Optimizing range of motion in cruciate-retaining mobile-bearing tka: experience with 2000 cases

We describe experience with 2000 cruciate-retaining Sigma RP total knee arthroplasties performed between September 2000 to January 2006. All procedures were performed with a midvastus arthrotomy, medioposterior release, and posterior condylar clean-out technique. This implant design uses a congruent polyethylene bearing to diminish contact stress while allowing rotation between the polyethylene bearing surface and tibial tray. Of the 2000 knees, 1596 had follow-up data at one year. Seven hundred-twenty-seven had an average flexion of 123 degrees, 692 had an average Knee Society Score of 94, and 672 had an average function score of 86.