Bearing surfaces for motion control in total knee arthroplasty

Abstract

A goal of knee replacement is to achieve normal function and kinematics. One solution is to preserve all of the ligaments and use compartmental components. However, if complete resurfacing is indicated, one or both of the cruciates is usually resected, and dished bearing surfaces are used to replace their function. Intercondylar cams can be added to ensure posterior femoral contacts in high flexion. In this paper, an alternative scheme is presented where the bearing surfaces are not simple combinations of radii but are based on converging or diverging mediallateral bearing spacing as flexion proceeds. This scheme produces natural roll-back with flexion, more pronounced on the lateral side, while preserving the laxity which is characteristic of the normal knee. It is proposed that this design can produce natural knee kinematics which may result in close to normal function. © 2005 Springer Medizin Verlag Heidelberg.