral and forearm fractures. Blakemore and colleagues¹³ reported a 33% rate of CS in children with displaced distal humeral and forearm fractures. A retrospective review of 16 cases of floating elbow treated at Boston Children’s Hospital found CS in 2 patients and incipient CS in 4 of 10 patients with forearm fractures treated with closed reduction and plaster casting. There were no signs of CS in 6 patients with distal humeral and forearm fractures stabilized with Kirschner wires.¹⁴ Given the data, we do not recommend circumferential casting for forearm fractures in children with floating elbow.

Forearm Fracture

Haasbeek and Cole¹⁵ reported CS in 5 (11%) of 46 children with open forearm fracture. Yuan and colleagues¹⁶ reported CS in 3 (6%) of 50 open forearm fractures and 3 of 30 closed fractures treated with closed reduction and intramedullary nailing. They found increased risk for CS in patients with longer operative time, indicating prolonged closed manipulation of these fractures as a risk factor for CS. They did not find any cases of CS among 205 forearm fractures treated with closed reduction and casting.

Flynn and colleagues17 reported CS in 2 of 30 patients treated with intramedullary nailing within 24 hours of injury and in 0 of 73 patients treated after 24 hours.

Blackman and colleagues¹⁸ reported CS in 3 (7.7%) of 39 open forearm fractures and 0 of 74 closed fractures treated operatively. In their series, a small incision was made to facilitate reduction in 38 (51.4%) of 74 closed fractures to decrease closed manipulation and operative time. The rate of CS after intramedullary nailing of closed forearm fractures was lower in this series than in similar reports in the literature.

Reported data indicate increased risk for CS in children with open forearm fractures and fractures treated with closed reduction and intramedullary nailing, especially performed within 24 hours of injury, and prolonged closed manipulation performed during surgery. We recommend close monitoring of all children with operatively treated forearm fractures and, in particular, children with the risk factors mentioned.

Femoral Fracture

Although CS after femoral shaft fractures is not common, CS has been reported after 90/90 spica casting of femoral shaft fractures in children. Mubarak and colleagues19 reported on 9 children who developed calf CS after treatment of femoral shaft fracture in 90/90 spica casts. The technique used in 7 of the 9 reported cases involved initial application of a short leg cast and then traction applied to the leg—believed to cause impinging of the cast on the posterior compartment of the leg. The authors recommended an alternative method of applying spica casts, which is beyond the scope of this review.

Tibial Fracture

Children with tibial fracture, especially a fracture sustained in a motor vehicle accident, are at risk for CS. Hope and Cole²⁰ found CS in 4 (4%) of 92 children with open tibial fracture.

Children with tibial tubercle fracture are at increased risk for CS because of concomitant vascular injury. Pandya and colleagues²¹ reported CS or vascular compromise in 4 of 40 patients with tibial tubercle fracture. We recommend close monitoring for signs of impending CS in children who present with high-energy tibial shaft fracture and tibial tubercle fracture.

Flynn and colleagues²² reported outcomes of 43 cases of acute CS of the leg in children treated at 2 pediatric trauma centers. Mean time from injury to fasciotomy was 20.5 hours (range, 3.9-118 hours). Functional outcome was excellent at time of follow-up; 41 of 43 cases had no sequelae, and the 2 patients who lost function underwent fasciotomy more than 80 hours after injury. Despite the long interval between injury and surgery, excellent results were achieved with fasciotomy, suggesting an increased potential for recovery in the pediatric population.

Mubarak²³ reported on 6 cases of distal tibial physis fracture in patients who presented with severe pain and swelling of the ankle, hyposthesia of the first web space, weakness of the extensor hallucis longus and extensor digitorum communis, and pain on passive flexion of the toes. In all these patients, intramuscular pressure was more than 40 mm Hg beneath the extensor retinaculum and less than 20 mm Hg in the anterior compartment. All patients experienced prompt relief of pain and improved sensation and strength within 24 hours after release of the superior extensor retinaculum and fracture stabilization.

Miscellaneous and Nontraumatic Causes of Compartment Syndrome

Neonatal CS is very rare, and diagnosis is often missed. Neonatal CS is thought to be caused by a combination of low neonatal blood pressure and birth trauma.²⁴ Ragland and colleagues²⁵ reported on 24 cases of neonatal CS; in only 1 case was the diagnosis made within 24 hours.They described a “sentinel skin lesion” on the forearm of each patient as the sign of neonatal CS. Late diagnosis results in contracture and growth arrest of the involved extremity. In their series, only 1 patient underwent fasciotomy within 24 hours, and it resulted in a good functional outcome. High clinical suspicion is the key to early diagnosis and treatment of this rare pathology.

Medical problems that cause intracompartmental bleeding (hepatic failure, renal failure, leukemia, hemophilia) have been cited as causing CS.^26-28 CS may be the first symptom of occult hemophilia²⁹ Correction of the coagulation defect may take priority over surgical treatment in these cases, though the decision should be made on a case-by-case basis.²⁶

CS in children can also be caused by snakebites. Shaw and Hosalkar³⁰ reported on successful use of antivenin in preventing the need for surgical treatment in 16 of 19 patients with rattlesnake bites. Two patients had limited surgical débridement, and 1 underwent fasciotomy for CS. The authors recommended using antivenin to prevent CS in children with snakebites.³⁰

Prasarn and colleagues² reported on 12 cases of upper extremity CS in children in the absence of fractures. Of the 12 patients, 10 were managed in an intensive care unit and had an obtunded sensorium. Etiology in 7 (58%) of the 12 cases was iatrogenic (intravenous infiltration, retained phlebotomy tourniquet). In this series, 4 amputations were performed on affected extremities.

Diagnosis

Identification of evolving CS in a child is difficult because of the child’s limited ability to communicate and anxiety about being examined by a stranger. Orthopedists are trained to look for the 5 Ps (pain, paresthesia, paralysis, pallor, pulselessness) associated with CS. Examining an anxious, frightened young child is difficult, and documenting the degree of pain is not practical in a child who may not be able or willing to communicate effectively.

In a series of 33 children with CS, Bae and colleagues³¹ found that the 5 Ps were relatively unreliable in making a timely diagnosis. The authors also found that increased analgesic use was documented a mean of 7.3 hours before a change in vascular status and that it was a more sensitive indicator of CS in children. The resulting recommendation is that children at risk for CS be closely monitored for the 3 As (increasing analgesic requirement, anxiety, agitation).³²

Regional anesthesia is used to control postoperative pain in adults and children.^33,34 Injudicious use may mask the primary symptom (pain) of CS.^32,35-38 Use of regional anesthesia in patients at high risk for CS is highly discouraged.

Although CS is a clinical diagnosis, compartment pressure measurements can be useful in making decisions in certain clinical scenarios. In an obtunded child or in a child with severe mental and communication disability, such a measurement can help confirm or rule out the diagnosis.

Normal compartment pressures are higher in children than in adults. Staudt and colleagues³⁹ compared pressures in 4 lower leg compartments of 20 healthy children and 20 healthy adults. Mean pressure varied from 13.3 mm Hg to 16.6 mm Hg in children and from 5.2 mm Hg to 9.7 mm Hg in adults—indicating higher normal pressure in lower leg compartments in children.

Compartment pressures were reported highest within 5 cm of the fracture site.⁴⁰ When clinically indicated, they should be measured in that area in an injured extremity. The pressure threshold that requires fasciotomy is debatable. Intracompartmental pressures of 30 to 45 mm Hg, or measurements less than 30 mm Hg of diastolic blood pressure (pressure change = diastolic blood pressure – compartment pressure), have been recommended as cutoffs by some authors.^41-44 As resting normal compartment pressures are higher in children, these cutoffs cannot be used as reliably in children as in adults. Direct measurement of intracompartmental pressure is invasive and can be difficult in an agitated, awake child. The potential utility of near-infrared spectroscopy in the diagnosis of increased compartment pressure has been reported.^45,46 This method uses differential light absorption properties of oxygenated hemoglobin to measure tissue ischemia—similar to the method used in pulse oximetry. Compared with pulse oximetry, near-infrared spectroscopy can sample deeper tissue (3 cm below skin level). Shuler and colleagues⁴⁵ reported near-infrared spectroscopy findings for 14 adults with acute CS. Lower tissue oxygenation levels correlated with increased intracompartmental pressures, but the authors could not define a cutoff for which near-infrared spectroscopy measurements would indicate significant tissue ischemia. Use of this method in diagnosing CS in children was described in a case report.⁴⁶

CS remains a clinical diagnosis. Informing family and staff about the signs and symptoms of this syndrome and closely monitoring analgesic use in these patients are crucial. Compartment pressure measurements can be used when the diagnosis is unclear, particularly in noncommunicative patients, but these values should be interpreted with caution.

Treatment

Once CS is diagnosed, emergent fasciotomy and decompression are indicated. Surgeons planning fasciotomy should be aware of the definitive treatment of the CS etiology. Treatment of clotting deficiency in cases caused by excessive bleeding, fracture fixation, and vascular repair may be indicated during fasciotomy and decompression.

Summary

Increased need for analgesics is often the first sign of CS in children and should be considered the sentinel alarm for ongoing tissue necrosis. CS remains a clinical diagnosis, and compartment pressure should be measured only as a confirmatory test in noncommunicative patients or when the diagnosis is unclear. Children with supracondylar humeral fractures, forearm fractures, tibial fractures, and medical risk factors for coagulopathy are at increased risk and should be monitored closely. When the diagnosis is made promptly and the condition is treated with fasciotomy, good long-term clinical results can be expected.

 Compartment syndrome (CS) is one of the true orthopedic emergencies. Identifying the high-risk patient, making a prompt diagnosis, and initiating effective treatment are the crucial steps in avoiding a poor outcome. A physician’s inability to communicate with young children can interfere with diagnosing CS in a timely fashion. Many young patients in hospitals are admitted to pediatric floors where routine orthopedic care is not the norm and staff are unfamiliar with the signs and symptoms of evolving CS. As orthopedic surgeons are often involved in caring for these patients, they should be aware of the aspects of CS that are unique to children and should be able to identify patients who are at risk and would benefit from close monitoring. In addition, given the consequences of late diagnosis, early diagnosis is important from a medicolegal standpoint. Only 44% of cases of adult and pediatric CS are decided in favor of treating physicians, compared with 75% of cases in other orthopedic malpractice claims.1,2

Risk Factors for Posttraumatic Compartment Syndrome

Supracondylar Humeral Fracture

CS is a well-described complication of this injury. CS develops in 0.1% to 0.3% of children who present with supracondylar humeral fracture.^3,4 Casted elbow flexion beyond 90° and concomitant vascular injury put these children at increased risk for CS. Mubarak and Carroll⁵ reported 9 cases of CS in the volar compartment of the forearm after an extension-type supracondylar humeral fracture and attributed 8 of them to elbow flexion beyond 90° after closed reduction. In 29 children with supracondylar humeral fracture,Battaglia and colleagues³ found the highest compartment pressure in the deep volar compartment, especially near the fracture site, as well as a significant increase in pressure with the elbow flexed beyond 90°.

In a study of children with supracondylar humeral fracture, Choi and colleagues⁶ found 2 cases of CS among 9 patients who presented with a pulseless, poorly perfused hand and no cases of CS among 24 patients who presented with a pulseless but well-perfused hand.

Studies have found that a treatment delay of 8 to 12 hours did not increase the rate of CS in Gartland type 2 and type 3 fractures.^7-10 The investigators in these studies did not recommend delaying treatment of patients with neurologic deficit and absent radial pulse. Ramachandran and colleagues4 reported 11 cases of CS in patients with low-energy supracondylar humeral fracture and intact radial pulse at presentation. The patients who developed CS presented with severe swelling, and their mean treatment delay was 22 hours (range, 6-64 hours). Given the data, we do not recommend delayed treatment for children with supracondylar humeral fracture and neurologic deficit or absent pulse. We do recommend close inpatient preoperative monitoring of patients with severe swelling.

CS after supracondylar humeral fracture is mostly seen in the volar compartment of the forearm, but it has also been reported in the mobile wad, the anterior arm compartment, and the posterior arm compartment.^11,12

Floating Elbow

CS has been reported in children with ipsilateral humeral and forearm fractures. Blakemore and colleagues¹³ reported a 33% rate of CS in children with displaced distal humeral and forearm fractures. A retrospective review of 16 cases of floating elbow treated at Boston Children’s Hospital found CS in 2 patients and incipient CS in 4 of 10 patients with forearm fractures treated with closed reduction and plaster casting. There were no signs of CS in 6 patients with distal humeral and forearm fractures stabilized with Kirschner wires.¹⁴ Given the data, we do not recommend circumferential casting for forearm fractures in children with floating elbow.

Forearm Fracture

Haasbeek and Cole¹⁵ reported CS in 5 (11%) of 46 children with open forearm fracture. Yuan and colleagues¹⁶ reported CS in 3 (6%) of 50 open forearm fractures and 3 of 30 closed fractures treated with closed reduction and intramedullary nailing. They found increased risk for CS in patients with longer operative time, indicating prolonged closed manipulation of these fractures as a risk factor for CS. They did not find any cases of CS among 205 forearm fractures treated with closed reduction and casting.

Flynn and colleagues17 reported CS in 2 of 30 patients treated with intramedullary nailing within 24 hours of injury and in 0 of 73 patients treated after 24 hours.

Blackman and colleagues¹⁸ reported CS in 3 (7.7%) of 39 open forearm fractures and 0 of 74 closed fractures treated operatively. In their series, a small incision was made to facilitate reduction in 38 (51.4%) of 74 closed fractures to decrease closed manipulation and operative time. The rate of CS after intramedullary nailing of closed forearm fractures was lower in this series than in similar reports in the literature.

Reported data indicate increased risk for CS in children with open forearm fractures and fractures treated with closed reduction and intramedullary nailing, especially performed within 24 hours of injury, and prolonged closed manipulation performed during surgery. We recommend close monitoring of all children with operatively treated forearm fractures and, in particular, children with the risk factors mentioned.

Femoral Fracture

Although CS after femoral shaft fractures is not common, CS has been reported after 90/90 spica casting of femoral shaft fractures in children. Mubarak and colleagues19 reported on 9 children who developed calf CS after treatment of femoral shaft fracture in 90/90 spica casts. The technique used in 7 of the 9 reported cases involved initial application of a short leg cast and then traction applied to the leg—believed to cause impinging of the cast on the posterior compartment of the leg. The authors recommended an alternative method of applying spica casts, which is beyond the scope of this review.

Tibial Fracture

Children with tibial fracture, especially a fracture sustained in a motor vehicle accident, are at risk for CS. Hope and Cole²⁰ found CS in 4 (4%) of 92 children with open tibial fracture.

Children with tibial tubercle fracture are at increased risk for CS because of concomitant vascular injury. Pandya and colleagues²¹ reported CS or vascular compromise in 4 of 40 patients with tibial tubercle fracture. We recommend close monitoring for signs of impending CS in children who present with high-energy tibial shaft fracture and tibial tubercle fracture.

Flynn and colleagues²² reported outcomes of 43 cases of acute CS of the leg in children treated at 2 pediatric trauma centers. Mean time from injury to fasciotomy was 20.5 hours (range, 3.9-118 hours). Functional outcome was excellent at time of follow-up; 41 of 43 cases had no sequelae, and the 2 patients who lost function underwent fasciotomy more than 80 hours after injury. Despite the long interval between injury and surgery, excellent results were achieved with fasciotomy, suggesting an increased potential for recovery in the pediatric population.

Mubarak²³ reported on 6 cases of distal tibial physis fracture in patients who presented with severe pain and swelling of the ankle, hyposthesia of the first web space, weakness of the extensor hallucis longus and extensor digitorum communis, and pain on passive flexion of the toes. In all these patients, intramuscular pressure was more than 40 mm Hg beneath the extensor retinaculum and less than 20 mm Hg in the anterior compartment. All patients experienced prompt relief of pain and improved sensation and strength within 24 hours after release of the superior extensor retinaculum and fracture stabilization.

Miscellaneous and Nontraumatic Causes of Compartment Syndrome

Neonatal CS is very rare, and diagnosis is often missed. Neonatal CS is thought to be caused by a combination of low neonatal blood pressure and birth trauma.²⁴ Ragland and colleagues²⁵ reported on 24 cases of neonatal CS; in only 1 case was the diagnosis made within 24 hours.They described a “sentinel skin lesion” on the forearm of each patient as the sign of neonatal CS. Late diagnosis results in contracture and growth arrest of the involved extremity. In their series, only 1 patient underwent fasciotomy within 24 hours, and it resulted in a good functional outcome. High clinical suspicion is the key to early diagnosis and treatment of this rare pathology.

