Early results of isoelastic hemiarthroplasty in chronic shoulder arthritis

Fourteen isoelastic shoulder hemiarthroplasties were studied in patients with shoulder pain due to chronic rheumatoid arthritis and osteoarthritis unresponsive to conservative means. The average follow-up was 27 months (range: 12-46 months) and the average patient age was 66.4 years (range: 54-79 years). A Constant shoulder score was used to assess results. Pain relief was obtained in 85.7% of patients. Function scores averaged 8 preoperatively and 13 postoperatively. Subjectively, 12 patients improved. Average gain was 33 degrees of abduction, 35 degrees of flexion, and 21 degrees of external rotation. Internal rotation improved by two levels on the spine. Total shoulder scores improved from an average of 42 points preoperatively to 78 points postoperatively. There was 1 complication of immediate postoperative dislocation. Early results with isoelastic (polyacetyl resin) shoulder hemiarthroplasty are encouraging. The prosthesis is inexpensive and easy to use, requires minimal bone resection, involves cementless fixation, and has established results in tumor surgery. Its long-term value for chronic arthritis will be reported as part of an ongoing prospective study.