Method of surface oxidizing zirconium and zirconium alloys and resulting product

• US 20060259150A1
• Filed: 05/10/2006
• Published: 11/16/2006
• Est. Priority Date: 03/27/1997
• Status: Active Grant

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Hunter, Gordon, Asgian, Catherine M., Hines, Gary L.
• Granted Patent: US 7,582,117 B2
• Time in Patent Office: Days
• US Class Current: 623/22.150
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/367 Proximal or metaphyseal parts of shafts trochanteric devices connected to said proximal parts A61F2/30739
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/40 for shoulders
• CPC Class Codes: A61F 2/4241 for hands, e.g. fingers
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2002/30322 differing in surface structures
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30838 Microstructures
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/30909 Nets
• CPC Class Codes: A61F 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2250/0026 : differing in surface structures
• CPC Class Codes: A61F 2310/00089 : Zirconium or Zr-based alloys
• CPC Class Codes: A61F 2310/00634 : Coating made of zirconium oxide or hydroxides
• CPC Class Codes: A61L 27/047 : Other specific metals or alloys not covered by A61L27/042 - A61L27/045 or A61L27/06
• CPC Class Codes: A61L 27/306 : Other specific inorganic materials not covered by A61L27/303 - A61L27/32
• CPC Class Codes: C23C 8/02 : Pretreatment of the material to be coated C23C8/04 takes precedence
• CPC Class Codes: C23C 8/10 : Oxidising

Abstract

A coating of blue-black or black oxidized zirconium of uniform and controlled thickness on a zirconium or zirconium alloy material is accomplished through the use of a single phase crystalline material substrate having an altered surface roughness. An oxidized zirconium coating of uniform and controlled thickness is especially useful on orthopedic implants of zirconium or zirconium-based alloys to provide low friction, highly wear resistant surfaces on artificial joints, such as, but not limited to, hip joints, knee joints, shoulders, elbows, and spinal implants. The uniformly thick oxidized zirconium surface of controlled depth on prostheses provide a barrier against implant corrosion caused by ionization of the metal prostheses. The invention is also useful in non-articulating implant devices such as bone plates, bone screws, etc.

Claims

1-45. -45. (canceled)

46. A prosthesis for implantation in a patient, comprising:

(a) a hip prosthesis body for implantation into a femor comprising a head portion formed of zirconium or zirconium alloy;

(b) a bearing surface on the head portion of the prosthesis body;

(c) an acetabular cup having an inner surface formed of an organic polymer or a polymer-based composite, said inner surface being adapted to cooperate with the bearing surface on the head portion; and

(d) a coating of blue-black or black oxidized zirconium of uniform thickness directly on the bearing surface of the head portion for reducing wear of the acetabular cup inner surface prepared by the process comprising the steps of altering the surface roughness of a zirconium or zirconium alloy having a single phase crystalline structure and uniform composition and subsequently oxidizing said zirconium or zirconium alloy.

47. The prosthesis of claim 46, wherein said blue-black or black oxidized zirconium coating of uniform thickness is of a thickness of up to about 20 microns.

48. The prosthesis of claim 46, wherein said blue-black or black oxidized zirconium coating of uniform thickness is of a thickness of up to about 10 microns.

49. The prosthesis of claim 46, wherein the prosthesis body further comprises an irregular surface structure adapted to accommodate tissue ingrowth on a portion of the prosthesis body.

50. The prosthesis of claim 49 wherein the irregular surface structure is formed of zirconium or zirconium alloy beads connected to the outer surface of the prosthesis body, wherein at least a portion of the surface of the beads is oxidized to blue-black or black oxidized zirconium.

51. The prosthesis of claim 49, wherein the irregular surface structure is formed of zirconium or zirconium alloy wire mesh connected to the outer surface of the prosthesis body, wherein at least a portion of the surface of the mesh is oxidized to blue-black or black oxidized zirconium.

52. A prosthesis for implantation in a patient, comprising:

(a) a prosthesis body having an external surface at least a portion of which is formed of zirconium or zirconium alloy, each having single phase crystalline structure and uniform composition and an altered surface roughness;

(b) a blue-black or black oxidized zirconium coating of uniform thickness formed on said portion of the external surface by inducing an altered surface roughness on at least said portion of the external surface and subjecting said portion of the external surface of said prosthesis body to an oxidation process; and

,

wherein the prosthesis body comprises a spinal implant.

53. A non-articulating medical implant formed at least in part of zirconium or zirconium alloy material comprising a partial or complete coat of blue-black or black oxidized zirconium of uniform thickness prepared by the process comprising the steps of altering the surface roughness of a zirconium or zirconium alloy having a single phase crystalline structure and uniform composition and subsequently oxidizing said zirconium or zirconium alloy.

54. The medical implant of claim 53 selected from the group consisting of bone plates and bone screws.