Method and apparatus for use of porous implants

• US 20060241781A1
• Filed: 02/17/2006
• Published: 10/26/2006
• Est. Priority Date: 04/21/2005
• 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., Hershberger, Troy W., Ronk, Robert M., Brown, David R.
• Granted Patent: US 7,597,715 B2
• Time in Patent Office: Days
• US Class Current: 623/23.430
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/4609 of acetabular cups
• CPC Class Codes: A61F 2002/30535 Special structural features of bone or joint prostheses not otherwise provided for
• CPC Class Codes: A61F 2250/0058 Additional features; Implant or prostheses properties not otherwise provided for

Abstract

An orthopedic prosthesis for implantation into a bone of a patient includes a porous metal shell adapted to be affixed within the bone. The porous metal shell includes an outer surface adapted to receive bone ingrowth and an inner surface adapted to engage a liner. The porous metal shell is porous from the outer surface to the inner surface. A non-porous member may be affixed to the porous metal shell. The non-porous member may include a piercing member extending from the outer surface, the piercing member adapted to penetrate the bone in an implanted position. The non-porous member may include spikes or fins. In one example, the piercing member may define a reduced material cross section at an interface with the outer surface of the porous metal shell. The piercing member may be adapted to be broken at the reduced material cross section and removed from the porous metal shell.

Claims

1. An orthopedic prosthesis for implantation into a bone of a patient, said orthopedic prosthesis comprising:

a porous metal shell adapted to be affixed within the bone, said porous metal shell having an outer surface adapted to receive bone ingrowth after the implantation and an inner surface adapted to engage a liner, wherein said porous metal shell is porous from said outer surface to said inner surface; and

a non-porous member affixed to said porous metal shell.

2. The orthopedic prosthesis of claim 1 wherein said non-porous member is integrally formed with said porous metal shell.

3. The orthopedic prosthesis of claim 2 wherein said non-porous member includes at least one piercing member extending from said outer surface, said at least one piercing member adapted to penetrate the bone in an implanted position.

4. The orthopedic prosthesis of claim 3 wherein said at least one piercing member includes spikes.

5. The orthopedic prosthesis of claim 3 wherein said at least one piercing member includes fins.

6. The orthopedic prosthesis of claim 5 wherein said at least one piercing member defines a reduced material cross section at an interface with said outer surface of said porous metal shell and wherein said at least one piercing member is adapted to be broken at said reduced material cross section and removed from said outer surface of said porous metal shell.

7. The orthopedic prosthesis of claim 2 wherein said non-porous member includes a hemispherical webbing integrally formed within said porous metal shell.

8. The orthopedic prosthesis of claim 1 wherein said non-porous member includes grommets affixed through bores defined in said porous metal shell.

9. The orthopedic prosthesis of claim 1 wherein said non-porous members includes cannulated cylinders affixed through bores defined in said porous metal, said cannulated cylinders adapted to receive fixation members therethrough.

10. The orthopedic prosthesis of claim 1 wherein said porous metal shell has reduced porosity at a rim portion as compared to a remainder of said porous metal shell.

11. The orthopedic prosthesis of claim 1 wherein said porous metal shell has reduced porosity at said inner surface as compared to said outer surface.

12. An orthopedic prosthesis for implantation into a bone of a patient, said orthopedic prosthesis comprising:

an integrally formed shell having an outer portion comprising a first porous layer adapted to receive bone ingrowth after implantation, an inner portion comprising a second porous layer; and

an intermediate portion comprising a barrier; and

a fixation member adapted to be interoperatively inserted through said shell from the inner portion to the outer portion, said fixation member adapted to pierce said barrier;

wherein said barrier is adapted to inhibit particles from migrating from said inner portion to said outer portion.

13. The orthopedic prosthesis of claim 12, further comprising a bearing liner affixed to said inner portion.

14. The orthopedic prosthesis of claim 13 wherein said intermediate portion defines a thickness less than 50% of a thickness of said inner portion and a thickness of said outer portion.

15. The orthopedic prosthesis of claim 14 wherein said intermediate portion defines a thickness less than 25% of a thickness of said inner portion and a thickness of said outer portion.

16. The orthopedic prosthesis of claim 15 wherein said outer portion defines a radial rim, wherein said intermediate portion defines a collar affixed around said radial rim.

17. The orthopedic prosthesis of claim 12 wherein said fixation member includes a bone screw.

18. The orthopedic prosthesis of claim 12 wherein said integrally formed shell defines a hemispherical section and where said fixation member is adapted to be received at any desired location around said hemispherical section.

19. The orthopedic prosthesis of claim 18, further comprising a series of fixation members arranged around said hemispherical section in an implanted position.

20. The orthopedic prosthesis of claim 12 wherein said first and second porous layer define preformed passages adapted to accept a fastener therethrough.

21. An orthopedic prosthesis for implantation into a bone of a patient, said orthopedic prosthesis comprising:

an integrally formed shell having an outer portion, an inner portion and an intermediate portion;

wherein said outer portion comprises porous metal adapted to receive bone ingrowth after implantation;

wherein said inner portion comprises ceramic and defines a bearing surface; and

wherein said intermediate portion comprises a transition layer.

22. The orthopedic prosthesis of claim 21 wherein said inner portion defines a textured outboard surface.

23. The orthopedic prosthesis of claim 22 wherein said intermediate portion comprises at least one of powdered metal and ceramic.

24. The orthopedic prosthesis of claim 23 wherein said intermediate portion encapsulates said inner portion.

32. The orthopedic prosthesis of claim 24, further comprising an annular ring selectively located within an annular groove formed on the inner surface of the porous metal shell, said annular ring capturing a bearing liner within said porous metal shell.

25. An orthopedic prosthesis for implantation into a bone of a patient, said orthopedic prosthesis comprising:

a porous metal shell adapted to be affixed within the bone, said porous metal shell defining continuous porous metal from an inner surface to an outer surface, said outer surface adapted to receive bone ingrowth after the implantation; and

a non-porous rim affixed to a radial edge of said porous metal shell.

26. The orthopedic prosthesis of claim 25 wherein said non-porous rim is affixed to said porous metal shell at an interface surface.

27. The orthopedic prosthesis of claim 26 wherein said interface surface defines a metallurgical bond.

28. The orthopedic prosthesis of claim 26 wherein said radial edge of said porous metal shell defines a first annular pocket receiving a portion of said non-porous rim.

29. The orthopedic prosthesis of claim 26 wherein said non-porous rim defines a second annular pocket receiving a portion of said porous metal shell.

30. The orthopedic prosthesis of claim 26 wherein said non-porous rim defines a raised wall adapted to mate with an attachment tool.

31. The orthopedic prosthesis of claim 30 wherein said raised wall defines a tapered cross-section adapted to securably mate with a complementary tapered cross-section defined on said attachment tool.