POROUS SURFACE LAYERS WITH INCREASED SURFACE ROUGHNESS AND IMPLANTS INCORPORATING THE SAME

• US 20110245930A1
• Filed: 10/23/2009
• Published: 10/06/2011
• Est. Priority Date: 10/29/2008
• Status: Abandoned Application

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Alley, Carie Fincher, Gilmour, Laura J.
• Application Number:
  US13/126,737
• Publication Number:
  US 20110245930A1
• Time in Patent Office: Days
• US Class Current: 623/23.74
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• 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 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00089 Zirconium or Zr-based alloys
• CPC Class Codes: A61F 2310/00131 Tantalum or Ta-based alloys
• 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 27/306 Other specific inorganic materials not covered by A61L27/303 - A61L27/32
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

Systems and methods for providing tissue-interfacing surface layers with increased roughness can be attained by providing a metallic powder to a machined or previously machined tissue-interfacing surface of a porous foam structure. The metallic powder can have sizes and characteristics such that the porous structure can have an increased roughness at the tissue-interfacing machined surface while inhibiting the occlusion of the open pores in the porous metallic foam structure.

Claims

1-9. -9. (canceled)

10. A method for increasing the surface roughness of a porous structure, comprising:

bonding a plurality of powder particles to at least a portion of a machined tissue-interfacing outer surface of a machined porous structure having a desired shape,

wherein at least a portion of the plurality of powder particles has sufficient dimensions to increase the roughness of the machined tissue-interfacing outer surface of the machined porous structure without occluding a plurality of pores of the porous structure.

11. The method of claim 10 wherein at least a portion of the plurality of powder particles comprises asymmetric powder particles.

12. The method of claim 10 wherein the size of at least a portion of the plurality of powder particles is from about 75 micrometers to about 106 micrometers.

13. The method of claim 10 wherein said bonding step comprises

applying a binder to the machined tissue-facing outer surface of the machined porous structure;

subsequently applying said plurality of powder particles by a means selected from the group consisting of dipping, spraying, sprinkling, and any combination thereof; and

sintering said porous structure to bond a portion of said plurality of powder to at least a portion of the machined tissue-facing outer surface of the porous structure.

14. The method of claim 10 wherein the porous structure comprises a metal foam structure.

15. The method of claim 10 further comprising the step of attaching the porous structure to a substrate.

16. The method of claim 15, wherein the substrate comprises a metallic foam-coated implant selected from the group consisting of a knee implant, hip implant, a shoulder implant, a spinal implant, a tibial tray, an acetabular shell, a femoral stem, and a stem collar.

17. The method of claim 10 further comprising the step of applying one or more additional layers of said plurality of powder particles to one or more non-tissue-interfacing surfaces of the porous structure.

18. The method of claim 17, wherein the step of applying one or more additional layers occurs after the step of bonding a powder to a machined tissue-interfacing outer surface of the machined porous structure.

19. The method of claim 17, wherein at least one layer of the one or more additional layers comprises a plurality of fine spherical particles, wherein at least a portion of said particles has a size of less than about 45 micrometers.

21. A porous structure with increased surface roughness comprising:

a porous structure having a machined tissue-interfacing outer surface;

a plurality of powder particles bonded to at least a portion of said machined tissue-interfacing outer surface of the porous structure,

wherein at least a portion of the plurality of powder particles has sufficient dimensions to increase the roughness of the machined tissue-interfacing outer surface of the machined porous structure without occluding a plurality of pores of the porous structure.

22. The structure of claim 21 wherein at least a portion of the plurality of powder particles comprises asymmetric powder particles.

23. The structure of claim 21 wherein the size of at least a portion of the plurality of powder particles is from about 75 micrometers to about 106 micrometers.

24. The structure of claim 21 wherein the porous structure comprises a metal foam structure.

25. The structure of claim 21 further comprising a substrate attached a portion of said porous structure.

26. The structure of claim 25, wherein the substrate is a metallic foam-coated implant selected from the group consisting of a knee implant, hip implant, a shoulder implant, a spinal implant, a tibial tray, an acetabular shell, a femoral stem, and a stem collar.

27. The structure of claim 21 further comprising one or more additional layers of said plurality of powder particles bonded to one or more non-tissue-interfacing surfaces of the porous structure.

28. The structure of claim 21, wherein at least one layer of the one or more additional layers comprises a plurality of fine spherical particles, wherein at least a portion of said particles has a size of less than about 45 micrometers.

29. The structure of claim 21, wherein the size of at least a portion of the plurality of powder particles is between about 10% and 30% of the pore size of the porous structure.

30. The structure of claim 21, wherein the size of at least a portion of the plurality of powder particles is between about 30% and 70% of the pore size of the porous structure.

31. The structure of claim 21, wherein the size of at least a portion of the plurality of powder particles is between about 40% and 60% of the pore size of the porous structure.

32. The structure of claim 21, wherein the plurality of powder particles comprises material selected from a group consisting of titanium, titanium hydride, titanium dehydride, titanium alloy, cobalt-chrome alloy, tantalum, zirconium, zirconium alloy, and any combination thereof.