Medical problems that cause intracompartmental bleeding (hepatic failure, renal failure, leukemia, hemophilia) have been cited as causing CS.^26-28 CS may be the first symptom of occult hemophilia²⁹ Correction of the coagulation defect may take priority over surgical treatment in these cases, though the decision should be made on a case-by-case basis.²⁶

CS in children can also be caused by snakebites. Shaw and Hosalkar³⁰ reported on successful use of antivenin in preventing the need for surgical treatment in 16 of 19 patients with rattlesnake bites. Two patients had limited surgical débridement, and 1 underwent fasciotomy for CS. The authors recommended using antivenin to prevent CS in children with snakebites.³⁰

Prasarn and colleagues² reported on 12 cases of upper extremity CS in children in the absence of fractures. Of the 12 patients, 10 were managed in an intensive care unit and had an obtunded sensorium. Etiology in 7 (58%) of the 12 cases was iatrogenic (intravenous infiltration, retained phlebotomy tourniquet). In this series, 4 amputations were performed on affected extremities.

Diagnosis

Identification of evolving CS in a child is difficult because of the child’s limited ability to communicate and anxiety about being examined by a stranger. Orthopedists are trained to look for the 5 Ps (pain, paresthesia, paralysis, pallor, pulselessness) associated with CS. Examining an anxious, frightened young child is difficult, and documenting the degree of pain is not practical in a child who may not be able or willing to communicate effectively.

In a series of 33 children with CS, Bae and colleagues³¹ found that the 5 Ps were relatively unreliable in making a timely diagnosis. The authors also found that increased analgesic use was documented a mean of 7.3 hours before a change in vascular status and that it was a more sensitive indicator of CS in children. The resulting recommendation is that children at risk for CS be closely monitored for the 3 As (increasing analgesic requirement, anxiety, agitation).³²

Regional anesthesia is used to control postoperative pain in adults and children.^33,34 Injudicious use may mask the primary symptom (pain) of CS.^32,35-38 Use of regional anesthesia in patients at high risk for CS is highly discouraged.

Although CS is a clinical diagnosis, compartment pressure measurements can be useful in making decisions in certain clinical scenarios. In an obtunded child or in a child with severe mental and communication disability, such a measurement can help confirm or rule out the diagnosis.

Normal compartment pressures are higher in children than in adults. Staudt and colleagues³⁹ compared pressures in 4 lower leg compartments of 20 healthy children and 20 healthy adults. Mean pressure varied from 13.3 mm Hg to 16.6 mm Hg in children and from 5.2 mm Hg to 9.7 mm Hg in adults—indicating higher normal pressure in lower leg compartments in children.

Compartment pressures were reported highest within 5 cm of the fracture site.⁴⁰ When clinically indicated, they should be measured in that area in an injured extremity. The pressure threshold that requires fasciotomy is debatable. Intracompartmental pressures of 30 to 45 mm Hg, or measurements less than 30 mm Hg of diastolic blood pressure (pressure change = diastolic blood pressure – compartment pressure), have been recommended as cutoffs by some authors.^41-44 As resting normal compartment pressures are higher in children, these cutoffs cannot be used as reliably in children as in adults. Direct measurement of intracompartmental pressure is invasive and can be difficult in an agitated, awake child. The potential utility of near-infrared spectroscopy in the diagnosis of increased compartment pressure has been reported.^45,46 This method uses differential light absorption properties of oxygenated hemoglobin to measure tissue ischemia—similar to the method used in pulse oximetry. Compared with pulse oximetry, near-infrared spectroscopy can sample deeper tissue (3 cm below skin level). Shuler and colleagues⁴⁵ reported near-infrared spectroscopy findings for 14 adults with acute CS. Lower tissue oxygenation levels correlated with increased intracompartmental pressures, but the authors could not define a cutoff for which near-infrared spectroscopy measurements would indicate significant tissue ischemia. Use of this method in diagnosing CS in children was described in a case report.⁴⁶

CS remains a clinical diagnosis. Informing family and staff about the signs and symptoms of this syndrome and closely monitoring analgesic use in these patients are crucial. Compartment pressure measurements can be used when the diagnosis is unclear, particularly in noncommunicative patients, but these values should be interpreted with caution.

Treatment

Once CS is diagnosed, emergent fasciotomy and decompression are indicated. Surgeons planning fasciotomy should be aware of the definitive treatment of the CS etiology. Treatment of clotting deficiency in cases caused by excessive bleeding, fracture fixation, and vascular repair may be indicated during fasciotomy and decompression.

Summary

Increased need for analgesics is often the first sign of CS in children and should be considered the sentinel alarm for ongoing tissue necrosis. CS remains a clinical diagnosis, and compartment pressure should be measured only as a confirmatory test in noncommunicative patients or when the diagnosis is unclear. Children with supracondylar humeral fractures, forearm fractures, tibial fractures, and medical risk factors for coagulopathy are at increased risk and should be monitored closely. When the diagnosis is made promptly and the condition is treated with fasciotomy, good long-term clinical results can be expected.

First described by Runge¹ in 1873 and later termed lawn-tennis arm by Major² in 1883, lateral epicondylitis is a common cause of elbow pain, affecting 1% to 3% of the general population each year.^3,4 Given that prevalence estimates are up to 15% among workers in repetitive hand task industries,^5-7 symptoms of lateral epicondylitis are thought to be related to recurring wrist extension and alternating forearm pronation and supination.⁸ Between 80% and 90% of patients with lateral epicondylitis experience symptomatic improvement with conservative therapy,^9-11 including rest and use of nonsteroidal anti-inflammatory medications,¹² physical therapy,^13,14 corticosteroid injections,^10,15,16 orthoses,^17,18 and shock wave therapy.¹⁹ However, between 4% and 11% of patients with newly diagnosed lateral epicondylitis do not respond to prolonged (6- to 12-month) conservative treatment and then require operative intervention,^11,20,21 with some referral practices reporting rates as high as 25%.²²

Traditionally, operative management of lateral epicondylitis involved open débridement of the extensor carpi radialis brevis (ECRB).^11,20 More recently, the spectrum of operations for lateral epicondylitis has expanded to include procedures that repair the extensor origin after débridement of the torn tendon and angiofibroblastic dysplasia; procedures that use fasciotomy or direct release of the extensor origin from the epicondyle to relieve tension on the common extensor; procedures directed at the radial or posterior interosseous nerve; and procedures that use arthroscopic techniques to divide the orbicular ligament, reshape the radial head, or release the extensor origin.²³ There has been debate about the value of repairing the ECRB, lengthening the ECRB, simultaneously decompressing the radial nerve or resecting epicondylar bone, and performing the procedures percutaneously, endoscopically, or arthroscopically.^24-28 Despite multiple studies of the outcomes of these procedures,^11,29-31 little is known regarding US national trends for operative treatment of lateral epicondylitis. Understanding national practice patterns and disease burden is essential to allocation of limited health care resources.

We conducted a study to determine US national trends in use of ambulatory surgery for lateral epicondylitis. We focused on age, sex, surgical setting, anesthetic type, and payment method.

Methods

As the National Survey of Ambulatory Surgery³² (NSAS) is an administrative dataset in which all data are deidentified and available for public use, this study was exempt from requiring institutional review board approval.

NSAS data were used to analyze trends in treatment of lateral epicondylitis between 1994 and 2006. NSAS was undertaken by the National Center for Health Statistics (NCHS) of the Centers for Disease Control and Prevention (CDC) to obtain information about the use of ambulatory surgery in the United States. Since the early 1980s, ambulatory surgery has increased in the United States because of advances in medical technology and cost-containment initiatives.³³ The number of procedures being performed in ambulatory surgery centers increased from 31.5 million in 1996 to 53.3 million in 2006.³⁴ Funded by the CDC, NSAS is a national study that involves both hospital-based and freestanding ambulatory surgery centers and provides the most recent and comprehensive overview of ambulatory surgery in the United States.³⁵ Because of budgetary limitations, 2006 was the last year in which data for NSAS were collected. Data for NSAS come from Medicare-participating, noninstitutional hospitals (excluding military hospitals, federal facilities, and Veteran Affairs hospitals) in all 50 states and the District of Columbia with a minimum of 6 beds staffed for patient use. NSAS used only short-stay hospitals (hospitals with an average length of stay for all patients of less than 30 days) or hospitals that had a specialty of general (medical or surgical) or children’s general. NSAS was conducted in 1994, 1996, and 2006 with medical information recorded on patient abstracts coded by contract staff. NSAS selected a sample of ambulatory surgery visits using a systematic random sampling procedure, and selection of visits within each facility was done separately for each location where ambulatory surgery was performed. In 1994, 751 facilities were sampled, and 88% of hospitals responded. In 1996, 750 facilities were sampled, and 91% of hospitals responded. In 2006, 696 facilities were sampled, and 75% responded. The surveys used International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes³⁶ to classify medical diagnoses and procedures. To produce an unbiased national estimate, NCHS used multistage estimate procedures, including inflation by reciprocals of the probabilities of sample selection, population-weighting ratio adjustments, and adjustment for no response.³⁷

Demographic and medical information was obtained for people with an ICD-9-CM diagnosis code of lateral epicondylitis (726.32), using previously described techniques.³⁸ Data were then recorded for age, sex, facility type, insurance type, anesthesia type, diagnoses, and procedures.

Descriptive statistics consisted of means and standard deviations for continuous variables and frequency and percentages for discrete variables. Because NSAS data were collected on the basis of a probabilistic sample scheme, they were analyzed using a sampling weighting method. Sampling weights (inverse of selection probability) provided by the CDC were used to account for unequal sampling probabilities and to produce estimates for all visits in the United States. A Taylor linearization model provided by the CDC estimates was used to calculate standard error and confidence intervals (CIs) of the data. Standard error is a measure of sampling variability that occurs by chance because only a sample rather than the entire universe is surveyed. To define population parameters, NCHS chose 95% CIs along with a point estimate. Direct statistical comparison between years cannot be performed because of sampling differences in the database compared between years. The CIs, however, can suggest statistical differences if the data are nonoverlapping. US census data were used to obtain national population estimates for each year of the study (1994, 1996, 2006).³⁹ Rates were presented as number of procedures per 100,000 standard population. For age, a direct adjustment procedure was used, and the US population in 2000 was selected as the standard population. Applying sex-specific rates to the standard population and dividing by the total in the standard population, we calculated sex-adjusted rates for each year. All data were analyzed using SPSS Version 20 software.

Results

A total of 30,311 ambulatory surgical procedures (95% CI, 27,292-33,330) or 10.44 per 100,000 capita were recorded by NSAS for the treatment of lateral epicondylitis in 2006 (Table 1). This represents a large increase in the total number of ambulatory procedures, from 21,852 in 1994 (95% CI, 19,981-23,722; 7.29/100,000) and 20,372 in 1996 (95% CI, 18,660-22,083; 6.73/100,000).

Between 1994 and 2006, the sex-adjusted rate of ambulatory surgery for lateral epicondylitis increased by 85% among females (7.74/100,000 to 14.31/100,000), whereas the rate decreased by 31% among males (8.07/100,000 to 5.59/100,000) (Table 1). The age-adjusted rate of ambulatory surgery for lateral epicondylitis increased among all age groups except the 30–39 years group (Table 2). The largest increase in age-adjusted rates was found for patients older than 50 years (275%) between 1994 and 2006.

During the study period, use of regional anesthesia nearly doubled, from 17% to 30%, whereas use of general anesthesia decreased, from 69% to 57% (Table 3). At all time points, the most common procedure performed for lateral epicondylitis in ambulatory surgery centers was division/release of the joint capsule of the elbow (Table 4). Private insurance remained the most common source of payment for all study years, ranging from 52% to 60% (Table 5). The Figure shows that, between 1994 and 2006, the proportion of surgeries performed in a freestanding ambulatory center increased.

Discussion

In this descriptive epidemiologic study, we used NSAS data to investigate trends in ambulatory surgery for lateral epicondylitis between 1994 and 2006.³² Our results showed that total number of procedures and the population-adjusted rate of procedures for lateral epicondylitis increased during the study period. The largest increase in age-adjusted rates of surgery for lateral epicondylitis was found among patients older than 50 years, whereas the highest age-adjusted rate of ambulatory surgery for lateral epicondylitis was found among patients between ages 40 and 49 years. These findings are similar to those of previous studies, which have shown that most patients with lateral epicondylitis present in the fourth and fifth decades of life.²² Prior reports have suggested that the incidence of lateral epicondylitis in men and women is equal.²² The present study found a change in sex-adjusted rates of ambulatory surgery for lateral epicondylitis between 1994 and 2006. Specifically, in 1994, surgery rates for men and women were similar (8.07/100,000 and 7.74/100,000), but in 2006 the sex-adjusted rate of surgery for lateral epicondylitis was almost 3 times higher for women than for men (14.31/100,000 vs 5.59/100,000).

We also found that the population-adjusted rate of lateral epicondylectomy increased drastically, from 0.4 per 100,000 in 1994 to 3.53 per 100,000 in 2006. Lateral epicondylectomy involves excision of the tip of the lateral epicondyle (typically, 0.5 cm) to produce a cancellous bone surface to which the edges of the débrided extensor tendon can be approximated without tension.²³ It is possible that the increased rate of lateral epicondylectomy reflects evidence-based practice changes during the study period,²⁷ though denervation was found more favorable than epicondylectomy in a recent study by Berry and colleagues.⁴⁰ Future studies should investigate whether rates of epicondylectomy have changed since 2006. In addition, the present study showed a correlation between the introduction of arthroscopic techniques for the treatment of lateral epicondylitis and the period when much research was being conducted on the topic.^24,25,28 As arthroscopic techniques improve, their rates are likely to continue to increase.

Our results also showed an increase in procedures performed in freestanding facilities. The rise in ambulatory surgical volume, speculated to result from more procedures being performed in freestanding facilities,³⁴ has been reported with knee and shoulder arthroscopy.⁴¹ In addition, though general anesthesia remained the most used technique, our results showed a shift toward peripheral nerve blocks. The increase in regional anesthesia, which has also been noted in joint arthroscopy, is thought to stem from the advent of nerve-localizing technology, such as nerve stimulation and ultrasound guidance.⁴¹ Peripheral nerve blocks are favorable on both economic and quality measures, are associated with fewer opioid-related side effects, and overall provide better analgesia in comparison with opioids, highlighting their importance in the ambulatory setting.⁴²

Although large, national databases are well suited to epidemiologic research,⁴³ our study had limitations. As with all databases, NSAS is subject to data entry errors and coding errors.^44,45 However, the database administrators corrected for this by using a multistage estimate procedure with weighting adjustments for no response and population-weighting ratio adjustments.³⁵ Another limitation of this study is its lack of clinical detail, as procedure codes are general and do not allow differentiation between specific patients. Because of the retrospective nature of the analysis and the heterogeneity of the data, assessment of specific surgeries for lateral epicondylitis was limited. Although a strength of using NSAS to perform epidemiologic analyses is its large sample size, this also sacrifices specificity in terms of clinical insight. The results of this study may influence investigations to distinguish differences between procedures used in the treatment of lateral epicondylitis. Furthermore, the results of this study are limited to ambulatory surgery practice patterns in the United States between 1996 and 2006. Last, our ability to perform economic analyses was limited, as data on total hospital cost were not recorded by the surveys.

Conclusion

The increase in ambulatory surgery for lateral epicondylitis, demonstrated in this study, emphasizes the importance of national funding for surveys such as NSAS beyond 2006, as utilization trends may have considerable effects on health care policies that influence the quality of patient care.

