Patent ID: 7658767

Claim:
A hinged knee prosthesis comprising: a femoral component configured to be coupled to a femur and including a body and a side wall having an elongated slot formed therein, a tibial component configured to be coupled to a tibia and defining a cavity, a polymer bearing component positioned between the femoral component and the tibial component, the bearing component having (i) a medial bearing surface configured to articulate with a medial condyle surface of the femoral component and (ii) a lateral bearing surface configured to articulate with a lateral condyle surface of the femoral component, and a hinge assembly to pivotably couple the femoral component to the tibial component and to substantially prevent anterior/posterior movement of the bearing component with respect to the tibial component, the hinge assembly including (i) a piston configured to be received within the cavity of the tibial component and (ii) a hinge pin received through a bore formed in the piston and the elongated slot of the femoral component, the hinge pin to translate along the elongated slot relative to the femoral component to provide a variable axis of rotation for the femoral component.