Femoral neck prosthesis

Patent metadata

Field	Value
Publication number	US-9763790-B2
Application number	US-91525106-A
Country	US
Kind code	B2
Filing date	May 24, 2006
Priority date	May 24, 2005
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

The invention relates to a shaft for a femoral neck prosthesis, which comprises an anchoring area ( 27, 29 ) which is arranged inside the femur in order to anchor the prosthesis into bone, a head area which is axially adjacent to the anchoring area ( 27, 29 ) on the proximal side, said head area comprising a device ( 13 ) which is connected to the prosthesis head ( 15 ), in addition to a distal end which is arranged opposite the head area in the axial direction of the anchoring area ( 27, 29 ). The invention is characterised in that the maximum cross-sectional dimension of the head area is at the most equal and, in particular, smaller than the maximum diameter of the anchoring area ( 27, 29 ), in such a manner that the maximum cross-sectional dimension of the shaft ( 11 ) is in the anchoring area ( 27, 29 ).

First claim

The invention claimed is:

1. A shaft for a femoral neck prosthesis, comprising:
an anchorage region provided for arrangement in the interior of the femur for anchorage of the femoral neck prosthesis in the femur, the anchorage region having an anchorage region axis and a maximum radial extent with respect to the anchorage region axis, the anchorage region including an external threaded section with a spongiosa thread, wherein a maximum diameter of the external threaded section defines the maximum diameter of the shaft;
a head region unitarily formed with the external threaded section and including a truncated conical connection element that is to reside outside the femur for being received in a conical bore in a femoral head prosthesis for connecting the truncated conical connection element to the femoral head prosthesis by administering blows to the femoral head prosthesis when the truncated conical connection element is received in the conical bore, the head region situated proximally of the anchorage region in an axial direction of the anchorage region and having a maximum radial extent with respect to the anchorage region axis that is no larger than the maximum radial extent of the anchorage region, the external threaded section arranged proximate the head region; and
a distal end which is disposed opposite the head region in the axial direction of the anchorage region, wherein the maximum radial extent of the anchorage region comprises a maximum radial extent of the shaft with respect to the anchorage region axis.

2. A shaft in accordance with claim 1 , wherein the anchorage region includes a cementing section.

3. A shaft in accordance with claim 2 , wherein the cementing section has at least one recess for the reception of bone cement at its outer periphery.

4. A shaft in accordance with claim 3 , wherein the cementing section defines a cementing cross-section having a geometry of cross-shape or star shape in cross-section at least in an axial region, whereby the geometry of the cementing cross-section forms a plurality of substantially axially extending recesses.

5. A shaft in accordance with claim 4 , wherein the recesses extend up to a distal end of the cementing section.

6. A shaft in accordance with claim 3 , wherein the cementing section has a least one of a spiral and an annular circumferential groove which provides a recess for the reception of bone cement.

7. A shaft in accordance with claim 3 , wherein the recess is accessible from the distal end of the shaft.

8. A shaft in accordance with claim 3 , further comprising means for ensuring a fluid communication for a supply of bone cement from the distal end of the shaft to the recess.

9. A shaft in accordance with claim 2 , wherein the cementing section adjoins the external threaded section distally.

10. A shaft in accordance with claim 2 , wherein a maximum radial extent of the cementing section exceeds a maximum core diameter of the external threaded section by a maximum of ⅓ of the difference between a maximum external diameter of the external threaded section and the maximum core diameter of the external threaded section, and is at most the same size as the maximum core diameter of the external threaded section.

11. A shaft in accordance with claim 2 , wherein a maximum radial extent of the cementing section is at least the same size as the maximum radial extent of the head region.

12. A shaft in accordance with claim 1 , wherein the spongiosa thread has at least one of a substantially constant core diameter and a substantially constant external diameter.

13. A shaft in accordance with claim 1 , wherein the external threaded section has a thread height of at least 4.5 mm.

14. A shaft in accordance with claim 1 , wherein the maximum radial extent of the head region exceeds a maximum core diameter of the external threaded section by a maximum of ⅓ of the difference between a maximum external diameter of the external threaded section and the maximum core diameter of the external threaded section, and is at most the same size as the maximum core diameter of the external threaded section.

15. A shaft in accordance with claim 1 , wherein the anchorage region includes a cementing section, the cementing section including a sealing section proximate a distal end of the cementing section.

16. A shaft in accordance with claim 15 , wherein the sealing section is made in thread form.

17. A shaft in accordance with claim 16 , wherein the thread form of the sealing section corresponds to the spongiosa thread of the external threaded section of the anchorage region with respect to at least one of the dimension of the external diameter and the thread height.

18. A shaft in accordance with claim 1 , wherein the head region and the anchorage region are arranged coaxially.

19. A shaft in accordance with claim 1 , wherein the anchorage region includes a cementing section, the head region and at least one of the cementing section and the external threaded section being arranged coaxially.

20. A shaft in accordance with claim 1 , wherein the head region defines a head region axis and the anchorage region defines an anchorage region axis, the truncated conical connection element disposed along the head region axis, the head region axis parallel to the anchorage region axis.

21. A shaft for a femoral neck prosthesis, comprising:
an anchorage section provided for arrangement in the interior of the femur for anchorage of the femoral neck prosthesis in the femur, wherein the anchorage section includes an external threaded section with a spongiosa thread, wherein a maximum diameter of the external threaded section defines the maximum diameter of the shaft, and the anchorage section having an anchorage section axis and a maximum radial extent with respect to the anchorage section axis;
a head region including a truncated conical connection element that is to reside outside the femur for being received in a conical bore in a femoral head prosthesis for connecting the truncated conical connection element to the femoral head prosthesis by administering blows to the femoral head prosthesis when the truncated conical connection element is received in the conical bore, the head region situated proximally of the anchorage section in an axial direction of the anchorage section and having a maximum radial extent with respect to the anchorage section axis that is no larger than the maximum radial extent of the anchorage section; and
a distal end cementing section which is disposed opposite the head region in the axial direction of the anchorage section, the distal end cementing section coupled to the anchorage section with an axial segment of the cementing section received in a blind bore in the anchorage section, wherein the blind bore includes an entrance into the blind bore which occurs at a distal end of the anchorage section with the blind bore terminating distally of a proximal end of the truncated conical connection element of the head region, wherein the maximum extent of the anchorage section comprises a maximum radial extent of the shaft with respect to the anchorage section axis, the distal end cementing section sized to receive cement proximate the cementing section, the cementing section adjoining the threaded section distally.

22. A shaft in accordance with claim 21 , wherein the cementing section has at least one recess for the reception of bone cement at its outer periphery.

23. A shaft in accordance with claim 22 , wherein

Assignees

• Grappiolo Guido
• Willi Roland
• Zimmer Gmbh

Inventors

• Grappiolo Guido
• Willi Roland

Classifications

• A61F2002/4635

  using minimally invasive surgery · CPC title

• A61F2230/0058

  X-shaped · CPC title

• A61F2002/30331

  made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit · CPC title

• A61F2002/30474

  using an intermediate sleeve interposed between both prosthetic parts to be coupled · CPC title

• A61F2002/30827

  Plurality of grooves · CPC title