Presenting reports included pain, mass, pseudowinging, and snapping of the scapula ... patients with a symptomatic osteochondroma of the scapula treated with ...
ORTHOPEDICS November 2010;33(11):804.
Scapular Osteochondromas Treated With Surgical Excision by CPT Nathan L. Frost, MD, MS; CPT Stephen A. Parada, MD; LTC Mark W. Manoso, MD; COL Edward Arrington, MD; COL Paul Benfanti, MD
Abstract A retrospective review was performed of all osteochondroma excisions at our institution from 1994 to 2007. Postoperative functional assessment was completed with use of the Disabilities of the Arm, Shoulder and Hand (DASH) survey and a self-report questionnaire. Eight osteochondromas were excised at a mean patient age of 21.63 years. Presenting reports included pain, mass, pseudowinging, and snapping of the scapula. Physical examination identified pseudowinging, palpable mass, and pain with shoulder motion. The lesions arose from the ventral surface of the scapula in 5 patients, the dorsal surface in 2, and the inferior acromion in 1. The resected specimen averaged 10.8cm3. A reactive bursa was found and resected in 4 patients. At mean of 4.17 years postresection, no signs of recurrence were found in 7 patients (88%). The single patient with a recurrence had undergone 2 additional surgical procedures. Six patients (75%) reported no/mild pain with routine and strenuous activities. One patient reported moderate and 1 patient reported moderate/severe pain with routine and strenuous activities. Four patients reported post-resection function as excellent, 2 as good, 1 as average/good, and 1 as average/poor. Six patients (75%) reported feeling very satisfied with the results, 1 reported feeling satisfied, and 1 reported feeling unsatisfied. The average DASH score was 11.7 (range, 0.00-46.67). No winging or pseudowinging was identified in those available for examination, and no difference was identified in range of motion comparing the operative to the nonoperative upper extremity. Near normal functional outcomes can be expected following excision of scapular osteochondromas. Osteochondromas are osteocartilaginous exostoses that account for 35% to 46% of all benign neoplasms of bone.1,2 These lesions are thought to arise from aberrant growth of normal epiphyseal growth plate cartilage.3,4 Typical locations include the metaphyseal regions of long bones such as the distal femur, proximal tibia, or proximal humerus.1 Literature on involvement of other anatomic areas is limited to isolated case reports.5-10 This article presents our case series of 8 patients with a symptomatic osteochondroma of the scapula treated with surgical excision.
Materials and Methods We performed a retrospective review of all surgeries performed at our institution from 1994 to 2007 and identified all excisions of osteochondromas. The study was approved through our Institutional Review Board. Operative reports were evaluated to determine location and size of mass, presence or absence of reactive bursa, and presence of any intraoperative complications. A review of inpatient and outpatient medical records was performed to determine the presenting complaint, pertinent physical examination findings, and presence of recurrence following excision. Postoperative functional assessment of all patients who underwent surgical excision of an osteochondroma of the scapula was carried out with administration of the Disabilities of the Army, Shoulder, and Hand (DASH) survey, as well as completion of a self-report questionnaire. The DASH was chosen due to its self-report nature, which allowed for ease in administration as well as its previous validation as a measure of upper extremity function.11 Those patients available underwent a repeat physical examination by 1 of 2 attending physicians (M.W.M., P.L.B.), as well as repeat radiographic evaluation.
Surgical Technique The surgical approach used was dictated by the location of the mass. A dorsally based incision paralleling the medial border of the scapula was used in 6 patients and a dorsally based incision along the scapular spine in the remaining 2. Dissection was carried out down to the level of the mass with the aid of electrocautery. Muscle fibers were either elevated in a subperiosteal manner or split in line with the fibers, depending on the location of the mass. The mass was easily identifiable in all patients. Any overlying bursa was removed in its entirety. Once the mass was clearly identified, it was excised with the aid of a small osteotome or Cloward drill based on surgeon preference. Any divided muscle was reapproximated, and the wound was closed in standard fashion.
Results Sixty-three symptomatic osteochondromas were excised during the study period, 8 of which involved the scapula (12.7%). Mean patient age at the time of resection was 21.63 years (range, 7.17-37.33 years; SD, 10.24), and symptoms had been present for a mean time of 1.29 years (range, 0.08-4.0 years; SD, 1.43 years) prior to diagnosis. The lesions were most often unilateral, although bilateral involvement was found in 1 patient. The lesions were solitary in all but 1 patient, who was found to have multiple lesions within the same scapula. The lesions involved the left scapula in 5 patients and the right scapula in the remaining 3. Initial presenting complaint was painful range of motion (ROM) in 4 patients, pain and temperature insensitivity over the mass in 1, pain with activities and the presence of an enlarging mass in 1, pseudowinging of the involved scapula in 1, and snapping of the scapula in 1.
