Pfizer Hospital Products Group, Inc.

Stryker Technologies Corporation

Larry J Gustavson

Kathy K Wang

John H Dumbleton

Melvin M Schwartz

Orthopaedic wires, cables, and methods of making them are based on the discovery that, in clinical orthopaedic applications, material toughness and fatigue strength are as important or more important than ultimate tensile strength. The wires and cables of the invention have a tensile strength lower than 280 ksi, but higher than 175 ksi. The presently preferred wires and cables have a tensile strength of 210-240 ksi. The fatigue strength of the wires and cables of the invention is between six and ten times that of other high strength cables used in orthopaedic applications. One method of making the wires and cables includes annealing high tensile strength wire or cable to reduce its tensile strength and thereby increase its fatigue strength. Another method is to cold work fully annealed wire or cable to the extent of decreasing its cross section by approximately 18%. Presently preferred wires and cables according to the invention are made from chromium-cobalt alloy, preferably wrought VITALLIUM (registered trademark) alloy.

Orthopaedic wires and cables and methods of making same

A prosthetic part for use as an orthopaedic implant has a cast metal base member and a tissue ingrowth surface spaced outwardly therefrom. The tissue ingrowth surface is in the form of a cast metal lattice element which covers at least a part of the outer surface of the base member. The cast metal lattice element is cast simultaneously and integrally with the base member from the same metal. This metal may be any well known castable material for orthopaedic implants such as Vitallium or titanium. The lattice element is in the form of a grid-like mesh which includes spaced members cast integrally with the wire mesh and the base member to space the lattice element a predetermined distance above the prosthesis surface. An investment casting technique wherein a meltable material is coated with a ceramic casting shell is utilized to produce the integrally cast orthopaedic implant and tissue ingrowth surface.

Cast bone ingrowth surface

A prosthetic part for use as an orthopedic implant has a base member defining an outer surface for implantation adjacent a prepared bone surface. The outer surface includes a recessed area having a predetermined shape and depth. A first rigid plate having this predetermined shape and having a plurality of elongated slots formed therein is fixedly attached within the recesssed area of the base member. A second rigid plate also having the same predetermined shape as the recess and also having a plurality of elongated slots formed therein is attached to the first rigid plate. The elongated slots of the second plate are angularly offset with respect to the elongated slots in the first plate to produce a controlled porosity. The thicknesses of the first and second plates are predetermined so that the outer surface of the second plate is continuous with the non-recessed outer surface of the base member.

Porous fixation surface

Method for preparing a high strength, low modulus, ductile, biocompatible titanium base alloy containing one or more isomorphous beta stabilizers, eutectoid beta stabilizers and optional alpha stabilizers, characterized by a modulus of elasticity not exceeding 100 GPa; comprising blending pre-selected amounts of the alloying ingredients, melting the blend in a plasma arc furnace, allowing the melt to cool and solidify, vaccum arc remelting and thermomechanically processing the resulting solid to provide the desired alloy.

Method of making high strength, low modulus, ductile, biocompatible

A high strength, low modulus, ductile, biocompatible titanium base alloy containing one or more isomorphous beta stabilizers, eutectoid beta stabilizers and optional alpha stabilizers, characterized by a modulus of elasticity not exceeding 100 GPa; a method for the preparation of said alloy and prostheses made from said alloy.

High strength, low modulus, ductile, biopcompatible titanium alloy

A dispersion strengthened cobalt-chromium-molybdenum alloy produced by gas atomization containing a fine oxide dispersion, and characterized, after fabrication by gas atomization, thermomechanical processing and further high temperature exposure, by excellent corrosion resistance, high fatigue strength, high ductility and high temperature stability; a process for producing said alloy and prostheses formed from said alloy.

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Dover, NJ, United States of America

Larry J Gustavson