Shoulder arthroplasty with the Neer Mark-II prosthesis.

Total shoulder joint replacement was used as primary intervention in 50 shoulders--35 with rheumatoid arthritis, eight with osteoarthritis, and seven with traumatic arthritis. Follow-up time was 27 (12-42) months. The primary indication for the operation was chronic severe pain; improvements in motion and function were secondary objectives. Relief of pain was obtained in 46 of 50 shoulders. The best results regarding pain, motion, and function were obtained in the osteoarthritic group. The majority of patients with rheumatoid arthritis obtained pain relief and the largest increase in range of motion occurred in this group, although full range of motion was never regained. The results in patients with traumatic arthritis seemed unpredictable. Two shoulders were complicated by glenoid loosening, one by humeral subluxation, and one by musculocutaneous nerve palsy.