Case Reports

Revision total knee arthroplasty (TKA) is frequently complicated by bone loss and ligament instability, necessitating specialized implants to increase constraint and transmit forces away from the joint surface. Femoral stems are commonly used to enhance fixation and distribute force from the condyles to the metaphysis or diaphysis, to higher-quality bone capable of sustaining the forces at the knee joint.

Modular implants are now commonplace in revision surgery, because they allow intraoperative customization of the implant to the patient’s anatomy, degree of bone loss, and need for metaphyseal or diaphyseal fixation. However, these advantages are not without a downside. The modular junction introduces potential weaknesses in the implant, which may lead to early failure.

We report a case of loosening of a Triathlon TS (Stryker) femoral component that was not evident on preoperative radiographs. To our knowledge, this complication has not been reported with this particular revision knee system. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old woman underwent 2-stage revision left TKA secondary to infection at an outside institution. She had undergone 17 prior knee surgeries with multiple revisions prior to this most recent revision surgery. A constrained implant was used at her last reimplantation secondary to ligamentous laxity after extensive débridement for infection. A Triathlon TS revision knee system with cemented stemmed tibial and femoral components was implanted; stems designed for uncemented fixation were cemented. She had a history of a quadriceps tendon tear, which was repaired prior to her revision, and quadricepsplasty was performed at the time of revision.

Seven years after this revision surgery, the patient presented to our clinic with progressive global instability, occasional effusions, and 2 documented episodes of frank dislocation. On examination, she was unstable in flexion and extension. Her extensor mechanism was intact, although with 7º active lag. She had a palpable quadriceps tendon defect. Her passive range of motion was 0º to 130º. Her active range of motion was 7º to 130º. Her erythrocyte sedimentation rate and C-reactive protein levels were within normal limits, and aspiration was negative for infection. Radiographs showed apparently well-fixed components with cemented femoral and tibial stems (Figures 1A, 1B).

The patient underwent revision surgery for global instability with the surgical goal to upsize the polyethylene insert and advance the quadriceps to improve stability. In the operating room, a defect in the quadriceps mechanism was seen between the vastus medialis obliquus (VMO) and the patella, as well as a large effusion. Upon removal of the polyethylene insert, the tibial and patellar components were examined and found to be well fixed. The femoral component was grossly loose. On closer inspection, the condylar portion was found to be rotating in the axial plane freely on the well-fixed cemented stem in the femoral canal (Figures 2A-2D). The entire femoral component was removed with some difficulty because the well-fixed uncemented stem design was cemented in place. This required a small, anterior episiotomy of the femur. Reconstruction of the femur was performed using a trabecular metal cone, a cemented stem, and condylar component with distal and posterior augments (Figures 3A, 3B). A shorter, thinner stem was implanted and cemented into the previous cement mantle. A 19-mm constrained polyethylene liner was selected (the prior liner was 13 mm), which gave adequate stability with range of motion 0º to 130º. The VMO was advanced approximately 1.5 cm at the time of closure of the arthrotomy. The patient was implanted with the same Triathlon TS system, because the tibial component was well fixed, well positioned, and did not require revision.

Discussion

The need and use of stemmed, modular femoral components for revision TKA is neither questioned nor a novel concept in arthroplasty.¹ Femoral bone defects encountered in revision arthroplasty generally lack sufficient cortical integrity to support an unstemmed component. Biomechanical analyses have reliably demonstrated improved initial stability and reduced relative motion provided by femoral stem extension.^2,3 Correspondingly, significant translational and rotational movements of the femoral component when disconnected from the stem presumably correspond with clinical observations of instability.³ We report a unique case of failure of the modular junction of a stemmed femoral component in revision TKA that was not readily apparent on plain radiographs.

Dissociation of a cemented stem from the condylar portion of the component has been described at our institution with a different implant design.⁴ To our knowledge, we describe the first report of failure at the modular junction of the Triathlon TS femoral component. 

Interestingly, relative motion has been shown to increase with increasing flexion in a biomechanical study² using the same Triathlon TS system. The authors of that study found they were unable to complete testing at flexion greater than 30º because, absent the stabilizing influence of surrounding ligament and muscle, the sample deformation was so significant that it caused fracture.² In the case of our patient, the incompetence of her extensor mechanism likely resulted in increased forces transmitted through the implant than might be expected in more physiologic circumstances. This higher stress may account in part for the failure of the implant at the known weakest point, the stem-condyle modular junction.

Modular implants are routinely used, given the variability of scenarios encountered in revision surgery and the need for customization to provide the best approximation of physiologic functioning of the joint. However, modular components introduce junctional points, which are potential points of failure. Stresses on the femoral component occur in multiple dimensions besides the axial loading and medial-lateral, anterior-posterior rocking seen with the tibial component. The maximum stress is observed at the distal-most aspect of the stiffest or most well-fixed components, in this case, the articulation between the cemented stem and the cemented condylar component. Poor distal femoral fixation compounds the problem.

Numerous case reports have documented such failures in other knee systems. Issack and colleagues⁵ described 2 cases of fracture through the taper lock between the femoral component and the stem extension in the Optetrak stemmed-constrained condylar knee prosthesis (Exactech). Westrich and colleagues⁶ reported disengagement of the locking bolt of the Insall-Burstein II Constrained Condylar Knee (Zimmer) leading to failure. Lim and colleagues⁴ reported stem-condyle junctional failure of the Total Condylar III (DePuy, Johnson & Johnson) due to locking-screw failure. Butt and colleagues⁷ reported a case of failure at the femoral component–stem junction caused by screw breakage. All of these cases involved failure at the condylar-stem junction that was readily apparent on routine preoperative imaging.

Our case is noteworthy because there was no preoperative radiographic evidence that the components were loose or the junction had failed. As with many revision systems observed by Fehring and colleagues,⁸ determination of fixation is often based on the appearance of the stem because the distal femoral interfaces may be obscured by the intercondylar box. This suggests that a loose component at the stem-condylar junction could easily be overlooked and not appropriately revised based on imaging alone. A solution for achieving stability at the time of revision surgery is to obtain good distal bone apposition and fixation. In this case, a cemented stem with a metaphyseal cone was used for femoral fixation (Figures 3A, 3B).

While long-term, abnormally high stress transmitted through the modular junction may account for the implant’s failure, to our knowledge, this is the first report of its kind related to this particular implant. If quadriceps weakness contributed to this failure, it is worth considering that quadriceps weakness is common after TKA and may persist without appropriate rehabilitation and activity. Furthermore, the lack of evidence on plain radiographs makes this particular form of failure very difficult to screen. A high degree of suspicion for loosening should be maintained in patients with pain and instability after revision TKA with this implant as well as with other modular revision knee systems.

Revision total knee arthroplasty (TKA) is frequently complicated by bone loss and ligament instability, necessitating specialized implants to increase constraint and transmit forces away from the joint surface. Femoral stems are commonly used to enhance fixation and distribute force from the condyles to the metaphysis or diaphysis, to higher-quality bone capable of sustaining the forces at the knee joint.

Modular implants are now commonplace in revision surgery, because they allow intraoperative customization of the implant to the patient’s anatomy, degree of bone loss, and need for metaphyseal or diaphyseal fixation. However, these advantages are not without a downside. The modular junction introduces potential weaknesses in the implant, which may lead to early failure.

We report a case of loosening of a Triathlon TS (Stryker) femoral component that was not evident on preoperative radiographs. To our knowledge, this complication has not been reported with this particular revision knee system. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old woman underwent 2-stage revision left TKA secondary to infection at an outside institution. She had undergone 17 prior knee surgeries with multiple revisions prior to this most recent revision surgery. A constrained implant was used at her last reimplantation secondary to ligamentous laxity after extensive débridement for infection. A Triathlon TS revision knee system with cemented stemmed tibial and femoral components was implanted; stems designed for uncemented fixation were cemented. She had a history of a quadriceps tendon tear, which was repaired prior to her revision, and quadricepsplasty was performed at the time of revision.

Seven years after this revision surgery, the patient presented to our clinic with progressive global instability, occasional effusions, and 2 documented episodes of frank dislocation. On examination, she was unstable in flexion and extension. Her extensor mechanism was intact, although with 7º active lag. She had a palpable quadriceps tendon defect. Her passive range of motion was 0º to 130º. Her active range of motion was 7º to 130º. Her erythrocyte sedimentation rate and C-reactive protein levels were within normal limits, and aspiration was negative for infection. Radiographs showed apparently well-fixed components with cemented femoral and tibial stems (Figures 1A, 1B).

The patient underwent revision surgery for global instability with the surgical goal to upsize the polyethylene insert and advance the quadriceps to improve stability. In the operating room, a defect in the quadriceps mechanism was seen between the vastus medialis obliquus (VMO) and the patella, as well as a large effusion. Upon removal of the polyethylene insert, the tibial and patellar components were examined and found to be well fixed. The femoral component was grossly loose. On closer inspection, the condylar portion was found to be rotating in the axial plane freely on the well-fixed cemented stem in the femoral canal (Figures 2A-2D). The entire femoral component was removed with some difficulty because the well-fixed uncemented stem design was cemented in place. This required a small, anterior episiotomy of the femur. Reconstruction of the femur was performed using a trabecular metal cone, a cemented stem, and condylar component with distal and posterior augments (Figures 3A, 3B). A shorter, thinner stem was implanted and cemented into the previous cement mantle. A 19-mm constrained polyethylene liner was selected (the prior liner was 13 mm), which gave adequate stability with range of motion 0º to 130º. The VMO was advanced approximately 1.5 cm at the time of closure of the arthrotomy. The patient was implanted with the same Triathlon TS system, because the tibial component was well fixed, well positioned, and did not require revision.

Discussion

The need and use of stemmed, modular femoral components for revision TKA is neither questioned nor a novel concept in arthroplasty.¹ Femoral bone defects encountered in revision arthroplasty generally lack sufficient cortical integrity to support an unstemmed component. Biomechanical analyses have reliably demonstrated improved initial stability and reduced relative motion provided by femoral stem extension.^2,3 Correspondingly, significant translational and rotational movements of the femoral component when disconnected from the stem presumably correspond with clinical observations of instability.³ We report a unique case of failure of the modular junction of a stemmed femoral component in revision TKA that was not readily apparent on plain radiographs.

Dissociation of a cemented stem from the condylar portion of the component has been described at our institution with a different implant design.⁴ To our knowledge, we describe the first report of failure at the modular junction of the Triathlon TS femoral component. 

Interestingly, relative motion has been shown to increase with increasing flexion in a biomechanical study² using the same Triathlon TS system. The authors of that study found they were unable to complete testing at flexion greater than 30º because, absent the stabilizing influence of surrounding ligament and muscle, the sample deformation was so significant that it caused fracture.² In the case of our patient, the incompetence of her extensor mechanism likely resulted in increased forces transmitted through the implant than might be expected in more physiologic circumstances. This higher stress may account in part for the failure of the implant at the known weakest point, the stem-condyle modular junction.

Modular implants are routinely used, given the variability of scenarios encountered in revision surgery and the need for customization to provide the best approximation of physiologic functioning of the joint. However, modular components introduce junctional points, which are potential points of failure. Stresses on the femoral component occur in multiple dimensions besides the axial loading and medial-lateral, anterior-posterior rocking seen with the tibial component. The maximum stress is observed at the distal-most aspect of the stiffest or most well-fixed components, in this case, the articulation between the cemented stem and the cemented condylar component. Poor distal femoral fixation compounds the problem.

Numerous case reports have documented such failures in other knee systems. Issack and colleagues⁵ described 2 cases of fracture through the taper lock between the femoral component and the stem extension in the Optetrak stemmed-constrained condylar knee prosthesis (Exactech). Westrich and colleagues⁶ reported disengagement of the locking bolt of the Insall-Burstein II Constrained Condylar Knee (Zimmer) leading to failure. Lim and colleagues⁴ reported stem-condyle junctional failure of the Total Condylar III (DePuy, Johnson & Johnson) due to locking-screw failure. Butt and colleagues⁷ reported a case of failure at the femoral component–stem junction caused by screw breakage. All of these cases involved failure at the condylar-stem junction that was readily apparent on routine preoperative imaging.

Our case is noteworthy because there was no preoperative radiographic evidence that the components were loose or the junction had failed. As with many revision systems observed by Fehring and colleagues,⁸ determination of fixation is often based on the appearance of the stem because the distal femoral interfaces may be obscured by the intercondylar box. This suggests that a loose component at the stem-condylar junction could easily be overlooked and not appropriately revised based on imaging alone. A solution for achieving stability at the time of revision surgery is to obtain good distal bone apposition and fixation. In this case, a cemented stem with a metaphyseal cone was used for femoral fixation (Figures 3A, 3B).

While long-term, abnormally high stress transmitted through the modular junction may account for the implant’s failure, to our knowledge, this is the first report of its kind related to this particular implant. If quadriceps weakness contributed to this failure, it is worth considering that quadriceps weakness is common after TKA and may persist without appropriate rehabilitation and activity. Furthermore, the lack of evidence on plain radiographs makes this particular form of failure very difficult to screen. A high degree of suspicion for loosening should be maintained in patients with pain and instability after revision TKA with this implant as well as with other modular revision knee systems.

Revision total knee arthroplasty (TKA) is frequently complicated by bone loss and ligament instability, necessitating specialized implants to increase constraint and transmit forces away from the joint surface. Femoral stems are commonly used to enhance fixation and distribute force from the condyles to the metaphysis or diaphysis, to higher-quality bone capable of sustaining the forces at the knee joint.

Modular implants are now commonplace in revision surgery, because they allow intraoperative customization of the implant to the patient’s anatomy, degree of bone loss, and need for metaphyseal or diaphyseal fixation. However, these advantages are not without a downside. The modular junction introduces potential weaknesses in the implant, which may lead to early failure.

We report a case of loosening of a Triathlon TS (Stryker) femoral component that was not evident on preoperative radiographs. To our knowledge, this complication has not been reported with this particular revision knee system. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old woman underwent 2-stage revision left TKA secondary to infection at an outside institution. She had undergone 17 prior knee surgeries with multiple revisions prior to this most recent revision surgery. A constrained implant was used at her last reimplantation secondary to ligamentous laxity after extensive débridement for infection. A Triathlon TS revision knee system with cemented stemmed tibial and femoral components was implanted; stems designed for uncemented fixation were cemented. She had a history of a quadriceps tendon tear, which was repaired prior to her revision, and quadricepsplasty was performed at the time of revision.

Seven years after this revision surgery, the patient presented to our clinic with progressive global instability, occasional effusions, and 2 documented episodes of frank dislocation. On examination, she was unstable in flexion and extension. Her extensor mechanism was intact, although with 7º active lag. She had a palpable quadriceps tendon defect. Her passive range of motion was 0º to 130º. Her active range of motion was 7º to 130º. Her erythrocyte sedimentation rate and C-reactive protein levels were within normal limits, and aspiration was negative for infection. Radiographs showed apparently well-fixed components with cemented femoral and tibial stems (Figures 1A, 1B).

The patient underwent revision surgery for global instability with the surgical goal to upsize the polyethylene insert and advance the quadriceps to improve stability. In the operating room, a defect in the quadriceps mechanism was seen between the vastus medialis obliquus (VMO) and the patella, as well as a large effusion. Upon removal of the polyethylene insert, the tibial and patellar components were examined and found to be well fixed. The femoral component was grossly loose. On closer inspection, the condylar portion was found to be rotating in the axial plane freely on the well-fixed cemented stem in the femoral canal (Figures 2A-2D). The entire femoral component was removed with some difficulty because the well-fixed uncemented stem design was cemented in place. This required a small, anterior episiotomy of the femur. Reconstruction of the femur was performed using a trabecular metal cone, a cemented stem, and condylar component with distal and posterior augments (Figures 3A, 3B). A shorter, thinner stem was implanted and cemented into the previous cement mantle. A 19-mm constrained polyethylene liner was selected (the prior liner was 13 mm), which gave adequate stability with range of motion 0º to 130º. The VMO was advanced approximately 1.5 cm at the time of closure of the arthrotomy. The patient was implanted with the same Triathlon TS system, because the tibial component was well fixed, well positioned, and did not require revision.

Discussion

The need and use of stemmed, modular femoral components for revision TKA is neither questioned nor a novel concept in arthroplasty.¹ Femoral bone defects encountered in revision arthroplasty generally lack sufficient cortical integrity to support an unstemmed component. Biomechanical analyses have reliably demonstrated improved initial stability and reduced relative motion provided by femoral stem extension.^2,3 Correspondingly, significant translational and rotational movements of the femoral component when disconnected from the stem presumably correspond with clinical observations of instability.³ We report a unique case of failure of the modular junction of a stemmed femoral component in revision TKA that was not readily apparent on plain radiographs.

Dissociation of a cemented stem from the condylar portion of the component has been described at our institution with a different implant design.⁴ To our knowledge, we describe the first report of failure at the modular junction of the Triathlon TS femoral component. 

Interestingly, relative motion has been shown to increase with increasing flexion in a biomechanical study² using the same Triathlon TS system. The authors of that study found they were unable to complete testing at flexion greater than 30º because, absent the stabilizing influence of surrounding ligament and muscle, the sample deformation was so significant that it caused fracture.² In the case of our patient, the incompetence of her extensor mechanism likely resulted in increased forces transmitted through the implant than might be expected in more physiologic circumstances. This higher stress may account in part for the failure of the implant at the known weakest point, the stem-condyle modular junction.

Modular implants are routinely used, given the variability of scenarios encountered in revision surgery and the need for customization to provide the best approximation of physiologic functioning of the joint. However, modular components introduce junctional points, which are potential points of failure. Stresses on the femoral component occur in multiple dimensions besides the axial loading and medial-lateral, anterior-posterior rocking seen with the tibial component. The maximum stress is observed at the distal-most aspect of the stiffest or most well-fixed components, in this case, the articulation between the cemented stem and the cemented condylar component. Poor distal femoral fixation compounds the problem.

Numerous case reports have documented such failures in other knee systems. Issack and colleagues⁵ described 2 cases of fracture through the taper lock between the femoral component and the stem extension in the Optetrak stemmed-constrained condylar knee prosthesis (Exactech). Westrich and colleagues⁶ reported disengagement of the locking bolt of the Insall-Burstein II Constrained Condylar Knee (Zimmer) leading to failure. Lim and colleagues⁴ reported stem-condyle junctional failure of the Total Condylar III (DePuy, Johnson & Johnson) due to locking-screw failure. Butt and colleagues⁷ reported a case of failure at the femoral component–stem junction caused by screw breakage. All of these cases involved failure at the condylar-stem junction that was readily apparent on routine preoperative imaging.

Our case is noteworthy because there was no preoperative radiographic evidence that the components were loose or the junction had failed. As with many revision systems observed by Fehring and colleagues,⁸ determination of fixation is often based on the appearance of the stem because the distal femoral interfaces may be obscured by the intercondylar box. This suggests that a loose component at the stem-condylar junction could easily be overlooked and not appropriately revised based on imaging alone. A solution for achieving stability at the time of revision surgery is to obtain good distal bone apposition and fixation. In this case, a cemented stem with a metaphyseal cone was used for femoral fixation (Figures 3A, 3B).

While long-term, abnormally high stress transmitted through the modular junction may account for the implant’s failure, to our knowledge, this is the first report of its kind related to this particular implant. If quadriceps weakness contributed to this failure, it is worth considering that quadriceps weakness is common after TKA and may persist without appropriate rehabilitation and activity. Furthermore, the lack of evidence on plain radiographs makes this particular form of failure very difficult to screen. A high degree of suspicion for loosening should be maintained in patients with pain and instability after revision TKA with this implant as well as with other modular revision knee systems.

The sesamoid bones are a major contributor to normal gait, with more than 50% of body weight transmitted through the hallux metatarsophalangeal joint (MTPJ) complex. There are varying amounts of stress on the sesamoids, dependent on the gait cycle.^1,2 The sesamoids act as a fulcrum to increase the mechanical force of the flexor hallucis brevis tendon.³ Sesamoid pathology can be a source of significant morbidity in patients, especially young athletes or laborers who spend long hours on their feet. More common causes of isolated sesamoid discomfort include sesamoiditis, fracture, and avascular necrosis, with neoplastic, infectious, and inflammatory conditions rarely isolated to the sesamoid.

Gout is a systemic disorder of uric acid metabolism characterized by deposition of monosodium urate crystals in soft tissues and joints.¹ This deposition leads to tophus formation with an accompanying inflammatory response. Gout progresses through 3 stages, beginning with acute gout, which may end with chronic, recurrent, and tophaceous gouty arthritis. The hallux MTPJ is the most common joint affected by gout, with few case reports of primary sesamoid gout.^1-2,4 We present a case of gout, with radiographic findings isolated to the medial sesamoid, that mimicked a neoplastic process in a patient with no known history of gout. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old laborer presented for evaluation of a right sesamoid injury he sustained 4 months earlier when he fell off a ladder and had acute onset plantar hallux MTPJ pain and swelling. He was treated by an outside physician for a presumptive diagnosis of a medial sesamoid fracture with rest and controlled ankle movement (CAM) boot immobilization that resulted in slowly improving symptoms. In discussion of the patient’s history, he reported that 1 year earlier he had a traumatic event with similar symptoms of MTPJ pain and swelling. At that time, treatment with a CAM boot resulted in complete resolution of pain. His outside physician performed a hematologic workup for gout, which showed a normal uric acid level.

On examination, the patient presented with edema to the right hallux MTPJ and mild tenderness to palpation of the medial sesamoid. He had no pain with motion of the hallux MTPJ or with palpation of the lateral sesamoid. His radiographs showed a bipartite versus fractured sesamoid (Figures 1A, 1B) and serial magnetic resonance imaging (MRI) showed an MTPJ effusion and hyperintense signal in the medial sesamoid, but no erosive findings or soft-tissue masses (Figures 2A, 2B).

The patient was treated with wedge-sandal forefoot offloading, leading to resolution of symptoms over 6 weeks, at which point he was transitioned to normal shoe wear and allowed to progress in his activity as dictated by his symptoms. He presented for reevaluation approximately 2 weeks later with acute, atraumatic onset of plantar left hallux pain and swelling. His examination showed diffuse hallux MTPJ swelling and tenderness isolated to the medial sesamoid. An attempt at aspiration of the MTPJ yielded no fluid, and the patient again was placed in a forefoot-offloading sandal.

Radiographs of the left foot showed an expansile destructive lesion of the medial sesamoid with interval change from his previous imaging approximately 3 months earlier, obtained as part of his contralateral foot evaluation (Figure 3). MRI with and without contrast showed an expansile process isolated to the medial sesamoid with cortical thinning and marrow replacement (Figures 4A-4D). 

Because of continued discomfort and lack of a definitive diagnosis, an excisional biopsy of the sesamoid was performed. Intraoperatively, the sesamoid was extensively fragmented with near complete replacement by a chalky tophus, as well as chalky deposition throughout the hallux MTPJ. No significant degenerative changes were observed. Surgical pathology showed bone and fibroconnective tissue with deposits of negative birefringement needle-shaped crystals consistent with monosodium urate deposition and foreign body histocytic reaction, as well as repair reaction of bone (Figures 5A, 5B).

Postoperatively, the patient was again placed in a forefoot-offloading wedge sandal for 6 weeks, followed by progression of activity as dictated by his symptoms. He was also evaluated by a rheumatologist and started on medical treatment for gout, with complete resolution of his bilateral hallux pain. He has been able to return to his previous employment.