First described by Runge¹ in 1873 and later termed lawn-tennis arm by Major² in 1883, lateral epicondylitis is a common cause of elbow pain, affecting 1% to 3% of the general population each year.^3,4 Given that prevalence estimates are up to 15% among workers in repetitive hand task industries,^5-7 symptoms of lateral epicondylitis are thought to be related to recurring wrist extension and alternating forearm pronation and supination.⁸ Between 80% and 90% of patients with lateral epicondylitis experience symptomatic improvement with conservative therapy,^9-11 including rest and use of nonsteroidal anti-inflammatory medications,¹² physical therapy,^13,14 corticosteroid injections,^10,15,16 orthoses,^17,18 and shock wave therapy.¹⁹ However, between 4% and 11% of patients with newly diagnosed lateral epicondylitis do not respond to prolonged (6- to 12-month) conservative treatment and then require operative intervention,^11,20,21 with some referral practices reporting rates as high as 25%.²²

Traditionally, operative management of lateral epicondylitis involved open débridement of the extensor carpi radialis brevis (ECRB).^11,20 More recently, the spectrum of operations for lateral epicondylitis has expanded to include procedures that repair the extensor origin after débridement of the torn tendon and angiofibroblastic dysplasia; procedures that use fasciotomy or direct release of the extensor origin from the epicondyle to relieve tension on the common extensor; procedures directed at the radial or posterior interosseous nerve; and procedures that use arthroscopic techniques to divide the orbicular ligament, reshape the radial head, or release the extensor origin.²³ There has been debate about the value of repairing the ECRB, lengthening the ECRB, simultaneously decompressing the radial nerve or resecting epicondylar bone, and performing the procedures percutaneously, endoscopically, or arthroscopically.^24-28 Despite multiple studies of the outcomes of these procedures,^11,29-31 little is known regarding US national trends for operative treatment of lateral epicondylitis. Understanding national practice patterns and disease burden is essential to allocation of limited health care resources.

We conducted a study to determine US national trends in use of ambulatory surgery for lateral epicondylitis. We focused on age, sex, surgical setting, anesthetic type, and payment method.

Methods

As the National Survey of Ambulatory Surgery³² (NSAS) is an administrative dataset in which all data are deidentified and available for public use, this study was exempt from requiring institutional review board approval.

NSAS data were used to analyze trends in treatment of lateral epicondylitis between 1994 and 2006. NSAS was undertaken by the National Center for Health Statistics (NCHS) of the Centers for Disease Control and Prevention (CDC) to obtain information about the use of ambulatory surgery in the United States. Since the early 1980s, ambulatory surgery has increased in the United States because of advances in medical technology and cost-containment initiatives.³³ The number of procedures being performed in ambulatory surgery centers increased from 31.5 million in 1996 to 53.3 million in 2006.³⁴ Funded by the CDC, NSAS is a national study that involves both hospital-based and freestanding ambulatory surgery centers and provides the most recent and comprehensive overview of ambulatory surgery in the United States.³⁵ Because of budgetary limitations, 2006 was the last year in which data for NSAS were collected. Data for NSAS come from Medicare-participating, noninstitutional hospitals (excluding military hospitals, federal facilities, and Veteran Affairs hospitals) in all 50 states and the District of Columbia with a minimum of 6 beds staffed for patient use. NSAS used only short-stay hospitals (hospitals with an average length of stay for all patients of less than 30 days) or hospitals that had a specialty of general (medical or surgical) or children’s general. NSAS was conducted in 1994, 1996, and 2006 with medical information recorded on patient abstracts coded by contract staff. NSAS selected a sample of ambulatory surgery visits using a systematic random sampling procedure, and selection of visits within each facility was done separately for each location where ambulatory surgery was performed. In 1994, 751 facilities were sampled, and 88% of hospitals responded. In 1996, 750 facilities were sampled, and 91% of hospitals responded. In 2006, 696 facilities were sampled, and 75% responded. The surveys used International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes³⁶ to classify medical diagnoses and procedures. To produce an unbiased national estimate, NCHS used multistage estimate procedures, including inflation by reciprocals of the probabilities of sample selection, population-weighting ratio adjustments, and adjustment for no response.³⁷

Demographic and medical information was obtained for people with an ICD-9-CM diagnosis code of lateral epicondylitis (726.32), using previously described techniques.³⁸ Data were then recorded for age, sex, facility type, insurance type, anesthesia type, diagnoses, and procedures.

Descriptive statistics consisted of means and standard deviations for continuous variables and frequency and percentages for discrete variables. Because NSAS data were collected on the basis of a probabilistic sample scheme, they were analyzed using a sampling weighting method. Sampling weights (inverse of selection probability) provided by the CDC were used to account for unequal sampling probabilities and to produce estimates for all visits in the United States. A Taylor linearization model provided by the CDC estimates was used to calculate standard error and confidence intervals (CIs) of the data. Standard error is a measure of sampling variability that occurs by chance because only a sample rather than the entire universe is surveyed. To define population parameters, NCHS chose 95% CIs along with a point estimate. Direct statistical comparison between years cannot be performed because of sampling differences in the database compared between years. The CIs, however, can suggest statistical differences if the data are nonoverlapping. US census data were used to obtain national population estimates for each year of the study (1994, 1996, 2006).³⁹ Rates were presented as number of procedures per 100,000 standard population. For age, a direct adjustment procedure was used, and the US population in 2000 was selected as the standard population. Applying sex-specific rates to the standard population and dividing by the total in the standard population, we calculated sex-adjusted rates for each year. All data were analyzed using SPSS Version 20 software.

Results

A total of 30,311 ambulatory surgical procedures (95% CI, 27,292-33,330) or 10.44 per 100,000 capita were recorded by NSAS for the treatment of lateral epicondylitis in 2006 (Table 1). This represents a large increase in the total number of ambulatory procedures, from 21,852 in 1994 (95% CI, 19,981-23,722; 7.29/100,000) and 20,372 in 1996 (95% CI, 18,660-22,083; 6.73/100,000).

Between 1994 and 2006, the sex-adjusted rate of ambulatory surgery for lateral epicondylitis increased by 85% among females (7.74/100,000 to 14.31/100,000), whereas the rate decreased by 31% among males (8.07/100,000 to 5.59/100,000) (Table 1). The age-adjusted rate of ambulatory surgery for lateral epicondylitis increased among all age groups except the 30–39 years group (Table 2). The largest increase in age-adjusted rates was found for patients older than 50 years (275%) between 1994 and 2006.

During the study period, use of regional anesthesia nearly doubled, from 17% to 30%, whereas use of general anesthesia decreased, from 69% to 57% (Table 3). At all time points, the most common procedure performed for lateral epicondylitis in ambulatory surgery centers was division/release of the joint capsule of the elbow (Table 4). Private insurance remained the most common source of payment for all study years, ranging from 52% to 60% (Table 5). The Figure shows that, between 1994 and 2006, the proportion of surgeries performed in a freestanding ambulatory center increased.

Discussion

In this descriptive epidemiologic study, we used NSAS data to investigate trends in ambulatory surgery for lateral epicondylitis between 1994 and 2006.³² Our results showed that total number of procedures and the population-adjusted rate of procedures for lateral epicondylitis increased during the study period. The largest increase in age-adjusted rates of surgery for lateral epicondylitis was found among patients older than 50 years, whereas the highest age-adjusted rate of ambulatory surgery for lateral epicondylitis was found among patients between ages 40 and 49 years. These findings are similar to those of previous studies, which have shown that most patients with lateral epicondylitis present in the fourth and fifth decades of life.²² Prior reports have suggested that the incidence of lateral epicondylitis in men and women is equal.²² The present study found a change in sex-adjusted rates of ambulatory surgery for lateral epicondylitis between 1994 and 2006. Specifically, in 1994, surgery rates for men and women were similar (8.07/100,000 and 7.74/100,000), but in 2006 the sex-adjusted rate of surgery for lateral epicondylitis was almost 3 times higher for women than for men (14.31/100,000 vs 5.59/100,000).

We also found that the population-adjusted rate of lateral epicondylectomy increased drastically, from 0.4 per 100,000 in 1994 to 3.53 per 100,000 in 2006. Lateral epicondylectomy involves excision of the tip of the lateral epicondyle (typically, 0.5 cm) to produce a cancellous bone surface to which the edges of the débrided extensor tendon can be approximated without tension.²³ It is possible that the increased rate of lateral epicondylectomy reflects evidence-based practice changes during the study period,²⁷ though denervation was found more favorable than epicondylectomy in a recent study by Berry and colleagues.⁴⁰ Future studies should investigate whether rates of epicondylectomy have changed since 2006. In addition, the present study showed a correlation between the introduction of arthroscopic techniques for the treatment of lateral epicondylitis and the period when much research was being conducted on the topic.^24,25,28 As arthroscopic techniques improve, their rates are likely to continue to increase.

Our results also showed an increase in procedures performed in freestanding facilities. The rise in ambulatory surgical volume, speculated to result from more procedures being performed in freestanding facilities,³⁴ has been reported with knee and shoulder arthroscopy.⁴¹ In addition, though general anesthesia remained the most used technique, our results showed a shift toward peripheral nerve blocks. The increase in regional anesthesia, which has also been noted in joint arthroscopy, is thought to stem from the advent of nerve-localizing technology, such as nerve stimulation and ultrasound guidance.⁴¹ Peripheral nerve blocks are favorable on both economic and quality measures, are associated with fewer opioid-related side effects, and overall provide better analgesia in comparison with opioids, highlighting their importance in the ambulatory setting.⁴²

Although large, national databases are well suited to epidemiologic research,⁴³ our study had limitations. As with all databases, NSAS is subject to data entry errors and coding errors.^44,45 However, the database administrators corrected for this by using a multistage estimate procedure with weighting adjustments for no response and population-weighting ratio adjustments.³⁵ Another limitation of this study is its lack of clinical detail, as procedure codes are general and do not allow differentiation between specific patients. Because of the retrospective nature of the analysis and the heterogeneity of the data, assessment of specific surgeries for lateral epicondylitis was limited. Although a strength of using NSAS to perform epidemiologic analyses is its large sample size, this also sacrifices specificity in terms of clinical insight. The results of this study may influence investigations to distinguish differences between procedures used in the treatment of lateral epicondylitis. Furthermore, the results of this study are limited to ambulatory surgery practice patterns in the United States between 1996 and 2006. Last, our ability to perform economic analyses was limited, as data on total hospital cost were not recorded by the surveys.

Conclusion

The increase in ambulatory surgery for lateral epicondylitis, demonstrated in this study, emphasizes the importance of national funding for surveys such as NSAS beyond 2006, as utilization trends may have considerable effects on health care policies that influence the quality of patient care.

First described by Runge¹ in 1873 and later termed lawn-tennis arm by Major² in 1883, lateral epicondylitis is a common cause of elbow pain, affecting 1% to 3% of the general population each year.^3,4 Given that prevalence estimates are up to 15% among workers in repetitive hand task industries,^5-7 symptoms of lateral epicondylitis are thought to be related to recurring wrist extension and alternating forearm pronation and supination.⁸ Between 80% and 90% of patients with lateral epicondylitis experience symptomatic improvement with conservative therapy,^9-11 including rest and use of nonsteroidal anti-inflammatory medications,¹² physical therapy,^13,14 corticosteroid injections,^10,15,16 orthoses,^17,18 and shock wave therapy.¹⁹ However, between 4% and 11% of patients with newly diagnosed lateral epicondylitis do not respond to prolonged (6- to 12-month) conservative treatment and then require operative intervention,^11,20,21 with some referral practices reporting rates as high as 25%.²²

Traditionally, operative management of lateral epicondylitis involved open débridement of the extensor carpi radialis brevis (ECRB).^11,20 More recently, the spectrum of operations for lateral epicondylitis has expanded to include procedures that repair the extensor origin after débridement of the torn tendon and angiofibroblastic dysplasia; procedures that use fasciotomy or direct release of the extensor origin from the epicondyle to relieve tension on the common extensor; procedures directed at the radial or posterior interosseous nerve; and procedures that use arthroscopic techniques to divide the orbicular ligament, reshape the radial head, or release the extensor origin.²³ There has been debate about the value of repairing the ECRB, lengthening the ECRB, simultaneously decompressing the radial nerve or resecting epicondylar bone, and performing the procedures percutaneously, endoscopically, or arthroscopically.^24-28 Despite multiple studies of the outcomes of these procedures,^11,29-31 little is known regarding US national trends for operative treatment of lateral epicondylitis. Understanding national practice patterns and disease burden is essential to allocation of limited health care resources.

We conducted a study to determine US national trends in use of ambulatory surgery for lateral epicondylitis. We focused on age, sex, surgical setting, anesthetic type, and payment method.

Methods

As the National Survey of Ambulatory Surgery³² (NSAS) is an administrative dataset in which all data are deidentified and available for public use, this study was exempt from requiring institutional review board approval.

NSAS data were used to analyze trends in treatment of lateral epicondylitis between 1994 and 2006. NSAS was undertaken by the National Center for Health Statistics (NCHS) of the Centers for Disease Control and Prevention (CDC) to obtain information about the use of ambulatory surgery in the United States. Since the early 1980s, ambulatory surgery has increased in the United States because of advances in medical technology and cost-containment initiatives.³³ The number of procedures being performed in ambulatory surgery centers increased from 31.5 million in 1996 to 53.3 million in 2006.³⁴ Funded by the CDC, NSAS is a national study that involves both hospital-based and freestanding ambulatory surgery centers and provides the most recent and comprehensive overview of ambulatory surgery in the United States.³⁵ Because of budgetary limitations, 2006 was the last year in which data for NSAS were collected. Data for NSAS come from Medicare-participating, noninstitutional hospitals (excluding military hospitals, federal facilities, and Veteran Affairs hospitals) in all 50 states and the District of Columbia with a minimum of 6 beds staffed for patient use. NSAS used only short-stay hospitals (hospitals with an average length of stay for all patients of less than 30 days) or hospitals that had a specialty of general (medical or surgical) or children’s general. NSAS was conducted in 1994, 1996, and 2006 with medical information recorded on patient abstracts coded by contract staff. NSAS selected a sample of ambulatory surgery visits using a systematic random sampling procedure, and selection of visits within each facility was done separately for each location where ambulatory surgery was performed. In 1994, 751 facilities were sampled, and 88% of hospitals responded. In 1996, 750 facilities were sampled, and 91% of hospitals responded. In 2006, 696 facilities were sampled, and 75% responded. The surveys used International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes³⁶ to classify medical diagnoses and procedures. To produce an unbiased national estimate, NCHS used multistage estimate procedures, including inflation by reciprocals of the probabilities of sample selection, population-weighting ratio adjustments, and adjustment for no response.³⁷

Demographic and medical information was obtained for people with an ICD-9-CM diagnosis code of lateral epicondylitis (726.32), using previously described techniques.³⁸ Data were then recorded for age, sex, facility type, insurance type, anesthesia type, diagnoses, and procedures.

Descriptive statistics consisted of means and standard deviations for continuous variables and frequency and percentages for discrete variables. Because NSAS data were collected on the basis of a probabilistic sample scheme, they were analyzed using a sampling weighting method. Sampling weights (inverse of selection probability) provided by the CDC were used to account for unequal sampling probabilities and to produce estimates for all visits in the United States. A Taylor linearization model provided by the CDC estimates was used to calculate standard error and confidence intervals (CIs) of the data. Standard error is a measure of sampling variability that occurs by chance because only a sample rather than the entire universe is surveyed. To define population parameters, NCHS chose 95% CIs along with a point estimate. Direct statistical comparison between years cannot be performed because of sampling differences in the database compared between years. The CIs, however, can suggest statistical differences if the data are nonoverlapping. US census data were used to obtain national population estimates for each year of the study (1994, 1996, 2006).³⁹ Rates were presented as number of procedures per 100,000 standard population. For age, a direct adjustment procedure was used, and the US population in 2000 was selected as the standard population. Applying sex-specific rates to the standard population and dividing by the total in the standard population, we calculated sex-adjusted rates for each year. All data were analyzed using SPSS Version 20 software.

Results

A total of 30,311 ambulatory surgical procedures (95% CI, 27,292-33,330) or 10.44 per 100,000 capita were recorded by NSAS for the treatment of lateral epicondylitis in 2006 (Table 1). This represents a large increase in the total number of ambulatory procedures, from 21,852 in 1994 (95% CI, 19,981-23,722; 7.29/100,000) and 20,372 in 1996 (95% CI, 18,660-22,083; 6.73/100,000).

Between 1994 and 2006, the sex-adjusted rate of ambulatory surgery for lateral epicondylitis increased by 85% among females (7.74/100,000 to 14.31/100,000), whereas the rate decreased by 31% among males (8.07/100,000 to 5.59/100,000) (Table 1). The age-adjusted rate of ambulatory surgery for lateral epicondylitis increased among all age groups except the 30–39 years group (Table 2). The largest increase in age-adjusted rates was found for patients older than 50 years (275%) between 1994 and 2006.

