Endoprosthetic surface replacement of the humeral head

The concept of an endoprosthetic surface replacement of the humeral head di ffers from that of stemmed endoprostheses. It is the replacement of the des troyed joint surface with reconstruction of the normal anatomy and minimal bone resection. The aim of this prospective study was to evaluate the short -term results of a newly developed cup arthroplasty (Durom-Cup) for the hum eral head. In a prospective study, 39 patients with 46 Durom-Cups were evaluated preop eratively and every 3 months postoperatively. The average follow-up was 15/-9 months. The group included 28 shoulders with rheumatoid arthritis, 15 j oints with osteoarthritis, and 3 humeral head necroses. The Constant-score and SAS-function score were used. The Constant-score increased from 20.25+/-9.06 points preoperatively to 46. 62+/-14.05 at 3 months, to 48.11+/-14.49 at 6 months, and to 55.25+/-11.6 a t 9 months postoperatively. The Constant-score stayed at this level during further follow-up and was 55.81+/-16.31 at 12 months postoperatively. The b est results were seen in the group of humeral head necroses with a Constant -score of 71.0+/-12.2 compared to 54.66+/-13.89 in the group of osteoarthri tis and 56.78+/-13.33 in patients with rheumatoid arthritis at 12 months po stoperatively. The results with the Durom-Cup are encouraging so that cup arthroplasty see ms to be a good alternative to stemmed prostheses. The main advantages of t he humeral head resurfacing are the bone-preserving fixation and the relati vely simple surgical technique.