Patent ID: 7799083

Claim:
A motion restoring prosthesis to be interposed between the ends of mammalian bones adjoining a natural appendage or spinal joint to provide articulation therebetween comprising: two components, each component defining an outer surface for attachment to a respect bone end and an articulating surface for engaging the articulating surface of the other component; at least one of the components having an inner and outer section, the inner section defining the articulating surface and being formed of a primary, relatively hard, stiff material having a first flexural modulus, the outer section defining a bone facing surface to be attached to one of the bone ends and formed of a secondary softer material having a second flexural modulus, the first flexural modulus being greater than the second flexural modulus, the outer section functioning as a stress softening material to more evenly distribute the forces from the articulating surfaces to the associated bone end, wherein the bone facing surface of said at least one component has been roughened and/or made uneven to enhance an attachment of adjacent bone and covered with a thin coating of Ti within a range of 0.5 to 15 microns in thickness to enable bone-on growth while maintaining an appropriate distribution of forces through the thin coating of Ti to permit the stress shielding characteristic of the coated secondary softer material to be operative.