Total condylar III knee prosthesis. Long-term follow-up study.

The total condylar III knee prosthesis (TCP III) is a constrained, unlinked knee that provides medial and lateral stability through a rectangular tibial post and a high femoral box. Thirty-one knees were implanted in 25 patients. There were 17 primary arthroplasties and 14 revisions. The average follow-up period was 3.8 years. The average arc of motion was improved from 63 degrees to 97 degrees. This resulted in 77% good and excellent results. There were five failures (16%), all of which occurred in the revision group. These results compare favorably with results of constrained prostheses; however, the deformity in this group was quite severe. The major indications for use of TCP III would be medial ligament loss, severe valgus or combined deformities, or cases of unstable revision in which a surface arthroplasty will not suffice. The prosthesis should not be used in cases that demonstrate massive bone loss. In those cases, the prosthesis should have a weight-bearing intramedullary stem to transfer stress lines to cortical bone.