Discussion

The sesamoid bones are an important component of the hallux MTPJ complex, giving a mechanical advantage to the flexor hallucis brevis tendons in plantar flexion of the hallux.⁵ Many pathologic conditions have been well described in the literature, including fracture, sesamoiditis, nonunion, avascular necrosis, and plantar keratosis. There is also a 10% incidence of bipartite sesamoids, most commonly isolated to the medial sesamoid, with up to 25% of patients presenting with bilateral bipartite sesamoids.⁵ Neoplastic processes of the sesamoid are rare, with a paucity of reports in the literature.^6,7  Gout is a condition in which hyperuricemia, due to an imbalance in uric acid production and excretion, leads to deposition of monosodium urate crystals in joints, bones, and soft tissues, causing an inflammatory reaction. Risk factors for gout are male sex, advanced age, and ethnicity, as well as obesity, high protein diet, alcohol use, hypertension, and certain medications. Precipitation of acute attacks has been associated with acute trauma, and the first MTPJ is the most common location for an acute attack.⁸

Isolated sesamoid lesions are rare, with few isolated case reports in the literature. Benign and malignant lesions appear most often in the metatarsals, with the calcaneus being the second most commonly afflicted site.⁹ The typical differential diagnosis for isolated lytic bone lesions includes fibrous dysplasia, osteoblastoma, giant cell tumor, metastatic lesion, multiple myeloma, aneurysmal bone cyst, chondroblastoma, brown tumor, infection, eosinophilic granuloma, enchondroma, and bone cyst, with no reports in the literature to our knowledge of these entities presenting in the hallux MTPJ sesamoid. In contrast, gout typically begins with normal radiographic findings, and later leads to erosive, “punched out” lesions on either side of the MTPJ.²

Hyperuricemia is an essential part of the pathophysiology of gout, but not all patients with an acute gouty attack have elevated uric acid levels and, in contrast, may actually have normal or low levels in 12% to 43% of cases.⁸ The most accurate time frame for assessment of serum uric acid levels is 2 weeks or more after subsidence of an acute event.⁸ The normal uric acid levels seen in our patient were most likely due to the fact that the workup was undertaken during an acute attack. The difficulty with establishing the diagnosis was compounded by bilateral involvement, history of trauma, negative joint aspiration, and atypical radiographic findings. A number of reports have described patients with tophus deposits prior to or in the absence of gouty arthritis or a gouty attack.¹⁰ Risk factors for this presentation include female sex, the predominant or exclusive involvement of fingers, chronic kidney disease, and treatment with a diuretic or anti-inflammatory drug.¹⁰

Conclusion

Our case report illustrates the difficulty in diagnosing an acute gouty attack in a patient with a history of trauma and atypical radiographic findings. The hallux MTPJ is the most common location of acute gouty attacks, but the medial sesamoid as an isolated location is a rare site of presentation. The combination of pain isolated to palpation of the sesamoid and radiographs that showed an aggressive and rapidly expansile lesion of the medial sesamoid raised concerns about a neoplastic lesion. Practitioners should consider acute gout in patients with sesamoid pain and with radiographs showing an expansile sesamoid lesion.

The sesamoid bones are a major contributor to normal gait, with more than 50% of body weight transmitted through the hallux metatarsophalangeal joint (MTPJ) complex. There are varying amounts of stress on the sesamoids, dependent on the gait cycle.^1,2 The sesamoids act as a fulcrum to increase the mechanical force of the flexor hallucis brevis tendon.³ Sesamoid pathology can be a source of significant morbidity in patients, especially young athletes or laborers who spend long hours on their feet. More common causes of isolated sesamoid discomfort include sesamoiditis, fracture, and avascular necrosis, with neoplastic, infectious, and inflammatory conditions rarely isolated to the sesamoid.

Gout is a systemic disorder of uric acid metabolism characterized by deposition of monosodium urate crystals in soft tissues and joints.¹ This deposition leads to tophus formation with an accompanying inflammatory response. Gout progresses through 3 stages, beginning with acute gout, which may end with chronic, recurrent, and tophaceous gouty arthritis. The hallux MTPJ is the most common joint affected by gout, with few case reports of primary sesamoid gout.^1-2,4 We present a case of gout, with radiographic findings isolated to the medial sesamoid, that mimicked a neoplastic process in a patient with no known history of gout. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old laborer presented for evaluation of a right sesamoid injury he sustained 4 months earlier when he fell off a ladder and had acute onset plantar hallux MTPJ pain and swelling. He was treated by an outside physician for a presumptive diagnosis of a medial sesamoid fracture with rest and controlled ankle movement (CAM) boot immobilization that resulted in slowly improving symptoms. In discussion of the patient’s history, he reported that 1 year earlier he had a traumatic event with similar symptoms of MTPJ pain and swelling. At that time, treatment with a CAM boot resulted in complete resolution of pain. His outside physician performed a hematologic workup for gout, which showed a normal uric acid level.

On examination, the patient presented with edema to the right hallux MTPJ and mild tenderness to palpation of the medial sesamoid. He had no pain with motion of the hallux MTPJ or with palpation of the lateral sesamoid. His radiographs showed a bipartite versus fractured sesamoid (Figures 1A, 1B) and serial magnetic resonance imaging (MRI) showed an MTPJ effusion and hyperintense signal in the medial sesamoid, but no erosive findings or soft-tissue masses (Figures 2A, 2B).

The patient was treated with wedge-sandal forefoot offloading, leading to resolution of symptoms over 6 weeks, at which point he was transitioned to normal shoe wear and allowed to progress in his activity as dictated by his symptoms. He presented for reevaluation approximately 2 weeks later with acute, atraumatic onset of plantar left hallux pain and swelling. His examination showed diffuse hallux MTPJ swelling and tenderness isolated to the medial sesamoid. An attempt at aspiration of the MTPJ yielded no fluid, and the patient again was placed in a forefoot-offloading sandal.

Radiographs of the left foot showed an expansile destructive lesion of the medial sesamoid with interval change from his previous imaging approximately 3 months earlier, obtained as part of his contralateral foot evaluation (Figure 3). MRI with and without contrast showed an expansile process isolated to the medial sesamoid with cortical thinning and marrow replacement (Figures 4A-4D). 

Because of continued discomfort and lack of a definitive diagnosis, an excisional biopsy of the sesamoid was performed. Intraoperatively, the sesamoid was extensively fragmented with near complete replacement by a chalky tophus, as well as chalky deposition throughout the hallux MTPJ. No significant degenerative changes were observed. Surgical pathology showed bone and fibroconnective tissue with deposits of negative birefringement needle-shaped crystals consistent with monosodium urate deposition and foreign body histocytic reaction, as well as repair reaction of bone (Figures 5A, 5B).

Postoperatively, the patient was again placed in a forefoot-offloading wedge sandal for 6 weeks, followed by progression of activity as dictated by his symptoms. He was also evaluated by a rheumatologist and started on medical treatment for gout, with complete resolution of his bilateral hallux pain. He has been able to return to his previous employment.

Discussion

The sesamoid bones are an important component of the hallux MTPJ complex, giving a mechanical advantage to the flexor hallucis brevis tendons in plantar flexion of the hallux.⁵ Many pathologic conditions have been well described in the literature, including fracture, sesamoiditis, nonunion, avascular necrosis, and plantar keratosis. There is also a 10% incidence of bipartite sesamoids, most commonly isolated to the medial sesamoid, with up to 25% of patients presenting with bilateral bipartite sesamoids.⁵ Neoplastic processes of the sesamoid are rare, with a paucity of reports in the literature.^6,7  Gout is a condition in which hyperuricemia, due to an imbalance in uric acid production and excretion, leads to deposition of monosodium urate crystals in joints, bones, and soft tissues, causing an inflammatory reaction. Risk factors for gout are male sex, advanced age, and ethnicity, as well as obesity, high protein diet, alcohol use, hypertension, and certain medications. Precipitation of acute attacks has been associated with acute trauma, and the first MTPJ is the most common location for an acute attack.⁸

Isolated sesamoid lesions are rare, with few isolated case reports in the literature. Benign and malignant lesions appear most often in the metatarsals, with the calcaneus being the second most commonly afflicted site.⁹ The typical differential diagnosis for isolated lytic bone lesions includes fibrous dysplasia, osteoblastoma, giant cell tumor, metastatic lesion, multiple myeloma, aneurysmal bone cyst, chondroblastoma, brown tumor, infection, eosinophilic granuloma, enchondroma, and bone cyst, with no reports in the literature to our knowledge of these entities presenting in the hallux MTPJ sesamoid. In contrast, gout typically begins with normal radiographic findings, and later leads to erosive, “punched out” lesions on either side of the MTPJ.²

Hyperuricemia is an essential part of the pathophysiology of gout, but not all patients with an acute gouty attack have elevated uric acid levels and, in contrast, may actually have normal or low levels in 12% to 43% of cases.⁸ The most accurate time frame for assessment of serum uric acid levels is 2 weeks or more after subsidence of an acute event.⁸ The normal uric acid levels seen in our patient were most likely due to the fact that the workup was undertaken during an acute attack. The difficulty with establishing the diagnosis was compounded by bilateral involvement, history of trauma, negative joint aspiration, and atypical radiographic findings. A number of reports have described patients with tophus deposits prior to or in the absence of gouty arthritis or a gouty attack.¹⁰ Risk factors for this presentation include female sex, the predominant or exclusive involvement of fingers, chronic kidney disease, and treatment with a diuretic or anti-inflammatory drug.¹⁰

Conclusion

Our case report illustrates the difficulty in diagnosing an acute gouty attack in a patient with a history of trauma and atypical radiographic findings. The hallux MTPJ is the most common location of acute gouty attacks, but the medial sesamoid as an isolated location is a rare site of presentation. The combination of pain isolated to palpation of the sesamoid and radiographs that showed an aggressive and rapidly expansile lesion of the medial sesamoid raised concerns about a neoplastic lesion. Practitioners should consider acute gout in patients with sesamoid pain and with radiographs showing an expansile sesamoid lesion.

The sesamoid bones are a major contributor to normal gait, with more than 50% of body weight transmitted through the hallux metatarsophalangeal joint (MTPJ) complex. There are varying amounts of stress on the sesamoids, dependent on the gait cycle.^1,2 The sesamoids act as a fulcrum to increase the mechanical force of the flexor hallucis brevis tendon.³ Sesamoid pathology can be a source of significant morbidity in patients, especially young athletes or laborers who spend long hours on their feet. More common causes of isolated sesamoid discomfort include sesamoiditis, fracture, and avascular necrosis, with neoplastic, infectious, and inflammatory conditions rarely isolated to the sesamoid.

Gout is a systemic disorder of uric acid metabolism characterized by deposition of monosodium urate crystals in soft tissues and joints.¹ This deposition leads to tophus formation with an accompanying inflammatory response. Gout progresses through 3 stages, beginning with acute gout, which may end with chronic, recurrent, and tophaceous gouty arthritis. The hallux MTPJ is the most common joint affected by gout, with few case reports of primary sesamoid gout.^1-2,4 We present a case of gout, with radiographic findings isolated to the medial sesamoid, that mimicked a neoplastic process in a patient with no known history of gout. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old laborer presented for evaluation of a right sesamoid injury he sustained 4 months earlier when he fell off a ladder and had acute onset plantar hallux MTPJ pain and swelling. He was treated by an outside physician for a presumptive diagnosis of a medial sesamoid fracture with rest and controlled ankle movement (CAM) boot immobilization that resulted in slowly improving symptoms. In discussion of the patient’s history, he reported that 1 year earlier he had a traumatic event with similar symptoms of MTPJ pain and swelling. At that time, treatment with a CAM boot resulted in complete resolution of pain. His outside physician performed a hematologic workup for gout, which showed a normal uric acid level.

On examination, the patient presented with edema to the right hallux MTPJ and mild tenderness to palpation of the medial sesamoid. He had no pain with motion of the hallux MTPJ or with palpation of the lateral sesamoid. His radiographs showed a bipartite versus fractured sesamoid (Figures 1A, 1B) and serial magnetic resonance imaging (MRI) showed an MTPJ effusion and hyperintense signal in the medial sesamoid, but no erosive findings or soft-tissue masses (Figures 2A, 2B).

The patient was treated with wedge-sandal forefoot offloading, leading to resolution of symptoms over 6 weeks, at which point he was transitioned to normal shoe wear and allowed to progress in his activity as dictated by his symptoms. He presented for reevaluation approximately 2 weeks later with acute, atraumatic onset of plantar left hallux pain and swelling. His examination showed diffuse hallux MTPJ swelling and tenderness isolated to the medial sesamoid. An attempt at aspiration of the MTPJ yielded no fluid, and the patient again was placed in a forefoot-offloading sandal.

Radiographs of the left foot showed an expansile destructive lesion of the medial sesamoid with interval change from his previous imaging approximately 3 months earlier, obtained as part of his contralateral foot evaluation (Figure 3). MRI with and without contrast showed an expansile process isolated to the medial sesamoid with cortical thinning and marrow replacement (Figures 4A-4D). 

Because of continued discomfort and lack of a definitive diagnosis, an excisional biopsy of the sesamoid was performed. Intraoperatively, the sesamoid was extensively fragmented with near complete replacement by a chalky tophus, as well as chalky deposition throughout the hallux MTPJ. No significant degenerative changes were observed. Surgical pathology showed bone and fibroconnective tissue with deposits of negative birefringement needle-shaped crystals consistent with monosodium urate deposition and foreign body histocytic reaction, as well as repair reaction of bone (Figures 5A, 5B).

Postoperatively, the patient was again placed in a forefoot-offloading wedge sandal for 6 weeks, followed by progression of activity as dictated by his symptoms. He was also evaluated by a rheumatologist and started on medical treatment for gout, with complete resolution of his bilateral hallux pain. He has been able to return to his previous employment.

Discussion

The sesamoid bones are an important component of the hallux MTPJ complex, giving a mechanical advantage to the flexor hallucis brevis tendons in plantar flexion of the hallux.⁵ Many pathologic conditions have been well described in the literature, including fracture, sesamoiditis, nonunion, avascular necrosis, and plantar keratosis. There is also a 10% incidence of bipartite sesamoids, most commonly isolated to the medial sesamoid, with up to 25% of patients presenting with bilateral bipartite sesamoids.⁵ Neoplastic processes of the sesamoid are rare, with a paucity of reports in the literature.^6,7  Gout is a condition in which hyperuricemia, due to an imbalance in uric acid production and excretion, leads to deposition of monosodium urate crystals in joints, bones, and soft tissues, causing an inflammatory reaction. Risk factors for gout are male sex, advanced age, and ethnicity, as well as obesity, high protein diet, alcohol use, hypertension, and certain medications. Precipitation of acute attacks has been associated with acute trauma, and the first MTPJ is the most common location for an acute attack.⁸

Isolated sesamoid lesions are rare, with few isolated case reports in the literature. Benign and malignant lesions appear most often in the metatarsals, with the calcaneus being the second most commonly afflicted site.⁹ The typical differential diagnosis for isolated lytic bone lesions includes fibrous dysplasia, osteoblastoma, giant cell tumor, metastatic lesion, multiple myeloma, aneurysmal bone cyst, chondroblastoma, brown tumor, infection, eosinophilic granuloma, enchondroma, and bone cyst, with no reports in the literature to our knowledge of these entities presenting in the hallux MTPJ sesamoid. In contrast, gout typically begins with normal radiographic findings, and later leads to erosive, “punched out” lesions on either side of the MTPJ.²

Hyperuricemia is an essential part of the pathophysiology of gout, but not all patients with an acute gouty attack have elevated uric acid levels and, in contrast, may actually have normal or low levels in 12% to 43% of cases.⁸ The most accurate time frame for assessment of serum uric acid levels is 2 weeks or more after subsidence of an acute event.⁸ The normal uric acid levels seen in our patient were most likely due to the fact that the workup was undertaken during an acute attack. The difficulty with establishing the diagnosis was compounded by bilateral involvement, history of trauma, negative joint aspiration, and atypical radiographic findings. A number of reports have described patients with tophus deposits prior to or in the absence of gouty arthritis or a gouty attack.¹⁰ Risk factors for this presentation include female sex, the predominant or exclusive involvement of fingers, chronic kidney disease, and treatment with a diuretic or anti-inflammatory drug.¹⁰

Conclusion

Our case report illustrates the difficulty in diagnosing an acute gouty attack in a patient with a history of trauma and atypical radiographic findings. The hallux MTPJ is the most common location of acute gouty attacks, but the medial sesamoid as an isolated location is a rare site of presentation. The combination of pain isolated to palpation of the sesamoid and radiographs that showed an aggressive and rapidly expansile lesion of the medial sesamoid raised concerns about a neoplastic lesion. Practitioners should consider acute gout in patients with sesamoid pain and with radiographs showing an expansile sesamoid lesion.

The literature includes only 2 case reports of bony avulsion fracture of the origin of the brachioradialis^1,2 and, up until now, no case reports of isolated avulsion of the extensor carpi radialis longus and brachioradialis origins from the lateral epicondyle and lateral supracondylar ridge. In this article, we report the case of a 31-year-old man who sustained this injury during a fall onto his outstretched right hand, and we present our surgical repair technique. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 31-year-old right hand–dominant garbage truck worker sustained a right elbow injury and presented 2 months later. He described slipping and falling onto his outstretched right hand while doing his work. He could not describe the exact mechanism or action or position of the arm at time of impact but thought he tried to catch himself on the truck during the fall. At time of injury, he had immediate pain and swelling to the lateral aspect of the right elbow and difficulty when he attempted lifting. He denied antecedent elbow symptoms before the injury. After evaluation by an outside occupational medicine physician, he engaged in treatment consisting of activity modification and physical therapy, including range-of-motion (ROM) exercises and iontophoresis. This course of management failed to completely relieve his symptoms, and he was unable to return to work.

The patient presented to our institution 9 weeks after injury with complaints of pain along the lateral aspect of the elbow, painful flexion-extension, and continued swelling. The pain had been unrelieved with anti-inflammatory medications and opioids. Physical examination revealed tenderness and swelling along the lateral epicondyle and extensor mass of the right elbow. The patient had tenderness, marked weakness, and a palpable soft-tissue defect at the origin of the extensor mass with resisted extension of the wrist (Figure 1). Elbow ROM was from 20° to 120° of flexion, 60° of pronation, and 60° of supination. No varus or valgus instability was present about the elbow. Radiographs did not show any fracture or dislocation. Magnetic resonance imaging (MRI) did not definitively show extensor tendon avulsion but did identify signal change of the common extensor tendon (Figures 2A, 2B). Advanced imaging was inconclusive, but, given the patient’s history and physical examination findings, he was diagnosed with an avulsion injury of the origin of the extensor mass of the right elbow.

The patient was brought to the operating room, administered general anesthesia, and placed supine on the operating table with a tourniquet on the upper arm. A lateral 4.5-cm incision was made centered over the lateral epicondyle. The origin of the extensor mass was exposed, and isolated avulsions of the extensor carpi radialis longus and the brachioradialis were identified (Figures 3, 4). Underlying the avulsed sleeve of tissue, the origin of the extensor carpi radialis brevis was found intact. The lateral supracondylar ridge and the lateral epicondyle of the humerus were débrided, and 3 transosseous holes were drilled (using a 2.3-mm bit) through the lateral epicondyle. Four Mason-Allen sutures were placed into the tendon of the common extensor origin using No. 2 braided polyester suture (Ethibond Excel, Ethicon) (Figure 5). The tendon was reduced down to the native footprint, and the sutures were passed through the drill holes and tied down securely (Figure 6). The skin was then closed using layered 4-0 absorbable monofilament suture (Monocryl, Ethicon). The patient was placed in a posterior mold plaster splint with 90° of elbow flexion and with the wrist in 30° of extension.

On postoperative day 3, the patient was seen for a wound check and was placed in a long-arm fiberglass cast (90° of elbow flexion, forearm in neutral, 25° of wrist extension) for immobilization. One week after surgery, he was transitioned to a removable thermoplastic splint, and physical therapy for ROM was initiated. He was allowed therapist-guided active extension of the elbow and flexion of the wrist but was restricted to passive flexion of the elbow and extension of the wrist. Seven weeks after surgery, passive ROM about the elbow was measured, and he was found to have 120° of flexion, 0° extension, 80° pronation, and 80° supination. At 12 weeks, the physical therapy regimen was advanced to include muscle strengthening and active wrist extension and elbow flexion. At 16 weeks, the wrist extensors demonstrated 5/5 strength (Medical Research Council grading system), and the patient was cleared for full activity and weight-bearing without restriction. He returned to work pain-free and without restrictions 18 weeks after surgery. At 2-year follow-up, he had a Mayo performance elbow score of 100 and an Oxford elbow score of 48.^3,4 He had full active ROM, full strength, and no subjective pain and was back doing heavy lifting at his job.

Discussion

The brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis originate from the anterolateral aspect of the lateral column of the distal humeral metaphysis and form the dorsal mobile wad. The origin of the brachioradialis is about 7 cm in length and begins about 10 to 11 cm above the elbow.⁵ The origin and insertions of the mobile wad, specifically the brachioradialis, provide a tremendous mechanical advantage with respect to elbow flexion against resistance, particularly with the forearm in the pronated and semipronated positions.⁶ With the elbow in 30° of flexion, a force 3 times the body weight can be encountered during strenuous lifting.^6,7 We hypothesized these large forces likely led to this injury pattern in the patient we have described.

The literature includes 2 case reports of avulsion fracture of the brachioradialis muscle from its origin on the lateral supracondylar humeral ridge.^1,2 To our knowledge, however, there have been no reports of pure avulsion. In our patient’s case, there was no bony fracture, but rather avulsion of the extensor carpi radialis longus and brachioradialis at their origin, with the underlying fibers of the extensor carpi radialis brevis remaining in continuity. Because of the rarity of this injury pattern, there was a significant delay in diagnosis. On initial presentation, the differential diagnosis for lateral elbow pain and tenderness included occult fracture, intracapsular plica, osteochondritis dissecans lesion, radial tunnel syndrome, lateral or posterolateral instability, and lateral epicondylitis. Given the absence of antecedent elbow symptoms before the injury, the dynamic soft-tissue asymmetry of the mobile wad with wrist extension, and the palpable soft-tissue defect, we thought the presentation was inconsistent with a simple inflammatory or overuse syndrome, such as lateral epicondylitis. In addition, the physical examination findings were inconsistent with radial tunnel syndrome or disruption of the lateral collateral ligament complex. Elbow MRI did not show an occult fracture, plica, or osteochondritis dissecans lesion but did reveal joint effusion and signal change in the common extensor tendon origin. Interestingly, MRI did not definitively show a tear of the mobile wad. This may be explained by the fact that the fibers of the underlying extensor carpi radialis brevis remained intact. Also potentially involved are the static nature of MRI and potentially suboptimal sequencing and axis of acquisition resulting from the relative infrequency of imaging this joint at certain health care institutions. Our case demonstrates the limitations of MRI in this setting and highlights the need for a detailed history and thorough physical examination for diagnosis.

Funk and colleagues⁸ used electromyography (EMG) to study the activity of the elbow musculature in uninjured subjects. EMG data were obtained with the elbow joint subjected to resisted flexion, extension, abduction, and adduction. During resisted elbow flexion, there was an increasing amount of activity in the extensor carpi radialis with larger angles of elbow flexion. In addition, the brachioradialis demonstrated the most muscle activity of any of the elbow flexors with 90° or more of elbow flexion and forearm pronation, as opposed to other positions in which the brachialis was the primary flexor. For this reason, we hypothesized that our patient’s forearm was pronated and his elbow flexed to 90° or more when he braced for impact. The ensuing injury resulted from a violent eccentric contraction that caused extensive rupture of the lateral elbow musculature from its broad origin. With the forearm in supination or neutral position, we would have expected a possible injury to the distal biceps as opposed to the brachioradialis and extensor carpi radialis.

In our patient, this injury caused much functional disability, especially with elbow flexion and wrist extension. We hypothesized that, for the muscles to function properly, anatomical restoration would have to be achieved at their known footprint to maintain their mechanical advantage. Therefore, surgical intervention was indicated in our patient, an active laborer. Given the absence of an osseous fracture fragment in this injury pattern, healing must occur at the bone–tendon interface. As tendinous healing is more tenuous and protracted than osseous healing, we preferred transosseous repair. We believed that better tendon-to-bone healing would be possible with drilled osseous tunnels rather than with suture anchors. New studies describing alternative successful methods of treatment would add to our limited body of knowledge regarding this rare injury.

