Patent ID: 7968209

Claim:
A medical implant comprising: (a) a first implant portion, said first implant portion having a bearing surface; (b) a second implant portion, said second implant portion having a bearing surface; (c) wherein the bearing surface of said first implant portion and the bearing surface of said second implant portion each having a size and shape to engage or cooperate with one another; (d) wherein one or both of the two portions of the medical implant comprises a biocompatible alloy having an elastic modulus less than 200 GPa; (e) wherein the difference in radius of the mating portions is greater than about 50 microns; and (f) wherein one or both of said first implant portion and said second implant portion consists of: a substrate; and a diffusion hardened zone in contact with said substrate, said diffusion hardened zone comprising a diffusion hardening species, said diffusion hardened zone having a thickness of 5 microns or greater.