Avoiding instability: The features that matter

When replacing the human knee, we attempt to reproduce the stability of the normal knee so that the patient perceives the knee arthroplasty to feel and function similar to a normal knee. Avoiding instability requires understanding the definition and implication of stability to the implant design features and the arthroplasty procedure. The purpose of this paper is to define the elements of stability in total knee arthroplasty and to explain the mechanics of the knee that will translate to optimal knee stability after TKA.