Conclusion

This is the first report of avulsion of the extensor carpi radialis longus and brachioradialis from their origins. Given the biomechanics and anatomy of the dorsal mobile wad, we posit that our patient’s injury occurred when he fell onto his outstretched hand secondary to overwhelming eccentric muscle contracture at time of impact. This injury caused significant upper extremity dysfunction, and surgical intervention was required.

The literature includes only 2 case reports of bony avulsion fracture of the origin of the brachioradialis^1,2 and, up until now, no case reports of isolated avulsion of the extensor carpi radialis longus and brachioradialis origins from the lateral epicondyle and lateral supracondylar ridge. In this article, we report the case of a 31-year-old man who sustained this injury during a fall onto his outstretched right hand, and we present our surgical repair technique. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 31-year-old right hand–dominant garbage truck worker sustained a right elbow injury and presented 2 months later. He described slipping and falling onto his outstretched right hand while doing his work. He could not describe the exact mechanism or action or position of the arm at time of impact but thought he tried to catch himself on the truck during the fall. At time of injury, he had immediate pain and swelling to the lateral aspect of the right elbow and difficulty when he attempted lifting. He denied antecedent elbow symptoms before the injury. After evaluation by an outside occupational medicine physician, he engaged in treatment consisting of activity modification and physical therapy, including range-of-motion (ROM) exercises and iontophoresis. This course of management failed to completely relieve his symptoms, and he was unable to return to work.

The patient presented to our institution 9 weeks after injury with complaints of pain along the lateral aspect of the elbow, painful flexion-extension, and continued swelling. The pain had been unrelieved with anti-inflammatory medications and opioids. Physical examination revealed tenderness and swelling along the lateral epicondyle and extensor mass of the right elbow. The patient had tenderness, marked weakness, and a palpable soft-tissue defect at the origin of the extensor mass with resisted extension of the wrist (Figure 1). Elbow ROM was from 20° to 120° of flexion, 60° of pronation, and 60° of supination. No varus or valgus instability was present about the elbow. Radiographs did not show any fracture or dislocation. Magnetic resonance imaging (MRI) did not definitively show extensor tendon avulsion but did identify signal change of the common extensor tendon (Figures 2A, 2B). Advanced imaging was inconclusive, but, given the patient’s history and physical examination findings, he was diagnosed with an avulsion injury of the origin of the extensor mass of the right elbow.

The patient was brought to the operating room, administered general anesthesia, and placed supine on the operating table with a tourniquet on the upper arm. A lateral 4.5-cm incision was made centered over the lateral epicondyle. The origin of the extensor mass was exposed, and isolated avulsions of the extensor carpi radialis longus and the brachioradialis were identified (Figures 3, 4). Underlying the avulsed sleeve of tissue, the origin of the extensor carpi radialis brevis was found intact. The lateral supracondylar ridge and the lateral epicondyle of the humerus were débrided, and 3 transosseous holes were drilled (using a 2.3-mm bit) through the lateral epicondyle. Four Mason-Allen sutures were placed into the tendon of the common extensor origin using No. 2 braided polyester suture (Ethibond Excel, Ethicon) (Figure 5). The tendon was reduced down to the native footprint, and the sutures were passed through the drill holes and tied down securely (Figure 6). The skin was then closed using layered 4-0 absorbable monofilament suture (Monocryl, Ethicon). The patient was placed in a posterior mold plaster splint with 90° of elbow flexion and with the wrist in 30° of extension.

On postoperative day 3, the patient was seen for a wound check and was placed in a long-arm fiberglass cast (90° of elbow flexion, forearm in neutral, 25° of wrist extension) for immobilization. One week after surgery, he was transitioned to a removable thermoplastic splint, and physical therapy for ROM was initiated. He was allowed therapist-guided active extension of the elbow and flexion of the wrist but was restricted to passive flexion of the elbow and extension of the wrist. Seven weeks after surgery, passive ROM about the elbow was measured, and he was found to have 120° of flexion, 0° extension, 80° pronation, and 80° supination. At 12 weeks, the physical therapy regimen was advanced to include muscle strengthening and active wrist extension and elbow flexion. At 16 weeks, the wrist extensors demonstrated 5/5 strength (Medical Research Council grading system), and the patient was cleared for full activity and weight-bearing without restriction. He returned to work pain-free and without restrictions 18 weeks after surgery. At 2-year follow-up, he had a Mayo performance elbow score of 100 and an Oxford elbow score of 48.^3,4 He had full active ROM, full strength, and no subjective pain and was back doing heavy lifting at his job.

Discussion

The brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis originate from the anterolateral aspect of the lateral column of the distal humeral metaphysis and form the dorsal mobile wad. The origin of the brachioradialis is about 7 cm in length and begins about 10 to 11 cm above the elbow.⁵ The origin and insertions of the mobile wad, specifically the brachioradialis, provide a tremendous mechanical advantage with respect to elbow flexion against resistance, particularly with the forearm in the pronated and semipronated positions.⁶ With the elbow in 30° of flexion, a force 3 times the body weight can be encountered during strenuous lifting.^6,7 We hypothesized these large forces likely led to this injury pattern in the patient we have described.

The literature includes 2 case reports of avulsion fracture of the brachioradialis muscle from its origin on the lateral supracondylar humeral ridge.^1,2 To our knowledge, however, there have been no reports of pure avulsion. In our patient’s case, there was no bony fracture, but rather avulsion of the extensor carpi radialis longus and brachioradialis at their origin, with the underlying fibers of the extensor carpi radialis brevis remaining in continuity. Because of the rarity of this injury pattern, there was a significant delay in diagnosis. On initial presentation, the differential diagnosis for lateral elbow pain and tenderness included occult fracture, intracapsular plica, osteochondritis dissecans lesion, radial tunnel syndrome, lateral or posterolateral instability, and lateral epicondylitis. Given the absence of antecedent elbow symptoms before the injury, the dynamic soft-tissue asymmetry of the mobile wad with wrist extension, and the palpable soft-tissue defect, we thought the presentation was inconsistent with a simple inflammatory or overuse syndrome, such as lateral epicondylitis. In addition, the physical examination findings were inconsistent with radial tunnel syndrome or disruption of the lateral collateral ligament complex. Elbow MRI did not show an occult fracture, plica, or osteochondritis dissecans lesion but did reveal joint effusion and signal change in the common extensor tendon origin. Interestingly, MRI did not definitively show a tear of the mobile wad. This may be explained by the fact that the fibers of the underlying extensor carpi radialis brevis remained intact. Also potentially involved are the static nature of MRI and potentially suboptimal sequencing and axis of acquisition resulting from the relative infrequency of imaging this joint at certain health care institutions. Our case demonstrates the limitations of MRI in this setting and highlights the need for a detailed history and thorough physical examination for diagnosis.

Funk and colleagues⁸ used electromyography (EMG) to study the activity of the elbow musculature in uninjured subjects. EMG data were obtained with the elbow joint subjected to resisted flexion, extension, abduction, and adduction. During resisted elbow flexion, there was an increasing amount of activity in the extensor carpi radialis with larger angles of elbow flexion. In addition, the brachioradialis demonstrated the most muscle activity of any of the elbow flexors with 90° or more of elbow flexion and forearm pronation, as opposed to other positions in which the brachialis was the primary flexor. For this reason, we hypothesized that our patient’s forearm was pronated and his elbow flexed to 90° or more when he braced for impact. The ensuing injury resulted from a violent eccentric contraction that caused extensive rupture of the lateral elbow musculature from its broad origin. With the forearm in supination or neutral position, we would have expected a possible injury to the distal biceps as opposed to the brachioradialis and extensor carpi radialis.

In our patient, this injury caused much functional disability, especially with elbow flexion and wrist extension. We hypothesized that, for the muscles to function properly, anatomical restoration would have to be achieved at their known footprint to maintain their mechanical advantage. Therefore, surgical intervention was indicated in our patient, an active laborer. Given the absence of an osseous fracture fragment in this injury pattern, healing must occur at the bone–tendon interface. As tendinous healing is more tenuous and protracted than osseous healing, we preferred transosseous repair. We believed that better tendon-to-bone healing would be possible with drilled osseous tunnels rather than with suture anchors. New studies describing alternative successful methods of treatment would add to our limited body of knowledge regarding this rare injury.

Conclusion

This is the first report of avulsion of the extensor carpi radialis longus and brachioradialis from their origins. Given the biomechanics and anatomy of the dorsal mobile wad, we posit that our patient’s injury occurred when he fell onto his outstretched hand secondary to overwhelming eccentric muscle contracture at time of impact. This injury caused significant upper extremity dysfunction, and surgical intervention was required.

The literature includes only 2 case reports of bony avulsion fracture of the origin of the brachioradialis^1,2 and, up until now, no case reports of isolated avulsion of the extensor carpi radialis longus and brachioradialis origins from the lateral epicondyle and lateral supracondylar ridge. In this article, we report the case of a 31-year-old man who sustained this injury during a fall onto his outstretched right hand, and we present our surgical repair technique. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 31-year-old right hand–dominant garbage truck worker sustained a right elbow injury and presented 2 months later. He described slipping and falling onto his outstretched right hand while doing his work. He could not describe the exact mechanism or action or position of the arm at time of impact but thought he tried to catch himself on the truck during the fall. At time of injury, he had immediate pain and swelling to the lateral aspect of the right elbow and difficulty when he attempted lifting. He denied antecedent elbow symptoms before the injury. After evaluation by an outside occupational medicine physician, he engaged in treatment consisting of activity modification and physical therapy, including range-of-motion (ROM) exercises and iontophoresis. This course of management failed to completely relieve his symptoms, and he was unable to return to work.

The patient presented to our institution 9 weeks after injury with complaints of pain along the lateral aspect of the elbow, painful flexion-extension, and continued swelling. The pain had been unrelieved with anti-inflammatory medications and opioids. Physical examination revealed tenderness and swelling along the lateral epicondyle and extensor mass of the right elbow. The patient had tenderness, marked weakness, and a palpable soft-tissue defect at the origin of the extensor mass with resisted extension of the wrist (Figure 1). Elbow ROM was from 20° to 120° of flexion, 60° of pronation, and 60° of supination. No varus or valgus instability was present about the elbow. Radiographs did not show any fracture or dislocation. Magnetic resonance imaging (MRI) did not definitively show extensor tendon avulsion but did identify signal change of the common extensor tendon (Figures 2A, 2B). Advanced imaging was inconclusive, but, given the patient’s history and physical examination findings, he was diagnosed with an avulsion injury of the origin of the extensor mass of the right elbow.

The patient was brought to the operating room, administered general anesthesia, and placed supine on the operating table with a tourniquet on the upper arm. A lateral 4.5-cm incision was made centered over the lateral epicondyle. The origin of the extensor mass was exposed, and isolated avulsions of the extensor carpi radialis longus and the brachioradialis were identified (Figures 3, 4). Underlying the avulsed sleeve of tissue, the origin of the extensor carpi radialis brevis was found intact. The lateral supracondylar ridge and the lateral epicondyle of the humerus were débrided, and 3 transosseous holes were drilled (using a 2.3-mm bit) through the lateral epicondyle. Four Mason-Allen sutures were placed into the tendon of the common extensor origin using No. 2 braided polyester suture (Ethibond Excel, Ethicon) (Figure 5). The tendon was reduced down to the native footprint, and the sutures were passed through the drill holes and tied down securely (Figure 6). The skin was then closed using layered 4-0 absorbable monofilament suture (Monocryl, Ethicon). The patient was placed in a posterior mold plaster splint with 90° of elbow flexion and with the wrist in 30° of extension.

On postoperative day 3, the patient was seen for a wound check and was placed in a long-arm fiberglass cast (90° of elbow flexion, forearm in neutral, 25° of wrist extension) for immobilization. One week after surgery, he was transitioned to a removable thermoplastic splint, and physical therapy for ROM was initiated. He was allowed therapist-guided active extension of the elbow and flexion of the wrist but was restricted to passive flexion of the elbow and extension of the wrist. Seven weeks after surgery, passive ROM about the elbow was measured, and he was found to have 120° of flexion, 0° extension, 80° pronation, and 80° supination. At 12 weeks, the physical therapy regimen was advanced to include muscle strengthening and active wrist extension and elbow flexion. At 16 weeks, the wrist extensors demonstrated 5/5 strength (Medical Research Council grading system), and the patient was cleared for full activity and weight-bearing without restriction. He returned to work pain-free and without restrictions 18 weeks after surgery. At 2-year follow-up, he had a Mayo performance elbow score of 100 and an Oxford elbow score of 48.^3,4 He had full active ROM, full strength, and no subjective pain and was back doing heavy lifting at his job.

Discussion

The brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis originate from the anterolateral aspect of the lateral column of the distal humeral metaphysis and form the dorsal mobile wad. The origin of the brachioradialis is about 7 cm in length and begins about 10 to 11 cm above the elbow.⁵ The origin and insertions of the mobile wad, specifically the brachioradialis, provide a tremendous mechanical advantage with respect to elbow flexion against resistance, particularly with the forearm in the pronated and semipronated positions.⁶ With the elbow in 30° of flexion, a force 3 times the body weight can be encountered during strenuous lifting.^6,7 We hypothesized these large forces likely led to this injury pattern in the patient we have described.

The literature includes 2 case reports of avulsion fracture of the brachioradialis muscle from its origin on the lateral supracondylar humeral ridge.^1,2 To our knowledge, however, there have been no reports of pure avulsion. In our patient’s case, there was no bony fracture, but rather avulsion of the extensor carpi radialis longus and brachioradialis at their origin, with the underlying fibers of the extensor carpi radialis brevis remaining in continuity. Because of the rarity of this injury pattern, there was a significant delay in diagnosis. On initial presentation, the differential diagnosis for lateral elbow pain and tenderness included occult fracture, intracapsular plica, osteochondritis dissecans lesion, radial tunnel syndrome, lateral or posterolateral instability, and lateral epicondylitis. Given the absence of antecedent elbow symptoms before the injury, the dynamic soft-tissue asymmetry of the mobile wad with wrist extension, and the palpable soft-tissue defect, we thought the presentation was inconsistent with a simple inflammatory or overuse syndrome, such as lateral epicondylitis. In addition, the physical examination findings were inconsistent with radial tunnel syndrome or disruption of the lateral collateral ligament complex. Elbow MRI did not show an occult fracture, plica, or osteochondritis dissecans lesion but did reveal joint effusion and signal change in the common extensor tendon origin. Interestingly, MRI did not definitively show a tear of the mobile wad. This may be explained by the fact that the fibers of the underlying extensor carpi radialis brevis remained intact. Also potentially involved are the static nature of MRI and potentially suboptimal sequencing and axis of acquisition resulting from the relative infrequency of imaging this joint at certain health care institutions. Our case demonstrates the limitations of MRI in this setting and highlights the need for a detailed history and thorough physical examination for diagnosis.

Funk and colleagues⁸ used electromyography (EMG) to study the activity of the elbow musculature in uninjured subjects. EMG data were obtained with the elbow joint subjected to resisted flexion, extension, abduction, and adduction. During resisted elbow flexion, there was an increasing amount of activity in the extensor carpi radialis with larger angles of elbow flexion. In addition, the brachioradialis demonstrated the most muscle activity of any of the elbow flexors with 90° or more of elbow flexion and forearm pronation, as opposed to other positions in which the brachialis was the primary flexor. For this reason, we hypothesized that our patient’s forearm was pronated and his elbow flexed to 90° or more when he braced for impact. The ensuing injury resulted from a violent eccentric contraction that caused extensive rupture of the lateral elbow musculature from its broad origin. With the forearm in supination or neutral position, we would have expected a possible injury to the distal biceps as opposed to the brachioradialis and extensor carpi radialis.

In our patient, this injury caused much functional disability, especially with elbow flexion and wrist extension. We hypothesized that, for the muscles to function properly, anatomical restoration would have to be achieved at their known footprint to maintain their mechanical advantage. Therefore, surgical intervention was indicated in our patient, an active laborer. Given the absence of an osseous fracture fragment in this injury pattern, healing must occur at the bone–tendon interface. As tendinous healing is more tenuous and protracted than osseous healing, we preferred transosseous repair. We believed that better tendon-to-bone healing would be possible with drilled osseous tunnels rather than with suture anchors. New studies describing alternative successful methods of treatment would add to our limited body of knowledge regarding this rare injury.

Conclusion

This is the first report of avulsion of the extensor carpi radialis longus and brachioradialis from their origins. Given the biomechanics and anatomy of the dorsal mobile wad, we posit that our patient’s injury occurred when he fell onto his outstretched hand secondary to overwhelming eccentric muscle contracture at time of impact. This injury caused significant upper extremity dysfunction, and surgical intervention was required.

THE CASE

A 3-year-old girl was brought to our clinic with a generalized rash over her scalp, face, neck, chest, abdomen, back, perianal area, extremities, and the plantar surface of her right foot. On physical examination, we noted many round, hyperpigmented, brown and reddish pink, well-circumscribed macules on her body (FIGURE). Only a few of these macules had appeared on the girl’s trunk within the first 3 months of her life, but since then they’d increased in number and spread to other parts of her body as she’d aged. The lesions became edematous and erythematous with tactile irritation. Darier’s sign (the development of a hive or wheal when a lesion is stroked) was present.

The patient’s vitals at the time of examination included a temperature of 98.2°F, respiratory rate of 17 breaths/min, heart rate of 92 beats/min, blood pressure of 100/66 mm Hg, and oxygen saturation level of 100% on room air. The girl’s parents said they hadn’t traveled. There was no mucosal involvement and no systemic involvement. The patient had no past surgical or medical history, was not taking any medications, and had no significant birth history. A skin biopsy was performed.

THE DIAGNOSIS

Based on the presence of a positive Darier’s sign and the results of the skin biopsy (which showed increased mast cells), we diagnosed urticaria pigmentosa (UP), which is the most common form of cutaneous mastocytosis.¹

The diagnosis had been delayed for almost 3 years because of several factors. For one thing, there had been few lesions present early in the child’s life, and as a result, the parents chalked them up to “beauty marks.” Then, as the lesions started to increase in number, the parents thought bed bugs were to blame.

As time went on, the parents attempted to treat their daughter’s hives with homeopathic remedies suggested by family members. When the lesions didn’t resolve with homeopathic remedies, the parents tried over-the-counter H1 and H2 antihistamines such as diphenhydramine, loratadine, and ranitidine. When these treatments failed, the parents brought their child to our office for medical evaluation.

DISCUSSION

UP is a chronic skin disorder in which there is an abnormal proliferation of mast cells in the dermis of the skin. It is considered an orphan disease.¹ UP that presents in children is most often benign. Approximately 50% of cases occur before 6 months of age and 25% occur before puberty.² The lesions are often self-limited and completely resolve in approximately 50% of patients by puberty.³ By adulthood, the lesions either resolve or some lightly colored non-urticating macules remain; however, some patients will continue to have a positive Darier’s sign.⁴

Dermatologic symptoms. A patient with UP may present with brown or reddish maculopapules, papules, nodules, pruritus, and flushing of the face. Darier’s sign is usually seen in cases of UP; in a study of mastocytosis in children, Darier’s sign was present in 94% of cases.⁵ Lesions are more prominent in areas where clothes can rub the skin, and they often vary in size and appearance. The presence of lesions can vary from localized and scant to hundreds located over the entire body. UP can be difficult to identify when the lesions are limited, which can lead to delayed diagnosis and treatment.⁶

Systemic involvement. UP also can affect the skeleton, bone marrow, liver, spleen, lymph nodes, gastrointestinal tract, kidneys, cardiovascular system, and/or central nervous system. Skeletal involvement may manifest as osteoporosis or bone pain in 10% to 20% of patients with UP.⁷ Bone marrow involvement may progress to anemia or mast cell leukemia. UP can result in hepatomegaly or enlarged lymph nodes. Patients may experience nausea, diarrhea, or abdominal pain if the gastrointestinal tract is affected. Cardiovascular involvement may manifest as tachycardia and shock.⁸

Urticaria pigmentosa lesions are often self-limited and completely resolve in about half of patients by puberty.

Diagnosis of UP is made based on the physical exam findings noted earlier, as well as skin biopsy laboratory results. Skin biopsy will reveal increased mast cells. In up to two-thirds of patients who have systemic involvement, laboratory testing will show elevated urine histamine levels, as well as elevated serum concentrations of tryptase.⁹

UP can appear similar to many other skin conditions

The differential diagnosis of UP can include urticaria, atopic dermatitis, contact dermatitis, pityriasis rosea, an allergic reaction/drug eruption, Henoch-Schonlein purpura, erythema multiforme, fifth disease, folliculitis, guttate psoriasis, miliaria rubra, insect bites, viral exanthem, lichen planus, and scabies.^10,11 In addition to the clinical appearance of the rash, these conditions can be distinguished from UP by skin biopsy and other relevant tests, as well as a thorough history.

Treatment options include antihistamines, corticosteroids, PUVA

Patients with UP should be instructed to avoid precipitating factors such as temperature changes, friction, alcohol ingestion, aspirin, physical exertion, or opiates. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA (psoralen plus ultraviolet A photochemotherapy).³ PUVA is normally avoided in pediatric patients because it is associated with an increased risk of skin cancer later in life.¹²

Our patient. We prescribed a topical corticosteroid, 0.05% betamethasone dipropionate cream, and oral cromolyn sodium 100 mg qid for our patient, but this failed to significantly improve the macules. The patient and parents grew increasingly anxious. Ultimately, the parents decided to have their daughter treated with PUVA in limited amounts. Topical psoralen was also used. After 2 months of treatment, the patient’s lesions substantially improved and many of them disappeared. In addition, the parents were educated on the importance of sunscreen and limiting their daughter’s exposure to the sun, when possible.

THE TAKEAWAY

UP can be diagnosed by taking a thorough history and conducting a physical examination; a skin biopsy that reveals increased mast cells will confirm the diagnosis. UP is usually self-limited and resolves in about one-half of patients by puberty. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA. Patients should be referred to a specialist if their symptoms become severe, systemic UP is suspected, or they do not respond to therapy.

THE CASE

A 3-year-old girl was brought to our clinic with a generalized rash over her scalp, face, neck, chest, abdomen, back, perianal area, extremities, and the plantar surface of her right foot. On physical examination, we noted many round, hyperpigmented, brown and reddish pink, well-circumscribed macules on her body (FIGURE). Only a few of these macules had appeared on the girl’s trunk within the first 3 months of her life, but since then they’d increased in number and spread to other parts of her body as she’d aged. The lesions became edematous and erythematous with tactile irritation. Darier’s sign (the development of a hive or wheal when a lesion is stroked) was present.

The patient’s vitals at the time of examination included a temperature of 98.2°F, respiratory rate of 17 breaths/min, heart rate of 92 beats/min, blood pressure of 100/66 mm Hg, and oxygen saturation level of 100% on room air. The girl’s parents said they hadn’t traveled. There was no mucosal involvement and no systemic involvement. The patient had no past surgical or medical history, was not taking any medications, and had no significant birth history. A skin biopsy was performed.

THE DIAGNOSIS

Based on the presence of a positive Darier’s sign and the results of the skin biopsy (which showed increased mast cells), we diagnosed urticaria pigmentosa (UP), which is the most common form of cutaneous mastocytosis.¹

The diagnosis had been delayed for almost 3 years because of several factors. For one thing, there had been few lesions present early in the child’s life, and as a result, the parents chalked them up to “beauty marks.” Then, as the lesions started to increase in number, the parents thought bed bugs were to blame.

