Tool

• US 20050245934A1
• Filed: 04/20/2005
• Published: 11/03/2005
• Est. Priority Date: 04/20/2004
• Status: Abandoned Application

• Current Assignee: Finsbury (Development) Limited (WPP PLC)
• Original Assignee: Finsbury (Development) Limited (WPP PLC)
• Inventors: Wozencroft, Robert Michael, Tuke, Michael A., Scott, Gareth
• Application Number:
  US11/110,985
• Publication Number:
  US 20050245934A1
• Time in Patent Office: Days
• US Class Current: 606/79
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length

Abstract

An alignment guide for use in femoral head surgery comprising: a support arm having a proximal and a distal end; a ring located at the distal end of the support arm and angled to the plane of the support arm; and a collar located at the proximal end of the support arm, the support arm being configured such that the axis of the bore of the collar is located above the ring.

Claims

1. An alignment guide for use in femoral head surgery comprising:

a support arm having a proximal and a distal end;

a ring located at the distal end of the support arm and angled to the plane of the support arm; and

a collar located at the proximal end of the support arm;

the support arm being configured such that the axis of the bore of the collar is located above and the ring.

2. An alignment guide according to claim 1 wherein the ring is angled at between 80°

and 100°

to the plane of the support arm.

3. An alignment guide according to claim 1 wherein the ring is substantially perpendicular to the plane of the support arm.

4. An alignment guide according to claim 1 wherein the bore of the collar is located in line with the centre point of the ring.

5. An alignment guide according to claim 1 wherein the ring is adjustable such that the centre of the ring can be displaced from the main axis of the alignment guide.

6. The alignment guide according to claim 1 additionally including a cannulated rod, said rod being a sliding fit in the collar.

7. The alignment guide according to claim 6 wherein a locking means is provided to lock the rod in position.

8. The alignment guide according to claim 7 wherein the locking means is a locking screw.

9. The alignment guide according to claims 6 wherein the cannulated rod has teeth located at a proximal end.

10. The alignment guide according to claim 6 wherein the cannulated rod additionally includes measuring indica.

11. The alignment guide according to claim 1 wherein the outside edge of the ring is sized to replicate the size of a femoral head.

12. The alignment guide according to claim 11 wherein the ring includes markings which when in the ring is used as a size check can represent the position of the skirt of a prosthesis.

13. The alignment guide according to claim 1 wherein the ring is a C-ring.

14. The alignment guide according to claim 1 wherein the ring is an expandable iris.

15. The alignment guide according to claim 1 wherein the ring includes a removable portion, said removable portion being hinged to the remainder of the ring and moveable from an open to a closed position.

16. The alignment guide according to claim 1 wherein the ring is formed of two arms which are each hinged to allow movement from an open to a closed position.

17. The alignment guide according to claim 16 wherein when in the closed position, the arms complete a circle.

18. The alignment guide according to claim 1 wherein the ring is formed of two arms one of which is fixed and the other of which is movable form an open to a closed position.

19. The alignment guide according to claim 1 wherein the collar has a slot extending along at least a portion thereof.

20. The alignment guide according to claim 1 wherein a flag is included at the distal end of the support arm and extends below the position of the ring.

21. The alignment guide according to claim 1 wherein in use the ring replicates the rim of a resurfacing head prosthesis.

22. The alignment guide according to claim 1 additionally includes a saw cutting guide mounted on the support arm, collar or, where present, on the cannulated rod.

23. The alignment guide according to claim 1 wherein the ring is demountable.

24. The alignment guide according to claim 1 in combination with an elongate distal alignment guide which by referencing the back of the knee will reference the leg alignment axis..

25. A kit comprising the alignment guide of claim 23 and a plurality of rings.

26. A kit according to claim 25 wherein the plurality of rings are of differing sizes.

27. A kit according to claim 25 wherein the kit additionally includes an elongate distal alignment guide which by referencing the back of the knee will reference the leg alignment axis.

28. A method of preparing the head of a femur for femoral head resurfacing wherein the method comprises:

exposing the head of a femur;

locating the alignment guide according to claim 1 beneath the head of the femur at the head-neck junction; and

machining the head of the femur.

29. A method according to claim 28 wherein the method comprises:

exposing the head of the femur;

locating the alignment guide according to claim 1 beneath the head of the femur at the head-neck junction;

inserting a drill through the collar and drilling a well into the head of the femur;

removing the drill;

removing the top of the head of the femur;

removing the alignment guide;

inserting a guide rod into the well;

locating a sleeve cutter on the guide rod and cutting the head; and

optionally chamfer cutting the head.