Prosthetic revision knee system

• US 20060241635A1
• Filed: 04/06/2005
• Published: 10/26/2006
• Est. Priority Date: 04/06/2005
• Status: Active Grant

• Current Assignee: Globus Medical, Inc.
• Original Assignee: Trigon Incorporated
• Inventors: Jones, Scott, Stevens, Donald A., Stumpo, David J.
• Granted Patent: US 7,628,794 B2
• Time in Patent Office: Days
• US Class Current: 606/87
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2002/30604 modular

Abstract

The present invention provides a femoral component, and a method for surgical implantation of a femoral prosthesis, comprised of a revision knee implant and corresponding cutting block system. In particular, the revision knee implant, comprised of a femoral component having incremental markings thereon and a femoral stem, and corresponding cutting block system having corresponding incremental markings thereon, enables a surgeon maximally to position the cutting block adjacent as much area as possible of a distal femur of a patient and to infinitely position the femoral component in the exact position indicated by the cutting block.

Claims

1. In a system for providing revision knee surgery, and specifically the surgical implantation of a femoral component of a revision knee, the method comprising:

reaming a distal femur of a patient to enlarge the femoral canal therein;

inserting in said femoral canal thus enlarged a trial stem attached to a cutting block, said cutting block having a front surface and a back surface and further having incremental markings on the front surface thereof, wherein said trial stem is hingedly attached to said back surface of said cutting block and further wherein said trial stem is able to rotate through about 10 degrees laterally around a longitudinal axis running perpendicularly to the back surface of said cutting block;

adjusting said cutting block by means of an adjustment screw to position said cutting block adjacent a maximal area as possible of said distal femur;

reading and noting the incremental adjustment thus made on said front surface of said cutting block;

using said cutting block to cut the distal femur to fit a femoral component bearing incremental markings thereon;

removing said cutting block and said trial stem from said distal femur;

affixing a bushing having an upper portion and a base portion to said femoral component bearing incremental markings thereon by affixing said bushing to the same location on said femoral component as was read from the incremental markings of said cutting block;

attaching a femoral stem to said bushing; and

implanting said femoral stem and said femoral component into said distal femur.

2. The method of claim 1, further comprising adjusting said cutting block in an anterior-posterior direction.

3. The method of claim 1, wherein the cutting block has a plurality of cutting slots defined therein.

4. The method of claim 3, wherein the cutting slots are comprised of an anterior resection slot, an anterior chamfer slot, a posterior chamfer slot and three posterior resection slots.

5. The method of claim 1, wherein the bushing is locked onto the femoral component by means of a locking member.

6. The method of claim 5, wherein the locking member is a set screw.

7. The method of claim 1, wherein said base portion of said bushing has mating surfaces.

8. The method of claim 7, wherein said mating surfaces are in the form of dovetails.

9. The method of claim 1, wherein the femoral component has spaced apart condylar portions defining an intercondylar region therebetween, said intercondylar region having an elongate engagement surface extending in an anterior-posterior direction.

10. The method of claim 9, wherein the bushing is configured for sliding engagement with said engagement surface of said intercondylar region for movement in said anterior-posterior direction.

11. The method of claim 9, wherein said femoral component is configured such that a plane of symmetry is defined between the condylar portions in the anterior-posterior direction.

12. The method of claim 11, wherein said upper portion of said bushing defines a central axis offset from the plane of symmetry at an acute angle.

13. The method of claim 11, wherein said upper portion of said bushing is offset to a degree to substantially match the valgus angle of the patient.

14. The method of claim 13, wherein said upper portion of said bushing is configured for secure attachment to said femoral stem to align said femoral stem at said acute angle along the central axis of said upper portion.

15. The method of claim 14, wherein said acute angle is a canting angle ranging from between about 0 to 9 degrees.

16. The method of claim 14, wherein said acute angle is a canting angle of one of 0, 3, 5 or 7 degrees.

17. A femoral prosthesis comprising a femoral component having an anterior surface, a posterior surface, and a pair of spaced-apart condylar portions that define an intercondylar region, wherein incremental markings are provided adjacent said intercondylar region and further wherein said incremental markings correspond in position and are identical in magnitude to corresponding incremental markings on a corresponding cutting block designed for use in preparing a patient'"'"'s bone to receive said femoral component.

18. Components for use in a system for providing a revision knee surgery, comprising a femoral component according to claim 17 and a cutting block having a multiple of cutting slots therein, wherein said cutting slots are comprised of an anterior resection slot, an anterior chamfer slot, a posterior chamfer slot and three posterior resection slots, and further wherein said incremental markings on said femoral component correspond in position and are identical in magnitude to a second set of incremental markings centrally located on said cutting block.