As time went on, the parents attempted to treat their daughter’s hives with homeopathic remedies suggested by family members. When the lesions didn’t resolve with homeopathic remedies, the parents tried over-the-counter H1 and H2 antihistamines such as diphenhydramine, loratadine, and ranitidine. When these treatments failed, the parents brought their child to our office for medical evaluation.

DISCUSSION

UP is a chronic skin disorder in which there is an abnormal proliferation of mast cells in the dermis of the skin. It is considered an orphan disease.¹ UP that presents in children is most often benign. Approximately 50% of cases occur before 6 months of age and 25% occur before puberty.² The lesions are often self-limited and completely resolve in approximately 50% of patients by puberty.³ By adulthood, the lesions either resolve or some lightly colored non-urticating macules remain; however, some patients will continue to have a positive Darier’s sign.⁴

Dermatologic symptoms. A patient with UP may present with brown or reddish maculopapules, papules, nodules, pruritus, and flushing of the face. Darier’s sign is usually seen in cases of UP; in a study of mastocytosis in children, Darier’s sign was present in 94% of cases.⁵ Lesions are more prominent in areas where clothes can rub the skin, and they often vary in size and appearance. The presence of lesions can vary from localized and scant to hundreds located over the entire body. UP can be difficult to identify when the lesions are limited, which can lead to delayed diagnosis and treatment.⁶

Systemic involvement. UP also can affect the skeleton, bone marrow, liver, spleen, lymph nodes, gastrointestinal tract, kidneys, cardiovascular system, and/or central nervous system. Skeletal involvement may manifest as osteoporosis or bone pain in 10% to 20% of patients with UP.⁷ Bone marrow involvement may progress to anemia or mast cell leukemia. UP can result in hepatomegaly or enlarged lymph nodes. Patients may experience nausea, diarrhea, or abdominal pain if the gastrointestinal tract is affected. Cardiovascular involvement may manifest as tachycardia and shock.⁸

Urticaria pigmentosa lesions are often self-limited and completely resolve in about half of patients by puberty.

Diagnosis of UP is made based on the physical exam findings noted earlier, as well as skin biopsy laboratory results. Skin biopsy will reveal increased mast cells. In up to two-thirds of patients who have systemic involvement, laboratory testing will show elevated urine histamine levels, as well as elevated serum concentrations of tryptase.⁹

UP can appear similar to many other skin conditions

The differential diagnosis of UP can include urticaria, atopic dermatitis, contact dermatitis, pityriasis rosea, an allergic reaction/drug eruption, Henoch-Schonlein purpura, erythema multiforme, fifth disease, folliculitis, guttate psoriasis, miliaria rubra, insect bites, viral exanthem, lichen planus, and scabies.^10,11 In addition to the clinical appearance of the rash, these conditions can be distinguished from UP by skin biopsy and other relevant tests, as well as a thorough history.

Treatment options include antihistamines, corticosteroids, PUVA

Patients with UP should be instructed to avoid precipitating factors such as temperature changes, friction, alcohol ingestion, aspirin, physical exertion, or opiates. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA (psoralen plus ultraviolet A photochemotherapy).³ PUVA is normally avoided in pediatric patients because it is associated with an increased risk of skin cancer later in life.¹²

Our patient. We prescribed a topical corticosteroid, 0.05% betamethasone dipropionate cream, and oral cromolyn sodium 100 mg qid for our patient, but this failed to significantly improve the macules. The patient and parents grew increasingly anxious. Ultimately, the parents decided to have their daughter treated with PUVA in limited amounts. Topical psoralen was also used. After 2 months of treatment, the patient’s lesions substantially improved and many of them disappeared. In addition, the parents were educated on the importance of sunscreen and limiting their daughter’s exposure to the sun, when possible.

THE TAKEAWAY

UP can be diagnosed by taking a thorough history and conducting a physical examination; a skin biopsy that reveals increased mast cells will confirm the diagnosis. UP is usually self-limited and resolves in about one-half of patients by puberty. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA. Patients should be referred to a specialist if their symptoms become severe, systemic UP is suspected, or they do not respond to therapy.

THE CASE

A 3-year-old girl was brought to our clinic with a generalized rash over her scalp, face, neck, chest, abdomen, back, perianal area, extremities, and the plantar surface of her right foot. On physical examination, we noted many round, hyperpigmented, brown and reddish pink, well-circumscribed macules on her body (FIGURE). Only a few of these macules had appeared on the girl’s trunk within the first 3 months of her life, but since then they’d increased in number and spread to other parts of her body as she’d aged. The lesions became edematous and erythematous with tactile irritation. Darier’s sign (the development of a hive or wheal when a lesion is stroked) was present.

The patient’s vitals at the time of examination included a temperature of 98.2°F, respiratory rate of 17 breaths/min, heart rate of 92 beats/min, blood pressure of 100/66 mm Hg, and oxygen saturation level of 100% on room air. The girl’s parents said they hadn’t traveled. There was no mucosal involvement and no systemic involvement. The patient had no past surgical or medical history, was not taking any medications, and had no significant birth history. A skin biopsy was performed.

THE DIAGNOSIS

Based on the presence of a positive Darier’s sign and the results of the skin biopsy (which showed increased mast cells), we diagnosed urticaria pigmentosa (UP), which is the most common form of cutaneous mastocytosis.¹

The diagnosis had been delayed for almost 3 years because of several factors. For one thing, there had been few lesions present early in the child’s life, and as a result, the parents chalked them up to “beauty marks.” Then, as the lesions started to increase in number, the parents thought bed bugs were to blame.

As time went on, the parents attempted to treat their daughter’s hives with homeopathic remedies suggested by family members. When the lesions didn’t resolve with homeopathic remedies, the parents tried over-the-counter H1 and H2 antihistamines such as diphenhydramine, loratadine, and ranitidine. When these treatments failed, the parents brought their child to our office for medical evaluation.

DISCUSSION

UP is a chronic skin disorder in which there is an abnormal proliferation of mast cells in the dermis of the skin. It is considered an orphan disease.¹ UP that presents in children is most often benign. Approximately 50% of cases occur before 6 months of age and 25% occur before puberty.² The lesions are often self-limited and completely resolve in approximately 50% of patients by puberty.³ By adulthood, the lesions either resolve or some lightly colored non-urticating macules remain; however, some patients will continue to have a positive Darier’s sign.⁴

Dermatologic symptoms. A patient with UP may present with brown or reddish maculopapules, papules, nodules, pruritus, and flushing of the face. Darier’s sign is usually seen in cases of UP; in a study of mastocytosis in children, Darier’s sign was present in 94% of cases.⁵ Lesions are more prominent in areas where clothes can rub the skin, and they often vary in size and appearance. The presence of lesions can vary from localized and scant to hundreds located over the entire body. UP can be difficult to identify when the lesions are limited, which can lead to delayed diagnosis and treatment.⁶

Systemic involvement. UP also can affect the skeleton, bone marrow, liver, spleen, lymph nodes, gastrointestinal tract, kidneys, cardiovascular system, and/or central nervous system. Skeletal involvement may manifest as osteoporosis or bone pain in 10% to 20% of patients with UP.⁷ Bone marrow involvement may progress to anemia or mast cell leukemia. UP can result in hepatomegaly or enlarged lymph nodes. Patients may experience nausea, diarrhea, or abdominal pain if the gastrointestinal tract is affected. Cardiovascular involvement may manifest as tachycardia and shock.⁸

Urticaria pigmentosa lesions are often self-limited and completely resolve in about half of patients by puberty.

Diagnosis of UP is made based on the physical exam findings noted earlier, as well as skin biopsy laboratory results. Skin biopsy will reveal increased mast cells. In up to two-thirds of patients who have systemic involvement, laboratory testing will show elevated urine histamine levels, as well as elevated serum concentrations of tryptase.⁹

UP can appear similar to many other skin conditions

The differential diagnosis of UP can include urticaria, atopic dermatitis, contact dermatitis, pityriasis rosea, an allergic reaction/drug eruption, Henoch-Schonlein purpura, erythema multiforme, fifth disease, folliculitis, guttate psoriasis, miliaria rubra, insect bites, viral exanthem, lichen planus, and scabies.^10,11 In addition to the clinical appearance of the rash, these conditions can be distinguished from UP by skin biopsy and other relevant tests, as well as a thorough history.

Treatment options include antihistamines, corticosteroids, PUVA

Patients with UP should be instructed to avoid precipitating factors such as temperature changes, friction, alcohol ingestion, aspirin, physical exertion, or opiates. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA (psoralen plus ultraviolet A photochemotherapy).³ PUVA is normally avoided in pediatric patients because it is associated with an increased risk of skin cancer later in life.¹²

Our patient. We prescribed a topical corticosteroid, 0.05% betamethasone dipropionate cream, and oral cromolyn sodium 100 mg qid for our patient, but this failed to significantly improve the macules. The patient and parents grew increasingly anxious. Ultimately, the parents decided to have their daughter treated with PUVA in limited amounts. Topical psoralen was also used. After 2 months of treatment, the patient’s lesions substantially improved and many of them disappeared. In addition, the parents were educated on the importance of sunscreen and limiting their daughter’s exposure to the sun, when possible.

THE TAKEAWAY

UP can be diagnosed by taking a thorough history and conducting a physical examination; a skin biopsy that reveals increased mast cells will confirm the diagnosis. UP is usually self-limited and resolves in about one-half of patients by puberty. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA. Patients should be referred to a specialist if their symptoms become severe, systemic UP is suspected, or they do not respond to therapy.

Osteochondromas are common benign bone tumors composed of a bony protrusion with an overlying cartilage cap.¹ This lesion constitutes 24% to 40% of all benign bone tumors, and the great majority arise from the metaphyseal region of long bones.² The scapula accounts for only 3% to 5% of all osteochondromas; however, this lesion is the most common benign bone tumor to involve the scapula.³

In contrast, cutaneous bronchogenic cyst of the scapula is an exceedingly rare pathology. The bronchogenic cyst is a congenital cystic mass lined by tracheobronchial structures and respiratory epithelium.⁴ These are most commonly located in the thorax, although numerous remote locations have also been described, including cutaneous cysts.⁵ The overall incidence of bronchogenic cysts is thought to be 1 in 42,000 to 1 in 68,000.⁶ There are only 15 case reports of cutaneous bronchogenic cysts in the scapular region.⁷

We report the case of a novel dual lesion of both an osteochondroma and a contiguous cutaneous bronchogenic cyst in the scapula. The patient’s guardian provided written informed consent for print and electronic publication of this case report.

Case Report

A 12-month-old boy presented to our clinic with the complaint of a mass over the left scapula. The mass was first noted incidentally several weeks earlier during bathing. Examination revealed a firm, subcutaneous, nontender mass measuring 1×2 cm located over the spine of the scapula. There were no overlying skin changes, and there was normal function of the ipsilateral upper extremity. Anteroposterior and lateral chest radiographs revealed no abnormality. Magnetic resonance imaging (MRI) showed an exostosis projecting from the scapular spine measuring 2×6×7 mm with an adjacent cystic mass measuring 5×8×9 mm that was thought to represent bursitis (Figure 1). The decision was made to observe the mass. 

The patient returned to clinic at age 31 months with a new complaint of scant drainage of serous fluid from a pinprick-sized hole located just superolateral to the scapular mass. The child’s mother reported daily manual expression of fluid from the mass via the hole, without which the mass would enlarge. There were no local or systemic signs of infection. A repeat MRI again revealed an exostosis with an adjacent cystic mass with interval enlargement of the cyst (Figure 2). At age 4.5 years, the decision was made to proceed with excision of the osteochondroma and adjacent cystic mass.

The mass was approached via a 2-cm incision designed to excise the tract to the skin. Dissection revealed a sinus tract connecting to a well-defined cystic sac. This sac was attached to the underlying exostosis. The exostosis and attached cyst were excised en bloc. The cyst was opened, revealing foul-smelling, cloudy white fluid that was sent for culture; the specimen was sent for pathology.

The fluid culture grew mixed flora, with no Staphylococcus aureus, group A streptococcus, or Pseudomonas aeruginosa identified. The pathologic examination identified bone with a cartilaginous cap, consistent with osteochondroma (Figure 3), as well as a cyst lined by respiratory epithelium with patchy areas of squamous epithelium and surrounding mucus glands, consistent with bronchogenic cyst (Figure 4). Figure 5 shows the contiguous nature of the 2 lesions.

The postoperative course was uneventful. The patient returned to full use of the left upper extremity and had resolution of all drainage. 

Discussion

Osteochondromas are thought to arise from aberrant growth of the epiphyseal growth plate cartilage. A small portion of the physis herniates past the groove of Ranvier and grows parallel to the normal physis with medullary continuity. This can occur idiopathically or, more rarely, secondary to an identified injury to the growth plate.¹

The formation of bronchogenic cysts is most often attributed to anomalous budding of the ventral foregut during fetal development,⁴ hence the alternative designation of these cysts as foregut cysts. An extrathoracic location of the cyst has been postulated to stem from 2 possible events: a preexisting cyst may migrate out of the thorax prior to closure of the sternal plates, or sternal plate closure may itself pinch off the cyst.^8,9 An alternative explanation is in situ metaplastic development of respiratory epithelium.¹⁰ When located near the skin, these cysts often drain clear fluid.¹¹

Scapular osteochondromas are known to cause various pathologies of the shoulder girdle, including snapping scapula syndrome, chest wall deformity, shoulder impingement, and bursa formation.^12-17 This case, however, is the first known finding of a scapular osteochondroma with a contiguous cutaneous bronchogenic cyst. A putative explanation for their co-occurrence is that local disturbances caused by one lesion stimulated the formation of the second. The direct connection between the bronchogenic cyst and the bone, as has been reported in 3 cases,^7,9,18 seems to favor this explanation. Definitive conclusions regarding any causal relationship are beyond the scope of this single case report.

Definitive management of bronchogenic cysts is complete excision, although the diagnosis is often not made until histopathologic examination has been completed.¹⁹ Osteochondromas are managed with observation unless they are symptomatic.² Malignant degeneration is a rare but documented occurrence in both lesions.^2,20

Conclusion

In approaching the pediatric patient with a cystic mass over the scapula, a cutaneous bronchogenic cyst may be included in the differential diagnosis. This lesion can occur in isolation or can be found with another pathology, such as osteochondroma, as reported here.

Osteochondromas are common benign bone tumors composed of a bony protrusion with an overlying cartilage cap.¹ This lesion constitutes 24% to 40% of all benign bone tumors, and the great majority arise from the metaphyseal region of long bones.² The scapula accounts for only 3% to 5% of all osteochondromas; however, this lesion is the most common benign bone tumor to involve the scapula.³

In contrast, cutaneous bronchogenic cyst of the scapula is an exceedingly rare pathology. The bronchogenic cyst is a congenital cystic mass lined by tracheobronchial structures and respiratory epithelium.⁴ These are most commonly located in the thorax, although numerous remote locations have also been described, including cutaneous cysts.⁵ The overall incidence of bronchogenic cysts is thought to be 1 in 42,000 to 1 in 68,000.⁶ There are only 15 case reports of cutaneous bronchogenic cysts in the scapular region.⁷

We report the case of a novel dual lesion of both an osteochondroma and a contiguous cutaneous bronchogenic cyst in the scapula. The patient’s guardian provided written informed consent for print and electronic publication of this case report.

Case Report

A 12-month-old boy presented to our clinic with the complaint of a mass over the left scapula. The mass was first noted incidentally several weeks earlier during bathing. Examination revealed a firm, subcutaneous, nontender mass measuring 1×2 cm located over the spine of the scapula. There were no overlying skin changes, and there was normal function of the ipsilateral upper extremity. Anteroposterior and lateral chest radiographs revealed no abnormality. Magnetic resonance imaging (MRI) showed an exostosis projecting from the scapular spine measuring 2×6×7 mm with an adjacent cystic mass measuring 5×8×9 mm that was thought to represent bursitis (Figure 1). The decision was made to observe the mass. 

The patient returned to clinic at age 31 months with a new complaint of scant drainage of serous fluid from a pinprick-sized hole located just superolateral to the scapular mass. The child’s mother reported daily manual expression of fluid from the mass via the hole, without which the mass would enlarge. There were no local or systemic signs of infection. A repeat MRI again revealed an exostosis with an adjacent cystic mass with interval enlargement of the cyst (Figure 2). At age 4.5 years, the decision was made to proceed with excision of the osteochondroma and adjacent cystic mass.

The mass was approached via a 2-cm incision designed to excise the tract to the skin. Dissection revealed a sinus tract connecting to a well-defined cystic sac. This sac was attached to the underlying exostosis. The exostosis and attached cyst were excised en bloc. The cyst was opened, revealing foul-smelling, cloudy white fluid that was sent for culture; the specimen was sent for pathology.

The fluid culture grew mixed flora, with no Staphylococcus aureus, group A streptococcus, or Pseudomonas aeruginosa identified. The pathologic examination identified bone with a cartilaginous cap, consistent with osteochondroma (Figure 3), as well as a cyst lined by respiratory epithelium with patchy areas of squamous epithelium and surrounding mucus glands, consistent with bronchogenic cyst (Figure 4). Figure 5 shows the contiguous nature of the 2 lesions.

The postoperative course was uneventful. The patient returned to full use of the left upper extremity and had resolution of all drainage. 

Discussion

Osteochondromas are thought to arise from aberrant growth of the epiphyseal growth plate cartilage. A small portion of the physis herniates past the groove of Ranvier and grows parallel to the normal physis with medullary continuity. This can occur idiopathically or, more rarely, secondary to an identified injury to the growth plate.¹

The formation of bronchogenic cysts is most often attributed to anomalous budding of the ventral foregut during fetal development,⁴ hence the alternative designation of these cysts as foregut cysts. An extrathoracic location of the cyst has been postulated to stem from 2 possible events: a preexisting cyst may migrate out of the thorax prior to closure of the sternal plates, or sternal plate closure may itself pinch off the cyst.^8,9 An alternative explanation is in situ metaplastic development of respiratory epithelium.¹⁰ When located near the skin, these cysts often drain clear fluid.¹¹

Scapular osteochondromas are known to cause various pathologies of the shoulder girdle, including snapping scapula syndrome, chest wall deformity, shoulder impingement, and bursa formation.^12-17 This case, however, is the first known finding of a scapular osteochondroma with a contiguous cutaneous bronchogenic cyst. A putative explanation for their co-occurrence is that local disturbances caused by one lesion stimulated the formation of the second. The direct connection between the bronchogenic cyst and the bone, as has been reported in 3 cases,^7,9,18 seems to favor this explanation. Definitive conclusions regarding any causal relationship are beyond the scope of this single case report.

Definitive management of bronchogenic cysts is complete excision, although the diagnosis is often not made until histopathologic examination has been completed.¹⁹ Osteochondromas are managed with observation unless they are symptomatic.² Malignant degeneration is a rare but documented occurrence in both lesions.^2,20

Conclusion

In approaching the pediatric patient with a cystic mass over the scapula, a cutaneous bronchogenic cyst may be included in the differential diagnosis. This lesion can occur in isolation or can be found with another pathology, such as osteochondroma, as reported here.

Osteochondromas are common benign bone tumors composed of a bony protrusion with an overlying cartilage cap.¹ This lesion constitutes 24% to 40% of all benign bone tumors, and the great majority arise from the metaphyseal region of long bones.² The scapula accounts for only 3% to 5% of all osteochondromas; however, this lesion is the most common benign bone tumor to involve the scapula.³

In contrast, cutaneous bronchogenic cyst of the scapula is an exceedingly rare pathology. The bronchogenic cyst is a congenital cystic mass lined by tracheobronchial structures and respiratory epithelium.⁴ These are most commonly located in the thorax, although numerous remote locations have also been described, including cutaneous cysts.⁵ The overall incidence of bronchogenic cysts is thought to be 1 in 42,000 to 1 in 68,000.⁶ There are only 15 case reports of cutaneous bronchogenic cysts in the scapular region.⁷

We report the case of a novel dual lesion of both an osteochondroma and a contiguous cutaneous bronchogenic cyst in the scapula. The patient’s guardian provided written informed consent for print and electronic publication of this case report.

Case Report

A 12-month-old boy presented to our clinic with the complaint of a mass over the left scapula. The mass was first noted incidentally several weeks earlier during bathing. Examination revealed a firm, subcutaneous, nontender mass measuring 1×2 cm located over the spine of the scapula. There were no overlying skin changes, and there was normal function of the ipsilateral upper extremity. Anteroposterior and lateral chest radiographs revealed no abnormality. Magnetic resonance imaging (MRI) showed an exostosis projecting from the scapular spine measuring 2×6×7 mm with an adjacent cystic mass measuring 5×8×9 mm that was thought to represent bursitis (Figure 1). The decision was made to observe the mass. 

The patient returned to clinic at age 31 months with a new complaint of scant drainage of serous fluid from a pinprick-sized hole located just superolateral to the scapular mass. The child’s mother reported daily manual expression of fluid from the mass via the hole, without which the mass would enlarge. There were no local or systemic signs of infection. A repeat MRI again revealed an exostosis with an adjacent cystic mass with interval enlargement of the cyst (Figure 2). At age 4.5 years, the decision was made to proceed with excision of the osteochondroma and adjacent cystic mass.

The mass was approached via a 2-cm incision designed to excise the tract to the skin. Dissection revealed a sinus tract connecting to a well-defined cystic sac. This sac was attached to the underlying exostosis. The exostosis and attached cyst were excised en bloc. The cyst was opened, revealing foul-smelling, cloudy white fluid that was sent for culture; the specimen was sent for pathology.

The fluid culture grew mixed flora, with no Staphylococcus aureus, group A streptococcus, or Pseudomonas aeruginosa identified. The pathologic examination identified bone with a cartilaginous cap, consistent with osteochondroma (Figure 3), as well as a cyst lined by respiratory epithelium with patchy areas of squamous epithelium and surrounding mucus glands, consistent with bronchogenic cyst (Figure 4). Figure 5 shows the contiguous nature of the 2 lesions.

The postoperative course was uneventful. The patient returned to full use of the left upper extremity and had resolution of all drainage. 

Discussion

Osteochondromas are thought to arise from aberrant growth of the epiphyseal growth plate cartilage. A small portion of the physis herniates past the groove of Ranvier and grows parallel to the normal physis with medullary continuity. This can occur idiopathically or, more rarely, secondary to an identified injury to the growth plate.¹

The formation of bronchogenic cysts is most often attributed to anomalous budding of the ventral foregut during fetal development,⁴ hence the alternative designation of these cysts as foregut cysts. An extrathoracic location of the cyst has been postulated to stem from 2 possible events: a preexisting cyst may migrate out of the thorax prior to closure of the sternal plates, or sternal plate closure may itself pinch off the cyst.^8,9 An alternative explanation is in situ metaplastic development of respiratory epithelium.¹⁰ When located near the skin, these cysts often drain clear fluid.¹¹

Scapular osteochondromas are known to cause various pathologies of the shoulder girdle, including snapping scapula syndrome, chest wall deformity, shoulder impingement, and bursa formation.^12-17 This case, however, is the first known finding of a scapular osteochondroma with a contiguous cutaneous bronchogenic cyst. A putative explanation for their co-occurrence is that local disturbances caused by one lesion stimulated the formation of the second. The direct connection between the bronchogenic cyst and the bone, as has been reported in 3 cases,^7,9,18 seems to favor this explanation. Definitive conclusions regarding any causal relationship are beyond the scope of this single case report.

Definitive management of bronchogenic cysts is complete excision, although the diagnosis is often not made until histopathologic examination has been completed.¹⁹ Osteochondromas are managed with observation unless they are symptomatic.² Malignant degeneration is a rare but documented occurrence in both lesions.^2,20

Conclusion

In approaching the pediatric patient with a cystic mass over the scapula, a cutaneous bronchogenic cyst may be included in the differential diagnosis. This lesion can occur in isolation or can be found with another pathology, such as osteochondroma, as reported here.

