Total knee arthroplasty in rheumatoid arthritis.

The results of total knee arthroplasty (TKA) have improved steadily during the past decade due to refinements in design, fixation, and surgical technique. A review of the evolution of prosthetic design and of the clinical performance of the concept of cruciate-sparing knee arthroplasty provides both direction for improvement and cause for optimism. The results of 798 TKAs performed in one institution were reviewed to validate the principles and concepts of prosthetic design and surgical technique. During the years reviewed the incidence of good and excellent results rose from 67% to 92%, while revision rates declined. Failures resulting in revision were due to loosening in 1.3% of the knees, patellofemoral pain in 1.8%, and infection in 0.4%. Patients with rheumatoid arthritis (RA) achieve results similar to those of patients with osteoarthritis with regard to range of motion and pain relief; the polyarticular nature of RA results in some decrease in functional outcome, primarily related to disease in other joints. In the relatively short follow-up evaluation, the failure rate is acceptably low, and radiolucent lines, indicative of potential later failure, appear to be diminishing in frequency and extent. The improving success rate in each successive series of TKAs reviewed in this paper provides grounds for optimism regarding the future of TKA, and important lessons can be derived from the failures.