Early results of isoelastic hemiarthroplasty in chronic shoulder arthritis

Fourteen isoelastic shoulder hemiarthroplasties were studied in patients wi th shoulder pain due to chronic rheumatoid arthritis and osteoarthritis unr esponsive 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 ye ars). A Constant shoulder score was used to assess results. Pain relief was obtai ned in 85.7% of patients. Function scores averaged 8 preoperatively and 13 postoperatively. Subjectively, 12 patients improved. Average gain was 33 de grees of abduction, 35 degrees of flexion, and 21 degrees of external rotat ion. Internal rotation improved by two levels on the spine. Total shoulder scores improved from an average of 42 points preoperatively to 78 points po stoperatively. There was 1 complication of immediate postoperative dislocat ion. Early results with isoelastic (polyacetyl resin) shoulder hemiarthroplasty are encouraging. The prosthesis is inexpensive and easy to use, requires mi nimal bone resection, involves cementless fixation, and has established res ults in tumor surgery. Its long-term value for chronic arthritis will be re ported as part of an ongoing prospective study.