Osseointegrated silicone implants: 18 patients with 57 MCP joints followed for 2 years

Abstract
20 patients were operated on consecutively with osseointegrated MCP joint prostheses in 64 joints at our department between September 1993 and February 1995. The one-stage procedure included joint resection and cancellous bone grafting from the iliac crest before insertion of screw-shaped titanium fixtures, connected with a flexible silicone spacer. 18 patients (57 joints) were clinically and radiographically examined at median 28 (1 8-37) months postoperatively. Indications for surgery were joint destruction due to chronic arthritis in 17 patients (56 joints), and posttraumatic arthrosis in 1 patient (1 joint). Postoperative median range of motion was 40 (15-85) degrees, with an extension deficit of 30 (-20-70) degrees. 16 patients were satisfied, and had good pain relief and substantially improved postoperative hand function, evaluated with the standardized Sollerman hand function test. Radiographic osseointegration was obtained in 11 2 of 11 4 titanium fixtures (98%), but fracture of the silicone spacer was observed in 14 implants (25%). We conclude that osseointegration of longitudinal titanium fixtures in the bone marrow canal is possible in a one-stage procedure, but our findings show the need for a new, more durable joint spacer.