In-situ oxidized textured surfaces for prosthetic devices and method of making same

• US 7,258,810 B2
• Filed: 12/06/2002
• Issued: 08/21/2007
• Est. Priority Date: 12/06/2001
• Status: Expired due to Term

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Hunter, Gordon, Gupta, Harsh, Heuer, Daniel, Fesmire, Randy
• Primary Examiner(s): Hassanzadeh; Parviz
• Assistant Examiner(s): CULBERT, ROBERTS P
• Application Number:
  US10/313,205
• Publication Number:
  US 20030125808A1
• Time in Patent Office: 1,719 Days
• Field of Search: 623/23.5, 623/23.6, 623/16.11, 623/20.17, 623/23.29, 623/23.3, 623/23.31, 623/23.55, 427/2.24, 427/2.26, 216/100, 216/108, 216/40, 216/41, 216/42
• US Class Current: 216/41
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• 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 2/3804 for elbows
• 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 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• 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 2002/30878 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 2002/30922 : Hardened surfaces
• CPC Class Codes: A61F 2002/30925 : etched
• 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 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00089 : Zirconium or Zr-based alloys
• CPC Class Codes: A61F 2310/00095 : Niobium or Nb-based alloys
• CPC Class Codes: A61F 2310/00125 : Hafnium or Hf-based alloys
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00634 : Coating made of zirconium oxide or hydroxides
• CPC Class Codes: A61L 2400/18 : Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• CPC Class Codes: A61L 27/04 : Metals or alloys
• 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 31/022 : Metals or alloys
• CPC Class Codes: C23C 8/02 : Pretreatment of the material to be coated C23C8/04 takes precedence
• CPC Class Codes: C23C 8/04 : Treatment of selected surface areas, e.g. using masks
• CPC Class Codes: C23C 8/10 : Oxidising

Abstract

A textured surface and oxidation layer coating on a metallic material is accomplished through the chemical and/or electrochemical etching of the surface to modify the surface texture and an in-situ oxidation procedure. The surface is useful for the fabrication of prosthetic devices, particularly medical implants, due to the corrosion and wear resistance imparted by the oxidation layer and the ability to enhance grafting of the implant onto bone imparted by the surface texture.

Claims

1. A method of producing a modified surface on a metallic medical implant comprising the steps of:

modifying the texture of at least a portion of the surface of said metallic medical implant to a roughness of R_max of about 0.4 mm or greater to form a texture-modified surface; and

, oxidizing at least a portion of the texture-modified surface of said metallic medical implant to form a texture-modified, diffusion hardened surface on said metallic medical implant.

2. The method of claim 1 wherein said step of modifying comprises a chemical or electrochemical etching.

3. The method of claim 2 wherein said etching comprises etching with acid.

4. The method of claim 2 wherein said etching comprises the further step of applying a maskant to the surface of the metallic medical implant.

5. The method of claim 4 wherein the maskant is randomly applied.

6. The method of claim 4 wherein said step of applying a maskant comprises the step of spraying or sputtering of maskant onto said surface of said metallic medical implant.

7. The method of claim 6 wherein said step of spraying or sputtering comprises a random application of maskant.

8. The method of claim 4 wherein said step of applying a maskant to the surface of the metallic medical implant is characterized by fully covering said surface with said maskant and thereafter partially removing a portion of said maskant.

9. The method of claim 8 wherein said step of partially removing comprises the step of laser ablating a portion of said maskant.

10. The method of claim 1, wherein said step of oxidizing comprises air, steam, or water oxidation processes.

11. The method of claim 1, wherein the metallic surface comprises zirconium or zirconium alloy.

12. The method of claim 11 wherein said zirconium alloy is selected from the group consisting of:

zirconium with up to about 4.5 percent by weight hafnium and up to about 3.0 percent by weight niobium;

zirconium with up to about 4.5 percent by weight hafnium;

zirconium with 2.5 to 2.8 percent by weight niobium; and

;

titanium with about 13 percent by weight niobium and about 13 percent by weight zirconium.