Method and apparatus for acetabular reconstruction

• US 20030212459A1
• Filed: 07/23/2002
• Published: 11/13/2003
• Est. Priority Date: 02/23/2001
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Gibbs, Phillip M.
• Granted Patent: US 7,291,177 B2
• Time in Patent Office: Days
• US Class Current: 623/22.32
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/30734 Modular inserts, sleeves or augments, e.g. placed on proximal part of stem for fixation purposes or wedges for bridging a bone defect
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• 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

A trial system for an acetabular prosthesis is described. The acetabular prosthesis is generally for implantation in an acetabulum and surrounding pelvis. The acetabular prosthesis includes an acetabular cup having a substantially concave inner surface and a substantially convex outer surface. The described acetabular prosthesis is especially useful in revision hip implant procedures where significant bone tissue loss has occurred either in or around the acetabulum and/or the pelvis. A trial shell is provided to trial a range of motion of the hip joint before implanting a prosthetic shell into the acetabular prosthesis.

Claims

1. A system to provide a determination of an alignment of a prosthetic bearing in an acetabular prosthesis, the system comprising:

a trial shell including;

a body having an interior and an exterior defining an elongated track extending between said interior and said exterior; and

an attachment mechanism to selectively and operably interconnect said trial shell and the acetabular prosthesis;

wherein when said trial shell is operably interconnected to the acetabular prosthesis said trial shell is substantially immobile relative the acetabular prosthesis;

wherein said trial shell determines an appropriate alignment of the prosthetic bearing.

2. The system of claim 1, wherein the acetabular prosthesis includes:

an acetabular cup generally defining a portion of a hollow sphere and having a pole;

at least one bore defined substantially near said pole; and

wherein said attachment mechanism engages said acetabular cup in said one bore.

3. The system of claim 2, wherein said track extends along said trial shell a distance between about 60 degrees and about 120 degrees.

4. The system of claim 2, wherein said trial shell is able to move in at least two degrees of freedom, wherein first degree of freedom is rotationally around said pole, and wherein a second degree of freedom is along said track relative said pole.

5. The system of claim 1, wherein said attachment mechanism includes a member that extends through said track, wherein said member selectively engages said body.

6. The system of claim 1, wherein said attachment mechanism includes:

a member having an attachment end and an engagement end;

the acetabular prosthesis including an attachment portion, wherein said attachment end of said member operably engages said attachment portion; and

said trial shell defining an orientation portion, wherein said engagement end operably engages said orientation portion;

wherein said member operably interconnects said trial shell and the acetabular prosthesis allowing a plurality of selected orientations to be created.

7. The system of claim 6, further comprising:

a locking member adapted to engage said member;

wherein said locking member engages said member to operably couple said member and said trial shell.

8. An acetabular prosthesis system to replace an acetabulum that allows trialing for a shell component, comprising:

an acetabular prosthesis; and

a trial shell operable to be selectively oriented relative said acetabular prosthesis in at least two degrees of freedom;

wherein said trial shell trials at least one orientation by being selectively fixed in the at least one orientation relative said acetabular prosthesis.

9. The acetabular prosthesis system of claim 8, further comprising:

a connection mechanism to selectively fix said trial shell relative said acetabular prosthesis.

10. The acetabular prosthesis system of claim 9,

said acetabular cup includes a pole region;

said acetabular cup defines at least one bore near said pole region; and

wherein said connection mechanism selectively engages said acetabular cup in said bore.

11. The acetabular prosthesis system of claim 9, wherein said trial shell includes:

a body defines an exterior and an interior; and

said body defines a track extending between said interior and said exterior;

wherein said connection mechanism includes a member that extends through said track;

wherein said member selectively engages said body.

12. The acetabular prosthesis system of claim 8, wherein said two degrees of freedom include a first rotationally around said pole and a second along said track relative said pole.

13. The acetabular prosthesis system of claim 9, wherein said connection mechanism includes:

a member having an attachment end and an engagement end;

said acetabular prosthesis including an attachment portion, wherein said attachment end of said member operably engages said attachment portion; and

said trial shell defines an orientation portion, wherein said engagement end operably engages said orientation portion;

wherein said member operably interconnects said trial shell and the acetabular prosthesis allowing a plurality of determined orientations to be created.

14. The acetabular prosthesis system of claim 13, wherein said member includes a screw having a threaded shank and a head portion;

said attachment portion includes a thread formed in said acetabular prosthesis;

wherein said threaded shank and said attachment portion cooperate to draw said head portion against said trial shell such that said head portion applies a force great enough to fix said trial shell in a predetermined orientation.

15. The acetabular prosthesis system of claim 8, further comprising:

a shell;

wherein said shell is affixed relative said acetabular prosthesis substantially in said at least one orientation of said trial component.

16. The acetabular prosthesis system of claim 8, further comprising:

a trial acetabular prosthesis, wherein said trial acetabular prosthesis operably engages the acetabulum to determine an orientation of said acetabular prosthesis.

