An artificial knee joint that includes a femoral component with a
specially shaped bearing surface and a tibial component, whose surface
interacts with the femoral surfaces. The interaction provides for the
motion and stability characteristics of the anatomic knee. The
interaction between the femoral and tibial surfaces is such that as the
knee is flexed to maximum, the femoral component moves posteriorly on the
tibial surface, more so on the lateral side than on the medial side. This
is accomplished by the interaction of a projecting tibial post inside a
cupola in the center of the femoral component, and by the saggital radius
on the medial side being smaller than that on the lateral side. The
prevention of anterior sliding of the femur on the tibia in early flexion
is accomplished by the interaction between a distal-anterior recess on
the medial side of the femur and an apposing raised pad on the tibial
surface. Rotational laxity at all angles is allowed by the presence of
only one recess pad and by non-conforming femoral-tibial surfaces on the
lateral side.