 This prospective, randomized, single-blinded clinical trial compared a mobile-bearing total knee system with two types of fixed-bearing total knee systems in patients undergoing cemented total knee arthroplasty. The devices to be used are FDA approved: the Sigma Knee System mobile-bearing, the Sigma, Pressfit Condylar posterior cruciate substituting fixed-bearing system with a metal backed tibial tray, and the Sigma press-fit condylar posterior cruciate substituting system fixed bearing with an all polyethylene tibial tray. 