Abstract: A method of surface hardening cobalt-chromium based orthopedic implant devices, and a cobalt-chromium orthopedic implant device prepared by the disclosed method. An orthopedic implant device made of a cobalt-chromium or cobalt-chromium-molybdenum alloy, such as ASTM F-75 or ASTM F-799 is exposed to molecular nitrogen gas or ionized nitrogen at a process temperature and for a process time duration sufficient to enhance surface hardness and wear resistance properties, without the formation of a measurable nitrogen layer that tends to increase surface roughness and brittleness and diminish wear resistance properties. The process temperature is in the range of 500.degree. F. to 2400.degree. F., preferably about 1400.degree. F., and the process time duration at the preferred process temperature is approximately 48 hours.

Abstract: A femoral component of a knee prosthesis, including a cobalt-based alloy substrate and a titanium fiber metal pad bonded thereto by means of an interlayer of a cobalt-based alloy including nickel. More specifically, a method of bonding a titanium porous surface to a cobalt-based alloy in an orthopaedic implant device, by first applying an interlayer of a cobalt-based alloy including nickel to the substrate and then bonding a porous structure to the interlayer. In one embodiment, an interlayer of L-605 is first applied to a substrate of Co-Cr-Mo by diffusion bonding at approximately 2200.degree. F. and then a fiber metal pad of CP-titanium is diffusion bonded to the interlayer at approximately 1650.degree. F. A layer of CP-titanium may optionally be placed intermediate the fiber metal pad and interlayer before the second diffusion step. In an alternative embodiment, MP-35N alloy may be substituted for the L-605 alloy.

Abstract: A method of surface hardening titanium orthopedic implant devices, and a titanium orthopedic implant device prepared by the disclosed method. An orthopedic implant device made of pure titanium or a titanium alloy, such as Ti-6Al-4V (ELI) is exposed to molecular nitrogen gas at a process temperature and for a process time duration sufficient to enhance surface hardness and wear resistance properties, without the formation of a measurable TiN layer that tends to increase surface roughness and diminish wear resistance properties. The process temperature is in the range of 750.degree. F. to 1300.degree. F., preferably about 1100.degree. F. and the process time duration at the preferred process temperature is approximately 8 hours. The hardened surface of the titanium implant occurs primarily due to solid solution hardening of the titanium with nitrogen by dissolution.

Abstract: A prosthetic implant including a base portion and an additional portion which is to be securely attached to the base portion. The additional portion includes at least one post extending therefrom which is adapted to be readily received in a corresponding reverse tapered hole in the base portion. The post is adapted to be mechanically spread out to cause at least a portion of the post to become wider than the opening of the hole, thus resisting subsequent separation of the post from the hole. This secures the additional portion to the base portion of the implant. The post may be a stud-type extension integrally formed with or secured to the additional portion, or the post may be a separate member which is received in a post hole in the additional portion such that the post portion of the separate member extends from the additional portion. The post may be solid or may have a channel therethrough. The additional portion may include a substrate with a porous surface bonded or secured thereto.

Abstract: A surface treatment process for stainless steel orthopedic implant devices and an orthopedic implant device surface treated in accordance with the disclosed process are disclosed. A rough ground or machined stainless steel part is shot blasted with stainless steel shot. The device is then shot blasted with glass beads having a nominal size of between one-tenth and one-half that of the stainless steel shot. Electropolishing and passivation follow the shot blasting steps. A part thus treated includes a heavily cold-worked outer layer that enhances the fatigue properties of the stainless steel orthopedic implant device.