In a two-year follow-up on sixteen total shoulder arthroplasties done with the semiconstrained Stanmore prosthesis, we found that patients with rheumatoid arthritis or osteoarthritis of the glenohumeral joint noted a greater relief of pain, were more satisfied with their surgery, used fewer analgesics, and had a greater increase in range of motion than patients with traumatic arthritis. Patients with irreparable rotator-cuff injury demonstrated the poorest range of motion postoperatively. Younger patients gained significantly more motion than older patients. All patients continued to have difficulty with lifting heavy loads. Complications consisted of one patient with a chronically dislocating prosthesis, one patient with a deep wound infection, and one with a postoperative wound dehiscence. The average follow-up was 31.4 months, ranging from twenty-four to fifty-three months.