US Patent 6893467 Knee prosthesis

The invention concerns a prosthesis wherein the contact surfaces of the femoral part (i), the insert (3) and the knee joint are defined by the combination of two curves, a spiral-type curve in the saggital plane following an undulating curve (sinusoidal) in the frontal plane. The latter comprises two concave lateral parts and a central dome-shaped convex part, the three parts being connected without any angulation, protuberance, or flat parts or bends and providing continuous medio-lateral contact on the three zones, from complete extension to complete bending, and a concave-convex nesting in the central zone.