Classification of Mobile-Bearing Knee Designs: Mobility and Constraint

Restoration of normal knee joint function through surgical reconstruction is dependent upon load-sharing between the implant and the surrounding soft-tissue structures. Mobile-bearing knee designs offer the advantage of maximally conforming geometry while diminishing constraint forces to fixation interfaces through plateau mobility. The degree of mobility afforded by these designs in the anterior-posterior, medial-lateral, and rotational directions defines the required interaction between the soft tissues and the design geometry to maintain a stable articulation.