During the study period, use of regional anesthesia nearly doubled, from 17% to 30%, whereas use of general anesthesia decreased, from 69% to 57% (Table 3). At all time points, the most common procedure performed for lateral epicondylitis in ambulatory surgery centers was division/release of the joint capsule of the elbow (Table 4). Private insurance remained the most common source of payment for all study years, ranging from 52% to 60% (Table 5). The Figure shows that, between 1994 and 2006, the proportion of surgeries performed in a freestanding ambulatory center increased.

Discussion

In this descriptive epidemiologic study, we used NSAS data to investigate trends in ambulatory surgery for lateral epicondylitis between 1994 and 2006.³² Our results showed that total number of procedures and the population-adjusted rate of procedures for lateral epicondylitis increased during the study period. The largest increase in age-adjusted rates of surgery for lateral epicondylitis was found among patients older than 50 years, whereas the highest age-adjusted rate of ambulatory surgery for lateral epicondylitis was found among patients between ages 40 and 49 years. These findings are similar to those of previous studies, which have shown that most patients with lateral epicondylitis present in the fourth and fifth decades of life.²² Prior reports have suggested that the incidence of lateral epicondylitis in men and women is equal.²² The present study found a change in sex-adjusted rates of ambulatory surgery for lateral epicondylitis between 1994 and 2006. Specifically, in 1994, surgery rates for men and women were similar (8.07/100,000 and 7.74/100,000), but in 2006 the sex-adjusted rate of surgery for lateral epicondylitis was almost 3 times higher for women than for men (14.31/100,000 vs 5.59/100,000).

We also found that the population-adjusted rate of lateral epicondylectomy increased drastically, from 0.4 per 100,000 in 1994 to 3.53 per 100,000 in 2006. Lateral epicondylectomy involves excision of the tip of the lateral epicondyle (typically, 0.5 cm) to produce a cancellous bone surface to which the edges of the débrided extensor tendon can be approximated without tension.²³ It is possible that the increased rate of lateral epicondylectomy reflects evidence-based practice changes during the study period,²⁷ though denervation was found more favorable than epicondylectomy in a recent study by Berry and colleagues.⁴⁰ Future studies should investigate whether rates of epicondylectomy have changed since 2006. In addition, the present study showed a correlation between the introduction of arthroscopic techniques for the treatment of lateral epicondylitis and the period when much research was being conducted on the topic.^24,25,28 As arthroscopic techniques improve, their rates are likely to continue to increase.

Our results also showed an increase in procedures performed in freestanding facilities. The rise in ambulatory surgical volume, speculated to result from more procedures being performed in freestanding facilities,³⁴ has been reported with knee and shoulder arthroscopy.⁴¹ In addition, though general anesthesia remained the most used technique, our results showed a shift toward peripheral nerve blocks. The increase in regional anesthesia, which has also been noted in joint arthroscopy, is thought to stem from the advent of nerve-localizing technology, such as nerve stimulation and ultrasound guidance.⁴¹ Peripheral nerve blocks are favorable on both economic and quality measures, are associated with fewer opioid-related side effects, and overall provide better analgesia in comparison with opioids, highlighting their importance in the ambulatory setting.⁴²

Although large, national databases are well suited to epidemiologic research,⁴³ our study had limitations. As with all databases, NSAS is subject to data entry errors and coding errors.^44,45 However, the database administrators corrected for this by using a multistage estimate procedure with weighting adjustments for no response and population-weighting ratio adjustments.³⁵ Another limitation of this study is its lack of clinical detail, as procedure codes are general and do not allow differentiation between specific patients. Because of the retrospective nature of the analysis and the heterogeneity of the data, assessment of specific surgeries for lateral epicondylitis was limited. Although a strength of using NSAS to perform epidemiologic analyses is its large sample size, this also sacrifices specificity in terms of clinical insight. The results of this study may influence investigations to distinguish differences between procedures used in the treatment of lateral epicondylitis. Furthermore, the results of this study are limited to ambulatory surgery practice patterns in the United States between 1996 and 2006. Last, our ability to perform economic analyses was limited, as data on total hospital cost were not recorded by the surveys.

Conclusion

The increase in ambulatory surgery for lateral epicondylitis, demonstrated in this study, emphasizes the importance of national funding for surveys such as NSAS beyond 2006, as utilization trends may have considerable effects on health care policies that influence the quality of patient care.

In shoulder arthroplasty, it is not uncommon for patients to receive postoperative blood transfusions; rates range from 7% to 43%.^1-6 Allogeneic blood transfusions (ABTs) are costly and not entirely free of risks.⁷ The risk for infection has decreased because of improved screening and risk reduction strategies, but there are still significant risks associated with ABTs, such as clerical errors, acute and delayed hemolytic reactions, graft-versus-host reactions, transfusion-related acute lung injury, and anaphylaxis.^8-10 As use of shoulder arthroplasty continues to increase, the importance of minimizing unnecessary transfusions is growing as well.⁷

Predictive factors for ABT have been explored in other orthopedic settings, yet little has been done in shoulder arthroplasty.^1-6,11-15 Previous shoulder arthroplasty studies have shown that low preoperative hemoglobin (Hb) levels are independent risk factors for postoperative blood transfusion. However, there is debate over the significance of other variables, such as procedure type, age, sex, and medical comorbidities. Further, prior studies were limited by relatively small samples from single institutions; the largest series included fewer than 600 patients.^1-6

We conducted a study to determine predictors of ABT in a large cohort of patients admitted to US hospitals for shoulder arthroplasty. We also wanted to evaluate the effect of ABT on postoperative outcomes, including inpatient mortality, adverse events, prolonged hospital stay, and nonroutine discharge. According to the null hypothesis, in shoulder arthroplasty there will be no difference in risk factors between patients who require ABT and those who did not, after accounting for confounding variables.

Materials and Methods

This study was exempt from institutional review board approval, as all data were appropriately deidentified before use in this project. We used the Nationwide Inpatient Sample (NIS) to retrospectively study the period 2002–2011, from which all demographic, clinical, and resource use data were derived.¹⁶ NIS, an annual survey conducted by the Agency for Healthcare Research and Quality (AHRQ) since 1988, has generated a huge amount of data, forming the largest all-payer inpatient care database in the United States. Yearly samples contain discharge data from about 8 million hospital stays at more than 1000 hospitals across 46 states, approximating a 20% random sample of all hospital discharges at participating institutions.¹⁷ These data are then weighted to generate statistically valid national estimates.

The NIS database uses International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) codes to identify 15 medical diagnoses up to the year 2008 and a maximum of 25 medical diagnoses and 15 procedures thereafter. In addition, the database includes information on patient and hospital characteristics as well as inpatient outcomes such as length of stay, total hospitalization charges, and discharge disposition.^18,19 Given its large sample size and data volume, NIS is a powerful tool in the analysis of data associated with a multitude of medical diagnoses and procedures.²⁰

We used the NIS database to study a population of 422,371 patients (age, >18 years) who underwent total shoulder arthroplasty (TSA) or hemiarthroplasty (HSA) between 2002 and 2011. ICD-9-CM procedure codes for TSA (81.80, 81.88) and HSA (81.81) were used to identify this population. We also analyzed data for reverse TSA for the year 2011. Then we divided our target population into 2 different cohorts: patients who did not receive any blood transfusion products and patients who received a transfusion of allogeneic packed cells (ICD-9-CM code 99.04 was used to identify the latter cohort).

In this study, normal distribution of the dataset was assumed, given the large sample size. The 2 cohorts were evaluated through bivariate analysis using the Pearson χ² test for categorical data and the independent-samples t test for continuous data. The extent to which diagnosis, age, race, sex, and medical comorbidities were predictive of blood transfusion after TSA or HSA was evaluated through multivariate binary logistic regression analysis. Statistical significance was set at P < .05. All statistical analyses and data modeling were performed with SPSS Version 22.0.

Results

Using the NIS database, we stratified an estimated 422,371 patients who presented for shoulder arthroplasty between January 1, 2002, and December 31, 2011, into a TSA cohort (59.3%) and an HSA cohort (40.7%). Eight percent (33,889) of all patients received an ABT; the proportion of patients who received ABT was higher (P < .001) for the HSA cohort (55.6%) than the TSA cohort (39.4%). Further, the rate of ABT after shoulder arthroplasty showed an upward inclination (Figure).

Demographically, patients who received ABT tended (P < .001) to be older (74±11 years vs 68±11 years) and of a minority race (black or Hispanic) and to fall in either the lowest range of median household income (21.5% vs 20.7%; ≤$38,999) or the highest (27.3% vs 25.4%; ≥$63,000). Shoulder arthroplasty with ABT occurred more often (P < .001) at hospitals that were urban (13.3% vs 11.3%), medium in size (27.3% vs 23.4%), and nonteaching (56.2% vs 54.3%). In addition, ABT was used more often (P < .001) in patients with a primary diagnosis of fracture (43.1% vs 14.3%) or fracture nonunion (4.4% vs 2.1%). These groups also had a longer (P < .001) hospital stay (5.0±4.3 days vs 2.5±2.2 days). Table 1 summarizes these findings.

The 2 cohorts were then analyzed for presence of medical comorbidities (Table 2). Patients who required ABT during shoulder arthroplasty had a significantly (P < .001) higher prevalence of congestive heart failure, chronic lung disease, hypertension, uncomplicated and complicated diabetes mellitus, liver disease, renal failure, fluid and electrolyte disorders, pulmonary circulatory disease, weight loss, coagulopathy, and deficiency anemia.

In multivariate regression modeling (Table 3), demographic predictors of ABT (P < .001) included increasing age (odds ratio [OR], 1.03 per year; 95% confidence interval [95% CI], 1.03-1.03), female sex (OR, 1.55; 95% CI, 1.51-1.60), and minority race (black or Hispanic). Odds of requiring ABT were higher for patients with Medicare (OR, 1.25; 95% CI, 1.20-1.30) and patients with Medicaid (OR, 1.63; 95% CI, 1.51-1.77) than for patients with private insurance.

ABT was more likely to be required (P < .001) in patients with a primary diagnosis of fracture (OR, 4.49; 95% CI, 4.34-4.65), avascular necrosis (OR, 2.06; 95% CI, 1.91-2.22), rheumatoid arthritis (OR, 1.91; 95% CI, 1.72-2.12), fracture nonunion (OR, 3.55; 95% CI, 3.33-3.79), or rotator cuff arthropathy (OR, 1.47; 95% CI, 1.41-1.54) than for patients with osteoarthritis. Moreover, compared with patients having HSA, patients having TSA were more likely to require ABT (OR, 1.20; 95% CI, 1.17-1.24). According to the analysis restricted to the year 2011, compared with patients having anatomical TSAs, patients having reverse TSAs were 1.6 times more likely (P < .001) to require ABT (OR, 1.63; 95% CI, 1.50-1.79).

With the exception of obesity, all comorbidities were significant (P < .001) independent predictors of ABT after shoulder arthroplasty: deficiency anemia (OR, 3.42; 95% CI, 3.32-3.52), coagulopathy (OR, 2.54; 95% CI, 2.36-2.73), fluid and electrolyte disorders (OR, 1.91; 95% CI, 1.84-1.97), and weight loss (OR, 1.78; 95% CI, 1.58-2.00).

Patients who received ABT were more likely to experience adverse events (OR, 1.74; 95% CI, 1.68-1.81), prolonged hospital stay (OR, 3.21; 95% CI, 3.12-3.30), and nonroutine discharge (OR, 1.77; 95% CI, 1.72-1.82) (Table 4). There was no difference in mortality between the 2 cohorts.

Discussion

There is an abundance of literature on blood transfusions in hip and knee arthroplasty, but there are few articles on ABT in shoulder arthroplasty, and they all report data from single institutions with relatively low caseloads.^{1,2,11-13,15,21} In the present study, we investigated ABT in shoulder arthroplasty from the perspective of a multi-institutional database with a caseload of more than 400,000. Given the rapidly increasing rates of shoulder arthroplasty, it is important to further examine this issue to minimize unnecessary blood transfusion and its associated risks and costs.⁷

We found that 8% of patients who had shoulder arthroplasty received ABT, which is consistent with previously reported transfusion rates (range, 7%-43%).^1-6 Rates of ABT after shoulder arthroplasty have continued to rise. The exception, a decrease during the year 2010, can be explained by increased efforts to more rigidly follow transfusion indication guidelines to reduce the number of potentially unnecessary ABTs.^21-24 Our study also identified numerous significant independent predictors of ABT in shoulder arthroplasty: age, sex, race, insurance status, procedure type, primary diagnoses, and multiple medical comorbidities.

Demographics

According to our analysis, more than 80% of patients who received ABT were over age 65 years, which aligns with what several other studies have demonstrated: Increasing age is a predictor of ABT, despite higher rates of comorbidities and lower preoperative Hb levels in this population.^{1,2,4,5,25-27} Consistent with previous work, female sex was predictive of ABT.^2,5 It has been suggested that females are more likely predisposed to ABT because of lower preoperative Hb and smaller blood mass.^2,5,28 Interestingly, our study showed a higher likelihood of ABT in both black and Hispanic populations. Further, patients with Medicare or Medicaid were more likely to receive ABT.

Primary Diagnosis

Although patients with a primary diagnosis of osteoarthritis constitute the majority of patients who undergo shoulder arthroplasty, our analysis showed that patients with a diagnosis of proximal humerus fracture were more likely to receive ABT. This finding is reasonable given studies showing the high prevalence of proximal humerus fractures in elderly women.^29,30 Similarly, patients with a humerus fracture nonunion were more likely to receive a blood transfusion, which is unsurprising given the increased complexity associated with arthroplasty in this predominately elderly population.³¹ Interestingly, compared with patients with osteoarthritis, patients with any one of the other primary diagnoses were more likely to require a transfusion—proximal humerus fracture being the most significant, followed by humerus fracture nonunion, avascular necrosis, rheumatoid arthritis, and rotator cuff arthropathy.

Type of Arthroplasty

Bivariate analysis revealed that 55.6% of the patients who received ABT underwent HSA; the other 44.4% underwent TSA. The effect of primary diagnosis on procedure choice likely played a role in this finding. HSA indications include humerus fracture, which has been associated with increased ABT, whereas patients with osteoarthritis requiring TSA are significantly less likely to require ABT, as reflected in this analysis.^7,32-34 Previous studies have failed to show a difference in blood transfusion rates between TSA and HSA.^2,4-6,35 Conversely, with confounding factors controlled for, multivariate logistic regression analysis showed that TSA was 1.2 times more likely than HSA to require ABT, which could be explained by the increased operative time, case complexity, and blood loss that may be associated with the glenoid exposure.^36,37 With analysis restricted to the year 2011, patients with reverse TSAs were 1.6 times more likely than patients with anatomical TSAs to receive a blood transfusion (OR, 1.63; 95% CI, 1.50-1.79). Although this finding differs from what was previously reported, it fits given that patients having reverse TSAs are often older and may present with a more significant comorbidity profile.³ In addition, there are the increased technical surgical aspects associated with “salvage surgery” for challenging indications such as cuff arthropathy and failed previous arthroplasty.^38-41

Medical Comorbidities

Patients who received ABT were more likely to present with numerous medical comorbidities. Previous studies have indicated that the presence of multiple medical comorbidities significantly increased blood transfusion rates, possibly by working synergistically.⁴² All studies of blood transfusion in shoulder arthroplasty concluded that lower preoperative Hb was an independent predictor.^1-6 Schumer and colleagues⁴ reported a 4-fold increase in likelihood of blood transfusion in patients with a preoperative Hb level less than 12.5 g/dL. In addition, Millett and colleagues⁶ showed a 20-fold increase in likelihood of transfusion in patients with a preoperative Hb level less than 11.0 g/dL compared with patients with a level higher than 13.0 g/dL. Patients with a Hb level between 11.0 and 13.0 g/dL showed a 5-fold increase in likelihood of transfusion.⁶ We should note that correction of preoperative anemia through various pharmacologic methods (eg, erythropoietin, intravenous iron supplementation) has been shown to decrease postoperative transfusion rates.^43,44 Although we could not include preoperative Hb levels in the present study, given inherent limitations in using NIS, our multivariate analysis showed that preoperative deficiency anemia and coagulopathy were the most significant predictors of ABT.

In addition, the multivariate logistic regression model showed that both cardiac disease and diabetes were independent predictors of ABT, confirming data reported by Ahmadi and colleagues.¹ Although not as well characterized in other studies, in the current analysis multiple other medical comorbidities, including fluid and electrolyte abnormalities, weight loss, liver disease, renal failure, and chronic lung disease, had significant predictive value. Contrarily, obesity significantly decreased the odds of ABT, likely because of higher baseline blood volume in obese patients.