Posterior spinal fusion for adolescent idiopathic scoliosis is a relatively common procedure. However, intestinal obstruction is a possible complication in the case of an asthenic adolescent with weight loss after surgery. We present the case of a 12-year-old girl who underwent an uncomplicated posterior spinal fusion with instrumentation for scoliosis and who developed nausea, emesis, and abdominal pain. We also discuss the origins, epidemiology, diagnosis, and treatment of superior mesenteric artery syndrome (SMAS), a rare condition. The patient’s parents provided written informed consent for print and electronic publication of this case report.

Case Report

The patient was a 12-year-old girl with juvenile idiopathic scoliosis. She was seen by a pediatric orthopedist at age 8 after her primary care physician noticed a curve in her back during her physical examination. Given her age and primary curve of 25º, magnetic resonance imaging was ordered, which was negative for syrinx, tethered cord, or bony abnormalities. An underarm thoracolumbosacral orthosis (Boston Brace) was prescribed to be worn 23 hours/day. There was inconsistent follow-up over the next 4 years, and her curve progressed to 55º (right thoracic) and 47º in the lumbar spine (Figures 1, 2). Given the magnitude of the curves, surgical intervention was recommended, because bracing would no longer be beneficial. 

The patient was healthy and appeared vibrant with no medical issues. She weighed 49 kg and her height was 162 cm (body mass index [BMI], 18.6; normal). She underwent segmental posterior spinal instrumentation, and a fusion was performed from T4 to L4 using a cobalt chrome rod. Postoperatively, there were no problems. Her diet was slowly advanced from clear liquids to regular food over 3 days. She was discharged on postoperative day 4. She had no abdominal distention, pain, or nausea. The family was instructed about pain medication (oxycodone liquid, 5 mg every 4 hours as needed) and how to prevent and treat constipation. 

Three days after discharge, her mother called to inquire about positioning because the patient was uncomfortable owing to back pain. There were no abdominal complaints, and she was taking her pain medicine every 4 hours. She was instructed to lie in a comfortable position and to ambulate several times daily. The patient took little food or fluids because of a lack of appetite and back pain. On postoperative day 8, she presented to the emergency department with complaints of generalized abdominal pain and 1 day’s emesis. The patient had not had a bowel movement postoperatively. An acute abdominal series (AAS) was obtained (Figure 3), which noted a nonobstructive bowel gas pattern, with some increased colonic fecal retention. The patient was given intravenous (IV) fluids and an IV anti-emetic, and was admitted for observation. The pediatric surgical team evaluated her and concluded her symptoms resulted from constipation. Her symptoms improved over 2 to 3 days, and she had several bowel movements on day 2 after taking polyethylene glycol, sennosides, and bisacodyl suppositories. At discharge, she was noted to be passing gas, and her abdominal examination revealed no tenderness or guarding. She had mild distention, but it had improved from the previous day. She ate breakfast and ambulated several times. She had no complaints of abdominal pain and was released home with her parents. Staff reiterated instructions regarding constipation, diet, and follow-up. Her discharge weight was 48 kg (down 1 kg) and her BMI was 17.2 (down 1.4; underweight). Her height was now 165 cm (up 3 cm). Postoperative radiographs noted stable fixation with corrected curves (Figures 4, 5).

At home, the patient ate little but continued to drink fluids. On postdischarge day 3, she developed nausea, bilious emesis, and generalized abdominal pain. She returned to the emergency department. At this point, the patient weighed 44.5 kg (down 6.6 kg since the initial surgery) and her BMI was 16.1 (down 2.5; underweight). She was admitted, and IV fluids were initiated. She had more than 1300 mL of bilious emesis. A nasogastric (NG) tube was inserted. Initial laboratory findings were unremarkable other than an increase in serum lipase of 261 U/L. Her amylase level was within normal limits. An AAS was again completed and showed a distended stomach and loop of small bowel below the liver with an air fluid level. There were also distended loops of bowel in the pelvis (Figure 6). 

A pediatric surgical consultant examined her the next morning. An upper gastrointestinal series (UGI) was obtained and showed air fluid levels in the stomach with prompt gastric emptying into a normal caliber duodenal bulb. However, with supine positioning, there was significant dilatation of the second portion of the duodenum with abrupt vertical cutoff just to the right of the spine, compatible with SMAS (Figure 7). There was reflux of contrast material into the stomach from the duodenum, with no passage of barium into the distal duodenum. After the UGI, a nasojejunal (NJ) feeding tube was placed. The tip was left at the beginning of the fourth part of the duodenum. Repeated attempts to pass the NJ feeding tube beyond the fourth part of the duodenum were unsuccessful because of massive gastric distention. The patient was taken to the operating room for placement of a Stamm gastrostomy feeding tube with insertion of a transgastric jejunal (G-J) feeding tube under fluoroscopy (Figure 5). The patient had the G-J feeding tube in place for 6 weeks to augment her enteral nutrition. As she gained weight, her duodenal emptying improved. She gradually transitioned to normal oral intake. She has done well since the G-J feeding tube was removed. 

Discussion

Von Rokitansky first described SMAS in the mid-1800s.¹ The exact pathology was further defined 60 years later when vascular involvement was determined to be the definitive mechanism of obstruction.^2-4 Superior mesenteric artery syndrome is caused by the superior mesenteric vessels compressing the third portion of the duodenum, resulting in an extrinsic obstruction. This syndrome is also commonly called Wilkie disease, after Dr. David Wilkie, who first published in 1927 results of a comprehensive series of 75 patients.¹ The syndrome is also known as arteriomesenteric duodenal compression, aortomesenteric syndrome, chronic duodenal ileus, megaduodenum, and cast syndrome.^1,4,5 The term cast syndrome was derived from events in 1878, when Willet applied a body cast to a scoliosis patient who died after what was termed “fatal vomiting.”³

Epidemiology, Incidence, and Prevalence

While not unheard of, SMAS is an uncommon disorder. There have been only 400 documented reports in the English-language literature since 1980.^5-8 Studies have stated that the incidence of the affected population is less than 0.4%.^5,7,9,10 However, SMAS has been reported to have a mortality rate as high as 33% because of the uncommon nature of the disease and prolonged duration between onset of symptoms and diagnosis.^7,9,11,12 The incidence of SMAS is higher after surgical procedures to correct spinal deformities, with rates between 0.5% and 4.7%.^10,12,13 Females are affected more frequently than males (3:2 ratio).^1,9,14 One large study with 80 patients that spanned 10 years reported that female incidence was 66%, and another study with 75 patients also observed that two-thirds of the patients were women.^1,7 This syndrome commonly affects patients who are tall and thin with an asthenic body habitus.^1,6,11,12 Superior mesenteric artery syndrome develops more commonly in younger patients. Previous studies noted that two-thirds of patients were between ages 10 and 39 years.^1,8 However, given the right set of medical conditions, it can occur in patients of any age.^2,9,15,16 In young, thin patients with scoliosis, the risk of developing SMAS after spinal fusion with instrumentation increases, given their already low weight coupled with the surgical intervention at the height of their longitudinal growth spurt.^1,11,12 

Other patients also at increased risk for developing SMAS include those with anorexia nervosa, psychiatric/emotional disorders, or drug addiction. It can also be found in persons on prolonged bedrest, those who have increased their activity and lost weight volitionally, or patients with illness or injuries, such as burns, trauma, or significant postoperative complications that decrease caloric intake and keep them in a supine position.^2,6,17 The syndrome can be acute or chronic in its presentation.

Anatomy and Physiology

The superior mesenteric artery (SMA) comes off the right anterolateral portion of the abdominal aorta, which is just anterior to the L1 vertebra. It passes over the third part of the duodenum, generally at the L2 level (Figure 8A). The duodenum passes across the aorta at the level of the L3 vertebral body and is suspended between the aorta and the SMA by the ligament of Treitz (Figure 8B).³ The angle between the aorta and SMA (aortomesenteric angle) typically ranges from 25º to 60º with an average of 45º (Figure 8A). The distance between the aorta and SMA at the level of the duodenum is called the aortomesenteric distance, and it normally measures from 10 mm to 28 mm. Obstruction is usually observed at 2 mm to 8 mm (Figure 8C).^1,3

Compression and outlet obstruction from narrowing of the SMA aortomesenteric angle can be caused by a multitude of problems.^3,5,9,17 In chronic conditions, narrowing of the aorto-mesenteric angle could be the result of a shortened ligament, or a low origin of the SMA on the aorta, or a high insertion of the duodenum at the ligament of Treitz. Postoperatively, any change in anatomy caused by adhesions could result in compression as well. Most commonly, however, in those with significant weight loss, such as postoperative spinal fusion patients, there is loss of retroperitoneal fat, which normally acts as a cushion around the duodenum. This allows the SMA to move posteriorly obstructing the duodenum. Lying in a recumbent position along with weight loss also puts patients at risk after surgery.^3,5,9,17 SMAS should be distinguished from other conditions that can cause duodenal obstruction, such as duodenal hematomas and congenital webs. 

Symptoms and Patient Presentation

Whether SMAS is acute or chronic, most patients with SMAS present in a similar fashion. Almost all patients with acute SMAS complain of abdominal pain, nausea, and emesis (usually bilious) that usually occur after eating. Early satiety is commonly observed, resulting from delayed gastric emptying. Abdominal pain may improve when patients lie prone and are in the knee-chest, or lateral decubitus, position. These patients frequently have upper abdominal distention because of massive retention of gastric contents.^4,6,16,18,19 Most spinal fusion patients present with these symptoms 7 to 10 days after surgery.^11-13

Diagnosis

Our first diagnostic tool is a comprehensive history and physical examination. Once that is complete, many radiologic tests can be used to confirm the anatomic abnormality. The first test ordered is a simple AAS, which may show a “double bubble sign” (Figure 6), indicative of duodenal obstruction.⁴ There are several other tests, and each facility and surgeon has a preference as to which is considered the “gold standard.” Upper gastrointestinal (GI) barium studies are the simplest and most reliable. The barium test shows foregut anatomy and, to some extent, function. In SMAS patients, one should see duodenal dilatation and failure of the contrast to flow past the third section of the duodenum, along with an abrupt termination of the barium column as the duodenum crosses the vertebrae. This is the traditional method of diagnosis. There is minimal radiation, and the cost is less than that of many other tests, but it can be uncomfortable for the patient.^1-4

At some institutions, an upper GI barium study is combined with angiography, which can be used to measure aortomesenteric angle and distance.^1,3 Other practitioners prefer computed tomography (CT) with 3-dimensional reconstruction, which allows for measurement of the aortomesenteric angle and distance. In 1 study, CT was found to have an extremely high sensitivity and specificity for these measurements.¹⁰ CT angiography also identifies the obstruction with increased sensitivity, but it is rarely necessary and provides more radiation exposure and increased cost.^1,6,14,19 Abdominal ultrasound has been used to measure the angle of the SMA and the aortomesenteric distance. When combined with endoscopy, this offers an alternative way to diagnose SMAS and decreases radiation exposure. However, it may require sedation or anesthesia.^7,15,17 Overall, 3 criteria are used to define whether a patient has SMAS: duodenal dilatation, an aortomesenteric angle that is less than 25º, and an SMA that is shown to be compressing the third part of the duodenum.⁵

Treatment

Conservative treatment of SMAS usually starts by removing any precipitating factors present, such as a splint or cast that was applied for scoliosis, or ending activity associated with significant weight loss. Medical management consists of IV hydration, anti-emetics, oral feeding restriction, posture therapy, and placement of an NG tube for decompression. In most cases, patients will need to have an NJ feeding tube passed distal to the site of obstruction. This provides access for enteral feeding, and patients will gradually gain weight, repleting their retroperitoneal fat stores, which pushes the SMA forward and relieves the pressure on the duodenum. Electrolyte balance should be closely monitored along with weight gain. A nutritionist is often consulted to prevent underfeeding, which can produce a slow return to weight gain, poor wound healing, and loss of lean body muscle mass; or overfeeding, which can result in hyperglycemia and respiratory failure. Once patients are stable on enteral feedings, they can begin a slow return to oral intake.^2-4,7,12 Total parental nutrition may be needed in some cases, but the risks associated with IV feeding usually outweigh the benefits.⁴ Almost all cases of acute SMAS can be successfully treated medically if diagnosed in a timely manner and supportive treatment begins promptly.⁷

Surgical intervention is rarely necessary for acute SMAS, but when conservative measures fail (after a 4- to 6-week trial), or in the presence of peptic ulcer disease or pancreatitis, this may become an appropriate option. In our patient, multiple attempts at passing an NJ feeding tube were unsuccessful, and she needed an operative procedure for insertion of a G-J feeding tube.  

Further surgical intervention is usually reserved for those patients with long-standing SMAS for whom medical management has failed or other issues, such as pancreatitis, colitis, or megaduodenum, have arisen. Many operations are described in the literature. A duodenojejunostomy to bypass the site of the obstruction is one option. Another is duodenal derotation (Strong procedure) to alter the aortomesenteric angle and place the third and fourth duodenal portions to the right of the SMA. Other procedures include a Roux-en-Y duodenojejunostomy and duodenal uncrossing. A lateral duodenojejunostomy between the second portion of the duodenum and the jejunum is considered the simplest surgical technique. It achieves successful outcomes in 90% of cases.^2-5,14 With regards to SMAS and scoliosis, it is extremely rare that this kind of surgical intervention would be necessary.

Conclusion

When planning operative spinal correction in scoliosis patients (especially females) who have a low BMI at the time of surgery and who have increased thoracic stiffness, be alert for signs and symptoms of SMAS. This rare complication can develop, and timely diagnosis and medical management will decrease morbidity and shorten the length of time needed for nutritional rehabilitation.

Posterior spinal fusion for adolescent idiopathic scoliosis is a relatively common procedure. However, intestinal obstruction is a possible complication in the case of an asthenic adolescent with weight loss after surgery. We present the case of a 12-year-old girl who underwent an uncomplicated posterior spinal fusion with instrumentation for scoliosis and who developed nausea, emesis, and abdominal pain. We also discuss the origins, epidemiology, diagnosis, and treatment of superior mesenteric artery syndrome (SMAS), a rare condition. The patient’s parents provided written informed consent for print and electronic publication of this case report.

Case Report

The patient was a 12-year-old girl with juvenile idiopathic scoliosis. She was seen by a pediatric orthopedist at age 8 after her primary care physician noticed a curve in her back during her physical examination. Given her age and primary curve of 25º, magnetic resonance imaging was ordered, which was negative for syrinx, tethered cord, or bony abnormalities. An underarm thoracolumbosacral orthosis (Boston Brace) was prescribed to be worn 23 hours/day. There was inconsistent follow-up over the next 4 years, and her curve progressed to 55º (right thoracic) and 47º in the lumbar spine (Figures 1, 2). Given the magnitude of the curves, surgical intervention was recommended, because bracing would no longer be beneficial. 

The patient was healthy and appeared vibrant with no medical issues. She weighed 49 kg and her height was 162 cm (body mass index [BMI], 18.6; normal). She underwent segmental posterior spinal instrumentation, and a fusion was performed from T4 to L4 using a cobalt chrome rod. Postoperatively, there were no problems. Her diet was slowly advanced from clear liquids to regular food over 3 days. She was discharged on postoperative day 4. She had no abdominal distention, pain, or nausea. The family was instructed about pain medication (oxycodone liquid, 5 mg every 4 hours as needed) and how to prevent and treat constipation. 

Three days after discharge, her mother called to inquire about positioning because the patient was uncomfortable owing to back pain. There were no abdominal complaints, and she was taking her pain medicine every 4 hours. She was instructed to lie in a comfortable position and to ambulate several times daily. The patient took little food or fluids because of a lack of appetite and back pain. On postoperative day 8, she presented to the emergency department with complaints of generalized abdominal pain and 1 day’s emesis. The patient had not had a bowel movement postoperatively. An acute abdominal series (AAS) was obtained (Figure 3), which noted a nonobstructive bowel gas pattern, with some increased colonic fecal retention. The patient was given intravenous (IV) fluids and an IV anti-emetic, and was admitted for observation. The pediatric surgical team evaluated her and concluded her symptoms resulted from constipation. Her symptoms improved over 2 to 3 days, and she had several bowel movements on day 2 after taking polyethylene glycol, sennosides, and bisacodyl suppositories. At discharge, she was noted to be passing gas, and her abdominal examination revealed no tenderness or guarding. She had mild distention, but it had improved from the previous day. She ate breakfast and ambulated several times. She had no complaints of abdominal pain and was released home with her parents. Staff reiterated instructions regarding constipation, diet, and follow-up. Her discharge weight was 48 kg (down 1 kg) and her BMI was 17.2 (down 1.4; underweight). Her height was now 165 cm (up 3 cm). Postoperative radiographs noted stable fixation with corrected curves (Figures 4, 5).

At home, the patient ate little but continued to drink fluids. On postdischarge day 3, she developed nausea, bilious emesis, and generalized abdominal pain. She returned to the emergency department. At this point, the patient weighed 44.5 kg (down 6.6 kg since the initial surgery) and her BMI was 16.1 (down 2.5; underweight). She was admitted, and IV fluids were initiated. She had more than 1300 mL of bilious emesis. A nasogastric (NG) tube was inserted. Initial laboratory findings were unremarkable other than an increase in serum lipase of 261 U/L. Her amylase level was within normal limits. An AAS was again completed and showed a distended stomach and loop of small bowel below the liver with an air fluid level. There were also distended loops of bowel in the pelvis (Figure 6). 

A pediatric surgical consultant examined her the next morning. An upper gastrointestinal series (UGI) was obtained and showed air fluid levels in the stomach with prompt gastric emptying into a normal caliber duodenal bulb. However, with supine positioning, there was significant dilatation of the second portion of the duodenum with abrupt vertical cutoff just to the right of the spine, compatible with SMAS (Figure 7). There was reflux of contrast material into the stomach from the duodenum, with no passage of barium into the distal duodenum. After the UGI, a nasojejunal (NJ) feeding tube was placed. The tip was left at the beginning of the fourth part of the duodenum. Repeated attempts to pass the NJ feeding tube beyond the fourth part of the duodenum were unsuccessful because of massive gastric distention. The patient was taken to the operating room for placement of a Stamm gastrostomy feeding tube with insertion of a transgastric jejunal (G-J) feeding tube under fluoroscopy (Figure 5). The patient had the G-J feeding tube in place for 6 weeks to augment her enteral nutrition. As she gained weight, her duodenal emptying improved. She gradually transitioned to normal oral intake. She has done well since the G-J feeding tube was removed. 

Discussion

Von Rokitansky first described SMAS in the mid-1800s.¹ The exact pathology was further defined 60 years later when vascular involvement was determined to be the definitive mechanism of obstruction.^2-4 Superior mesenteric artery syndrome is caused by the superior mesenteric vessels compressing the third portion of the duodenum, resulting in an extrinsic obstruction. This syndrome is also commonly called Wilkie disease, after Dr. David Wilkie, who first published in 1927 results of a comprehensive series of 75 patients.¹ The syndrome is also known as arteriomesenteric duodenal compression, aortomesenteric syndrome, chronic duodenal ileus, megaduodenum, and cast syndrome.^1,4,5 The term cast syndrome was derived from events in 1878, when Willet applied a body cast to a scoliosis patient who died after what was termed “fatal vomiting.”³

Epidemiology, Incidence, and Prevalence

While not unheard of, SMAS is an uncommon disorder. There have been only 400 documented reports in the English-language literature since 1980.^5-8 Studies have stated that the incidence of the affected population is less than 0.4%.^5,7,9,10 However, SMAS has been reported to have a mortality rate as high as 33% because of the uncommon nature of the disease and prolonged duration between onset of symptoms and diagnosis.^7,9,11,12 The incidence of SMAS is higher after surgical procedures to correct spinal deformities, with rates between 0.5% and 4.7%.^10,12,13 Females are affected more frequently than males (3:2 ratio).^1,9,14 One large study with 80 patients that spanned 10 years reported that female incidence was 66%, and another study with 75 patients also observed that two-thirds of the patients were women.^1,7 This syndrome commonly affects patients who are tall and thin with an asthenic body habitus.^1,6,11,12 Superior mesenteric artery syndrome develops more commonly in younger patients. Previous studies noted that two-thirds of patients were between ages 10 and 39 years.^1,8 However, given the right set of medical conditions, it can occur in patients of any age.^2,9,15,16 In young, thin patients with scoliosis, the risk of developing SMAS after spinal fusion with instrumentation increases, given their already low weight coupled with the surgical intervention at the height of their longitudinal growth spurt.^1,11,12 

Other patients also at increased risk for developing SMAS include those with anorexia nervosa, psychiatric/emotional disorders, or drug addiction. It can also be found in persons on prolonged bedrest, those who have increased their activity and lost weight volitionally, or patients with illness or injuries, such as burns, trauma, or significant postoperative complications that decrease caloric intake and keep them in a supine position.^2,6,17 The syndrome can be acute or chronic in its presentation.

Anatomy and Physiology

The superior mesenteric artery (SMA) comes off the right anterolateral portion of the abdominal aorta, which is just anterior to the L1 vertebra. It passes over the third part of the duodenum, generally at the L2 level (Figure 8A). The duodenum passes across the aorta at the level of the L3 vertebral body and is suspended between the aorta and the SMA by the ligament of Treitz (Figure 8B).³ The angle between the aorta and SMA (aortomesenteric angle) typically ranges from 25º to 60º with an average of 45º (Figure 8A). The distance between the aorta and SMA at the level of the duodenum is called the aortomesenteric distance, and it normally measures from 10 mm to 28 mm. Obstruction is usually observed at 2 mm to 8 mm (Figure 8C).^1,3

Compression and outlet obstruction from narrowing of the SMA aortomesenteric angle can be caused by a multitude of problems.^3,5,9,17 In chronic conditions, narrowing of the aorto-mesenteric angle could be the result of a shortened ligament, or a low origin of the SMA on the aorta, or a high insertion of the duodenum at the ligament of Treitz. Postoperatively, any change in anatomy caused by adhesions could result in compression as well. Most commonly, however, in those with significant weight loss, such as postoperative spinal fusion patients, there is loss of retroperitoneal fat, which normally acts as a cushion around the duodenum. This allows the SMA to move posteriorly obstructing the duodenum. Lying in a recumbent position along with weight loss also puts patients at risk after surgery.^3,5,9,17 SMAS should be distinguished from other conditions that can cause duodenal obstruction, such as duodenal hematomas and congenital webs. 

