Prosthesis

• US 20050197712A1
• Filed: 03/08/2005
• Published: 09/08/2005
• Est. Priority Date: 03/08/2004
• Status: Abandoned Application

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Blunn, Gordon William, Witt, Johan, Neilsen, Poul T., Bigsby, Robert John Andrew
• Application Number:
  US11/075,178
• Publication Number:
  US 20050197712A1
• Time in Patent Office: Days
• US Class Current: 623/23.27
• CPC Class Codes: A61B 17/744 the longitudinal elements coupled to an intramedullary nail
• CPC Class Codes: A61B 17/748 with means for adapting the angle between the longitudinal elements and the shaft axis of the femur
• CPC Class Codes: A61B 17/809 with bone-penetrating elements, e.g. blades or prongs bone staples A61B17/0642; intramedullary nails with a plate at an end A61B17/7233
• CPC Class Codes: A61B 17/8665 Nuts
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3601 for replacing only the epiphyseal or metaphyseal parts of the femur, e.g. endoprosthetic femoral heads or necks directly fixed to the natural femur by internal fixation devices non-prosthetic internal fixation devices for the femoral head or neck A61B17/74
• CPC Class Codes: A61F 2002/30233 Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30378 Spherically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/30797 internally-threaded
• CPC Class Codes: A61F 2002/30886 externally-threaded
• CPC Class Codes: A61F 2002/3625 Necks
• CPC Class Codes: A61F 2002/3631 with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/365 Connections of heads to necks
• CPC Class Codes: A61F 2002/369 Stepped shaft, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2220/0033 made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0041 using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2250/0006 for adjusting angular orientation
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

A prosthesis includes a body portion adapted to engage a bone. A rod is adapted to pass through the bone. A fixing element includes a bone engaging plate and a locking piece which engages the rod and is adapted to articulate with the bone engaging plate.

Claims

1. A prosthesis comprising:

a body portion adapted to engage a bone;

a rod which passes through the bone; and

a fixing element, comprising a bone engaging plate and a locking piece which engages the rod and is adapted to articulate with the bone engaging plate.

2. The prosthesis of claim 1 wherein the locking piece defines a first bearing surface that is rotatable about a second bearing surface defined on the bone engaging plate, and wherein the rotation is about an axis substantially perpendicular to a longitudinal axis of the rod.

3. The prosthesis of claim 2 wherein articulation of the locking piece with the bone engaging plate is spherical.

4. The prosthesis of claim 2 wherein the first and second bearing surfaces comprise a cobalt chrome alloy.

5. The prosthesis of claim 2 wherein the bone engaging plate includes attachment members adapted to secure the bone engaging plate to the bone.

6. The prosthesis of claim 5 wherein the attachment members include at least one of screws or spikes.

7. The prosthesis of claim 1 wherein the bone engaging plate defines a smooth outer surface adapted to allow free movement of soft tissue over the bone engaging plate.

8. The prosthesis of claim 1 wherein the body portion includes a stem of the prosthesis.

9. The prosthesis of claim 8 wherein the body portion is inserted into the bone in an implanted position.

10. The prosthesis of claim 9 wherein the body portion defines a substantially linear contour.

11. The prosthesis of claim 10 wherein the body portion is tapered toward a distal end.

12. The prosthesis of claim 11 wherein the body portion defines a rounded, trapezoidal shape.

13. The prosthesis of claim 12 wherein the rod is fixed to the body portion.

14. The prosthesis of claim 13 wherein the rod is integrally formed with the body portion.

15. The prosthesis of claim 14 wherein a distal end of the rod is threaded.

16. The prosthesis of claim 15 wherein the locking piece comprises a nut adapted to be engaged on the threaded end of the rod.

17. The prosthesis of claim 16 wherein the body portion defines a threaded bore.

18. The prosthesis of claim 17 wherein the rod includes a bolt and is adapted to be received in the threaded bore.

19. The prosthesis of claim 18 wherein the locking piece comprises a head of the bolt.

20. The prosthesis of claim 18 wherein the bone includes a femur and wherein the bone engaging plate is adapted to be positioned and fixed on a lateral cortex of the femur.

21. The prosthesis of claim 20 wherein the rod passes through the lateral cortex.

22. The prosthesis of claim 21 wherein the body portion is adapted to emerge from the femur at a position of a resected femoral neck.

23. The prosthesis of claim 22 wherein a proximal end of the body portion defines a neck adapted to mount a femoral head.

24. The prosthesis of claim 23 wherein the body portion defines a collar adapted to abut a resected surface of the femoral neck.

25. The prosthesis of claim 24 wherein at least one of the bone engaging plate, body portion and collar defines an outer surface having a porous coating adapted to facilitate bone ingrowth.

26. A method of implanting a prosthesis into bone comprising:

resecting a neck portion of the bone and defining a resected surface thereat;

inserting a stem into a bone tunnel formed in the bone;

abutting a collar disposed on a first end of the stem onto the resected surface;

locating a bone engaging plate disposed on a second end of the stem against an outer surface of the bone; and

advancing a bolt operatively coupled between the stem and the bone engaging plate relative the stem whereby spikes defined on the bone engaging plate drive into the bone surface.

27. The method of claim 26 wherein advancing the bolt compresses the stem and the collar into the bone.

28. The method claim 27 wherein locating the bone engaging plate against the outer surface includes locating the bone engaging plate against a lateral cortex of a femur.

29. The method of claim 28 wherein advancing the bolt includes rotating a first bearing surface defined on the locking plate about a second bearing surface defined on the bone engaging plate, and wherein the rotation is about an axis substantially perpendicular to a longitudinal axis of the bolt.