Abstract: A prosthesis for the surgical replacement of a dysfunctional knee joint is disclosed. The prosthesis includes a tibial platform, one or two tibial bearing inserts, and a femoral component.In a unicompartmental embodiment of the invention, the tibial platform includes a spike for securing the tibial platform to the tibia. The tibial platform, in the unicompartmental embodiment, includes a track, which may be curved, and which is slidably engaged in dovetail fashion by a tibial bearing insert, typically of high molecular weight polyethylene. The superior surface of the tibial bearing insert is concave spherical, designed to slidably engage the inferior surface of the femoral component. The inferior surface of the femoral component is generally convex spherical, with radius of curvature slightly smaller than the radius of curvature of the tibial bearing insert. In some embodiments the inferior surface of the femoral component may have two or more differing radii of curvature at different points on such surface.

Abstract: A prosthesis for the surgical replacement of a dysfunctional knee joint. The prosthesis includes a tibial platform, one or two tibial bearing inserts, and a femoral component.In a unicompartmental embodiment of the invention, the tibial platform includes a spike for securing the tibial platform to the tibia. The tibial platform, in the unicompartmental embodiment, includes a track, which may be curved, and which is slidably engaged in dovetail fashion by a tibial bearing insert. The superior surface of the tibial bearing insert is concave spherical, designed to slidably engage the inferior surface of the femoral component. The inferior surface of the femoral component is generally convex spherical, with radius of curvature slightly smaller than the radius of curvature of the tibial bearing insert.

Abstract: A prosthesis providing improvement over the floating center prosthetic joint of U.S. Pat. No. 3,916,451 by providing, inter alia, an improvement in the structure for retaining the floating ball in the humeral component and the strength of the lip of the floating ball, and further providing piston-cylinder means utilizing body fluid present in the implanted prosthesis to provide hydraulic action for reducing the amount of shock loads transmitted to the implanted prosthesis during normal human activity.