Symptoms and Patient Presentation

Whether SMAS is acute or chronic, most patients with SMAS present in a similar fashion. Almost all patients with acute SMAS complain of abdominal pain, nausea, and emesis (usually bilious) that usually occur after eating. Early satiety is commonly observed, resulting from delayed gastric emptying. Abdominal pain may improve when patients lie prone and are in the knee-chest, or lateral decubitus, position. These patients frequently have upper abdominal distention because of massive retention of gastric contents.^4,6,16,18,19 Most spinal fusion patients present with these symptoms 7 to 10 days after surgery.^11-13

Diagnosis

Our first diagnostic tool is a comprehensive history and physical examination. Once that is complete, many radiologic tests can be used to confirm the anatomic abnormality. The first test ordered is a simple AAS, which may show a “double bubble sign” (Figure 6), indicative of duodenal obstruction.⁴ There are several other tests, and each facility and surgeon has a preference as to which is considered the “gold standard.” Upper gastrointestinal (GI) barium studies are the simplest and most reliable. The barium test shows foregut anatomy and, to some extent, function. In SMAS patients, one should see duodenal dilatation and failure of the contrast to flow past the third section of the duodenum, along with an abrupt termination of the barium column as the duodenum crosses the vertebrae. This is the traditional method of diagnosis. There is minimal radiation, and the cost is less than that of many other tests, but it can be uncomfortable for the patient.^1-4

At some institutions, an upper GI barium study is combined with angiography, which can be used to measure aortomesenteric angle and distance.^1,3 Other practitioners prefer computed tomography (CT) with 3-dimensional reconstruction, which allows for measurement of the aortomesenteric angle and distance. In 1 study, CT was found to have an extremely high sensitivity and specificity for these measurements.¹⁰ CT angiography also identifies the obstruction with increased sensitivity, but it is rarely necessary and provides more radiation exposure and increased cost.^1,6,14,19 Abdominal ultrasound has been used to measure the angle of the SMA and the aortomesenteric distance. When combined with endoscopy, this offers an alternative way to diagnose SMAS and decreases radiation exposure. However, it may require sedation or anesthesia.^7,15,17 Overall, 3 criteria are used to define whether a patient has SMAS: duodenal dilatation, an aortomesenteric angle that is less than 25º, and an SMA that is shown to be compressing the third part of the duodenum.⁵

Treatment

Conservative treatment of SMAS usually starts by removing any precipitating factors present, such as a splint or cast that was applied for scoliosis, or ending activity associated with significant weight loss. Medical management consists of IV hydration, anti-emetics, oral feeding restriction, posture therapy, and placement of an NG tube for decompression. In most cases, patients will need to have an NJ feeding tube passed distal to the site of obstruction. This provides access for enteral feeding, and patients will gradually gain weight, repleting their retroperitoneal fat stores, which pushes the SMA forward and relieves the pressure on the duodenum. Electrolyte balance should be closely monitored along with weight gain. A nutritionist is often consulted to prevent underfeeding, which can produce a slow return to weight gain, poor wound healing, and loss of lean body muscle mass; or overfeeding, which can result in hyperglycemia and respiratory failure. Once patients are stable on enteral feedings, they can begin a slow return to oral intake.^2-4,7,12 Total parental nutrition may be needed in some cases, but the risks associated with IV feeding usually outweigh the benefits.⁴ Almost all cases of acute SMAS can be successfully treated medically if diagnosed in a timely manner and supportive treatment begins promptly.⁷

Surgical intervention is rarely necessary for acute SMAS, but when conservative measures fail (after a 4- to 6-week trial), or in the presence of peptic ulcer disease or pancreatitis, this may become an appropriate option. In our patient, multiple attempts at passing an NJ feeding tube were unsuccessful, and she needed an operative procedure for insertion of a G-J feeding tube.  

Further surgical intervention is usually reserved for those patients with long-standing SMAS for whom medical management has failed or other issues, such as pancreatitis, colitis, or megaduodenum, have arisen. Many operations are described in the literature. A duodenojejunostomy to bypass the site of the obstruction is one option. Another is duodenal derotation (Strong procedure) to alter the aortomesenteric angle and place the third and fourth duodenal portions to the right of the SMA. Other procedures include a Roux-en-Y duodenojejunostomy and duodenal uncrossing. A lateral duodenojejunostomy between the second portion of the duodenum and the jejunum is considered the simplest surgical technique. It achieves successful outcomes in 90% of cases.^2-5,14 With regards to SMAS and scoliosis, it is extremely rare that this kind of surgical intervention would be necessary.

Conclusion

When planning operative spinal correction in scoliosis patients (especially females) who have a low BMI at the time of surgery and who have increased thoracic stiffness, be alert for signs and symptoms of SMAS. This rare complication can develop, and timely diagnosis and medical management will decrease morbidity and shorten the length of time needed for nutritional rehabilitation.

Posterior spinal fusion for adolescent idiopathic scoliosis is a relatively common procedure. However, intestinal obstruction is a possible complication in the case of an asthenic adolescent with weight loss after surgery. We present the case of a 12-year-old girl who underwent an uncomplicated posterior spinal fusion with instrumentation for scoliosis and who developed nausea, emesis, and abdominal pain. We also discuss the origins, epidemiology, diagnosis, and treatment of superior mesenteric artery syndrome (SMAS), a rare condition. The patient’s parents provided written informed consent for print and electronic publication of this case report.

Case Report

The patient was a 12-year-old girl with juvenile idiopathic scoliosis. She was seen by a pediatric orthopedist at age 8 after her primary care physician noticed a curve in her back during her physical examination. Given her age and primary curve of 25º, magnetic resonance imaging was ordered, which was negative for syrinx, tethered cord, or bony abnormalities. An underarm thoracolumbosacral orthosis (Boston Brace) was prescribed to be worn 23 hours/day. There was inconsistent follow-up over the next 4 years, and her curve progressed to 55º (right thoracic) and 47º in the lumbar spine (Figures 1, 2). Given the magnitude of the curves, surgical intervention was recommended, because bracing would no longer be beneficial. 

The patient was healthy and appeared vibrant with no medical issues. She weighed 49 kg and her height was 162 cm (body mass index [BMI], 18.6; normal). She underwent segmental posterior spinal instrumentation, and a fusion was performed from T4 to L4 using a cobalt chrome rod. Postoperatively, there were no problems. Her diet was slowly advanced from clear liquids to regular food over 3 days. She was discharged on postoperative day 4. She had no abdominal distention, pain, or nausea. The family was instructed about pain medication (oxycodone liquid, 5 mg every 4 hours as needed) and how to prevent and treat constipation. 

Three days after discharge, her mother called to inquire about positioning because the patient was uncomfortable owing to back pain. There were no abdominal complaints, and she was taking her pain medicine every 4 hours. She was instructed to lie in a comfortable position and to ambulate several times daily. The patient took little food or fluids because of a lack of appetite and back pain. On postoperative day 8, she presented to the emergency department with complaints of generalized abdominal pain and 1 day’s emesis. The patient had not had a bowel movement postoperatively. An acute abdominal series (AAS) was obtained (Figure 3), which noted a nonobstructive bowel gas pattern, with some increased colonic fecal retention. The patient was given intravenous (IV) fluids and an IV anti-emetic, and was admitted for observation. The pediatric surgical team evaluated her and concluded her symptoms resulted from constipation. Her symptoms improved over 2 to 3 days, and she had several bowel movements on day 2 after taking polyethylene glycol, sennosides, and bisacodyl suppositories. At discharge, she was noted to be passing gas, and her abdominal examination revealed no tenderness or guarding. She had mild distention, but it had improved from the previous day. She ate breakfast and ambulated several times. She had no complaints of abdominal pain and was released home with her parents. Staff reiterated instructions regarding constipation, diet, and follow-up. Her discharge weight was 48 kg (down 1 kg) and her BMI was 17.2 (down 1.4; underweight). Her height was now 165 cm (up 3 cm). Postoperative radiographs noted stable fixation with corrected curves (Figures 4, 5).

At home, the patient ate little but continued to drink fluids. On postdischarge day 3, she developed nausea, bilious emesis, and generalized abdominal pain. She returned to the emergency department. At this point, the patient weighed 44.5 kg (down 6.6 kg since the initial surgery) and her BMI was 16.1 (down 2.5; underweight). She was admitted, and IV fluids were initiated. She had more than 1300 mL of bilious emesis. A nasogastric (NG) tube was inserted. Initial laboratory findings were unremarkable other than an increase in serum lipase of 261 U/L. Her amylase level was within normal limits. An AAS was again completed and showed a distended stomach and loop of small bowel below the liver with an air fluid level. There were also distended loops of bowel in the pelvis (Figure 6). 

A pediatric surgical consultant examined her the next morning. An upper gastrointestinal series (UGI) was obtained and showed air fluid levels in the stomach with prompt gastric emptying into a normal caliber duodenal bulb. However, with supine positioning, there was significant dilatation of the second portion of the duodenum with abrupt vertical cutoff just to the right of the spine, compatible with SMAS (Figure 7). There was reflux of contrast material into the stomach from the duodenum, with no passage of barium into the distal duodenum. After the UGI, a nasojejunal (NJ) feeding tube was placed. The tip was left at the beginning of the fourth part of the duodenum. Repeated attempts to pass the NJ feeding tube beyond the fourth part of the duodenum were unsuccessful because of massive gastric distention. The patient was taken to the operating room for placement of a Stamm gastrostomy feeding tube with insertion of a transgastric jejunal (G-J) feeding tube under fluoroscopy (Figure 5). The patient had the G-J feeding tube in place for 6 weeks to augment her enteral nutrition. As she gained weight, her duodenal emptying improved. She gradually transitioned to normal oral intake. She has done well since the G-J feeding tube was removed. 

Discussion

Von Rokitansky first described SMAS in the mid-1800s.¹ The exact pathology was further defined 60 years later when vascular involvement was determined to be the definitive mechanism of obstruction.^2-4 Superior mesenteric artery syndrome is caused by the superior mesenteric vessels compressing the third portion of the duodenum, resulting in an extrinsic obstruction. This syndrome is also commonly called Wilkie disease, after Dr. David Wilkie, who first published in 1927 results of a comprehensive series of 75 patients.¹ The syndrome is also known as arteriomesenteric duodenal compression, aortomesenteric syndrome, chronic duodenal ileus, megaduodenum, and cast syndrome.^1,4,5 The term cast syndrome was derived from events in 1878, when Willet applied a body cast to a scoliosis patient who died after what was termed “fatal vomiting.”³

Epidemiology, Incidence, and Prevalence

While not unheard of, SMAS is an uncommon disorder. There have been only 400 documented reports in the English-language literature since 1980.^5-8 Studies have stated that the incidence of the affected population is less than 0.4%.^5,7,9,10 However, SMAS has been reported to have a mortality rate as high as 33% because of the uncommon nature of the disease and prolonged duration between onset of symptoms and diagnosis.^7,9,11,12 The incidence of SMAS is higher after surgical procedures to correct spinal deformities, with rates between 0.5% and 4.7%.^10,12,13 Females are affected more frequently than males (3:2 ratio).^1,9,14 One large study with 80 patients that spanned 10 years reported that female incidence was 66%, and another study with 75 patients also observed that two-thirds of the patients were women.^1,7 This syndrome commonly affects patients who are tall and thin with an asthenic body habitus.^1,6,11,12 Superior mesenteric artery syndrome develops more commonly in younger patients. Previous studies noted that two-thirds of patients were between ages 10 and 39 years.^1,8 However, given the right set of medical conditions, it can occur in patients of any age.^2,9,15,16 In young, thin patients with scoliosis, the risk of developing SMAS after spinal fusion with instrumentation increases, given their already low weight coupled with the surgical intervention at the height of their longitudinal growth spurt.^1,11,12 

Other patients also at increased risk for developing SMAS include those with anorexia nervosa, psychiatric/emotional disorders, or drug addiction. It can also be found in persons on prolonged bedrest, those who have increased their activity and lost weight volitionally, or patients with illness or injuries, such as burns, trauma, or significant postoperative complications that decrease caloric intake and keep them in a supine position.^2,6,17 The syndrome can be acute or chronic in its presentation.

Anatomy and Physiology

The superior mesenteric artery (SMA) comes off the right anterolateral portion of the abdominal aorta, which is just anterior to the L1 vertebra. It passes over the third part of the duodenum, generally at the L2 level (Figure 8A). The duodenum passes across the aorta at the level of the L3 vertebral body and is suspended between the aorta and the SMA by the ligament of Treitz (Figure 8B).³ The angle between the aorta and SMA (aortomesenteric angle) typically ranges from 25º to 60º with an average of 45º (Figure 8A). The distance between the aorta and SMA at the level of the duodenum is called the aortomesenteric distance, and it normally measures from 10 mm to 28 mm. Obstruction is usually observed at 2 mm to 8 mm (Figure 8C).^1,3

Compression and outlet obstruction from narrowing of the SMA aortomesenteric angle can be caused by a multitude of problems.^3,5,9,17 In chronic conditions, narrowing of the aorto-mesenteric angle could be the result of a shortened ligament, or a low origin of the SMA on the aorta, or a high insertion of the duodenum at the ligament of Treitz. Postoperatively, any change in anatomy caused by adhesions could result in compression as well. Most commonly, however, in those with significant weight loss, such as postoperative spinal fusion patients, there is loss of retroperitoneal fat, which normally acts as a cushion around the duodenum. This allows the SMA to move posteriorly obstructing the duodenum. Lying in a recumbent position along with weight loss also puts patients at risk after surgery.^3,5,9,17 SMAS should be distinguished from other conditions that can cause duodenal obstruction, such as duodenal hematomas and congenital webs. 

Symptoms and Patient Presentation

Whether SMAS is acute or chronic, most patients with SMAS present in a similar fashion. Almost all patients with acute SMAS complain of abdominal pain, nausea, and emesis (usually bilious) that usually occur after eating. Early satiety is commonly observed, resulting from delayed gastric emptying. Abdominal pain may improve when patients lie prone and are in the knee-chest, or lateral decubitus, position. These patients frequently have upper abdominal distention because of massive retention of gastric contents.^4,6,16,18,19 Most spinal fusion patients present with these symptoms 7 to 10 days after surgery.^11-13

Diagnosis

Our first diagnostic tool is a comprehensive history and physical examination. Once that is complete, many radiologic tests can be used to confirm the anatomic abnormality. The first test ordered is a simple AAS, which may show a “double bubble sign” (Figure 6), indicative of duodenal obstruction.⁴ There are several other tests, and each facility and surgeon has a preference as to which is considered the “gold standard.” Upper gastrointestinal (GI) barium studies are the simplest and most reliable. The barium test shows foregut anatomy and, to some extent, function. In SMAS patients, one should see duodenal dilatation and failure of the contrast to flow past the third section of the duodenum, along with an abrupt termination of the barium column as the duodenum crosses the vertebrae. This is the traditional method of diagnosis. There is minimal radiation, and the cost is less than that of many other tests, but it can be uncomfortable for the patient.^1-4

At some institutions, an upper GI barium study is combined with angiography, which can be used to measure aortomesenteric angle and distance.^1,3 Other practitioners prefer computed tomography (CT) with 3-dimensional reconstruction, which allows for measurement of the aortomesenteric angle and distance. In 1 study, CT was found to have an extremely high sensitivity and specificity for these measurements.¹⁰ CT angiography also identifies the obstruction with increased sensitivity, but it is rarely necessary and provides more radiation exposure and increased cost.^1,6,14,19 Abdominal ultrasound has been used to measure the angle of the SMA and the aortomesenteric distance. When combined with endoscopy, this offers an alternative way to diagnose SMAS and decreases radiation exposure. However, it may require sedation or anesthesia.^7,15,17 Overall, 3 criteria are used to define whether a patient has SMAS: duodenal dilatation, an aortomesenteric angle that is less than 25º, and an SMA that is shown to be compressing the third part of the duodenum.⁵

Treatment

Conservative treatment of SMAS usually starts by removing any precipitating factors present, such as a splint or cast that was applied for scoliosis, or ending activity associated with significant weight loss. Medical management consists of IV hydration, anti-emetics, oral feeding restriction, posture therapy, and placement of an NG tube for decompression. In most cases, patients will need to have an NJ feeding tube passed distal to the site of obstruction. This provides access for enteral feeding, and patients will gradually gain weight, repleting their retroperitoneal fat stores, which pushes the SMA forward and relieves the pressure on the duodenum. Electrolyte balance should be closely monitored along with weight gain. A nutritionist is often consulted to prevent underfeeding, which can produce a slow return to weight gain, poor wound healing, and loss of lean body muscle mass; or overfeeding, which can result in hyperglycemia and respiratory failure. Once patients are stable on enteral feedings, they can begin a slow return to oral intake.^2-4,7,12 Total parental nutrition may be needed in some cases, but the risks associated with IV feeding usually outweigh the benefits.⁴ Almost all cases of acute SMAS can be successfully treated medically if diagnosed in a timely manner and supportive treatment begins promptly.⁷

Surgical intervention is rarely necessary for acute SMAS, but when conservative measures fail (after a 4- to 6-week trial), or in the presence of peptic ulcer disease or pancreatitis, this may become an appropriate option. In our patient, multiple attempts at passing an NJ feeding tube were unsuccessful, and she needed an operative procedure for insertion of a G-J feeding tube.  

Further surgical intervention is usually reserved for those patients with long-standing SMAS for whom medical management has failed or other issues, such as pancreatitis, colitis, or megaduodenum, have arisen. Many operations are described in the literature. A duodenojejunostomy to bypass the site of the obstruction is one option. Another is duodenal derotation (Strong procedure) to alter the aortomesenteric angle and place the third and fourth duodenal portions to the right of the SMA. Other procedures include a Roux-en-Y duodenojejunostomy and duodenal uncrossing. A lateral duodenojejunostomy between the second portion of the duodenum and the jejunum is considered the simplest surgical technique. It achieves successful outcomes in 90% of cases.^2-5,14 With regards to SMAS and scoliosis, it is extremely rare that this kind of surgical intervention would be necessary.

Conclusion

When planning operative spinal correction in scoliosis patients (especially females) who have a low BMI at the time of surgery and who have increased thoracic stiffness, be alert for signs and symptoms of SMAS. This rare complication can develop, and timely diagnosis and medical management will decrease morbidity and shorten the length of time needed for nutritional rehabilitation.

Isolated dislocation of the carpometacarpal (CMC) joint of the hand is a rare injury. While the dislocation can be dorsal or palmar, dorsal dislocation is more common. Palmar dislocations can be either ulnopalmar or radiopalmar. There are very few reports of isolated radiopalmar dislocations of the fifth CMC joint in the English-language literature.^1-3 We present a case of delayed presentation and management of radiopalmar dislocation of the fifth CMC joint. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 42-year-old man presented with polytrauma to our emergency department. He was stabilized initially, and open fractures were treated by débridement and external fixator application. During an examination 3 days after admission, swelling was noted in the right hand. On further study, there was splaying of the fifth digit and tenderness over the fourth and fifth CMC joints (Figure 1). No abnormal mobility or crepitus could be elicited. Plain radiographs of the right hand in anteroposterior and lateral views revealed radiopalmar dislocation of the fifth CMC joint (Figure 2). It was decided to reduce the dislocation immediately after the patient was declared fit for surgery.

Under axillary block, closed reduction was unsuccessful. Open reduction of the fifth CMC joint was performed through a dorsal incision. The base of the fifth metacarpal bone was found to be stripped of soft-tissue attachments and lying in a radiopalmar location. Reduction, which was checked under image intensifier, was found to be satisfactory (Figure 3). Reduction was stabilized by passing a smooth Kirschner wire (K-wire) from the fifth metacarpal to the hamate bone. After achieving hemostasis, the wound was closed in layers and a below-elbow splint was applied. The perioperative period was uneventful, and sutures were removed on postoperative day 10. The K-wire was removed after 4 weeks, and radiographs showed satisfactory position of the fifth CMC joint. Gentle active and passive mobilization of fingers and wrist were started. The patient had regained good function of the wrist and fingers 2 months after surgery (Figure 4).

Discussion

Carpometacarpal joint dislocations are uncommon injuries and account for less than 1% of hand injuries.⁴ They are classified as dorsal and volar (palmar) dislocations. Dorsal dislocations of the CMC joints occur more frequently than do volar dislocations, mainly affecting the fourth and fifth digits.⁵ Isolated volar or palmar dislocation of the fifth CMC joint is an uncommon injury that was first reported in 1918 by McWhorter.⁶ In 1968, Nalebuff⁷ classified the volar dislocations into 2 groups according to the direction of the displacement of the fifth metacarpal base: radiopalmar and ulnopalmar. Berg and Murphy⁸ found the hook of the hamate to deviate the metacarpal bone to either the ulnar or radial side. Tearing of all ligament and tendon attachments of the base of the fifth metacarpal results in radiopalmar dislocation.⁷ The attachments of ligaments and tendons remain intact in the ulnopalmar dislocation.⁷

The clinical features of this injury are pain and swelling about the base of the fifth metacarpal and axial deformity of the little finger with apparent shortening. The deep motor branch of the ulnar nerve lies volar to the fifth CMC joint as it courses around the hook of the hamate. It is vulnerable to injury in both dorsal^9,10 and volar¹¹ CMC dislocations. For radiologic evaluation, in addition to standard anteroposterior and lateral radiographs, a lateral view in 30º pronation of the hand can provide an improved view of the fifth CMC joint, as suggested by Bora and Didizian.¹²

The treatment of ulnopalmar dislocation has evolved. Ulnopalmar dislocations have been successfully treated by closed reduction without fixation,⁸ and by open reduction and K-wire fixation.^3,7,13

Radiopalmar dislocations are inherently unstable because of the tearing of all ligament and tendon attachments of the base of the fifth metacarpal.⁷ In our case of radiopalmar dislocation, diagnosis was delayed and attempts at closed reduction were unsuccessful. Therefore, it was treated by open reduction and K-wire fixation. In our case, open reduction and K-wire fixation for radiopalmar dislocation of the fifth CMC joint provided promising results.

Conclusion

Radiopalmar dislocation of the fifth CMC joint is a rare injury, and very few cases have been reported in the English-language literature. We report one such case, which was successfully treated with open reduction and K-wire fixation.

Isolated dislocation of the carpometacarpal (CMC) joint of the hand is a rare injury. While the dislocation can be dorsal or palmar, dorsal dislocation is more common. Palmar dislocations can be either ulnopalmar or radiopalmar. There are very few reports of isolated radiopalmar dislocations of the fifth CMC joint in the English-language literature.^1-3 We present a case of delayed presentation and management of radiopalmar dislocation of the fifth CMC joint. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 42-year-old man presented with polytrauma to our emergency department. He was stabilized initially, and open fractures were treated by débridement and external fixator application. During an examination 3 days after admission, swelling was noted in the right hand. On further study, there was splaying of the fifth digit and tenderness over the fourth and fifth CMC joints (Figure 1). No abnormal mobility or crepitus could be elicited. Plain radiographs of the right hand in anteroposterior and lateral views revealed radiopalmar dislocation of the fifth CMC joint (Figure 2). It was decided to reduce the dislocation immediately after the patient was declared fit for surgery.

Under axillary block, closed reduction was unsuccessful. Open reduction of the fifth CMC joint was performed through a dorsal incision. The base of the fifth metacarpal bone was found to be stripped of soft-tissue attachments and lying in a radiopalmar location. Reduction, which was checked under image intensifier, was found to be satisfactory (Figure 3). Reduction was stabilized by passing a smooth Kirschner wire (K-wire) from the fifth metacarpal to the hamate bone. After achieving hemostasis, the wound was closed in layers and a below-elbow splint was applied. The perioperative period was uneventful, and sutures were removed on postoperative day 10. The K-wire was removed after 4 weeks, and radiographs showed satisfactory position of the fifth CMC joint. Gentle active and passive mobilization of fingers and wrist were started. The patient had regained good function of the wrist and fingers 2 months after surgery (Figure 4).

Discussion

Carpometacarpal joint dislocations are uncommon injuries and account for less than 1% of hand injuries.⁴ They are classified as dorsal and volar (palmar) dislocations. Dorsal dislocations of the CMC joints occur more frequently than do volar dislocations, mainly affecting the fourth and fifth digits.⁵ Isolated volar or palmar dislocation of the fifth CMC joint is an uncommon injury that was first reported in 1918 by McWhorter.⁶ In 1968, Nalebuff⁷ classified the volar dislocations into 2 groups according to the direction of the displacement of the fifth metacarpal base: radiopalmar and ulnopalmar. Berg and Murphy⁸ found the hook of the hamate to deviate the metacarpal bone to either the ulnar or radial side. Tearing of all ligament and tendon attachments of the base of the fifth metacarpal results in radiopalmar dislocation.⁷ The attachments of ligaments and tendons remain intact in the ulnopalmar dislocation.⁷

The clinical features of this injury are pain and swelling about the base of the fifth metacarpal and axial deformity of the little finger with apparent shortening. The deep motor branch of the ulnar nerve lies volar to the fifth CMC joint as it courses around the hook of the hamate. It is vulnerable to injury in both dorsal^9,10 and volar¹¹ CMC dislocations. For radiologic evaluation, in addition to standard anteroposterior and lateral radiographs, a lateral view in 30º pronation of the hand can provide an improved view of the fifth CMC joint, as suggested by Bora and Didizian.¹²

The treatment of ulnopalmar dislocation has evolved. Ulnopalmar dislocations have been successfully treated by closed reduction without fixation,⁸ and by open reduction and K-wire fixation.^3,7,13

Radiopalmar dislocations are inherently unstable because of the tearing of all ligament and tendon attachments of the base of the fifth metacarpal.⁷ In our case of radiopalmar dislocation, diagnosis was delayed and attempts at closed reduction were unsuccessful. Therefore, it was treated by open reduction and K-wire fixation. In our case, open reduction and K-wire fixation for radiopalmar dislocation of the fifth CMC joint provided promising results.

