Patent ID: 8545570

Claim:
A hinged knee prosthesis, comprising: (a) a femoral component, the femoral component comprising medial and lateral condylar articulating surfaces; (b) a tibial component, the tibial component comprising medial and lateral articulating surfaces for articulating with the medial and lateral condylar articulating surfaces of the femoral component; and (c) a mechanical linkage connecting the femoral component to the tibial component; wherein the mechanical linkage, when connecting the femoral component to the tibial component, defines a flexion-extension axis about which the femoral component can rotate with respect to the tibial component; and wherein, when the mechanical linkage is connecting the femoral component to the tibial component and the medial and lateral condylar articulating surfaces of the femoral component are in contact with the articulating surfaces of the tibial component, articulating the hinged knee prosthesis from an extended orientation to a flexed orientation causes: (i) the flexion-extension axis to move in a superior to inferior direction while not moving in an anterior-posterior direction; and (ii) a lateral center of contact between the lateral condylar articulating surface of the femoral component and the lateral articulating surface of the tibial component to move in an anterior to posterior direction.