An unusual cause of shoulder pain: osteochondroma of ventral scapula (a case report)

Abstract

Osteochondromas mainly affect the metaphysis of long bones such as femur, humerus, and tibia. It is unusual in flat bones such as scapula. Osteochondroma of ventral surface of scapula is one of the rare cause of shoulder pain and difficult to diagnose in first place. We report the case of an 18-year old girl, presenting progressive right shoulder pain for two years. Physical examination showed an imbalance of the shoulders, a winging of the right scapula, and a snapping of the shoulder on mobilization. Radiographic evaluation showed a pedunculated bony structure extruding from the scapula. Computed tomography (CT) scanner and magnetic resonance imaging (MRI) revealed a bony exostosis along the medial border on the ventral surface of the right scapula. The patient had an excision of the exostosis. Histologic examination confirmed that the specimen was an osteochondroma with no signs of malignant transformation. The shoulder was immobilized for two weeks. The patient has regained full function of her shoulder, six weeks postoperatively.