Patient Outcomes

Patients who undergo shoulder arthroplasty with ABT are more likely to experience adverse events or a prolonged hospital stay and are more often discharged to a nursing home or an extended-care facility. In this population, however, deaths did not occur at a significantly higher rate—similar to what was found for patients who underwent hip or knee arthroplasty with blood transfusions.⁴⁵

Little has been done to investigate the effect of pharmacologic agents on the need for perioperative ABT for orthopedic shoulder procedures. Aprotinin, tranexamic acid, epoetin-α, and aminocaproic acid have all been effective in limiting ABT during the perioperative period in various orthopedic hip, knee, and spine procedures.^9,46-53 Given the increased morbidity associated with ABT, it may be beneficial to use similar methods to limit blood loss in high-risk patients undergoing shoulder arthroplasty.

Study Limitations

NIS has intrinsic limitations. Given its massive volume, it is subject to errors in both data entry and clinical coding. Moreover, the database lacks data that would have been useful in our study: preoperative Hb levels, intraoperative course, number of units transfused, total blood loss, use of blood conservation techniques, transfusion protocols, and severity of comorbidities. Reverse TSA was given a unique ICD-9-CM code in October 2010, so 2011 was the only year we were able to examine the relationship between reverse TSA and transfusions. Further, our analysis was unable to identify any medications, including chronic anticoagulants or postoperative prophylaxis, that have been shown to significantly affect blood transfusion rates.⁵⁴ Yet, there are obvious advantages to using the NIS database, as previously outlined across the medical landscape.

Conclusion

Our results confirmed previous findings and identified new predictors of ABT in shoulder arthroplasty in a large cohort. We examined demographics and perioperative complications while identifying predictors of ABT use. Patients who received ABT were older, female, and nonwhite and were covered by Medicare or Medicaid insurance, and many had a primary diagnosis of proximal humerus fracture. The ABT cohort had numerous medical comorbidities, including deficiency anemia and coagulopathy. Identifying this patient population is a prerequisite to educating patients while minimizing unnecessary risks and costs.

Using NIS data on a population of 422,371 patients who underwent shoulder arthroplasty, we identified the 5 likeliest predictors of ABT: fracture, fracture nonunion, deficiency anemia, coagulopathy, and avascular necrosis. Of the identified variables associated with ABT, deficiency anemia may be the most amenable to treatment; therefore, there may be benefit in delaying elective shoulder arthroplasty in this cohort. Given these findings, it is important to identify at-risk patients before surgery, with the intent to provide education and minimize risk.

In shoulder arthroplasty, it is not uncommon for patients to receive postoperative blood transfusions; rates range from 7% to 43%.^1-6 Allogeneic blood transfusions (ABTs) are costly and not entirely free of risks.⁷ The risk for infection has decreased because of improved screening and risk reduction strategies, but there are still significant risks associated with ABTs, such as clerical errors, acute and delayed hemolytic reactions, graft-versus-host reactions, transfusion-related acute lung injury, and anaphylaxis.^8-10 As use of shoulder arthroplasty continues to increase, the importance of minimizing unnecessary transfusions is growing as well.⁷

Predictive factors for ABT have been explored in other orthopedic settings, yet little has been done in shoulder arthroplasty.^1-6,11-15 Previous shoulder arthroplasty studies have shown that low preoperative hemoglobin (Hb) levels are independent risk factors for postoperative blood transfusion. However, there is debate over the significance of other variables, such as procedure type, age, sex, and medical comorbidities. Further, prior studies were limited by relatively small samples from single institutions; the largest series included fewer than 600 patients.^1-6

We conducted a study to determine predictors of ABT in a large cohort of patients admitted to US hospitals for shoulder arthroplasty. We also wanted to evaluate the effect of ABT on postoperative outcomes, including inpatient mortality, adverse events, prolonged hospital stay, and nonroutine discharge. According to the null hypothesis, in shoulder arthroplasty there will be no difference in risk factors between patients who require ABT and those who did not, after accounting for confounding variables.

Materials and Methods

This study was exempt from institutional review board approval, as all data were appropriately deidentified before use in this project. We used the Nationwide Inpatient Sample (NIS) to retrospectively study the period 2002–2011, from which all demographic, clinical, and resource use data were derived.¹⁶ NIS, an annual survey conducted by the Agency for Healthcare Research and Quality (AHRQ) since 1988, has generated a huge amount of data, forming the largest all-payer inpatient care database in the United States. Yearly samples contain discharge data from about 8 million hospital stays at more than 1000 hospitals across 46 states, approximating a 20% random sample of all hospital discharges at participating institutions.¹⁷ These data are then weighted to generate statistically valid national estimates.

The NIS database uses International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) codes to identify 15 medical diagnoses up to the year 2008 and a maximum of 25 medical diagnoses and 15 procedures thereafter. In addition, the database includes information on patient and hospital characteristics as well as inpatient outcomes such as length of stay, total hospitalization charges, and discharge disposition.^18,19 Given its large sample size and data volume, NIS is a powerful tool in the analysis of data associated with a multitude of medical diagnoses and procedures.²⁰

We used the NIS database to study a population of 422,371 patients (age, >18 years) who underwent total shoulder arthroplasty (TSA) or hemiarthroplasty (HSA) between 2002 and 2011. ICD-9-CM procedure codes for TSA (81.80, 81.88) and HSA (81.81) were used to identify this population. We also analyzed data for reverse TSA for the year 2011. Then we divided our target population into 2 different cohorts: patients who did not receive any blood transfusion products and patients who received a transfusion of allogeneic packed cells (ICD-9-CM code 99.04 was used to identify the latter cohort).

In this study, normal distribution of the dataset was assumed, given the large sample size. The 2 cohorts were evaluated through bivariate analysis using the Pearson χ² test for categorical data and the independent-samples t test for continuous data. The extent to which diagnosis, age, race, sex, and medical comorbidities were predictive of blood transfusion after TSA or HSA was evaluated through multivariate binary logistic regression analysis. Statistical significance was set at P < .05. All statistical analyses and data modeling were performed with SPSS Version 22.0.

Results

Using the NIS database, we stratified an estimated 422,371 patients who presented for shoulder arthroplasty between January 1, 2002, and December 31, 2011, into a TSA cohort (59.3%) and an HSA cohort (40.7%). Eight percent (33,889) of all patients received an ABT; the proportion of patients who received ABT was higher (P < .001) for the HSA cohort (55.6%) than the TSA cohort (39.4%). Further, the rate of ABT after shoulder arthroplasty showed an upward inclination (Figure).

Demographically, patients who received ABT tended (P < .001) to be older (74±11 years vs 68±11 years) and of a minority race (black or Hispanic) and to fall in either the lowest range of median household income (21.5% vs 20.7%; ≤$38,999) or the highest (27.3% vs 25.4%; ≥$63,000). Shoulder arthroplasty with ABT occurred more often (P < .001) at hospitals that were urban (13.3% vs 11.3%), medium in size (27.3% vs 23.4%), and nonteaching (56.2% vs 54.3%). In addition, ABT was used more often (P < .001) in patients with a primary diagnosis of fracture (43.1% vs 14.3%) or fracture nonunion (4.4% vs 2.1%). These groups also had a longer (P < .001) hospital stay (5.0±4.3 days vs 2.5±2.2 days). Table 1 summarizes these findings.

The 2 cohorts were then analyzed for presence of medical comorbidities (Table 2). Patients who required ABT during shoulder arthroplasty had a significantly (P < .001) higher prevalence of congestive heart failure, chronic lung disease, hypertension, uncomplicated and complicated diabetes mellitus, liver disease, renal failure, fluid and electrolyte disorders, pulmonary circulatory disease, weight loss, coagulopathy, and deficiency anemia.

In multivariate regression modeling (Table 3), demographic predictors of ABT (P < .001) included increasing age (odds ratio [OR], 1.03 per year; 95% confidence interval [95% CI], 1.03-1.03), female sex (OR, 1.55; 95% CI, 1.51-1.60), and minority race (black or Hispanic). Odds of requiring ABT were higher for patients with Medicare (OR, 1.25; 95% CI, 1.20-1.30) and patients with Medicaid (OR, 1.63; 95% CI, 1.51-1.77) than for patients with private insurance.

ABT was more likely to be required (P < .001) in patients with a primary diagnosis of fracture (OR, 4.49; 95% CI, 4.34-4.65), avascular necrosis (OR, 2.06; 95% CI, 1.91-2.22), rheumatoid arthritis (OR, 1.91; 95% CI, 1.72-2.12), fracture nonunion (OR, 3.55; 95% CI, 3.33-3.79), or rotator cuff arthropathy (OR, 1.47; 95% CI, 1.41-1.54) than for patients with osteoarthritis. Moreover, compared with patients having HSA, patients having TSA were more likely to require ABT (OR, 1.20; 95% CI, 1.17-1.24). According to the analysis restricted to the year 2011, compared with patients having anatomical TSAs, patients having reverse TSAs were 1.6 times more likely (P < .001) to require ABT (OR, 1.63; 95% CI, 1.50-1.79).

With the exception of obesity, all comorbidities were significant (P < .001) independent predictors of ABT after shoulder arthroplasty: deficiency anemia (OR, 3.42; 95% CI, 3.32-3.52), coagulopathy (OR, 2.54; 95% CI, 2.36-2.73), fluid and electrolyte disorders (OR, 1.91; 95% CI, 1.84-1.97), and weight loss (OR, 1.78; 95% CI, 1.58-2.00).

Patients who received ABT were more likely to experience adverse events (OR, 1.74; 95% CI, 1.68-1.81), prolonged hospital stay (OR, 3.21; 95% CI, 3.12-3.30), and nonroutine discharge (OR, 1.77; 95% CI, 1.72-1.82) (Table 4). There was no difference in mortality between the 2 cohorts.

Discussion

There is an abundance of literature on blood transfusions in hip and knee arthroplasty, but there are few articles on ABT in shoulder arthroplasty, and they all report data from single institutions with relatively low caseloads.^{1,2,11-13,15,21} In the present study, we investigated ABT in shoulder arthroplasty from the perspective of a multi-institutional database with a caseload of more than 400,000. Given the rapidly increasing rates of shoulder arthroplasty, it is important to further examine this issue to minimize unnecessary blood transfusion and its associated risks and costs.⁷

We found that 8% of patients who had shoulder arthroplasty received ABT, which is consistent with previously reported transfusion rates (range, 7%-43%).^1-6 Rates of ABT after shoulder arthroplasty have continued to rise. The exception, a decrease during the year 2010, can be explained by increased efforts to more rigidly follow transfusion indication guidelines to reduce the number of potentially unnecessary ABTs.^21-24 Our study also identified numerous significant independent predictors of ABT in shoulder arthroplasty: age, sex, race, insurance status, procedure type, primary diagnoses, and multiple medical comorbidities.

Demographics

According to our analysis, more than 80% of patients who received ABT were over age 65 years, which aligns with what several other studies have demonstrated: Increasing age is a predictor of ABT, despite higher rates of comorbidities and lower preoperative Hb levels in this population.^{1,2,4,5,25-27} Consistent with previous work, female sex was predictive of ABT.^2,5 It has been suggested that females are more likely predisposed to ABT because of lower preoperative Hb and smaller blood mass.^2,5,28 Interestingly, our study showed a higher likelihood of ABT in both black and Hispanic populations. Further, patients with Medicare or Medicaid were more likely to receive ABT.

Primary Diagnosis

Although patients with a primary diagnosis of osteoarthritis constitute the majority of patients who undergo shoulder arthroplasty, our analysis showed that patients with a diagnosis of proximal humerus fracture were more likely to receive ABT. This finding is reasonable given studies showing the high prevalence of proximal humerus fractures in elderly women.^29,30 Similarly, patients with a humerus fracture nonunion were more likely to receive a blood transfusion, which is unsurprising given the increased complexity associated with arthroplasty in this predominately elderly population.³¹ Interestingly, compared with patients with osteoarthritis, patients with any one of the other primary diagnoses were more likely to require a transfusion—proximal humerus fracture being the most significant, followed by humerus fracture nonunion, avascular necrosis, rheumatoid arthritis, and rotator cuff arthropathy.

Type of Arthroplasty

Bivariate analysis revealed that 55.6% of the patients who received ABT underwent HSA; the other 44.4% underwent TSA. The effect of primary diagnosis on procedure choice likely played a role in this finding. HSA indications include humerus fracture, which has been associated with increased ABT, whereas patients with osteoarthritis requiring TSA are significantly less likely to require ABT, as reflected in this analysis.^7,32-34 Previous studies have failed to show a difference in blood transfusion rates between TSA and HSA.^2,4-6,35 Conversely, with confounding factors controlled for, multivariate logistic regression analysis showed that TSA was 1.2 times more likely than HSA to require ABT, which could be explained by the increased operative time, case complexity, and blood loss that may be associated with the glenoid exposure.^36,37 With analysis restricted to the year 2011, patients with reverse TSAs were 1.6 times more likely than patients with anatomical TSAs to receive a blood transfusion (OR, 1.63; 95% CI, 1.50-1.79). Although this finding differs from what was previously reported, it fits given that patients having reverse TSAs are often older and may present with a more significant comorbidity profile.³ In addition, there are the increased technical surgical aspects associated with “salvage surgery” for challenging indications such as cuff arthropathy and failed previous arthroplasty.^38-41

Medical Comorbidities

Patients who received ABT were more likely to present with numerous medical comorbidities. Previous studies have indicated that the presence of multiple medical comorbidities significantly increased blood transfusion rates, possibly by working synergistically.⁴² All studies of blood transfusion in shoulder arthroplasty concluded that lower preoperative Hb was an independent predictor.^1-6 Schumer and colleagues⁴ reported a 4-fold increase in likelihood of blood transfusion in patients with a preoperative Hb level less than 12.5 g/dL. In addition, Millett and colleagues⁶ showed a 20-fold increase in likelihood of transfusion in patients with a preoperative Hb level less than 11.0 g/dL compared with patients with a level higher than 13.0 g/dL. Patients with a Hb level between 11.0 and 13.0 g/dL showed a 5-fold increase in likelihood of transfusion.⁶ We should note that correction of preoperative anemia through various pharmacologic methods (eg, erythropoietin, intravenous iron supplementation) has been shown to decrease postoperative transfusion rates.^43,44 Although we could not include preoperative Hb levels in the present study, given inherent limitations in using NIS, our multivariate analysis showed that preoperative deficiency anemia and coagulopathy were the most significant predictors of ABT.

In addition, the multivariate logistic regression model showed that both cardiac disease and diabetes were independent predictors of ABT, confirming data reported by Ahmadi and colleagues.¹ Although not as well characterized in other studies, in the current analysis multiple other medical comorbidities, including fluid and electrolyte abnormalities, weight loss, liver disease, renal failure, and chronic lung disease, had significant predictive value. Contrarily, obesity significantly decreased the odds of ABT, likely because of higher baseline blood volume in obese patients.

Patient Outcomes

Patients who undergo shoulder arthroplasty with ABT are more likely to experience adverse events or a prolonged hospital stay and are more often discharged to a nursing home or an extended-care facility. In this population, however, deaths did not occur at a significantly higher rate—similar to what was found for patients who underwent hip or knee arthroplasty with blood transfusions.⁴⁵

Little has been done to investigate the effect of pharmacologic agents on the need for perioperative ABT for orthopedic shoulder procedures. Aprotinin, tranexamic acid, epoetin-α, and aminocaproic acid have all been effective in limiting ABT during the perioperative period in various orthopedic hip, knee, and spine procedures.^9,46-53 Given the increased morbidity associated with ABT, it may be beneficial to use similar methods to limit blood loss in high-risk patients undergoing shoulder arthroplasty.

Study Limitations

NIS has intrinsic limitations. Given its massive volume, it is subject to errors in both data entry and clinical coding. Moreover, the database lacks data that would have been useful in our study: preoperative Hb levels, intraoperative course, number of units transfused, total blood loss, use of blood conservation techniques, transfusion protocols, and severity of comorbidities. Reverse TSA was given a unique ICD-9-CM code in October 2010, so 2011 was the only year we were able to examine the relationship between reverse TSA and transfusions. Further, our analysis was unable to identify any medications, including chronic anticoagulants or postoperative prophylaxis, that have been shown to significantly affect blood transfusion rates.⁵⁴ Yet, there are obvious advantages to using the NIS database, as previously outlined across the medical landscape.

