Total knee arthroplasty treatment of rheumatoid arthritis with severe versus moderate flexion contracture

Background: This study aims to explore the technique of soft tissue balance and joint tension maintenance in total knee arthroplasty (TKA) for the rheumatoid arthritis (RA) patients with flexion contracture of the knee. Methods: This retrospective study reviewed flexion contracture deformity of RA patients who underwent primary TKA and ligament and soft tissue balancing. Based on the flexion contracture deformity, the remaining 76 patients available for analysis were divided into two groups, i.e., severe flexion group (SF) and moderate flexion group (MF). Results: There were no intraoperative complications in this study. All patients had improved Knee Society Rating System scores and range of motion. The flexion contracture was completely corrected in MF and SF patients. There were no cases of patellar dislocation, but three cases had mild mediolateral instability in severe flexion group. Four knees (two knees in SF versus two knees in MF) had transient peroneal nerve palsy but recovered after conservative therapy. Conclusions: TKA can be performed successfully in the RA knees with severe flexion contracture. It is very important in TKA to maintain the joint stability in the condition of severe flexion contracture deformity of the RA knee.