Acetabular cup inserter for orthopedic

• US 5,584,837 A
• Filed: 01/27/1995
• Issued: 12/17/1996
• Est. Priority Date: 08/13/1993
• Status: Expired due to Term

• Current Assignee: Zimmer Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Thomas D. Petersen
• Inventors: Petersen, Thomas D.
• Primary Examiner(s): Harrison, Jessica J.
• Assistant Examiner(s): ONEILL, MICHAEL W
• Application Number:
  US08/379,019
• Time in Patent Office: 690 Days
• Field of Search: 279/103, 16/114 R, 294/58, 403/292, 606/91, 606/99, 606/100, 606/86, 173/211, 173/210
• US Class Current: 606/91
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4609 of acetabular cups
• CPC Class Codes: A61F 2002/30589 Sealing means
• CPC Class Codes: A61F 2002/3403 Polar aperture

Abstract

Embodiments of an acetabular cup inserter include an elongated stem to which a handle is assembled in such a way that its orientation with respect to the stem may be adjusted 360°, that is, completely about the periphery of the stem. A buttress device is provided to engage the metal cup resiliently by use of an O-ring which prevents metal-to-metal contact avoiding fretting of the cup surface. The various embodiments disclosed include one embodiment wherein the buttress is axially aligned with the majority of the stem length as well as an embodiment wherein the axis of the buttress is parallel to and offset from the axis of the majority of the stem.

Claims

1. An acetabular cup inserter, comprising an elongated stem having a proximal end and a distal end, said proximal end being adapted for connection to a prosthetic acetabular component, a handle extending outwardly from the elongated stem and being rotatable about the stem, and fastening means for securing the handle relative to the stem, said fastening means including a generally smooth conical surface on said stem engageable with a generally smooth correspondingly tapered conical passageway through the handle to fasten said handle in any one of an infinite number of rotative positions about a circumference of said stem.

2. The inserter of claim 1, wherein said fastening means includes locking means proximal of said handle for releasably wedging said tapered conical passageway onto said conical surface to fix a rotative position of said handle with respect to said stem.

5. The inserter of claim 1, wherein said conical surface is tapered from a larger diameter to a smaller diameter in a direction from said distal end to said proximal end, said locking means being located on said elongated stem proximal of said tapered surface.

6. The inserter of claim 5, wherein said locking means comprises a threaded surface on said stem proximal of said conical surface and a lock nut with threads complementary to said threaded surface, said lock nut being movable over said threaded surface and thereby engaging a proximal surface of said handle mount to move said handle mount distally on said stem to thereby wedge said conical passageway onto said conical surface.

21. The inserter of claim 1, wherein said buttressing means includes an O-ring captured and partially recessed in a groove.

22. The inserter of claim 21, wherein said groove is laterally spaced radially outwardly from an axis of elongation of said buttressing means.

23. The inserter of claim 22, further including a tapered surface surrounding said groove.

24. The inserter of claim 21, wherein said O-ring protrudes outwardly from said groove.

3. An acetabular cup inserter, comprising:

a) an elongated stem having a proximal end and a distal end;

b) a handle mount on said stem between said proximal end and distal end, said handle mount carrying a handle;

c) fastening means for releasably fastening said handle mount in any one of an infinite number of rotative positions about a circumference of said stem, said fastening means comprising a smooth conical surface on said stem, a correspondingly tapered smooth conical passageway through said handle mount, and locking means for moving said handle mount with respect to said stem to lock said handle mount in any of said rotative positions;

d) a striking surface on said distal end of said stem; and

e) an acetabular cup attaching, buttressing and impacting device on said proximal end of said stem including resilient buttressing means for preventing fretting of an acetabular cup to which said inserter may be attached.

4. The inserter of claim 3, wherein said handle is removably attachable to said handle mount.

7. The inserter of claim 3, wherein said striking surface is located on a knob mounted on said distal end.

8. The inserter of claim 3, wherein said acetabular cup attaching, buttressing and impacting device includes attaching means for attaching said inserter to an acetabular cup, said attaching means comprising an attachment member having first coupling structure complementary to second coupling structure on an acetabular cup.

9. The inserter of claim 8, wherein said first coupling structure comprises a threaded surface, a second coupling structure comprising a threaded passageway through an acetabular cup having threads complementary to said first coupling structure threaded surface.

10. The inserter of claim 9, wherein said first coupling structure is directly formed on said proximal end of said stem.

11. The inserter of claim 9, wherein said attaching, buttressing and impacting device comprises a separate member attachable on said proximal end of said stem.

12. The inserter of claim 11, wherein said stem proximal end has a threaded recess, said separate member having a distal threaded stem having threads complementary to said threaded recess whereby said separate member may be releasably attached on said proximal end of said stem.

13. The inserter of claim 10, further including a buttressing sleeve mountable on said stem proximal end.

14. The inserter of claim 13, wherein said stem proximal end includes an angled bend whereby said buttressing sleeve is laterally offset from said stem distal end.

15. The inserter of claim 14, wherein said sleeve has a tapered outer surface, said stem proximal end having a U-shaped terminus with a tapered inner surface complementary thereto.

16. The inserter of claim 13, wherein said buttressing means is formed on a proximal surface of said sleeve.

17. The inserter of claim 16, wherein said buttressing means comprises an O-ring partially recessed in a groove in said proximal surface.

18. The inserter of claim 12, wherein said buttressing means comprises a recess in a proximal surface of said separate member and an O-ring partially recessed in said proximal surface recess.

19. The inserter of claim 13, wherein said buttressing sleeve has a threaded recess threadably received on a threaded sleeve receiving surface on said stem spaced distally of said proximal end of said stem.

20. The inserter of claim 18, wherein acetabular cup threads are surrounded by a flat recessed area facing said stem when said stem is coupled thereto, said O-ring engaging said flat recessed area.

25. In an acetabular cup inserter including an elongated stem having a proximal end and a distal end, said distal end having a striking surface, said proximal end having attachment means for attaching said acetabular cup inserter to an acetabular cup at an attachment location thereon, the improvement comprising buttressing means surrounding said attachment means for preventing fretting of a surface of an acetabular cup to which said inserter may be attached, said buttressing means comprising a recess in said proximal end of said stem capturing and partially recessing an O-ring received therein, said recess preventing lateral movement of said O-ring with respect to said proximal end.

26. The inserter of claim 25, wherein said recess comprises an annular recess.

27. The inserter of claim 25, wherein said recess has a depth slightly greater than one-half a thickness of said O-ring.

28. The inserter of claim 25, wherein said O-ring is made of ethylene propylene.

29. The inserter of claim 25, wherein said proximal end includes a separate member attachable on said stem and carrying said buttressing means.

30. An acetabular cup inserter, comprising:

a) an elongated stem having a proximal end and a distal end;

b) a handle mount on said stem between said proximal end and distal end, said handle mount carrying a handle;

c) fastening means for releasably fastening said handle mount in any one of an infinite number of rotative positions about a circumference of said stem, said fastening means comprising a tapered surface on said stem, a correspondingly tapered passageway through said handle mount, and locking means for engaging said handle mount to lock said handle mount in any of said rotative positions;

d) a striking surface on said distal end of said stem; and

e) an acetabular cup attaching, buttressing and impacting device on said proximal end of said stem including resilient buttressing means including an O-ring captured and partially recessed in a groove for preventing fretting of an acetabular cup to which said inserter may be attached.