Method for forming porous metal implants

• US 7,883,661 B2
• Filed: 09/11/2009
• Issued: 02/08/2011
• Est. Priority Date: 02/17/2006
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Meridew, Jason D., Hamman, Ned M., Schlueter, Elizabeth A., Fleming, James B., Janson, Isaac, Kumar, Mukesh
• Primary Examiner(s): King; Roy
• Assistant Examiner(s): MAI, NGOCLAN THI
• Application Number:
  US12/558,300
• Publication Number:
  US 20100003155A1
• Time in Patent Office: 515 Days
• Field of Search: 419/2, 419/35, 419/37, 419/60, 752/45, 752/52
• US Class Current: 419/2
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/34 Acetabular cups
• 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 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30064 Coating or prosthesis-covering structure made of biodegradable material
• CPC Class Codes: A61F 2002/30166 H-shaped or I-shaped
• CPC Class Codes: A61F 2002/30169 Pi-shaped
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30205 conical
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30736 Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect
• CPC Class Codes: A61F 2002/30827 : Plurality of grooves
• 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 2002/3092 : having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30968 : Sintering
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0058 : soldered or brazed or welded
• CPC Class Codes: A61F 2230/0028 : Shapes in the form of latin or greek characters
• CPC Class Codes: A61F 2230/0047 : Pi-shaped
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00059 : Chromium or Cr-based alloys
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00592 : Coating or prosthesis-covering structure made of ceramics or of ceramic-like compounds
• CPC Class Codes: A61F 2310/00958 : Coating or prosthesis-covering structure made of bone or of bony tissue
• CPC Class Codes: A61F 2310/0097 : Coating or prosthesis-covering structure made of pharmaceutical products, e.g. antibiotics
• CPC Class Codes: A61F 2310/00976 : Coating or prosthesis-covering structure made of proteins or of polypeptides, e.g. of bone morphogenic proteins BMP or of transforming growth factors TGF
• CPC Class Codes: A61K 35/12 : Materials from mammals; Compositions comprising non-specified tissues or cells; Compositions comprising non-embryonic stem cells; Genetically modified cells vaccines or medicinal preparations containing antigens or antibodies A61K39/00
• CPC Class Codes: A61L 2300/25 : Peptides having up to 20 amino acids in a defined sequence
• CPC Class Codes: A61L 2300/406 : Antibiotics
• CPC Class Codes: A61L 2300/414 : Growth factors
• CPC Class Codes: A61L 2300/428 : Vitamins, e.g. tocopherol, riboflavin
• CPC Class Codes: A61L 2300/606 : Coatings
• CPC Class Codes: A61L 2300/64 : Animal cells
• CPC Class Codes: A61L 27/04 : Metals or alloys
• CPC Class Codes: A61L 27/54 : Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 27/56 : Porous materials, e.g. foams or sponges
• CPC Class Codes: B22F 1/10 : Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
• CPC Class Codes: B22F 1/103 : containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
• CPC Class Codes: B22F 2998/10 : Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/02 : Compacting only
• CPC Class Codes: B22F 3/04 : by applying fluid pressure , e.g. by cold isostatic pressing [CIP]
• CPC Class Codes: B22F 3/1021 : Removal of binder or filler removal of binder from ceramics C04B35/638
• CPC Class Codes: B22F 3/1125 : involving a foaming process
• CPC Class Codes: B22F 3/1216 : Container composition
• CPC Class Codes: C01P 2004/61 : Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C09C 1/00 : Treatment of specific inorganic materials other than fibrous fillers tenebrescent materials C09K9/00; luminescent materials C09K11/00; Preparation of carbon black

Abstract

A method for providing a porous metal implant. A mixture of a biocompatible metal, a spacing agent, and a binder is provided. The mixture is formed into a shaped the spacing agent is removed to form a plurality of pores in the implant. A shaped porous metal implant is also provided.

Claims

1. A method for preparing a porous metal implant comprising:

a. preparing a mixture comprising;

i. a biocompatible metal powder comprising a metal selected from the group consisting of titanium, cobalt, chromium, tantlum, iron and mixtures thereof;

ii. a spacing agent selected from the group consisting of hydrogen peroxide, urea, ammonium carbonate, ammonium bicarbonate, ammonium carbamate, calcium hydrogen phosphate, naphthalene, and mixtures thereof; and

iii. a non-polar liquid binder comprising d-limonene;

b. forming the mixture into a shape; and

c. heating the mixture so as to remove the spacing agent and sinter the metal powder.

2. The method of claim 1, wherein the biocompatible metal powder is selected from the group consisting of titanium, titanium alloys, cobalt, cobalt alloys, chromium, chromium alloys, tantalum, tantalum alloys, and stainless steel.

3. The method of claim 1, wherein the metal powder has a particle size of from about 5 micrometers to about 1500 micrometers.

4. The method of claim 1, wherein the spacing agent has a particle size of from about 1 micrometer to about 1500 micrometers.

5. The method of claim 1, wherein the binder and the spacing agent are cohesive during formation of the mixture and removal of the spacing agent.

6. The method of claim 1, wherein removing the heating the mixture comprises heating to a temperature which sublimes the spacing agent.

7. The method of claim 1, wherein the heating the mixture comprises sintering the metal under vacuum pressure after removing the spacing agent.

8. The method of claim 1, wherein the biocompatible metal powder comprises Ti-6Al-4V.

9. The moldable mixture according to method of claim 1, wherein the spacing agent comprises ammonium bicarbonate.