Conclusion

Our results confirmed previous findings and identified new predictors of ABT in shoulder arthroplasty in a large cohort. We examined demographics and perioperative complications while identifying predictors of ABT use. Patients who received ABT were older, female, and nonwhite and were covered by Medicare or Medicaid insurance, and many had a primary diagnosis of proximal humerus fracture. The ABT cohort had numerous medical comorbidities, including deficiency anemia and coagulopathy. Identifying this patient population is a prerequisite to educating patients while minimizing unnecessary risks and costs.

Using NIS data on a population of 422,371 patients who underwent shoulder arthroplasty, we identified the 5 likeliest predictors of ABT: fracture, fracture nonunion, deficiency anemia, coagulopathy, and avascular necrosis. Of the identified variables associated with ABT, deficiency anemia may be the most amenable to treatment; therefore, there may be benefit in delaying elective shoulder arthroplasty in this cohort. Given these findings, it is important to identify at-risk patients before surgery, with the intent to provide education and minimize risk.

In shoulder arthroplasty, it is not uncommon for patients to receive postoperative blood transfusions; rates range from 7% to 43%.^1-6 Allogeneic blood transfusions (ABTs) are costly and not entirely free of risks.⁷ The risk for infection has decreased because of improved screening and risk reduction strategies, but there are still significant risks associated with ABTs, such as clerical errors, acute and delayed hemolytic reactions, graft-versus-host reactions, transfusion-related acute lung injury, and anaphylaxis.^8-10 As use of shoulder arthroplasty continues to increase, the importance of minimizing unnecessary transfusions is growing as well.⁷

Predictive factors for ABT have been explored in other orthopedic settings, yet little has been done in shoulder arthroplasty.^1-6,11-15 Previous shoulder arthroplasty studies have shown that low preoperative hemoglobin (Hb) levels are independent risk factors for postoperative blood transfusion. However, there is debate over the significance of other variables, such as procedure type, age, sex, and medical comorbidities. Further, prior studies were limited by relatively small samples from single institutions; the largest series included fewer than 600 patients.^1-6

We conducted a study to determine predictors of ABT in a large cohort of patients admitted to US hospitals for shoulder arthroplasty. We also wanted to evaluate the effect of ABT on postoperative outcomes, including inpatient mortality, adverse events, prolonged hospital stay, and nonroutine discharge. According to the null hypothesis, in shoulder arthroplasty there will be no difference in risk factors between patients who require ABT and those who did not, after accounting for confounding variables.

Materials and Methods

This study was exempt from institutional review board approval, as all data were appropriately deidentified before use in this project. We used the Nationwide Inpatient Sample (NIS) to retrospectively study the period 2002–2011, from which all demographic, clinical, and resource use data were derived.¹⁶ NIS, an annual survey conducted by the Agency for Healthcare Research and Quality (AHRQ) since 1988, has generated a huge amount of data, forming the largest all-payer inpatient care database in the United States. Yearly samples contain discharge data from about 8 million hospital stays at more than 1000 hospitals across 46 states, approximating a 20% random sample of all hospital discharges at participating institutions.¹⁷ These data are then weighted to generate statistically valid national estimates.

The NIS database uses International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) codes to identify 15 medical diagnoses up to the year 2008 and a maximum of 25 medical diagnoses and 15 procedures thereafter. In addition, the database includes information on patient and hospital characteristics as well as inpatient outcomes such as length of stay, total hospitalization charges, and discharge disposition.^18,19 Given its large sample size and data volume, NIS is a powerful tool in the analysis of data associated with a multitude of medical diagnoses and procedures.²⁰

We used the NIS database to study a population of 422,371 patients (age, >18 years) who underwent total shoulder arthroplasty (TSA) or hemiarthroplasty (HSA) between 2002 and 2011. ICD-9-CM procedure codes for TSA (81.80, 81.88) and HSA (81.81) were used to identify this population. We also analyzed data for reverse TSA for the year 2011. Then we divided our target population into 2 different cohorts: patients who did not receive any blood transfusion products and patients who received a transfusion of allogeneic packed cells (ICD-9-CM code 99.04 was used to identify the latter cohort).

In this study, normal distribution of the dataset was assumed, given the large sample size. The 2 cohorts were evaluated through bivariate analysis using the Pearson χ² test for categorical data and the independent-samples t test for continuous data. The extent to which diagnosis, age, race, sex, and medical comorbidities were predictive of blood transfusion after TSA or HSA was evaluated through multivariate binary logistic regression analysis. Statistical significance was set at P < .05. All statistical analyses and data modeling were performed with SPSS Version 22.0.

Results

Using the NIS database, we stratified an estimated 422,371 patients who presented for shoulder arthroplasty between January 1, 2002, and December 31, 2011, into a TSA cohort (59.3%) and an HSA cohort (40.7%). Eight percent (33,889) of all patients received an ABT; the proportion of patients who received ABT was higher (P < .001) for the HSA cohort (55.6%) than the TSA cohort (39.4%). Further, the rate of ABT after shoulder arthroplasty showed an upward inclination (Figure).

Demographically, patients who received ABT tended (P < .001) to be older (74±11 years vs 68±11 years) and of a minority race (black or Hispanic) and to fall in either the lowest range of median household income (21.5% vs 20.7%; ≤$38,999) or the highest (27.3% vs 25.4%; ≥$63,000). Shoulder arthroplasty with ABT occurred more often (P < .001) at hospitals that were urban (13.3% vs 11.3%), medium in size (27.3% vs 23.4%), and nonteaching (56.2% vs 54.3%). In addition, ABT was used more often (P < .001) in patients with a primary diagnosis of fracture (43.1% vs 14.3%) or fracture nonunion (4.4% vs 2.1%). These groups also had a longer (P < .001) hospital stay (5.0±4.3 days vs 2.5±2.2 days). Table 1 summarizes these findings.

The 2 cohorts were then analyzed for presence of medical comorbidities (Table 2). Patients who required ABT during shoulder arthroplasty had a significantly (P < .001) higher prevalence of congestive heart failure, chronic lung disease, hypertension, uncomplicated and complicated diabetes mellitus, liver disease, renal failure, fluid and electrolyte disorders, pulmonary circulatory disease, weight loss, coagulopathy, and deficiency anemia.

In multivariate regression modeling (Table 3), demographic predictors of ABT (P < .001) included increasing age (odds ratio [OR], 1.03 per year; 95% confidence interval [95% CI], 1.03-1.03), female sex (OR, 1.55; 95% CI, 1.51-1.60), and minority race (black or Hispanic). Odds of requiring ABT were higher for patients with Medicare (OR, 1.25; 95% CI, 1.20-1.30) and patients with Medicaid (OR, 1.63; 95% CI, 1.51-1.77) than for patients with private insurance.

ABT was more likely to be required (P < .001) in patients with a primary diagnosis of fracture (OR, 4.49; 95% CI, 4.34-4.65), avascular necrosis (OR, 2.06; 95% CI, 1.91-2.22), rheumatoid arthritis (OR, 1.91; 95% CI, 1.72-2.12), fracture nonunion (OR, 3.55; 95% CI, 3.33-3.79), or rotator cuff arthropathy (OR, 1.47; 95% CI, 1.41-1.54) than for patients with osteoarthritis. Moreover, compared with patients having HSA, patients having TSA were more likely to require ABT (OR, 1.20; 95% CI, 1.17-1.24). According to the analysis restricted to the year 2011, compared with patients having anatomical TSAs, patients having reverse TSAs were 1.6 times more likely (P < .001) to require ABT (OR, 1.63; 95% CI, 1.50-1.79).

With the exception of obesity, all comorbidities were significant (P < .001) independent predictors of ABT after shoulder arthroplasty: deficiency anemia (OR, 3.42; 95% CI, 3.32-3.52), coagulopathy (OR, 2.54; 95% CI, 2.36-2.73), fluid and electrolyte disorders (OR, 1.91; 95% CI, 1.84-1.97), and weight loss (OR, 1.78; 95% CI, 1.58-2.00).

Patients who received ABT were more likely to experience adverse events (OR, 1.74; 95% CI, 1.68-1.81), prolonged hospital stay (OR, 3.21; 95% CI, 3.12-3.30), and nonroutine discharge (OR, 1.77; 95% CI, 1.72-1.82) (Table 4). There was no difference in mortality between the 2 cohorts.

Discussion

There is an abundance of literature on blood transfusions in hip and knee arthroplasty, but there are few articles on ABT in shoulder arthroplasty, and they all report data from single institutions with relatively low caseloads.^{1,2,11-13,15,21} In the present study, we investigated ABT in shoulder arthroplasty from the perspective of a multi-institutional database with a caseload of more than 400,000. Given the rapidly increasing rates of shoulder arthroplasty, it is important to further examine this issue to minimize unnecessary blood transfusion and its associated risks and costs.⁷

We found that 8% of patients who had shoulder arthroplasty received ABT, which is consistent with previously reported transfusion rates (range, 7%-43%).^1-6 Rates of ABT after shoulder arthroplasty have continued to rise. The exception, a decrease during the year 2010, can be explained by increased efforts to more rigidly follow transfusion indication guidelines to reduce the number of potentially unnecessary ABTs.^21-24 Our study also identified numerous significant independent predictors of ABT in shoulder arthroplasty: age, sex, race, insurance status, procedure type, primary diagnoses, and multiple medical comorbidities.

Demographics

According to our analysis, more than 80% of patients who received ABT were over age 65 years, which aligns with what several other studies have demonstrated: Increasing age is a predictor of ABT, despite higher rates of comorbidities and lower preoperative Hb levels in this population.^{1,2,4,5,25-27} Consistent with previous work, female sex was predictive of ABT.^2,5 It has been suggested that females are more likely predisposed to ABT because of lower preoperative Hb and smaller blood mass.^2,5,28 Interestingly, our study showed a higher likelihood of ABT in both black and Hispanic populations. Further, patients with Medicare or Medicaid were more likely to receive ABT.

Primary Diagnosis

Although patients with a primary diagnosis of osteoarthritis constitute the majority of patients who undergo shoulder arthroplasty, our analysis showed that patients with a diagnosis of proximal humerus fracture were more likely to receive ABT. This finding is reasonable given studies showing the high prevalence of proximal humerus fractures in elderly women.^29,30 Similarly, patients with a humerus fracture nonunion were more likely to receive a blood transfusion, which is unsurprising given the increased complexity associated with arthroplasty in this predominately elderly population.³¹ Interestingly, compared with patients with osteoarthritis, patients with any one of the other primary diagnoses were more likely to require a transfusion—proximal humerus fracture being the most significant, followed by humerus fracture nonunion, avascular necrosis, rheumatoid arthritis, and rotator cuff arthropathy.

Type of Arthroplasty

Bivariate analysis revealed that 55.6% of the patients who received ABT underwent HSA; the other 44.4% underwent TSA. The effect of primary diagnosis on procedure choice likely played a role in this finding. HSA indications include humerus fracture, which has been associated with increased ABT, whereas patients with osteoarthritis requiring TSA are significantly less likely to require ABT, as reflected in this analysis.^7,32-34 Previous studies have failed to show a difference in blood transfusion rates between TSA and HSA.^2,4-6,35 Conversely, with confounding factors controlled for, multivariate logistic regression analysis showed that TSA was 1.2 times more likely than HSA to require ABT, which could be explained by the increased operative time, case complexity, and blood loss that may be associated with the glenoid exposure.^36,37 With analysis restricted to the year 2011, patients with reverse TSAs were 1.6 times more likely than patients with anatomical TSAs to receive a blood transfusion (OR, 1.63; 95% CI, 1.50-1.79). Although this finding differs from what was previously reported, it fits given that patients having reverse TSAs are often older and may present with a more significant comorbidity profile.³ In addition, there are the increased technical surgical aspects associated with “salvage surgery” for challenging indications such as cuff arthropathy and failed previous arthroplasty.^38-41

Medical Comorbidities

Patients who received ABT were more likely to present with numerous medical comorbidities. Previous studies have indicated that the presence of multiple medical comorbidities significantly increased blood transfusion rates, possibly by working synergistically.⁴² All studies of blood transfusion in shoulder arthroplasty concluded that lower preoperative Hb was an independent predictor.^1-6 Schumer and colleagues⁴ reported a 4-fold increase in likelihood of blood transfusion in patients with a preoperative Hb level less than 12.5 g/dL. In addition, Millett and colleagues⁶ showed a 20-fold increase in likelihood of transfusion in patients with a preoperative Hb level less than 11.0 g/dL compared with patients with a level higher than 13.0 g/dL. Patients with a Hb level between 11.0 and 13.0 g/dL showed a 5-fold increase in likelihood of transfusion.⁶ We should note that correction of preoperative anemia through various pharmacologic methods (eg, erythropoietin, intravenous iron supplementation) has been shown to decrease postoperative transfusion rates.^43,44 Although we could not include preoperative Hb levels in the present study, given inherent limitations in using NIS, our multivariate analysis showed that preoperative deficiency anemia and coagulopathy were the most significant predictors of ABT.

In addition, the multivariate logistic regression model showed that both cardiac disease and diabetes were independent predictors of ABT, confirming data reported by Ahmadi and colleagues.¹ Although not as well characterized in other studies, in the current analysis multiple other medical comorbidities, including fluid and electrolyte abnormalities, weight loss, liver disease, renal failure, and chronic lung disease, had significant predictive value. Contrarily, obesity significantly decreased the odds of ABT, likely because of higher baseline blood volume in obese patients.

Patient Outcomes

Patients who undergo shoulder arthroplasty with ABT are more likely to experience adverse events or a prolonged hospital stay and are more often discharged to a nursing home or an extended-care facility. In this population, however, deaths did not occur at a significantly higher rate—similar to what was found for patients who underwent hip or knee arthroplasty with blood transfusions.⁴⁵

Little has been done to investigate the effect of pharmacologic agents on the need for perioperative ABT for orthopedic shoulder procedures. Aprotinin, tranexamic acid, epoetin-α, and aminocaproic acid have all been effective in limiting ABT during the perioperative period in various orthopedic hip, knee, and spine procedures.^9,46-53 Given the increased morbidity associated with ABT, it may be beneficial to use similar methods to limit blood loss in high-risk patients undergoing shoulder arthroplasty.

Study Limitations

NIS has intrinsic limitations. Given its massive volume, it is subject to errors in both data entry and clinical coding. Moreover, the database lacks data that would have been useful in our study: preoperative Hb levels, intraoperative course, number of units transfused, total blood loss, use of blood conservation techniques, transfusion protocols, and severity of comorbidities. Reverse TSA was given a unique ICD-9-CM code in October 2010, so 2011 was the only year we were able to examine the relationship between reverse TSA and transfusions. Further, our analysis was unable to identify any medications, including chronic anticoagulants or postoperative prophylaxis, that have been shown to significantly affect blood transfusion rates.⁵⁴ Yet, there are obvious advantages to using the NIS database, as previously outlined across the medical landscape.

Conclusion

Our results confirmed previous findings and identified new predictors of ABT in shoulder arthroplasty in a large cohort. We examined demographics and perioperative complications while identifying predictors of ABT use. Patients who received ABT were older, female, and nonwhite and were covered by Medicare or Medicaid insurance, and many had a primary diagnosis of proximal humerus fracture. The ABT cohort had numerous medical comorbidities, including deficiency anemia and coagulopathy. Identifying this patient population is a prerequisite to educating patients while minimizing unnecessary risks and costs.

Using NIS data on a population of 422,371 patients who underwent shoulder arthroplasty, we identified the 5 likeliest predictors of ABT: fracture, fracture nonunion, deficiency anemia, coagulopathy, and avascular necrosis. Of the identified variables associated with ABT, deficiency anemia may be the most amenable to treatment; therefore, there may be benefit in delaying elective shoulder arthroplasty in this cohort. Given these findings, it is important to identify at-risk patients before surgery, with the intent to provide education and minimize risk.

Olecranon fractures are relatively common in adults and constitute 10% of all upper extremity injuries.^1,2 An olecranon fracture may be sustained either directly (from blunt trauma or a fall onto the tip of the elbow) or indirectly (as a result of forceful hyperextension of the triceps during a fall onto an outstretched arm). Displaced olecranon fractures with extensor discontinuity require reduction and stabilization. One treatment option is tension band wiring (TBW), which is used to manage noncomminuted fractures.³ TBW, first described by Weber and Vasey⁴ in 1963, involves transforming the distractive forces of the triceps into dynamic compression forces across the olecranon articular surface using 2 intramedullary Kirschner wires (K-wires) and stainless steel wires looped in figure-of-8 fashion.

