Methods for making textured ceramic implants

• US 8,388,887 B2
• Filed: 04/12/2010
• Issued: 03/05/2013
• Est. Priority Date: 04/12/2010
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Gupta, Gautam, Norton, Daniel, King, Derek
• Primary Examiner(s): Lazorcik, Jason L
• Assistant Examiner(s): KEMMERLE III, RUSSELL J
• Application Number:
  US12/758,503
• Publication Number:
  US 20110251698A1
• Time in Patent Office: 1,058 Days
• Field of Search: 264/667
• US Class Current: 264/667
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61F 2002/3446 Single cups
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00592 Coating or prosthesis-covering structure made of ceramics or of ceramic-like compounds
• 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 27/10 Ceramics or glasses
• CPC Class Codes: A61L 27/306 Other specific inorganic materials not covered by A61L27/303 - A61L27/32
• CPC Class Codes: C04B 2111/00836 for medical or dental applications
• CPC Class Codes: C04B 35/00 Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 35/46 based on titanium oxides or titanates containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49
• CPC Class Codes: C04B 35/48 based on zirconium or hafnium oxides, zirconates, zircon or hafnates
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/581 based on aluminium nitride
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4521 application under increased pressure
• CPC Class Codes: C04B 41/4545 applied as a powdery material
• CPC Class Codes: C04B 41/4578 : Coating or impregnating of green ceramics or unset concrete
• CPC Class Codes: C04B 41/5025 : with ceramic materials copper oxide or solid solutions thereof C04B41/5074
• CPC Class Codes: C04B 41/87 : Ceramics

Abstract

A ceramic implant having a rough surface texture and a method for forming the same. The method includes forming a green body of a first ceramic composition. The green body is reduced to smaller pieces thereby forming ceramic fragments. A mold is filled with a second ceramic composition to form a ceramic base. Ceramic fragments are added to the mold and an outer layer is formed over at least a portion of the ceramic base. Pressure is applied to the mold to compress the outer layer onto the ceramic base and to form a green assembly. The green assembly is sintered to form a ceramic implant having a rough surface texture.

Claims

1. A method for forming a ceramic implant having a rough surface texture, the method comprising:

a. forming a green body of a first ceramic composition;

b. reducing the green body thereby forming ceramic fragments;

c. filling a mold with a second ceramic composition and compressing the second ceramic composition to a predetermined pressure to form a ceramic base;

d. adding the ceramic fragments to the mold and forming an outer layer over at least a portion of the ceramic base;

e. applying pressure to the mold to compress the outer layer onto the ceramic base and to form a green assembly; and

f. sintering the green assembly to form a ceramic implant having a rough surface texture.

2. The method of claim 1, wherein a ceramic powder is mixed with the ceramic fragments to form a mixture and the mixture is added to the mold to form the outer layer.

3. The method of claim 2, wherein the mixture comprises a weight ratio of ceramic powder to ceramic fragments from about 1:

5 to about 1;

3.

4. The method of claim 1, wherein a spacing agent is mixed with the ceramic fragments of the outer layer and the spacing agent is removed during sintering the green assembly.

5. The method of claim 1, further comprising sifting the ceramic fragments and selecting a desired particle size from about 0.5 mm to about 5 mm for use in forming the outer layer.

6. The method of claim 1, wherein at least one of the first and second ceramic compositions comprises a ceramic powder having an average particle diameter from about 0.1 μ

m to about 5 μ

m.

7. The method of claim 1, wherein the ceramic fragments have a size distribution wherein at least about 90% of the fragments have a diameter of from about 0.5 mm to about 5 mm, and at least about 25% of the fragments have a diameter of from about 1 mm to about 2 mm.

8. The method of claim 7, wherein the ceramic fragments are selected having a size distribution wherein about 75 wt % of the fragments have a diameter from about 1 mm to about 2 mm and about 25 wt % of the fragments have a diameter from about 2 mm to about 5 mm.

9. The method of claim 7, wherein the ceramic fragments are selected having a size distribution wherein about 50 wt % of the fragments have a diameter from about 1 mm to about 2 mm and about 50 wt % of the fragments have a diameter from about 2 mm to about 5 mm.

10. The method of claim 1, wherein applying pressure to the mold comprises using an isostatic pressing technique to compress the green assembly to a pressure of from about 50,000 to about 75,000 psi.

11. The method of claim 1, wherein applying pressure to the mold comprises pressing a plurality of the ceramic fragments into the ceramic base.

12. The method of claim 1, further comprising sintering the ceramic fragments prior to adding the ceramic fragments to the mold.

13. The method of claim 1, wherein the first and second ceramic compositions have substantially the same chemical composition.

14. The method of claim 1, wherein at least one of the first and second ceramic compositions comprises a ceramic selected from the group consisting of alumina, zirconia, metal nitride, metal carbide, and mixtures thereof.

15. The method of claim 1, further comprising shaping the ceramic base prior to adding the ceramic fragments to the mold and forming the outer layer.

16. The method of claim 15, wherein shaping the ceramic base comprises using a mandrel to shape and press the second ceramic composition.

17. The method of claim 1, further comprising depositing a porous metallic layer over at least a portion of the rough surface texture of the ceramic implant.

18. The method of claim 17, wherein the porous metallic layer comprises a titanium alloy.

19. The method of claim 1, further comprising depositing a layer of a titanium alloy over at least a portion of the rough surface texture of the implant using an ion beam enhanced deposition technique and further depositing a porous metallic layer over at least a portion of the titanium alloy layer using a porous plasma spray technique.

20. A method for forming a ceramic implant having a rough surface texture, the method comprising:

a. filling a mold with a ceramic composition and compressing the ceramic composition to a predetermined pressure to form a ceramic base;

b. adding ceramic fragments to the mold and forming an outer layer over at least a portion of the ceramic base;

c. applying pressure of from about 50,000 to about 75,000 psi to the mold to compress the outer layer onto the ceramic base and to form a green assembly; and

d. sintering the green assembly to form a ceramic implant having a rough surface texture.