Survivorship of unconstrained total shoulder arthroplasty.

The results of fifty-three unconstrained (Neer-II or Gristina) total shoulder arthroplasties were reviewed with the use of survivorship analysis. Failure was defined as the need for revision or the onset of the patient's dissatisfaction. The method of survivorship analysis is presented in detail. Fifty-one total shoulder arthroplasties were followed for a minimum of two years (average, sixty-seven months). The results are reported with the use of the American Shoulder and Elbow Surgeons' rating form. After eleven years, the survivorship was 73 per cent for all prostheses, 71 per cent for the Neer prostheses, and 92 per cent for all prostheses in patients who had rheumatoid arthritis. Data on survivorship of the Gristina prosthesis were available after four years only, at which time it was 100 per cent. The relief of pain, which was the primary reason for the operation, was good or excellent in 82 per cent, improved in 6 per cent, and poor in 12 per cent of the shoulders in these patients.