Conclusion

Radiopalmar dislocation of the fifth CMC joint is a rare injury, and very few cases have been reported in the English-language literature. We report one such case, which was successfully treated with open reduction and K-wire fixation.

Isolated dislocation of the carpometacarpal (CMC) joint of the hand is a rare injury. While the dislocation can be dorsal or palmar, dorsal dislocation is more common. Palmar dislocations can be either ulnopalmar or radiopalmar. There are very few reports of isolated radiopalmar dislocations of the fifth CMC joint in the English-language literature.^1-3 We present a case of delayed presentation and management of radiopalmar dislocation of the fifth CMC joint. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 42-year-old man presented with polytrauma to our emergency department. He was stabilized initially, and open fractures were treated by débridement and external fixator application. During an examination 3 days after admission, swelling was noted in the right hand. On further study, there was splaying of the fifth digit and tenderness over the fourth and fifth CMC joints (Figure 1). No abnormal mobility or crepitus could be elicited. Plain radiographs of the right hand in anteroposterior and lateral views revealed radiopalmar dislocation of the fifth CMC joint (Figure 2). It was decided to reduce the dislocation immediately after the patient was declared fit for surgery.

Under axillary block, closed reduction was unsuccessful. Open reduction of the fifth CMC joint was performed through a dorsal incision. The base of the fifth metacarpal bone was found to be stripped of soft-tissue attachments and lying in a radiopalmar location. Reduction, which was checked under image intensifier, was found to be satisfactory (Figure 3). Reduction was stabilized by passing a smooth Kirschner wire (K-wire) from the fifth metacarpal to the hamate bone. After achieving hemostasis, the wound was closed in layers and a below-elbow splint was applied. The perioperative period was uneventful, and sutures were removed on postoperative day 10. The K-wire was removed after 4 weeks, and radiographs showed satisfactory position of the fifth CMC joint. Gentle active and passive mobilization of fingers and wrist were started. The patient had regained good function of the wrist and fingers 2 months after surgery (Figure 4).

Discussion

Carpometacarpal joint dislocations are uncommon injuries and account for less than 1% of hand injuries.⁴ They are classified as dorsal and volar (palmar) dislocations. Dorsal dislocations of the CMC joints occur more frequently than do volar dislocations, mainly affecting the fourth and fifth digits.⁵ Isolated volar or palmar dislocation of the fifth CMC joint is an uncommon injury that was first reported in 1918 by McWhorter.⁶ In 1968, Nalebuff⁷ classified the volar dislocations into 2 groups according to the direction of the displacement of the fifth metacarpal base: radiopalmar and ulnopalmar. Berg and Murphy⁸ found the hook of the hamate to deviate the metacarpal bone to either the ulnar or radial side. Tearing of all ligament and tendon attachments of the base of the fifth metacarpal results in radiopalmar dislocation.⁷ The attachments of ligaments and tendons remain intact in the ulnopalmar dislocation.⁷

The clinical features of this injury are pain and swelling about the base of the fifth metacarpal and axial deformity of the little finger with apparent shortening. The deep motor branch of the ulnar nerve lies volar to the fifth CMC joint as it courses around the hook of the hamate. It is vulnerable to injury in both dorsal^9,10 and volar¹¹ CMC dislocations. For radiologic evaluation, in addition to standard anteroposterior and lateral radiographs, a lateral view in 30º pronation of the hand can provide an improved view of the fifth CMC joint, as suggested by Bora and Didizian.¹²

The treatment of ulnopalmar dislocation has evolved. Ulnopalmar dislocations have been successfully treated by closed reduction without fixation,⁸ and by open reduction and K-wire fixation.^3,7,13

Radiopalmar dislocations are inherently unstable because of the tearing of all ligament and tendon attachments of the base of the fifth metacarpal.⁷ In our case of radiopalmar dislocation, diagnosis was delayed and attempts at closed reduction were unsuccessful. Therefore, it was treated by open reduction and K-wire fixation. In our case, open reduction and K-wire fixation for radiopalmar dislocation of the fifth CMC joint provided promising results.

Conclusion

Radiopalmar dislocation of the fifth CMC joint is a rare injury, and very few cases have been reported in the English-language literature. We report one such case, which was successfully treated with open reduction and K-wire fixation.

Ollier disease, or multiple enchondromatosis, is a rare nonfamilial condition characterized by multiple cartilaginous tumors often beginning in early childhood. There is significant variation in disease distribution, location, size, number of lesions, and behavior, but the tumors are often located unilaterally.¹ Enchondromas are most commonly found in the metacarpals, metatarsals, and phalanges, and develop from metaphyseal bone in close proximity to the physis. They frequently present as painless masses or are incidentally noted during the evaluation of another musculoskeletal condition. Radiographically, enchondromas of the hands and feet appear as oval radiolucencies with thinned, sclerotic rims. The lesions have varying degrees of mineralization and endosteal scalloping, and may expand the bone.² Enchondromas usually enlarge until skeletal maturity and have been observed to ossify spontaneously.^1,3 The clinical course of Ollier disease is variable, and a number of cases of significant hand deformity and malignant transformation have been reported.^4-6

In this case report, we present a mild form of Ollier disease isolated to the patient’s left hand, which we followed for 8 years, demonstrating part of the natural history of these lesions. We discuss the patient’s clinical features, radiologic findings, diagnosis, treatment, prognosis, and follow-up, as well as review the literature. The patient and the patient’s family provided written informed consent for print and electronic publication of this case report.

Case Report

A 10-year-old, right-handed girl was referred to our department for the evaluation of left-hand masses. At age 3 years, the patient underwent a chondroma excision from the middle phalanx of her middle finger on her left hand. No operative or pathology report was available from this surgery, and the patient tolerated the procedure well without any complications. At the time of presentation, the masses did not cause any pain, motor or sensory dysfunction, or any systemic symptoms. No history of recent or distant trauma was elicited. The patient’s medical and family history was unremarkable.

On physical examination, there was a firm, immobile, nontender palpable mass over the dorsal aspect of the distal second metacarpal bone of the left hand. The mass extended medially between the second and third metacarpals. A second small, firm, nontender left-hand mass was palpated over the volar aspect of her proximal phalanx on her index finger. She was neurovascularly intact with full active range of motion of the metacarpophalangeal and proximal and distal interphalangeal joints. There was no angular deformity of the digits. Plain radiographs taken at the time of initial presentation showed a 2.3×1.7-cm radiolucent lesion located in the metaphysis and diaphysis of the second metacarpal of the left hand (Figures 1A-1C). The lesion had varying degrees of mineralization with cortical thinning and expansion in the volar, dorsal, radial, and ulnar directions, consistent with a chondroid lesion. The second and third lesions were oval radiolucencies with sclerotic rims located at the metaphyseal-diaphyseal junction of the proximal phalanx of the index finger and middle phalanx of the middle finger, respectively. No fractures were identified in the radiographs, and the physes were open at this time. The patient was diagnosed with multiple enchondromatosis, or Ollier disease.

Our case showed 1 episode of pain and tenderness to palpation at the second proximal phalanx approximately 6 months after initial presentation. We attributed the pain and tenderness to a small pathologic fracture but did not see radiographic evidence of this. We elected to provide a trial of supportive measures, such as splinting and buddy taping, and to monitor the pain with a tentative plan of open biopsy with curettage and bone grafting if the pain persisted or evidence of fracture was seen on radiographs. The pain and tenderness to palpation resolved at a follow-up visit, and the surgery was deferred.

The patient was treated nonoperatively at initial presentation given the lack of significant cosmetic deformity or functional compromise and was advised close follow-up at 3 and 6 months. Given the absence of disease progression, annual checks (ie, clinical examination and radiographs) in a skeletally immature patient were decided on after consultation with the patient and parent. The family was educated about the possibility of pathologic fracture from minimal trauma to the hand versus the small risk of iatrogenic physeal injury with surgical curettage and bone grafting. No protective splinting was offered. A favorable prognosis and reassurance was provided to the patient and family, given the absence of symptoms, low suspicion and risk of malignant transformation, and stability of the lesion. Serial radiographs showed gradual increases in the lesions’ sizes but were consistent with the stable growth of the metacarpal and phalanges. With the patient nearing skeletal maturity, no pathologic fractures were identified on radiography during follow-up, and the risks of surgery lessened with growth; however, the continued absence of symptoms led to the mutual decision to continue observation.

Nearly 8 years after initial presentation, plain radiographs showed closed physes and partially ossified bone masses (Figures 2A-2C). The metacarpal lesion measured 3.2×1.5 cm, and the cortex appeared thickened and regular. The proximal phalanx lesion had a thickened cortex without periosteal reaction, and the middle phalanx lesion appeared to be completely healed. The patient has been asymptomatic for many years, and she has retained complete function of her left hand without any growth retardation, angular deformity, or pathologic fracture. A small but potential risk of malignant transformation was discussed with the patient and her family, as was the need for lifetime follow-up. We intend to follow the enchondromas clinically and radiographically every 2 years and obtain new radiographs if the mass presents with new clinical findings, such as enlargement or pain, for surveillance of tumor transformation. If the patient desired or symptoms developed, curettage and bone grafting would be offered, and the surgical tissue would be sent for pathologic analysis. A bone scan that was obtained at the request of the patient, when she was 21 years old, showed no other sites of disease besides the fingers.

Discussion

Multiple enchondromatosis was first described by Ollier at the turn of the 19th century and has been estimated to affect one in every 100,000 persons.¹ The low prevalence and variable manifestations of Ollier disease lead clinicians to handle the disease and its complications, namely skeletal deformity and malignant transformation, on a case-by-case approach. Additionally, the prognosis of Ollier disease with malignant transformation is quite variable, with studies reporting the estimated incidence as 5% to 50%.⁷ Muramatsu and colleagues⁶ reported that the occurrence of malignant transformation of multiple enchondromas limited to the bones of the hand was extremely rare, with only 12 cases of malignant transformation. Enchondromas of the pelvis, scapula, and long bones of the extremities have increased risks and rates of secondary transformation to chondrosarcoma.⁸

A recent large European multicenter retrospective study investigating the clinical characteristics and behavior of enchondromas in 144 patients with Ollier disease has provided new information regarding this rare disease.⁷ Verdegaal and colleagues⁷ divided patients into 3 categories depending on their distribution of enchondromas. The development of chondrosarcoma was notably different between individuals with enchondromas limited to the small bones of the hands and feet (15%, group I) versus individuals with enchondromas limited to the long bones and flat bones (43%, group II) or individuals with enchondromas of the short, long, and flat bones (46%, group III).⁷ The only location found to be statistically significant for the development of chondrosarcoma was the pelvis.

The clinical findings associated with risk of malignant transformation of enchondromas are increasing size of the lesion and onset of pain and tenderness. Dahlin and Salvador⁹ reported that only 60% of patients with chondrosarcoma of the hand experience pain. The absence of pain may lead to a delay in patient presentation to the clinician.^5,6 Radiographic findings of malignant transformation include the classic features of temporal increases in the lesion’s size after skeletal maturity and cortical destruction associated with soft-tissue invasion. However, both findings are nonspecific for differentiating enchondromas from grade 1 chondrosarcomas as described by Geirnaerdt and colleagues.¹⁰

Sassoon and colleagues¹¹ reported on a series of hand enchondromas treated operatively. Subgroup analysis between pathologic fractures treated primarily or in delayed fashion showed similar outcomes for achieving full motion and similar number of complications; however, they noted that the delayed group required 7 more weeks of immobilization. Additionally, review of the whole series showed 1 episode of metacarpal shortening and 1 occurrence of angular malalignment. In our patient, we were concerned about introducing an iatrogenic cosmetic deformity, and we believed a pathologic fracture could be managed expectantly. Overall, patients without pathologic fracture treated surgically experienced a complication rate of 12%, whereas patients with a fracture had a complication rate of 20%.¹¹ The majority of patients with multiple enchondromatosis treated with surgical curettage and grafting had successful outcomes, with 86% of patients regaining full motion, but the recurrence rate was 21%.¹¹ Patients with expansile lesions regained less motion than patients with nonexpansile lesions. There was a single lesion believed preoperatively to be an enchondroma, but it underwent malignant transformation, as confirmed on intraoperative pathology. This patient had Maffucci syndrome and was treated with an amputation through the metacarpophalangeal joint.

There are 3 options for treating hand enchondromas: observation, curettage alone, or curettage with bone grafting. There is no consensus about conservative management, timing of intervention, or risk of pathologic fracture. Each patient is treated individually with attention to reason for presentation, number of lesions, associated pain, deformity, or pathologic fracture. Operative criteria include high risk of pathologic fracture based on location of enchondroma, cortical thinning, and previous pathologic fracture with resulting angular deformity. Nonoperative management may increase the risk of pathologic fracture, particularly in patients involved in aggressive contact sports, but the physician may offer protective splinting or counsel the patient on activity modification. Our case provides a study of the natural history of multiple enchondromatosis and shows mild increases in the lesions’ sizes during the 8-year follow-up. This was an expected finding given the patient’s immature skeleton. The lesions’ cortices continued to ossify after the physes closed and now provides an excellent comparison for the identification of future malignant changes. 

Histologic analysis of biopsied or surgically treated lesions contributes to the differentiation between benign hand enchondromas and chondrosarcoma. Pathologic findings must be correlated with clinical and radiographic findings because hand enchondromas contain cytologic features of chondrosarcoma.¹² In a series of 55 patients with chondrosarcoma, Liu and colleagues⁸ reported no cases from the hand. Verdegaal and colleagues⁷ reported a total of 13 chondrosarcomas in the metacarpals and hand phalanges in 97 group I and III patients. Five of these lesions were grade 1, 2 were grade 2, 1 was grade 3, and 5 lesions were unknown.

For patients with multiple enchondromatosis limited to the hands, prognosis is relatively good with respect to risk of secondary chondrosarcoma transformation, metastasis of secondary chondrosarcoma, and death. Verdegaal and colleagues⁷ reported the rate of secondary transformation in the hand to be 15%. Patil and colleagues¹³ reported no distant metastases in 23 patients with hand chondrosarcoma at mean follow-up of 8.5 years (range, 2-19 years), although none of their patients had Ollier disease. Verdegaal and colleagues⁷ reported 7 of the 8 deaths in their study were related to development of pulmonary metastases; however, none originated from chondrosarcomas in the hand. Additionally, there were no disease-related deaths in 29 group I patients. Herget and colleagues,¹⁴ in summarizing the literature, postulated that the overall survival rate of patients with secondary chondrosarcoma at 5 years is approximately 90%.

In our case, the patient, who had 3 enchondromas isolated to the left hand, can be categorized in group I. Thus, this case highlights the natural history of a patient with hand enchondromas and demonstrates that enchondromatosis of the short tubular bones of the hands can mature and ossify.

Ollier disease, or multiple enchondromatosis, is a rare nonfamilial condition characterized by multiple cartilaginous tumors often beginning in early childhood. There is significant variation in disease distribution, location, size, number of lesions, and behavior, but the tumors are often located unilaterally.¹ Enchondromas are most commonly found in the metacarpals, metatarsals, and phalanges, and develop from metaphyseal bone in close proximity to the physis. They frequently present as painless masses or are incidentally noted during the evaluation of another musculoskeletal condition. Radiographically, enchondromas of the hands and feet appear as oval radiolucencies with thinned, sclerotic rims. The lesions have varying degrees of mineralization and endosteal scalloping, and may expand the bone.² Enchondromas usually enlarge until skeletal maturity and have been observed to ossify spontaneously.^1,3 The clinical course of Ollier disease is variable, and a number of cases of significant hand deformity and malignant transformation have been reported.^4-6

In this case report, we present a mild form of Ollier disease isolated to the patient’s left hand, which we followed for 8 years, demonstrating part of the natural history of these lesions. We discuss the patient’s clinical features, radiologic findings, diagnosis, treatment, prognosis, and follow-up, as well as review the literature. The patient and the patient’s family provided written informed consent for print and electronic publication of this case report.

Case Report

A 10-year-old, right-handed girl was referred to our department for the evaluation of left-hand masses. At age 3 years, the patient underwent a chondroma excision from the middle phalanx of her middle finger on her left hand. No operative or pathology report was available from this surgery, and the patient tolerated the procedure well without any complications. At the time of presentation, the masses did not cause any pain, motor or sensory dysfunction, or any systemic symptoms. No history of recent or distant trauma was elicited. The patient’s medical and family history was unremarkable.

On physical examination, there was a firm, immobile, nontender palpable mass over the dorsal aspect of the distal second metacarpal bone of the left hand. The mass extended medially between the second and third metacarpals. A second small, firm, nontender left-hand mass was palpated over the volar aspect of her proximal phalanx on her index finger. She was neurovascularly intact with full active range of motion of the metacarpophalangeal and proximal and distal interphalangeal joints. There was no angular deformity of the digits. Plain radiographs taken at the time of initial presentation showed a 2.3×1.7-cm radiolucent lesion located in the metaphysis and diaphysis of the second metacarpal of the left hand (Figures 1A-1C). The lesion had varying degrees of mineralization with cortical thinning and expansion in the volar, dorsal, radial, and ulnar directions, consistent with a chondroid lesion. The second and third lesions were oval radiolucencies with sclerotic rims located at the metaphyseal-diaphyseal junction of the proximal phalanx of the index finger and middle phalanx of the middle finger, respectively. No fractures were identified in the radiographs, and the physes were open at this time. The patient was diagnosed with multiple enchondromatosis, or Ollier disease.

Our case showed 1 episode of pain and tenderness to palpation at the second proximal phalanx approximately 6 months after initial presentation. We attributed the pain and tenderness to a small pathologic fracture but did not see radiographic evidence of this. We elected to provide a trial of supportive measures, such as splinting and buddy taping, and to monitor the pain with a tentative plan of open biopsy with curettage and bone grafting if the pain persisted or evidence of fracture was seen on radiographs. The pain and tenderness to palpation resolved at a follow-up visit, and the surgery was deferred.

The patient was treated nonoperatively at initial presentation given the lack of significant cosmetic deformity or functional compromise and was advised close follow-up at 3 and 6 months. Given the absence of disease progression, annual checks (ie, clinical examination and radiographs) in a skeletally immature patient were decided on after consultation with the patient and parent. The family was educated about the possibility of pathologic fracture from minimal trauma to the hand versus the small risk of iatrogenic physeal injury with surgical curettage and bone grafting. No protective splinting was offered. A favorable prognosis and reassurance was provided to the patient and family, given the absence of symptoms, low suspicion and risk of malignant transformation, and stability of the lesion. Serial radiographs showed gradual increases in the lesions’ sizes but were consistent with the stable growth of the metacarpal and phalanges. With the patient nearing skeletal maturity, no pathologic fractures were identified on radiography during follow-up, and the risks of surgery lessened with growth; however, the continued absence of symptoms led to the mutual decision to continue observation.

Nearly 8 years after initial presentation, plain radiographs showed closed physes and partially ossified bone masses (Figures 2A-2C). The metacarpal lesion measured 3.2×1.5 cm, and the cortex appeared thickened and regular. The proximal phalanx lesion had a thickened cortex without periosteal reaction, and the middle phalanx lesion appeared to be completely healed. The patient has been asymptomatic for many years, and she has retained complete function of her left hand without any growth retardation, angular deformity, or pathologic fracture. A small but potential risk of malignant transformation was discussed with the patient and her family, as was the need for lifetime follow-up. We intend to follow the enchondromas clinically and radiographically every 2 years and obtain new radiographs if the mass presents with new clinical findings, such as enlargement or pain, for surveillance of tumor transformation. If the patient desired or symptoms developed, curettage and bone grafting would be offered, and the surgical tissue would be sent for pathologic analysis. A bone scan that was obtained at the request of the patient, when she was 21 years old, showed no other sites of disease besides the fingers.

Discussion

Multiple enchondromatosis was first described by Ollier at the turn of the 19th century and has been estimated to affect one in every 100,000 persons.¹ The low prevalence and variable manifestations of Ollier disease lead clinicians to handle the disease and its complications, namely skeletal deformity and malignant transformation, on a case-by-case approach. Additionally, the prognosis of Ollier disease with malignant transformation is quite variable, with studies reporting the estimated incidence as 5% to 50%.⁷ Muramatsu and colleagues⁶ reported that the occurrence of malignant transformation of multiple enchondromas limited to the bones of the hand was extremely rare, with only 12 cases of malignant transformation. Enchondromas of the pelvis, scapula, and long bones of the extremities have increased risks and rates of secondary transformation to chondrosarcoma.⁸

A recent large European multicenter retrospective study investigating the clinical characteristics and behavior of enchondromas in 144 patients with Ollier disease has provided new information regarding this rare disease.⁷ Verdegaal and colleagues⁷ divided patients into 3 categories depending on their distribution of enchondromas. The development of chondrosarcoma was notably different between individuals with enchondromas limited to the small bones of the hands and feet (15%, group I) versus individuals with enchondromas limited to the long bones and flat bones (43%, group II) or individuals with enchondromas of the short, long, and flat bones (46%, group III).⁷ The only location found to be statistically significant for the development of chondrosarcoma was the pelvis.

The clinical findings associated with risk of malignant transformation of enchondromas are increasing size of the lesion and onset of pain and tenderness. Dahlin and Salvador⁹ reported that only 60% of patients with chondrosarcoma of the hand experience pain. The absence of pain may lead to a delay in patient presentation to the clinician.^5,6 Radiographic findings of malignant transformation include the classic features of temporal increases in the lesion’s size after skeletal maturity and cortical destruction associated with soft-tissue invasion. However, both findings are nonspecific for differentiating enchondromas from grade 1 chondrosarcomas as described by Geirnaerdt and colleagues.¹⁰

Sassoon and colleagues¹¹ reported on a series of hand enchondromas treated operatively. Subgroup analysis between pathologic fractures treated primarily or in delayed fashion showed similar outcomes for achieving full motion and similar number of complications; however, they noted that the delayed group required 7 more weeks of immobilization. Additionally, review of the whole series showed 1 episode of metacarpal shortening and 1 occurrence of angular malalignment. In our patient, we were concerned about introducing an iatrogenic cosmetic deformity, and we believed a pathologic fracture could be managed expectantly. Overall, patients without pathologic fracture treated surgically experienced a complication rate of 12%, whereas patients with a fracture had a complication rate of 20%.¹¹ The majority of patients with multiple enchondromatosis treated with surgical curettage and grafting had successful outcomes, with 86% of patients regaining full motion, but the recurrence rate was 21%.¹¹ Patients with expansile lesions regained less motion than patients with nonexpansile lesions. There was a single lesion believed preoperatively to be an enchondroma, but it underwent malignant transformation, as confirmed on intraoperative pathology. This patient had Maffucci syndrome and was treated with an amputation through the metacarpophalangeal joint.

There are 3 options for treating hand enchondromas: observation, curettage alone, or curettage with bone grafting. There is no consensus about conservative management, timing of intervention, or risk of pathologic fracture. Each patient is treated individually with attention to reason for presentation, number of lesions, associated pain, deformity, or pathologic fracture. Operative criteria include high risk of pathologic fracture based on location of enchondroma, cortical thinning, and previous pathologic fracture with resulting angular deformity. Nonoperative management may increase the risk of pathologic fracture, particularly in patients involved in aggressive contact sports, but the physician may offer protective splinting or counsel the patient on activity modification. Our case provides a study of the natural history of multiple enchondromatosis and shows mild increases in the lesions’ sizes during the 8-year follow-up. This was an expected finding given the patient’s immature skeleton. The lesions’ cortices continued to ossify after the physes closed and now provides an excellent comparison for the identification of future malignant changes. 

