Knee prosthesis with accommodation for angular misalignment

Claim 1

In a knee prosthesis having a femoral component and a tibial component, the tibial component including a bearing member and the femoral component including an arcuate element for confronting and engaging the bearing member to accomplish articulation of the prosthesis, the femoral component and the tibial component ordinarily being aligned axially along a mechanical axis passing through the femoral head of the corresponding hip joint and the engagement between the arcuate element of the femoral component and the bearing member of the tibial component ordinarily taking place along complementary articular surface areas of the arcuate element and the bearing member, the improvement comprising misalignment accommodating means for accommodating limited angular misalignment between the femoral component and the tibial component while maintaining engagement between the arcuate element and the bearing member along complementary articular surface areas, said misalignment accommmodating means including complementary medial-lateral surface profile contours along the complementary articular surface areas, said surface profile contours having a medial-lateral articular radius defining an arcuate profile, the origin of which radius lies generally along said mechanical axis such that upon angular misalignment of the femoral component and the tibial component, the resulting relative medial-lateral displacement of the articular surface areas will be accommodated while area engagement between the arcuate element and the bearing member is maintained along said complementary articular surface areas.