Although many total knee designs predate the total condylar prosthesis designed by Insall and others, its introduction in 1973 marked the beginning of the total knee arthroplasty (TKA) era (Fig. 7.1). This prosthesis design allowed mechanical considerations to outweigh the desire to reproduce anatomically the kinematics of normal knee motion. Influenced largely by the previous Imperial College/London Hospital design, both cruciate ligaments were sacrificed, with sagittal plane stability maintained by the articular surface geometry. The original cemented total condylar prosthesis not only set the standard for survivorship of TKA but also formed the basis of designs for decades to follow. Newer knee replacement designs have now evolved to the point where several have reported long-term survivorships of over 90% at 15- to 20-year follow-up.