While winging of the scapula is a dynamic process caused by paralysis of the serratus anterior or trapezius muscles, pseudowinging has been defined as an increased scapular prominence from causes other than the above.6 Physical examination identified pseudowinging of the involved scapula in 4 patients, a palpable mass in 2, and pain with ROM about the involved shoulder in the remaining 2 (Figures 1, 2). The lesions arose from the ventral surface of the scapula in 5 patients, the dorsal surface in 2, and the inferior aspect of the acromion in 1. The surgical specimen averaged 10.8 cm3 in size (range, 1-30 cm3). A reactive bursa was identified and resected in 4 patients. No intra- or postoperative complications were noted (Table 1). Pathologic examination of the specimens confirmed the diagnosis in all cases, and no cartilage cap of >2 cm was noted in any of the specimens.
Figure 1: Photograph of a patient with a chief complaint of pain with range of motion of the right shoulder. Note pseudowinging of the right scapula present while standing at rest. This patient was treated concurrently in a long-arm cast for an ipsalateral scaphoid fracture. Figure 2: Posterior view illustrating pseudowinging of the right scapula.
At a mean time of 4.17 years post-resection, a self-report questionnaire and the DASH were administered to all patients (Table 2). No sign of recurrence was found in 7 patients (88%). The single patient with a recurrence had undergone 2 additional surgical procedures. Six patients (75%) reported no/mild pain with both routine and strenuous activities. One patient reported moderate pain and 1 patient moderate/severe pain with both routine and strenuous activities. Four patients reported their post-resection function as excellent, 2 as good, 1 as average/good, and 1 as average/poor. Six patients (75%) reported feeling very satisfied with their results, 1 reported feeling satisfied, and 1 reported feeling unsatisfied following surgical resection. The mean DASH score was 11.7 (range, 0.00-46.67).
Four patients (50%) were available for repeat physical examination (Table 3). No winging or pseudowinging was identified. No significant difference was identified in ROM comparing the operative to the contralateral, nonoperative upper extremity.
Discussion Osteochondromas account for 35% to 46% of all benign neoplasms of bone.1,2 Ninety percent of reported osteochondromas arise from the metaphyseal region of the proximal humerus, distal femur, and proximal tibia.1 Scapular involvement accounts for 3.0% to 4.6% of all reported osteochondromas.7,8 While comprising only a small minority of overall cases, these lesions represent 14.4% of all tumors of the scapula and 49% of benign scapular tumors.
12
The large percentage of osteochondromas involving the scapula in our series may be due to the close proximity of a large tertiary referral center to which many of the pediatric patients with benign osteochondromas from our area are referred for management. The literature involving osteochondroma of the scapula is limited to isolated case reports and small case series, none of which include functional assessment. Danielsson and el-Haddad7 reported on a case series of 3 pediatric patients with winging of the scapula due to osteochondromas arising from the ventral surface of the scapula treated with surgical excision. The contour of the scapula was found to return to normal, and all patients were reported to be pain free at follow-up. Esenkaya,8 Mohsen et al,2 and Nercessian and Denton10 have reported on solitary cases of osteochondroma of the scapula. These case reports indicated that symptoms resolved but lacked a functional outcome measure.
While the exact etiology of osteochondromas remains unknown, it is believed that normal epiphyseal cartilage becomes displaced and continues to grow away from the growth plate resulting in the typical mass.4 Diagnosis is made by histopathologic evaluation of the osteocartilaginous mass, which reveals enchondral or lamellar bone connected to normal bone by a thin stalk.
2,3
This stalk is in continuity with the medullary canal of the native bone. Pathologic specimens will also
demonstrate a cartilage cap of varying thickness. Benign lesions are known to have a cartilage cap of 2 cm in thickness raises concern for malignant transformation.
1,2
Growth of osteochondromas typically ends at the time of closure of the physis, and growth into adulthood should raise concern for
possible malignancy.13 Common presenting complaints of patients with an osteochondroma of the scapula include pain, decreased active ROM, crepitus with movements of the involved shoulder, and pseudowinging of the scapula.6-9 A mass may or may not be palpable. Routine radiographic evaluation often identifies a mass arising from the ventral surface of the scapula (Figure 3). Computed tomography scan provides more detail regarding the location and size of the mass (Figure 4). Treatment for symptomatic osteochondromas of the scapula is surgical excision of the mass and any reactive bursa. Overall prognosis following excision is good, although recurrence may occur if excision is incomplete (Figure 5).6,7,9
Figure 3: Scapular-Y radiograph showing typical appearance of an osteochondroma arising from the volar surface of the scapula. Figure 4: Axial CT of right shoulder showing typical appearance of osteochondroma of the scapula arising from the volar surface of the scapula. Note thin stalk of mass connected to medullary space of scapula. Figure 5: Repeat scapular-Y radiograph obtained 1.62 years post-resection.
In our case series, 12.7% of symptomatic osteochondromas treated with surgical excision involved the scapula. One patient experienced a recurrence requiring 2 additional surgical procedures that were performed at an outside institution. The ventral surface was involved most commonly, and isolated unilateral lesions predominated. Post-resection results show an overall good functional outcome. An average DASH score of 11.7 indicates little to no functional disability at 4.17 years postresection. An average score of
