Secondary synovial chondromatosis of the subacromial subdeltoid bursa with coexisting glenohumeral osteoarthritis: Case report.

Rationale: Synovial chondromatosis of the shoulder joint is uncommon; this condition usually affects the knee joint and the hip joint. Lesions of multiple chondral nodules form in the synovium and are usually found within the joint capsule. Treatment of synovial chondromatosis consists of loose body removal and synovectomy. In synovial chondromatosis of the shoulder, arthroscopic loose body removal and synovectomy have been reported with good outcomes. Arthroplasty can be a treatment option when osteoarthritis co-occurs at the affected joint. Since incidence of glenohumeral joint osteoarthritis is low compared to osteoarthritis of the knee or hip joints, reports of shoulder synovial chondromatosis treated with arthroplasty are scarce.

Patient Concerns: A 79-year-old woman presented with right shoulder pain with loss of motion for several years without a history of trauma.

Diagnoses: Degenerative changes in the humeral head and glenoid were noted and multiple loose bodies were found in the subdeltoid bursa, and the subacromial bursa. The pathology of loose bodies showed degenerated cartilage tissue and some bony components. Characteristic concentric rings of calcification were observed, indicative of secondary synovial chondromatosis. The diagnosis was secondary synovial chondromatosis of the subacromial subdeltoid bursa with coexisting glenohumeral osteoarthritis.

Interventions: The patient was treated with loose body removal, extensive synovectomy, bursectomy and reverse total shoulder arthroplasty.

Outcomes: Visual analog scale for shoulder pain, range of motion of shoulder joint had improved demonstrating a good short-term outcome and there was no radiographic evidence of disease recurrence.

Lessons: In synovial chondromatosis of the shoulder, loose bodies may form in the bursa. In combination with degenerative osteoarthritis of the glenohumeral joint, arthroplasty is a viable option.