Fifty-one knees in 40 patients with joint surface degeneration accompanied by fixed flexion contractures (FFC) greater than 20 degrees were treated with total knee arthroplasty using a minimally constrained posterior cruciate ligament retaining prosthesis. Special techniques were employed in an attempt to achieve maximal correction at the time of surgery. The residual FFC measured 3.1 degrees at the completion of the arthroplasty, 10.1 degrees at three months, and 7 degrees at two years. At 55 months postoperatively, the FFC for the osteoarthrotic group had improved from 25.5 degrees to 3.6 degrees, whereas the rheumatoid group improved from 28.7 degrees to 8.6 degrees. The average knee score for the osteoarthrotic group was 89 compared with 81 for the rheumatoid group. Knees that were left with greater residual FFC at the completion of the arthroplasty were found to have greater residual FFC at the latest review.