[Ulnar head prosthesis].

The ulnar head prosthesis has been the subject of a prospective multicenter-study since 1995. Until 2000, it has been used in 57 patients by the study group. In 35 patients, the indication was painful instability of the distal end of the ulna following previous resection arthroplasties, and in 22 patients it was painful arthritis of the distal radioulnar joint (DRUJ). The mean follow-up was 38 months. Pronation increased from a preoperative mean of 63 degrees to a postoperative value of 78 degrees, while supination increased from 43 degrees to 76 degrees. Grip strength improved from a preoperative mean of 51% to a postoperative mean of 77% of the opposite limb. Pain, measured on the verbal pain scale (1-4), was reduced remarkably from a preoperative mean level of 3.6 to a postoperative mean of 1.7. Patient' satisfaction was evaluated using the visual analog scale (0-10) and improved from a preoperative mean of 2.1 to a postoperative mean of 7.9. With one exception of loosening, we consistently found bony integration of the shaft of the prosthesis. Stability of the DRUJ was achieved in all but three patients. This method has given reliable and excellent results as a salvage procedure for failed resection arthroplasties of the DRUJ with painful instability of the distal end of the ulna. We consider the method an alternative treatment option for the arthritically destroyed DRUJ. Sufficient soft tissue to stabilise the prosthesis is needed to successfully reconstruct the DRUJ.