Long-term followup of posterior-cruciate-retaining TKR in patients with rheumatoid arthritis.

A consecutive series of 220 primary posterior-cruciate ligament-retaining total knee replacements were done in 148 patients with rheumatoid arthritis. From this group, 212 total knee replacements (141 patients) were followed up for an average of 10 years. Average knee scores at 5, 10, 15, and 20 years after operation improved to 86, 83, 88, and 89, respectively, and average function scores improved to 70, 72, 64, and 88, respectively. Five knees (2.4%) were revised for deep infection. Posterior instability, recurvaum, or mediolateral instability, combined or otherwise, occurred in 15% (32 knees; in 31 patients). Three tibial components (1.4%) were revised: one for suspected aseptic loosening and two for instability. Excluding infections and failed metal-backed patellas, Kaplan-Meier survival rates were 99.5%, 97.9%, and 96.5%, respectively. Favorable long-term results may be achieved with posterior-cruciate ligament-retaining total knee replacements in patients with rheumatoid arthritis. Concern remains, however, about rotational instability in certain cases associated with preoperative genu-valgum and ipsilateral planovalgus deformity.