Proximal bursitis in active polymyalgia rheumatica

Background: The cause of musculoskeletal symptoms in the proximal extremities of patients who have polymyalgia rheumatica is not completely understood. The diffuse and severe discomfort can only be partially explained by the mild joint synovitis that is observed in these patients. Objective: To determine the involvement of the synovial structures of the shoulder girdle of patients who have active symptoms of polymyalgia rheumatica. Design: Case-control study. Setting: 2 secondary referral centers of rheumatology. Patients: 13 case-patients who had active symptoms of polymyalgia rheumatica seen during a 6-month period, 9 control-patients who had early symptoms of elderly-onset rheumatoid arthritis, and 10 age-matched healthy controls. Measurements: Magnetic resonance imaging of the shoulder was done on the 13 case-patients, 9 control-patients, and 10 healthy controls. Results: The frequency of subacromial and subdeltoid bursitis was significantly higher in the case-patients (who had polymyalgia rheumatica) than in the control-patients (who had elderly-onset rheumatoid arthritis). The frequencies of synovitis of the joints and tenosynovitis of the biceps did not significantly differ between the 13 case-patients and the 9 control-patients. None of the healthy controls showed evidence of fluid accumulation in the joints, bursae, or sheaths of the long head of the biceps. Conclusions: Inflammation of subacromial and subdeltoid bursae in association with synovitis of the glenohumeral joints and tenosynovitis of the biceps may contribute to the diffuse discomfort in the shoulder girdle observed in patients with polymyalgia rheumatica.