Various modifications of the TBW technique of Weber and Vasey⁴ have been proposed to reduce the frequency of complications. These modifications include substituting screws for K-wires, aiming the angle of the K-wires into the anterior coronoid cortex or loop configuration of the stainless steel wire, using double knots and twisting procedures to finalize fixation, and using alternative materials for the loop construct.^5-8 In the literature and in our experience, patients often complain after surgery about prominent K-wires and the twisted knots used to tension the construct.^9-12 Surgeons also must address the technical difficulties of positioning the brittle wire without kinking, and avoiding slack while tensioning.

In this article, we report on the clinical outcomes of a series of 7 patients with olecranon fracture treated with a US Food and Drug Administration–approved novel isoelastic ultrahigh-molecular-weight polyethylene (UHMWPE) cerclage cable (Iso-Elastic Cerclage System, Kinamed).

Materials and Methods

Surgical Technique

The patient is arranged in a sloppy lateral position to allow access to the posterior elbow. A nonsterile tourniquet is placed on the upper arm, and the limb is sterilely prepared and draped in standard fashion. A posterolateral incision is made around the olecranon and extended proximally 6 cm and distally 6 cm along the subcutaneous border of the ulna. The fracture is visualized and comminution identified.

To provide anchorage for a pointed reduction clamp, the surgeon drills a 2.5-mm hole in the subcutaneous border of the ulnar shaft. The fracture is reduced in extension and the clamp affixed. The elbow is then flexed and the reduction confirmed visually and by imaging. After realignment of the articular surfaces, 2 longitudinal, parallel K-wires (diameter, 1.6-2.0 mm) are passed in antegrade direction through the proximal olecranon within the medullary canal of the shaft. The proximal ends must not cross the cortex so they may fully capture the figure-of-8 wire during subsequent, final advancement, and the distal ends must not pierce the anterior cortex. A 2.5-mm transverse hole is created distal to the fracture in the dorsal aspect of the ulnar shaft from medial to lateral at 2 times the distance from the tip of the olecranon to the fracture site. This hole is expanded with a 3.5-mm drill bit, allowing both strands of the cable to be passed simultaneously medial to lateral, making the figure-of-8. The 3.5-mm hole represents about 20% of the overall width of the bone, which we have not found to create a significant stress riser in either laboratory or clinical tests of this construct. Proximally, the cables are placed on the periosteum of the olecranon but deep to the triceps tendon and adjacent to the K-wires. The locking clip is placed on the posterolateral aspect of the elbow joint in a location where it can be covered with local tissue for adequate padding. The cable is then threaded through the clamping bracket and tightened slowly and gradually with a tensioning device to low torque level (Figure 1). At this stage, tension may be released to make any necessary adjustments. Last, the locking clip is deployed, securing the tension band in the clip, and the excess cable is trimmed with a scalpel. Softening and pliability of the cable during its insertion and tensioning should be noted.

The ends of the K-wires are now curved in a hook configuration. The tines of the hooks should be parallel to accommodate the cable, and then the triceps is sharply incised to bone. If the bone is hard, an awl is used to create a pilot hole so the hook may be impaled into bone while capturing the cable. Next, the triceps is closed over the pins, minimizing the potential for pin migration and backout. The 2 K-wires are left in place to keep the fragments in proper anatomical alignment during healing and to prevent displacement with elbow motion. Figure 2 is a schematic of the final construct, and Figure 3 shows the construct in a patient.

Reduction of the olecranon fracture is assessed by imaging in full extension to check for possible implant impingement. Last, we apply the previously harvested fracture callus to the fracture site. Layered closure is performed, and bulky soft dressings are applied. Postoperative immobilization with a splint is used. Gentle range-of-motion exercises begin in about 2 weeks and progress as pain allows.

A case example with preoperative and postoperative images taken at 3-month follow-up is provided in Figure 4. The entire surgical technique can be viewed in the Video.

Clinical Cases

Between July 2007 and February 2011, 7 patients with displaced olecranon fractures underwent osteosynthesis using the isoelastic tension band (Table 1). According to the Mayo classification system, 5 of these patients had type 2A fractures, 1 had a type 2B fracture with an ipsilateral nondisplaced radial neck fracture, and 1 had a type 3B fracture. There were 4 female and 3 male patients. The injury was on the dominant side in 3 patients. All patients gave informed consent to evaluation at subsequent office visits and completed outcomes questionnaires by mail several years after surgery. Mean follow-up at which outcome measures questionnaires were obtained was 3.3 years (range, 2.1-6.8 years). Exclusion criteria were age under 18 years and inability to provide informed consent, fracture patterns with extensive articular comminution, and open fractures. Permission to conduct this research was granted by institutional review board.

At each visit, patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH) functional outcome survey and were evaluated according to Broberg and Morrey’s elbow scoring system.^13,14 Chart review consisted of evaluation of medical records, including radiographs and orthopedic physician notes in which preoperative examination was documented, mechanism of injury was noted, radiologic fracture pattern was evaluated, and time to bony union was recorded. Elbow motion was documented. Grip strength was measured with a calibrated Jamar dynamometer (Sammons Preston Rolyan) set at level 2, as delineated in Broberg and Morrey’s functional elbow scoring system.

Results

The 7 patients were assessed at a mean final follow-up of 19 months after surgery and received a mean Broberg and Morrey score of good (92.2/100) (Table 2). Restoration of motion and strength was excellent; compared with contralateral extremity, mean flexion arc was 96%, and mean forearm rotation was 96%. Grip was 99% of the noninjured side, perhaps the result of increased conditioning from physical therapy. Patients completed outcomes questionnaires at a mean of 3.3 years after surgery. Mean (SD) DASH score at this longest follow-up was 12.6 (17.2) (Table 2). Patients were satisfied (mean, 9.8/10; range, 9.5-10) and had little pain (mean, 0.8/10; range, 0-3). All fractures united, and there were no infections. One patient had a satisfactory union with complete restoration of motion and continued to play sports vocationally but developed pain over the locking clip 5 years after the index procedure and decided to have the implant removed. He had no radiographic evidence of K-wire or implant migration. Another patient had a minor degree of implant irritation at longest follow-up but did not request hardware removal.

Discussion

Stainless steel wire is often used in TBW because of its widespread availability, low cost, lack of immunogenicity, and relative strength.⁷ However, stainless steel wire has several disadvantages. It is susceptible to low-cycle fatigue failure, and fatigue strength may be seriously reduced secondary to incidental trauma to the wire on implantation.^15,16 Other complications are kinking, skin irritation, implant prominence, fixation loss caused by wire loosening, and inadequate initial reduction potentially requiring revision.^10,12,17-21

Isoelastic cable is a new type of cerclage cable that consists of UHMWPE strands braided over a nylon core. The particular property profile of the isoelastic tension band gives the cable intrinsic elastic and pliable qualities. In addition, unlike stainless steel, the band maintains a uniform, continuous compression force across a fracture site.²² Multifilament braided cables fatigue and fray, but the isoelastic cerclage cable showed no evidence of fraying or breakage after 1 million loading cycles.^22,23 Compared with metal wire or braided metal cable, the band also has higher fatigue strength and higher ultimate tensile strength.⁷ Furthermore, the cable is less abrasive than stainless steel, so theoretically it is less irritating to surrounding subcutaneous tissue. Last, the pliability of the band allows the surgeon to create multiple loops of cable without the wire-failure side effects related to kinking, which is common with the metal construct.

In 2010, Ting and colleagues²⁴ retrospectively studied implant failure complications associated with use of isoelastic cerclage cables in the treatment of periprosthetic fractures in total hip arthroplasty. They reported a breakage rate of 0% and noted that previously published breakage data for metallic cerclage devices ranged from 0% to 44%. They concluded that isoelastic cables were not associated with material failure, and there were no direct complications related to the cables. Similarly, Edwards and colleagues²⁵ evaluated the same type of cable used in revision shoulder arthroplasty and reported excellent success and no failures. Although these data stem from use in the femur and humerus, we think the noted benefits apply to fractures of the elbow as well, as we observed a similar breakage rate (0%).

Various studies have addressed the clinical complaints and reoperation rates associated with retained metal implants after olecranon fixation. Traditional AO (Arbeitsgemeinschaft für Osteosynthesefragen) technique involves subcutaneous placement of stainless steel wires, which often results in tissue irritation. Reoperation rates as high as 80% have been reported, and a proportion of implant removals may in fact be caused by factors related to the subcutaneous placement of the metallic implants rather than K-wire migration alone.^5,12,18 A nonmetallic isoelastic tension band can provide a more comfortable and less irritating implant, which could reduce the need for secondary intervention related to painful subcutaneous implant. One of our 7 patients had a symptomatic implant removed 5 years after surgery. This patient complained of pain over the area of the tension band device clip, so after fracture healing the entire fixation device was removed in the operating room. If reoperation is necessary, removal of intramedullary K-wires is relatively simple using a minimal incision; removal of stainless steel TBW may require a larger approach if the twisted knots cannot be easily retrieved.

A study of compression forces created by stainless steel wire demonstrated that a “finely tuned mechanical sense” was needed to produce optimal fixation compression when using stainless steel wire.²⁶ It was observed that a submaximal twist created insufficient compressive force, while an ostensibly minimal increase in twisting force above optimum abruptly caused wire failure through breakage. Cerclage cables using clasping devices, such as the current isoelastic cerclage cable, were superior in ease of application. Furthermore, a clasping device allows for cable tension readjustment that is not possible with stainless steel wire. The clasping mechanism precludes the surgeon from having to bury the stainless steel knot and allows for the objective cable-tensioning not possible with stainless steel wire. Last, the tensioning device is titratable, which allows the surgeon to set the construct at a predetermined quantitative tension, which is of benefit in patients with osteopenia.

One limitation of this study is that it did not resolve the potential for K-wire migration, and we agree with previous recommendations that careful attention to surgical technique may avoid such a complication.¹⁰ In addition, the sample was small, and the study lacked a control group; a larger sample and a control group would have boosted study power. Nevertheless, the physical and functional outcomes associated with use of this technique were excellent. These results demonstrate an efficacious attempt to decrease secondary surgery rates and are therefore proof of concept that the isoelastic tension band may be used as an alternative to stainless steel in the TBW of displaced olecranon fractures with minimal or no comminution.

Conclusion

This easily reproducible technique for use of an isoelastic tension band in olecranon fracture fixation was associated with excellent physical and functional outcomes in a series of 7 patients. The rate of secondary intervention was slightly better for these patients than for patients treated with wire tension band fixation. Although more rigorous study of this device is needed, we think it is a promising alternative to wire tension band techniques.

Olecranon fractures are relatively common in adults and constitute 10% of all upper extremity injuries.^1,2 An olecranon fracture may be sustained either directly (from blunt trauma or a fall onto the tip of the elbow) or indirectly (as a result of forceful hyperextension of the triceps during a fall onto an outstretched arm). Displaced olecranon fractures with extensor discontinuity require reduction and stabilization. One treatment option is tension band wiring (TBW), which is used to manage noncomminuted fractures.³ TBW, first described by Weber and Vasey⁴ in 1963, involves transforming the distractive forces of the triceps into dynamic compression forces across the olecranon articular surface using 2 intramedullary Kirschner wires (K-wires) and stainless steel wires looped in figure-of-8 fashion.

Various modifications of the TBW technique of Weber and Vasey⁴ have been proposed to reduce the frequency of complications. These modifications include substituting screws for K-wires, aiming the angle of the K-wires into the anterior coronoid cortex or loop configuration of the stainless steel wire, using double knots and twisting procedures to finalize fixation, and using alternative materials for the loop construct.^5-8 In the literature and in our experience, patients often complain after surgery about prominent K-wires and the twisted knots used to tension the construct.^9-12 Surgeons also must address the technical difficulties of positioning the brittle wire without kinking, and avoiding slack while tensioning.

In this article, we report on the clinical outcomes of a series of 7 patients with olecranon fracture treated with a US Food and Drug Administration–approved novel isoelastic ultrahigh-molecular-weight polyethylene (UHMWPE) cerclage cable (Iso-Elastic Cerclage System, Kinamed).

Materials and Methods

Surgical Technique

The patient is arranged in a sloppy lateral position to allow access to the posterior elbow. A nonsterile tourniquet is placed on the upper arm, and the limb is sterilely prepared and draped in standard fashion. A posterolateral incision is made around the olecranon and extended proximally 6 cm and distally 6 cm along the subcutaneous border of the ulna. The fracture is visualized and comminution identified.

To provide anchorage for a pointed reduction clamp, the surgeon drills a 2.5-mm hole in the subcutaneous border of the ulnar shaft. The fracture is reduced in extension and the clamp affixed. The elbow is then flexed and the reduction confirmed visually and by imaging. After realignment of the articular surfaces, 2 longitudinal, parallel K-wires (diameter, 1.6-2.0 mm) are passed in antegrade direction through the proximal olecranon within the medullary canal of the shaft. The proximal ends must not cross the cortex so they may fully capture the figure-of-8 wire during subsequent, final advancement, and the distal ends must not pierce the anterior cortex. A 2.5-mm transverse hole is created distal to the fracture in the dorsal aspect of the ulnar shaft from medial to lateral at 2 times the distance from the tip of the olecranon to the fracture site. This hole is expanded with a 3.5-mm drill bit, allowing both strands of the cable to be passed simultaneously medial to lateral, making the figure-of-8. The 3.5-mm hole represents about 20% of the overall width of the bone, which we have not found to create a significant stress riser in either laboratory or clinical tests of this construct. Proximally, the cables are placed on the periosteum of the olecranon but deep to the triceps tendon and adjacent to the K-wires. The locking clip is placed on the posterolateral aspect of the elbow joint in a location where it can be covered with local tissue for adequate padding. The cable is then threaded through the clamping bracket and tightened slowly and gradually with a tensioning device to low torque level (Figure 1). At this stage, tension may be released to make any necessary adjustments. Last, the locking clip is deployed, securing the tension band in the clip, and the excess cable is trimmed with a scalpel. Softening and pliability of the cable during its insertion and tensioning should be noted.

The ends of the K-wires are now curved in a hook configuration. The tines of the hooks should be parallel to accommodate the cable, and then the triceps is sharply incised to bone. If the bone is hard, an awl is used to create a pilot hole so the hook may be impaled into bone while capturing the cable. Next, the triceps is closed over the pins, minimizing the potential for pin migration and backout. The 2 K-wires are left in place to keep the fragments in proper anatomical alignment during healing and to prevent displacement with elbow motion. Figure 2 is a schematic of the final construct, and Figure 3 shows the construct in a patient.

Reduction of the olecranon fracture is assessed by imaging in full extension to check for possible implant impingement. Last, we apply the previously harvested fracture callus to the fracture site. Layered closure is performed, and bulky soft dressings are applied. Postoperative immobilization with a splint is used. Gentle range-of-motion exercises begin in about 2 weeks and progress as pain allows.

A case example with preoperative and postoperative images taken at 3-month follow-up is provided in Figure 4. The entire surgical technique can be viewed in the Video.

Clinical Cases

Between July 2007 and February 2011, 7 patients with displaced olecranon fractures underwent osteosynthesis using the isoelastic tension band (Table 1). According to the Mayo classification system, 5 of these patients had type 2A fractures, 1 had a type 2B fracture with an ipsilateral nondisplaced radial neck fracture, and 1 had a type 3B fracture. There were 4 female and 3 male patients. The injury was on the dominant side in 3 patients. All patients gave informed consent to evaluation at subsequent office visits and completed outcomes questionnaires by mail several years after surgery. Mean follow-up at which outcome measures questionnaires were obtained was 3.3 years (range, 2.1-6.8 years). Exclusion criteria were age under 18 years and inability to provide informed consent, fracture patterns with extensive articular comminution, and open fractures. Permission to conduct this research was granted by institutional review board.

At each visit, patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH) functional outcome survey and were evaluated according to Broberg and Morrey’s elbow scoring system.^13,14 Chart review consisted of evaluation of medical records, including radiographs and orthopedic physician notes in which preoperative examination was documented, mechanism of injury was noted, radiologic fracture pattern was evaluated, and time to bony union was recorded. Elbow motion was documented. Grip strength was measured with a calibrated Jamar dynamometer (Sammons Preston Rolyan) set at level 2, as delineated in Broberg and Morrey’s functional elbow scoring system.