Histologic analysis of biopsied or surgically treated lesions contributes to the differentiation between benign hand enchondromas and chondrosarcoma. Pathologic findings must be correlated with clinical and radiographic findings because hand enchondromas contain cytologic features of chondrosarcoma.¹² In a series of 55 patients with chondrosarcoma, Liu and colleagues⁸ reported no cases from the hand. Verdegaal and colleagues⁷ reported a total of 13 chondrosarcomas in the metacarpals and hand phalanges in 97 group I and III patients. Five of these lesions were grade 1, 2 were grade 2, 1 was grade 3, and 5 lesions were unknown.

For patients with multiple enchondromatosis limited to the hands, prognosis is relatively good with respect to risk of secondary chondrosarcoma transformation, metastasis of secondary chondrosarcoma, and death. Verdegaal and colleagues⁷ reported the rate of secondary transformation in the hand to be 15%. Patil and colleagues¹³ reported no distant metastases in 23 patients with hand chondrosarcoma at mean follow-up of 8.5 years (range, 2-19 years), although none of their patients had Ollier disease. Verdegaal and colleagues⁷ reported 7 of the 8 deaths in their study were related to development of pulmonary metastases; however, none originated from chondrosarcomas in the hand. Additionally, there were no disease-related deaths in 29 group I patients. Herget and colleagues,¹⁴ in summarizing the literature, postulated that the overall survival rate of patients with secondary chondrosarcoma at 5 years is approximately 90%.

In our case, the patient, who had 3 enchondromas isolated to the left hand, can be categorized in group I. Thus, this case highlights the natural history of a patient with hand enchondromas and demonstrates that enchondromatosis of the short tubular bones of the hands can mature and ossify.

Ollier disease, or multiple enchondromatosis, is a rare nonfamilial condition characterized by multiple cartilaginous tumors often beginning in early childhood. There is significant variation in disease distribution, location, size, number of lesions, and behavior, but the tumors are often located unilaterally.¹ Enchondromas are most commonly found in the metacarpals, metatarsals, and phalanges, and develop from metaphyseal bone in close proximity to the physis. They frequently present as painless masses or are incidentally noted during the evaluation of another musculoskeletal condition. Radiographically, enchondromas of the hands and feet appear as oval radiolucencies with thinned, sclerotic rims. The lesions have varying degrees of mineralization and endosteal scalloping, and may expand the bone.² Enchondromas usually enlarge until skeletal maturity and have been observed to ossify spontaneously.^1,3 The clinical course of Ollier disease is variable, and a number of cases of significant hand deformity and malignant transformation have been reported.^4-6

In this case report, we present a mild form of Ollier disease isolated to the patient’s left hand, which we followed for 8 years, demonstrating part of the natural history of these lesions. We discuss the patient’s clinical features, radiologic findings, diagnosis, treatment, prognosis, and follow-up, as well as review the literature. The patient and the patient’s family provided written informed consent for print and electronic publication of this case report.

Case Report

A 10-year-old, right-handed girl was referred to our department for the evaluation of left-hand masses. At age 3 years, the patient underwent a chondroma excision from the middle phalanx of her middle finger on her left hand. No operative or pathology report was available from this surgery, and the patient tolerated the procedure well without any complications. At the time of presentation, the masses did not cause any pain, motor or sensory dysfunction, or any systemic symptoms. No history of recent or distant trauma was elicited. The patient’s medical and family history was unremarkable.

On physical examination, there was a firm, immobile, nontender palpable mass over the dorsal aspect of the distal second metacarpal bone of the left hand. The mass extended medially between the second and third metacarpals. A second small, firm, nontender left-hand mass was palpated over the volar aspect of her proximal phalanx on her index finger. She was neurovascularly intact with full active range of motion of the metacarpophalangeal and proximal and distal interphalangeal joints. There was no angular deformity of the digits. Plain radiographs taken at the time of initial presentation showed a 2.3×1.7-cm radiolucent lesion located in the metaphysis and diaphysis of the second metacarpal of the left hand (Figures 1A-1C). The lesion had varying degrees of mineralization with cortical thinning and expansion in the volar, dorsal, radial, and ulnar directions, consistent with a chondroid lesion. The second and third lesions were oval radiolucencies with sclerotic rims located at the metaphyseal-diaphyseal junction of the proximal phalanx of the index finger and middle phalanx of the middle finger, respectively. No fractures were identified in the radiographs, and the physes were open at this time. The patient was diagnosed with multiple enchondromatosis, or Ollier disease.

Our case showed 1 episode of pain and tenderness to palpation at the second proximal phalanx approximately 6 months after initial presentation. We attributed the pain and tenderness to a small pathologic fracture but did not see radiographic evidence of this. We elected to provide a trial of supportive measures, such as splinting and buddy taping, and to monitor the pain with a tentative plan of open biopsy with curettage and bone grafting if the pain persisted or evidence of fracture was seen on radiographs. The pain and tenderness to palpation resolved at a follow-up visit, and the surgery was deferred.

The patient was treated nonoperatively at initial presentation given the lack of significant cosmetic deformity or functional compromise and was advised close follow-up at 3 and 6 months. Given the absence of disease progression, annual checks (ie, clinical examination and radiographs) in a skeletally immature patient were decided on after consultation with the patient and parent. The family was educated about the possibility of pathologic fracture from minimal trauma to the hand versus the small risk of iatrogenic physeal injury with surgical curettage and bone grafting. No protective splinting was offered. A favorable prognosis and reassurance was provided to the patient and family, given the absence of symptoms, low suspicion and risk of malignant transformation, and stability of the lesion. Serial radiographs showed gradual increases in the lesions’ sizes but were consistent with the stable growth of the metacarpal and phalanges. With the patient nearing skeletal maturity, no pathologic fractures were identified on radiography during follow-up, and the risks of surgery lessened with growth; however, the continued absence of symptoms led to the mutual decision to continue observation.

Nearly 8 years after initial presentation, plain radiographs showed closed physes and partially ossified bone masses (Figures 2A-2C). The metacarpal lesion measured 3.2×1.5 cm, and the cortex appeared thickened and regular. The proximal phalanx lesion had a thickened cortex without periosteal reaction, and the middle phalanx lesion appeared to be completely healed. The patient has been asymptomatic for many years, and she has retained complete function of her left hand without any growth retardation, angular deformity, or pathologic fracture. A small but potential risk of malignant transformation was discussed with the patient and her family, as was the need for lifetime follow-up. We intend to follow the enchondromas clinically and radiographically every 2 years and obtain new radiographs if the mass presents with new clinical findings, such as enlargement or pain, for surveillance of tumor transformation. If the patient desired or symptoms developed, curettage and bone grafting would be offered, and the surgical tissue would be sent for pathologic analysis. A bone scan that was obtained at the request of the patient, when she was 21 years old, showed no other sites of disease besides the fingers.

Discussion

Multiple enchondromatosis was first described by Ollier at the turn of the 19th century and has been estimated to affect one in every 100,000 persons.¹ The low prevalence and variable manifestations of Ollier disease lead clinicians to handle the disease and its complications, namely skeletal deformity and malignant transformation, on a case-by-case approach. Additionally, the prognosis of Ollier disease with malignant transformation is quite variable, with studies reporting the estimated incidence as 5% to 50%.⁷ Muramatsu and colleagues⁶ reported that the occurrence of malignant transformation of multiple enchondromas limited to the bones of the hand was extremely rare, with only 12 cases of malignant transformation. Enchondromas of the pelvis, scapula, and long bones of the extremities have increased risks and rates of secondary transformation to chondrosarcoma.⁸

A recent large European multicenter retrospective study investigating the clinical characteristics and behavior of enchondromas in 144 patients with Ollier disease has provided new information regarding this rare disease.⁷ Verdegaal and colleagues⁷ divided patients into 3 categories depending on their distribution of enchondromas. The development of chondrosarcoma was notably different between individuals with enchondromas limited to the small bones of the hands and feet (15%, group I) versus individuals with enchondromas limited to the long bones and flat bones (43%, group II) or individuals with enchondromas of the short, long, and flat bones (46%, group III).⁷ The only location found to be statistically significant for the development of chondrosarcoma was the pelvis.

The clinical findings associated with risk of malignant transformation of enchondromas are increasing size of the lesion and onset of pain and tenderness. Dahlin and Salvador⁹ reported that only 60% of patients with chondrosarcoma of the hand experience pain. The absence of pain may lead to a delay in patient presentation to the clinician.^5,6 Radiographic findings of malignant transformation include the classic features of temporal increases in the lesion’s size after skeletal maturity and cortical destruction associated with soft-tissue invasion. However, both findings are nonspecific for differentiating enchondromas from grade 1 chondrosarcomas as described by Geirnaerdt and colleagues.¹⁰

Sassoon and colleagues¹¹ reported on a series of hand enchondromas treated operatively. Subgroup analysis between pathologic fractures treated primarily or in delayed fashion showed similar outcomes for achieving full motion and similar number of complications; however, they noted that the delayed group required 7 more weeks of immobilization. Additionally, review of the whole series showed 1 episode of metacarpal shortening and 1 occurrence of angular malalignment. In our patient, we were concerned about introducing an iatrogenic cosmetic deformity, and we believed a pathologic fracture could be managed expectantly. Overall, patients without pathologic fracture treated surgically experienced a complication rate of 12%, whereas patients with a fracture had a complication rate of 20%.¹¹ The majority of patients with multiple enchondromatosis treated with surgical curettage and grafting had successful outcomes, with 86% of patients regaining full motion, but the recurrence rate was 21%.¹¹ Patients with expansile lesions regained less motion than patients with nonexpansile lesions. There was a single lesion believed preoperatively to be an enchondroma, but it underwent malignant transformation, as confirmed on intraoperative pathology. This patient had Maffucci syndrome and was treated with an amputation through the metacarpophalangeal joint.

There are 3 options for treating hand enchondromas: observation, curettage alone, or curettage with bone grafting. There is no consensus about conservative management, timing of intervention, or risk of pathologic fracture. Each patient is treated individually with attention to reason for presentation, number of lesions, associated pain, deformity, or pathologic fracture. Operative criteria include high risk of pathologic fracture based on location of enchondroma, cortical thinning, and previous pathologic fracture with resulting angular deformity. Nonoperative management may increase the risk of pathologic fracture, particularly in patients involved in aggressive contact sports, but the physician may offer protective splinting or counsel the patient on activity modification. Our case provides a study of the natural history of multiple enchondromatosis and shows mild increases in the lesions’ sizes during the 8-year follow-up. This was an expected finding given the patient’s immature skeleton. The lesions’ cortices continued to ossify after the physes closed and now provides an excellent comparison for the identification of future malignant changes. 

Histologic analysis of biopsied or surgically treated lesions contributes to the differentiation between benign hand enchondromas and chondrosarcoma. Pathologic findings must be correlated with clinical and radiographic findings because hand enchondromas contain cytologic features of chondrosarcoma.¹² In a series of 55 patients with chondrosarcoma, Liu and colleagues⁸ reported no cases from the hand. Verdegaal and colleagues⁷ reported a total of 13 chondrosarcomas in the metacarpals and hand phalanges in 97 group I and III patients. Five of these lesions were grade 1, 2 were grade 2, 1 was grade 3, and 5 lesions were unknown.

For patients with multiple enchondromatosis limited to the hands, prognosis is relatively good with respect to risk of secondary chondrosarcoma transformation, metastasis of secondary chondrosarcoma, and death. Verdegaal and colleagues⁷ reported the rate of secondary transformation in the hand to be 15%. Patil and colleagues¹³ reported no distant metastases in 23 patients with hand chondrosarcoma at mean follow-up of 8.5 years (range, 2-19 years), although none of their patients had Ollier disease. Verdegaal and colleagues⁷ reported 7 of the 8 deaths in their study were related to development of pulmonary metastases; however, none originated from chondrosarcomas in the hand. Additionally, there were no disease-related deaths in 29 group I patients. Herget and colleagues,¹⁴ in summarizing the literature, postulated that the overall survival rate of patients with secondary chondrosarcoma at 5 years is approximately 90%.

In our case, the patient, who had 3 enchondromas isolated to the left hand, can be categorized in group I. Thus, this case highlights the natural history of a patient with hand enchondromas and demonstrates that enchondromatosis of the short tubular bones of the hands can mature and ossify.

THE CASE

A 72-year-old woman came to our internal medicine department clinic for a follow-up appointment for her fibromyalgia. Thirteen months earlier, she had sought care at our facility not only for fibromyalgia, but for insomnia, anxiety, depression, and urinary incontinence. At the time, we prescribed amitriptyline 10 mg/d—for her pain and depression—as well as clonazepam 10 mg/d and paracetamol 650 mg, as needed.

When she came in for the follow-up, she indicated that for the past 8 months, she’d been experiencing urinary retention that required her to self-catheterize 2 to 3 times a day. She said she hadn’t used other medicines or herbal products during this time.

The patient had visited her family physician several times over the previous few months, and had been referred to a urologist. During an episode of acute urinary retention, she went to the emergency department (ED), where the ED physician performed urinary catheterization and referred her to the hospital’s Urology Department. After 48 hours, she was evaluated by a urologist, who diagnosed chronic urinary retention related to a hypercontractile bladder, without any particular cause. She was advised to continue to catheterize herself when needed. She was also prescribed pyridostigmine bromide, but she stopped taking it because of abdominal pain and bloating.

Two months prior to her visit with us, the patient suffered a second acute urinary retention episode and returned to the ED. Urinary catheterization was performed for 72 hours. At her next visit to her urologist, she was told to continue self-catheterization and was prescribed silodosin 8 mg/d.

THE DIAGNOSIS

Based on the patient’s history, we suspected the urinary retention was secondary to the anticholinergic effects of amitriptyline. We were able to determine that the patient’s urinary retention was likely the result of an adverse drug reaction (ADR) by using the causality algorithm of the Spanish Pharmacovigilance System, which suggests the following criteria:¹ a) a positive time sequence (ie, onset of symptoms closely followed administration of the medication), b) the existence of an ADR that is well known and consistent with the mechanism of action of the drug,² c) symptoms that resolve after suspending the drug; d) no repeat exposure (to the adverse effects of amitriptyline) due to ethical reasons; and e) the absence of an alternative explanation for the symptoms.³

DISCUSSION

Although indicated for depression, amitriptyline is also used for other conditions, including nocturnal enuresis and chronic neuropathic pain.⁴ Amitriptyline exhibits anticholinergic effects that can cause symptoms related to the nervous system (agitation, disorientation, sleepiness, delirium, cognitive impairment), ocular system (blurred vision, dry eye, accommodation disturbances, increased intraocular pressure), cardiovascular system (tachycardia), gastrointestinal tract (dry mouth, paralytic ileus, constipation), urinary system (urinary retention); and skin and mucosal membranes (dryness).^5,6 Anticholinergic effects can also induce hyperthermia or increase the risk of falls.^5,6

Four other physicians had seen our patient, and none had considered the possibility that this was an adverse drug effect.

Anticholinergic medications can cause ADRs in high-risk older patients and thus are usually considered inappropriate for this patient population.⁶ The Anticholinergic Risk Scale (ARS) can be used to categorize medications based on their potential for anticholinergic adverse effects (TABLE).⁷ Amitriptyline is included in the group with the highest risk of ADRs. Amitriptyline is also included in the list of drugs that should be avoided in older adults, according to the 2012 American Geriatrics Society Beers Criteria.⁸

Our patient. We instructed her to stop taking amitriptyline, and her urinary retention disappeared within 48 hours. Two months later, she remained asymptomatic.

THE TAKEAWAY

Although many medications are known to cause adverse events, they can be missed when clinicians fail to pinpoint exactly when a new sign, symptom, or health problem appeared. This often leads to a chain reaction of unnecessary explorations, harmful treatment, patient suffering, and unjustified costs.^9-11 Our patient had seen 4 different health care providers (a family physician, urologist, and 2 ED physicians) before we saw her and ultimately made the diagnosis. Family physicians can prevent anticholinergic ADRs by using a scale, such as the ARS, before prescribing a medication.

THE CASE

A 72-year-old woman came to our internal medicine department clinic for a follow-up appointment for her fibromyalgia. Thirteen months earlier, she had sought care at our facility not only for fibromyalgia, but for insomnia, anxiety, depression, and urinary incontinence. At the time, we prescribed amitriptyline 10 mg/d—for her pain and depression—as well as clonazepam 10 mg/d and paracetamol 650 mg, as needed.

When she came in for the follow-up, she indicated that for the past 8 months, she’d been experiencing urinary retention that required her to self-catheterize 2 to 3 times a day. She said she hadn’t used other medicines or herbal products during this time.

The patient had visited her family physician several times over the previous few months, and had been referred to a urologist. During an episode of acute urinary retention, she went to the emergency department (ED), where the ED physician performed urinary catheterization and referred her to the hospital’s Urology Department. After 48 hours, she was evaluated by a urologist, who diagnosed chronic urinary retention related to a hypercontractile bladder, without any particular cause. She was advised to continue to catheterize herself when needed. She was also prescribed pyridostigmine bromide, but she stopped taking it because of abdominal pain and bloating.

Two months prior to her visit with us, the patient suffered a second acute urinary retention episode and returned to the ED. Urinary catheterization was performed for 72 hours. At her next visit to her urologist, she was told to continue self-catheterization and was prescribed silodosin 8 mg/d.

THE DIAGNOSIS

Based on the patient’s history, we suspected the urinary retention was secondary to the anticholinergic effects of amitriptyline. We were able to determine that the patient’s urinary retention was likely the result of an adverse drug reaction (ADR) by using the causality algorithm of the Spanish Pharmacovigilance System, which suggests the following criteria:¹ a) a positive time sequence (ie, onset of symptoms closely followed administration of the medication), b) the existence of an ADR that is well known and consistent with the mechanism of action of the drug,² c) symptoms that resolve after suspending the drug; d) no repeat exposure (to the adverse effects of amitriptyline) due to ethical reasons; and e) the absence of an alternative explanation for the symptoms.³

DISCUSSION

Although indicated for depression, amitriptyline is also used for other conditions, including nocturnal enuresis and chronic neuropathic pain.⁴ Amitriptyline exhibits anticholinergic effects that can cause symptoms related to the nervous system (agitation, disorientation, sleepiness, delirium, cognitive impairment), ocular system (blurred vision, dry eye, accommodation disturbances, increased intraocular pressure), cardiovascular system (tachycardia), gastrointestinal tract (dry mouth, paralytic ileus, constipation), urinary system (urinary retention); and skin and mucosal membranes (dryness).^5,6 Anticholinergic effects can also induce hyperthermia or increase the risk of falls.^5,6

Four other physicians had seen our patient, and none had considered the possibility that this was an adverse drug effect.

Anticholinergic medications can cause ADRs in high-risk older patients and thus are usually considered inappropriate for this patient population.⁶ The Anticholinergic Risk Scale (ARS) can be used to categorize medications based on their potential for anticholinergic adverse effects (TABLE).⁷ Amitriptyline is included in the group with the highest risk of ADRs. Amitriptyline is also included in the list of drugs that should be avoided in older adults, according to the 2012 American Geriatrics Society Beers Criteria.⁸

Our patient. We instructed her to stop taking amitriptyline, and her urinary retention disappeared within 48 hours. Two months later, she remained asymptomatic.

THE TAKEAWAY

Although many medications are known to cause adverse events, they can be missed when clinicians fail to pinpoint exactly when a new sign, symptom, or health problem appeared. This often leads to a chain reaction of unnecessary explorations, harmful treatment, patient suffering, and unjustified costs.^9-11 Our patient had seen 4 different health care providers (a family physician, urologist, and 2 ED physicians) before we saw her and ultimately made the diagnosis. Family physicians can prevent anticholinergic ADRs by using a scale, such as the ARS, before prescribing a medication.

THE CASE

A 72-year-old woman came to our internal medicine department clinic for a follow-up appointment for her fibromyalgia. Thirteen months earlier, she had sought care at our facility not only for fibromyalgia, but for insomnia, anxiety, depression, and urinary incontinence. At the time, we prescribed amitriptyline 10 mg/d—for her pain and depression—as well as clonazepam 10 mg/d and paracetamol 650 mg, as needed.

When she came in for the follow-up, she indicated that for the past 8 months, she’d been experiencing urinary retention that required her to self-catheterize 2 to 3 times a day. She said she hadn’t used other medicines or herbal products during this time.

The patient had visited her family physician several times over the previous few months, and had been referred to a urologist. During an episode of acute urinary retention, she went to the emergency department (ED), where the ED physician performed urinary catheterization and referred her to the hospital’s Urology Department. After 48 hours, she was evaluated by a urologist, who diagnosed chronic urinary retention related to a hypercontractile bladder, without any particular cause. She was advised to continue to catheterize herself when needed. She was also prescribed pyridostigmine bromide, but she stopped taking it because of abdominal pain and bloating.

Two months prior to her visit with us, the patient suffered a second acute urinary retention episode and returned to the ED. Urinary catheterization was performed for 72 hours. At her next visit to her urologist, she was told to continue self-catheterization and was prescribed silodosin 8 mg/d.

THE DIAGNOSIS

Based on the patient’s history, we suspected the urinary retention was secondary to the anticholinergic effects of amitriptyline. We were able to determine that the patient’s urinary retention was likely the result of an adverse drug reaction (ADR) by using the causality algorithm of the Spanish Pharmacovigilance System, which suggests the following criteria:¹ a) a positive time sequence (ie, onset of symptoms closely followed administration of the medication), b) the existence of an ADR that is well known and consistent with the mechanism of action of the drug,² c) symptoms that resolve after suspending the drug; d) no repeat exposure (to the adverse effects of amitriptyline) due to ethical reasons; and e) the absence of an alternative explanation for the symptoms.³

DISCUSSION

Although indicated for depression, amitriptyline is also used for other conditions, including nocturnal enuresis and chronic neuropathic pain.⁴ Amitriptyline exhibits anticholinergic effects that can cause symptoms related to the nervous system (agitation, disorientation, sleepiness, delirium, cognitive impairment), ocular system (blurred vision, dry eye, accommodation disturbances, increased intraocular pressure), cardiovascular system (tachycardia), gastrointestinal tract (dry mouth, paralytic ileus, constipation), urinary system (urinary retention); and skin and mucosal membranes (dryness).^5,6 Anticholinergic effects can also induce hyperthermia or increase the risk of falls.^5,6

Four other physicians had seen our patient, and none had considered the possibility that this was an adverse drug effect.

Anticholinergic medications can cause ADRs in high-risk older patients and thus are usually considered inappropriate for this patient population.⁶ The Anticholinergic Risk Scale (ARS) can be used to categorize medications based on their potential for anticholinergic adverse effects (TABLE).⁷ Amitriptyline is included in the group with the highest risk of ADRs. Amitriptyline is also included in the list of drugs that should be avoided in older adults, according to the 2012 American Geriatrics Society Beers Criteria.⁸

Our patient. We instructed her to stop taking amitriptyline, and her urinary retention disappeared within 48 hours. Two months later, she remained asymptomatic.

THE TAKEAWAY

Although many medications are known to cause adverse events, they can be missed when clinicians fail to pinpoint exactly when a new sign, symptom, or health problem appeared. This often leads to a chain reaction of unnecessary explorations, harmful treatment, patient suffering, and unjustified costs.^9-11 Our patient had seen 4 different health care providers (a family physician, urologist, and 2 ED physicians) before we saw her and ultimately made the diagnosis. Family physicians can prevent anticholinergic ADRs by using a scale, such as the ARS, before prescribing a medication.