Status of total shoulder arthroplasty.

Some patients with degenerative, rheumatoid, and traumatic diseases of the glenohumeral joint require treatment primarily to relieve pain. In the absence of complete knowledge of basic mechanical requirements, clinical trials with both constrained and resurfacing prosthesis were initiated. Three types of constrained prostheses were placed in 23 patients. Pain relief was satisfactory, but six reoperations were necessary and motion greater than 90 degrees was rarely achieved. Twenty-five prostheses that were used to replace the glenohumeral articulation, but were not stable by virtue of design, were implanted. Again, pain relief was excellent; mechanical problems were not present, and motion was almost always greater than 90 degrees. Achieving stability by capsular-muscle cuff repair has not been as great a problem as anticipated. These results suggest that more emphasis should be placed on repair of the glenohumeral stabilizing structures than on their replacement.