Abstract: The stem is cast about an irregular plug body, which is then removed, leaving a wall thickness that satisfies the opposing constraints of high strength and relatively low stiffness. The plug narrows the prosthesis wall thickness in upper regions thereof and strengthens the wall about regions of recessed or discontinuous features, or high load coupling, to assure that the stem has adequate strength in regions of high strain, while effectively coupling strain to surrounding bone. The prosthesis is produced in a range of sizes, and plugs or entire molds for casting the hollow body are readily made and modified by a three-dimensional printing mold fabrication technique.

Abstract: A bone prosthesis has a stem with a hollow interior and an external surface that allows wedging contact with surrounding bone while transferring strain at a level comparable to that of natural bone. The stem is cast about an irregular plug body, which is then removed, leaving a wall thickness that satisfies the opposing constraints of high strength and relatively low stiffness. The plug narrows the prosthesis wall thickness in upper regions thereof and strengthens the wall about regions of recessed or discontinuous features, or high load coupling, to assure that the stem has adequate strength in regions of high strain, while effectively coupling strain to surrounding bone. The prosthesis is produced in a range of sizes, and plugs or entire molds for casting the hollow body are readily made and modified by a three-dimensional printing mold fabrication technique.

Abstract: A knee joint prosthesis includes a femoral component, a tibial plateau and a tibial bearing member. The design and geometry of the articulation surfaces of the condylar elements of the femoral component and tibial bearing member is such that contact area between the articulation surfaces is maximized both in perfect alignment and in malalignment conditions. Moreover, contact stresses placed upon the articulation surfaces in perfect alignment and in malalignment are reduced. High contact area and low contact stress on the articulation surfaces can be maintained even while matching knee prosthesis components of different sizes.