Results

The 7 patients were assessed at a mean final follow-up of 19 months after surgery and received a mean Broberg and Morrey score of good (92.2/100) (Table 2). Restoration of motion and strength was excellent; compared with contralateral extremity, mean flexion arc was 96%, and mean forearm rotation was 96%. Grip was 99% of the noninjured side, perhaps the result of increased conditioning from physical therapy. Patients completed outcomes questionnaires at a mean of 3.3 years after surgery. Mean (SD) DASH score at this longest follow-up was 12.6 (17.2) (Table 2). Patients were satisfied (mean, 9.8/10; range, 9.5-10) and had little pain (mean, 0.8/10; range, 0-3). All fractures united, and there were no infections. One patient had a satisfactory union with complete restoration of motion and continued to play sports vocationally but developed pain over the locking clip 5 years after the index procedure and decided to have the implant removed. He had no radiographic evidence of K-wire or implant migration. Another patient had a minor degree of implant irritation at longest follow-up but did not request hardware removal.

Discussion

Stainless steel wire is often used in TBW because of its widespread availability, low cost, lack of immunogenicity, and relative strength.⁷ However, stainless steel wire has several disadvantages. It is susceptible to low-cycle fatigue failure, and fatigue strength may be seriously reduced secondary to incidental trauma to the wire on implantation.^15,16 Other complications are kinking, skin irritation, implant prominence, fixation loss caused by wire loosening, and inadequate initial reduction potentially requiring revision.^10,12,17-21

Isoelastic cable is a new type of cerclage cable that consists of UHMWPE strands braided over a nylon core. The particular property profile of the isoelastic tension band gives the cable intrinsic elastic and pliable qualities. In addition, unlike stainless steel, the band maintains a uniform, continuous compression force across a fracture site.²² Multifilament braided cables fatigue and fray, but the isoelastic cerclage cable showed no evidence of fraying or breakage after 1 million loading cycles.^22,23 Compared with metal wire or braided metal cable, the band also has higher fatigue strength and higher ultimate tensile strength.⁷ Furthermore, the cable is less abrasive than stainless steel, so theoretically it is less irritating to surrounding subcutaneous tissue. Last, the pliability of the band allows the surgeon to create multiple loops of cable without the wire-failure side effects related to kinking, which is common with the metal construct.

In 2010, Ting and colleagues²⁴ retrospectively studied implant failure complications associated with use of isoelastic cerclage cables in the treatment of periprosthetic fractures in total hip arthroplasty. They reported a breakage rate of 0% and noted that previously published breakage data for metallic cerclage devices ranged from 0% to 44%. They concluded that isoelastic cables were not associated with material failure, and there were no direct complications related to the cables. Similarly, Edwards and colleagues²⁵ evaluated the same type of cable used in revision shoulder arthroplasty and reported excellent success and no failures. Although these data stem from use in the femur and humerus, we think the noted benefits apply to fractures of the elbow as well, as we observed a similar breakage rate (0%).

Various studies have addressed the clinical complaints and reoperation rates associated with retained metal implants after olecranon fixation. Traditional AO (Arbeitsgemeinschaft für Osteosynthesefragen) technique involves subcutaneous placement of stainless steel wires, which often results in tissue irritation. Reoperation rates as high as 80% have been reported, and a proportion of implant removals may in fact be caused by factors related to the subcutaneous placement of the metallic implants rather than K-wire migration alone.^5,12,18 A nonmetallic isoelastic tension band can provide a more comfortable and less irritating implant, which could reduce the need for secondary intervention related to painful subcutaneous implant. One of our 7 patients had a symptomatic implant removed 5 years after surgery. This patient complained of pain over the area of the tension band device clip, so after fracture healing the entire fixation device was removed in the operating room. If reoperation is necessary, removal of intramedullary K-wires is relatively simple using a minimal incision; removal of stainless steel TBW may require a larger approach if the twisted knots cannot be easily retrieved.

A study of compression forces created by stainless steel wire demonstrated that a “finely tuned mechanical sense” was needed to produce optimal fixation compression when using stainless steel wire.²⁶ It was observed that a submaximal twist created insufficient compressive force, while an ostensibly minimal increase in twisting force above optimum abruptly caused wire failure through breakage. Cerclage cables using clasping devices, such as the current isoelastic cerclage cable, were superior in ease of application. Furthermore, a clasping device allows for cable tension readjustment that is not possible with stainless steel wire. The clasping mechanism precludes the surgeon from having to bury the stainless steel knot and allows for the objective cable-tensioning not possible with stainless steel wire. Last, the tensioning device is titratable, which allows the surgeon to set the construct at a predetermined quantitative tension, which is of benefit in patients with osteopenia.

One limitation of this study is that it did not resolve the potential for K-wire migration, and we agree with previous recommendations that careful attention to surgical technique may avoid such a complication.¹⁰ In addition, the sample was small, and the study lacked a control group; a larger sample and a control group would have boosted study power. Nevertheless, the physical and functional outcomes associated with use of this technique were excellent. These results demonstrate an efficacious attempt to decrease secondary surgery rates and are therefore proof of concept that the isoelastic tension band may be used as an alternative to stainless steel in the TBW of displaced olecranon fractures with minimal or no comminution.

Conclusion

This easily reproducible technique for use of an isoelastic tension band in olecranon fracture fixation was associated with excellent physical and functional outcomes in a series of 7 patients. The rate of secondary intervention was slightly better for these patients than for patients treated with wire tension band fixation. Although more rigorous study of this device is needed, we think it is a promising alternative to wire tension band techniques.

Olecranon fractures are relatively common in adults and constitute 10% of all upper extremity injuries.^1,2 An olecranon fracture may be sustained either directly (from blunt trauma or a fall onto the tip of the elbow) or indirectly (as a result of forceful hyperextension of the triceps during a fall onto an outstretched arm). Displaced olecranon fractures with extensor discontinuity require reduction and stabilization. One treatment option is tension band wiring (TBW), which is used to manage noncomminuted fractures.³ TBW, first described by Weber and Vasey⁴ in 1963, involves transforming the distractive forces of the triceps into dynamic compression forces across the olecranon articular surface using 2 intramedullary Kirschner wires (K-wires) and stainless steel wires looped in figure-of-8 fashion.

Various modifications of the TBW technique of Weber and Vasey⁴ have been proposed to reduce the frequency of complications. These modifications include substituting screws for K-wires, aiming the angle of the K-wires into the anterior coronoid cortex or loop configuration of the stainless steel wire, using double knots and twisting procedures to finalize fixation, and using alternative materials for the loop construct.^5-8 In the literature and in our experience, patients often complain after surgery about prominent K-wires and the twisted knots used to tension the construct.^9-12 Surgeons also must address the technical difficulties of positioning the brittle wire without kinking, and avoiding slack while tensioning.

In this article, we report on the clinical outcomes of a series of 7 patients with olecranon fracture treated with a US Food and Drug Administration–approved novel isoelastic ultrahigh-molecular-weight polyethylene (UHMWPE) cerclage cable (Iso-Elastic Cerclage System, Kinamed).

Materials and Methods

Surgical Technique

The patient is arranged in a sloppy lateral position to allow access to the posterior elbow. A nonsterile tourniquet is placed on the upper arm, and the limb is sterilely prepared and draped in standard fashion. A posterolateral incision is made around the olecranon and extended proximally 6 cm and distally 6 cm along the subcutaneous border of the ulna. The fracture is visualized and comminution identified.

To provide anchorage for a pointed reduction clamp, the surgeon drills a 2.5-mm hole in the subcutaneous border of the ulnar shaft. The fracture is reduced in extension and the clamp affixed. The elbow is then flexed and the reduction confirmed visually and by imaging. After realignment of the articular surfaces, 2 longitudinal, parallel K-wires (diameter, 1.6-2.0 mm) are passed in antegrade direction through the proximal olecranon within the medullary canal of the shaft. The proximal ends must not cross the cortex so they may fully capture the figure-of-8 wire during subsequent, final advancement, and the distal ends must not pierce the anterior cortex. A 2.5-mm transverse hole is created distal to the fracture in the dorsal aspect of the ulnar shaft from medial to lateral at 2 times the distance from the tip of the olecranon to the fracture site. This hole is expanded with a 3.5-mm drill bit, allowing both strands of the cable to be passed simultaneously medial to lateral, making the figure-of-8. The 3.5-mm hole represents about 20% of the overall width of the bone, which we have not found to create a significant stress riser in either laboratory or clinical tests of this construct. Proximally, the cables are placed on the periosteum of the olecranon but deep to the triceps tendon and adjacent to the K-wires. The locking clip is placed on the posterolateral aspect of the elbow joint in a location where it can be covered with local tissue for adequate padding. The cable is then threaded through the clamping bracket and tightened slowly and gradually with a tensioning device to low torque level (Figure 1). At this stage, tension may be released to make any necessary adjustments. Last, the locking clip is deployed, securing the tension band in the clip, and the excess cable is trimmed with a scalpel. Softening and pliability of the cable during its insertion and tensioning should be noted.

The ends of the K-wires are now curved in a hook configuration. The tines of the hooks should be parallel to accommodate the cable, and then the triceps is sharply incised to bone. If the bone is hard, an awl is used to create a pilot hole so the hook may be impaled into bone while capturing the cable. Next, the triceps is closed over the pins, minimizing the potential for pin migration and backout. The 2 K-wires are left in place to keep the fragments in proper anatomical alignment during healing and to prevent displacement with elbow motion. Figure 2 is a schematic of the final construct, and Figure 3 shows the construct in a patient.

Reduction of the olecranon fracture is assessed by imaging in full extension to check for possible implant impingement. Last, we apply the previously harvested fracture callus to the fracture site. Layered closure is performed, and bulky soft dressings are applied. Postoperative immobilization with a splint is used. Gentle range-of-motion exercises begin in about 2 weeks and progress as pain allows.

A case example with preoperative and postoperative images taken at 3-month follow-up is provided in Figure 4. The entire surgical technique can be viewed in the Video.

Clinical Cases

Between July 2007 and February 2011, 7 patients with displaced olecranon fractures underwent osteosynthesis using the isoelastic tension band (Table 1). According to the Mayo classification system, 5 of these patients had type 2A fractures, 1 had a type 2B fracture with an ipsilateral nondisplaced radial neck fracture, and 1 had a type 3B fracture. There were 4 female and 3 male patients. The injury was on the dominant side in 3 patients. All patients gave informed consent to evaluation at subsequent office visits and completed outcomes questionnaires by mail several years after surgery. Mean follow-up at which outcome measures questionnaires were obtained was 3.3 years (range, 2.1-6.8 years). Exclusion criteria were age under 18 years and inability to provide informed consent, fracture patterns with extensive articular comminution, and open fractures. Permission to conduct this research was granted by institutional review board.

At each visit, patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH) functional outcome survey and were evaluated according to Broberg and Morrey’s elbow scoring system.^13,14 Chart review consisted of evaluation of medical records, including radiographs and orthopedic physician notes in which preoperative examination was documented, mechanism of injury was noted, radiologic fracture pattern was evaluated, and time to bony union was recorded. Elbow motion was documented. Grip strength was measured with a calibrated Jamar dynamometer (Sammons Preston Rolyan) set at level 2, as delineated in Broberg and Morrey’s functional elbow scoring system.

Results

The 7 patients were assessed at a mean final follow-up of 19 months after surgery and received a mean Broberg and Morrey score of good (92.2/100) (Table 2). Restoration of motion and strength was excellent; compared with contralateral extremity, mean flexion arc was 96%, and mean forearm rotation was 96%. Grip was 99% of the noninjured side, perhaps the result of increased conditioning from physical therapy. Patients completed outcomes questionnaires at a mean of 3.3 years after surgery. Mean (SD) DASH score at this longest follow-up was 12.6 (17.2) (Table 2). Patients were satisfied (mean, 9.8/10; range, 9.5-10) and had little pain (mean, 0.8/10; range, 0-3). All fractures united, and there were no infections. One patient had a satisfactory union with complete restoration of motion and continued to play sports vocationally but developed pain over the locking clip 5 years after the index procedure and decided to have the implant removed. He had no radiographic evidence of K-wire or implant migration. Another patient had a minor degree of implant irritation at longest follow-up but did not request hardware removal.

Discussion

Stainless steel wire is often used in TBW because of its widespread availability, low cost, lack of immunogenicity, and relative strength.⁷ However, stainless steel wire has several disadvantages. It is susceptible to low-cycle fatigue failure, and fatigue strength may be seriously reduced secondary to incidental trauma to the wire on implantation.^15,16 Other complications are kinking, skin irritation, implant prominence, fixation loss caused by wire loosening, and inadequate initial reduction potentially requiring revision.^10,12,17-21

Isoelastic cable is a new type of cerclage cable that consists of UHMWPE strands braided over a nylon core. The particular property profile of the isoelastic tension band gives the cable intrinsic elastic and pliable qualities. In addition, unlike stainless steel, the band maintains a uniform, continuous compression force across a fracture site.²² Multifilament braided cables fatigue and fray, but the isoelastic cerclage cable showed no evidence of fraying or breakage after 1 million loading cycles.^22,23 Compared with metal wire or braided metal cable, the band also has higher fatigue strength and higher ultimate tensile strength.⁷ Furthermore, the cable is less abrasive than stainless steel, so theoretically it is less irritating to surrounding subcutaneous tissue. Last, the pliability of the band allows the surgeon to create multiple loops of cable without the wire-failure side effects related to kinking, which is common with the metal construct.

In 2010, Ting and colleagues²⁴ retrospectively studied implant failure complications associated with use of isoelastic cerclage cables in the treatment of periprosthetic fractures in total hip arthroplasty. They reported a breakage rate of 0% and noted that previously published breakage data for metallic cerclage devices ranged from 0% to 44%. They concluded that isoelastic cables were not associated with material failure, and there were no direct complications related to the cables. Similarly, Edwards and colleagues²⁵ evaluated the same type of cable used in revision shoulder arthroplasty and reported excellent success and no failures. Although these data stem from use in the femur and humerus, we think the noted benefits apply to fractures of the elbow as well, as we observed a similar breakage rate (0%).

Various studies have addressed the clinical complaints and reoperation rates associated with retained metal implants after olecranon fixation. Traditional AO (Arbeitsgemeinschaft für Osteosynthesefragen) technique involves subcutaneous placement of stainless steel wires, which often results in tissue irritation. Reoperation rates as high as 80% have been reported, and a proportion of implant removals may in fact be caused by factors related to the subcutaneous placement of the metallic implants rather than K-wire migration alone.^5,12,18 A nonmetallic isoelastic tension band can provide a more comfortable and less irritating implant, which could reduce the need for secondary intervention related to painful subcutaneous implant. One of our 7 patients had a symptomatic implant removed 5 years after surgery. This patient complained of pain over the area of the tension band device clip, so after fracture healing the entire fixation device was removed in the operating room. If reoperation is necessary, removal of intramedullary K-wires is relatively simple using a minimal incision; removal of stainless steel TBW may require a larger approach if the twisted knots cannot be easily retrieved.

A study of compression forces created by stainless steel wire demonstrated that a “finely tuned mechanical sense” was needed to produce optimal fixation compression when using stainless steel wire.²⁶ It was observed that a submaximal twist created insufficient compressive force, while an ostensibly minimal increase in twisting force above optimum abruptly caused wire failure through breakage. Cerclage cables using clasping devices, such as the current isoelastic cerclage cable, were superior in ease of application. Furthermore, a clasping device allows for cable tension readjustment that is not possible with stainless steel wire. The clasping mechanism precludes the surgeon from having to bury the stainless steel knot and allows for the objective cable-tensioning not possible with stainless steel wire. Last, the tensioning device is titratable, which allows the surgeon to set the construct at a predetermined quantitative tension, which is of benefit in patients with osteopenia.

One limitation of this study is that it did not resolve the potential for K-wire migration, and we agree with previous recommendations that careful attention to surgical technique may avoid such a complication.¹⁰ In addition, the sample was small, and the study lacked a control group; a larger sample and a control group would have boosted study power. Nevertheless, the physical and functional outcomes associated with use of this technique were excellent. These results demonstrate an efficacious attempt to decrease secondary surgery rates and are therefore proof of concept that the isoelastic tension band may be used as an alternative to stainless steel in the TBW of displaced olecranon fractures with minimal or no comminution.

Conclusion

This easily reproducible technique for use of an isoelastic tension band in olecranon fracture fixation was associated with excellent physical and functional outcomes in a series of 7 patients. The rate of secondary intervention was slightly better for these patients than for patients treated with wire tension band fixation. Although more rigorous study of this device is needed, we think it is a promising alternative to wire tension band techniques.