17. An acetabular prosthesis system to replace an acetabulum that allows trialing for a shell component, comprising:

a protrusio cage; and

a trial shell operable to be selectively oriented relative said protrusio cage in at least two degrees of freedom;

wherein said trial shell trials at least one orientation by being selectively fixed in the at least one orientation relative said protrusio cage.

18. The acetabular prosthesis system of claim 17, further comprising:

a connection mechanism to selectively fix said trial shell relative said protrusio cage.

19. The acetabular prosthesis system of claim 21, wherein said protrusio cage includes an acetabular cup that includes a pole region;

said protrusio cage defines at least one bore near said pole region; and

wherein said connection mechanism selectively engages said acetabular cup in said bore.

20. The acetabular prosthesis system of claim 18, wherein said trial shell includes:

a body defining an exterior and an interior; and

said body defines a track extending between said interior and said exterior;

wherein said connection mechanism includes a member that extends through said track;

wherein said member selectively engages said body.

21. The acetabular prosthesis system of claim 20, wherein said two degrees of freedom include a first rotationally around said pole and a second along said track relative said pole.

22. The acetabular prosthesis system of claim 20, wherein said interior defines a counter-bore, wherein said member is nestable in said counter-bore.

23. The acetabular prosthesis system of claim 17, further comprising:

a trial protrusio cage to trial at least one orientation for said protrusio cage.

24. The acetabular prosthesis system of claim 17, further comprising:

a shell;

wherein said shell is affixed relative said protrusio cage substantially in said at least one orientation of said trial shell.

25. The acetabular prosthesis of claim 18, further comprising:

a lock mechanism, wherein said lock mechanism operably couples said attachment mechanism to hold said attachment mechanism relative said trial shell before said attachment mechanism engages said protrusio cage.

26. A system to trial and implant an acetabular prosthesis into an acetabulum, comprising:

a trial protrusio acetabular prosthesis;

a protrusio acetabular prosthesis; and

a trial shell operable to be selectively oriented relative said protrusio acetabular prosthesis in at least two degrees of freedom;

wherein said trial shell trials at least one orientation by being selectively fixed in the at least one orientation relative said acetabular prosthesis.

27. The system of claim 26, further comprising:

an attachment member extending from said trial protrusio acetabular prosthesis; and

an attachment member trial spacer adapted to cooperate with said attachment member to determine an alignment of said trial protrusio acetabular prosthesis;

wherein said protrusio acetabular prosthesis is implanted substantially in said determined alignment.

28. The system of claim 26, further comprising:

a connection mechanism to selectively fix said trial shell relative said protrusio acetabular prosthesis.

29. The system of claim 28, wherein said trial shell includes:

a body having an exterior and an interior defining an elongated track extending between said interior and said exterior;

wherein said connection mechanism includes a member that extends through said track;

wherein said member selectively engages said body.

30. The system of claim 29, wherein said two degrees of freedom include a first rotationally around said pole and a second along said track relative said pole.

31. The system of claim 29, wherein said interior defines a counter-bore, wherein said member is nestable in said counter-bore.

32. The system of claim 26, further comprising:

a shell;

wherein said shell is affixed relative said protrusio acetabular prosthesis substantially in said at least one orientation of said trial shell.

33. A method of implanting an acetabular prosthesis in an acetabulum and providing a liner in the acetabular prosthesis in a selected orientation, the method comprising:

implanting the acetabular prosthesis;

disposing a trial shell in said acetabular prosthesis;

orienting the trial shell with at least two degrees of freedom in a first orientation;

fixing the trial shell in said first orientation; and

moving the femur through a range of motion relative the trial shell.

34. The method of claim 33, further comprising:

placing a head extending from the femur in the trial shell;

moving the femur through a range of motion while maintaining the head in the trial shell; and

determining the presence of contact between the femur or neck and the trial shell.

35. The method of claim 33, further comprising:

placing a head extending from the femur in the trial shell;

moving the femur through a range of motion while maintaining the head in the trial shell; and

determining the whether dislocation of the head occurs during said moving the femur through a range of motion.

36. The method of claim 33, wherein when determining the presence of contact determines contact is present, further including:

providing the trial shell in a second orientation;

fixing the trial shell in said second orientation; and

determining the presence of contact between the femur on the trial shell.

37. The method of claim 33, further comprising;

implanting the liner in said first orientation when there is substantially no contact between the femur and the trial liner.

38. The method of claim 33, further comprising:

implanting the liner in an orientation determined by said trial shell, wherein said determined orientation includes a minimum of contact between the femur and the trial shell.

39. The method of claim 33, further comprising;

preparing the acetabulum;

disposing a trial acetabular prosthesis in the acetabulum;

determining a selected orientation of the acetabular prosthesis.

40. The method of claim 33, wherein implanting the acetabular prosthesis includes implanting a protrusio acetabular prosthesis.