Abstract
Eighty-five knee replacements using a total condylar knee prosthesis in patients with rheumatoid arthritis (RA) were followed for 5 to 16 years (mean 8.3 years) . Three cases developed an aseptic loosening but only one case required revision surgery. The ten-year cumulative survival rates were 98.0% when revision was considered an indication of failure, and 95.4% when radiographic evidence of loosening was considered an indication of failure. No replaced knee developed primary or secondary infection. According to the Knee Func-tion Scoring System devised by three universities, scores averaged 42.6 points preoper-atively, 77.9 points one year postoperatively, and 69.8 points at the final follow-up. The decrease in the average total score between the one-year and the final follow-up evaluation was attributed primarily to a decrease in the score for walking ability and ADL. In some severe RA cases with multiple joint destruction, postoperative scores for walking ability, ADL and pain decreased with time. Durability of the total condylar knee prosthesis was good in RA patients, and the results of our investigation suggest that prevention of systemic progression of RA severity is important to maintain good knee function obtained after the arthroplasty.
