Natural alignment knee instruments

Patent metadata

Field	Value
Publication number	US-9855057-B2
Application number	US-201514747411-A
Country	US
Kind code	B2
Filing date	Jun 23, 2015
Priority date	May 21, 2010
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A method for aligning an orthopedic implant in a joint replacement includes determining the bone and cartilage deficiency from an undegenerated state caused by wear of a joint. Then a resection of a bone in the joint is made based on the deficiency of bone and cartilage from the undegenerated state and the size of a joint implant so as to locate the joint surface of the implant in the undegenerated cartilage location. The condylar wear from the undegenerated states may be assessed at a distal and posterior location on each of a medial and a lateral femoral condyle. A distal cut is made on the femur at a location adjusting for the condylar wear from the undegenerated state. The distal cut varus-valgus angle is oriented parallel to a plane across the distal femur after adjusting for wear in the distal location on the medial and lateral condyle.

First claim

The invention claimed is:

1. A tibial resection guide assembly, comprising:
an elongate rod;
a tibial resection guide adjustably mounted to the elongate rod and having a resection guide surface; and
a femoral referencing member adjustably mounted to the elongate rod, and having a proximal facing surface for contacting a distal femur and a distal facing convexly shaped surface for contacting respective tibial condyles of a proximal tibia, the proximal facing surface including first and second peg members extending therefrom for receipt within respective openings in the distal femur.

2. The assembly of claim 1 , wherein the proximal facing surface is planar.

3. The assembly of claim 1 , further comprising a plurality of femoral spacer elements attachable to the distal facing surface.

4. The assembly of claim 3 , wherein the plurality of femoral spacer elements each have proximal and distal surfaces defining a thickness therebetween, the thickness of each femoral spacer element being different than the thickness of the other femoral spacer elements.

5. The assembly of claim 4 , wherein the thickness of the femoral spacer elements differs in 1 mm increments.

6. The assembly of claim 5 , wherein the plurality of femoral spacer elements is comprised of first, second, and third femoral spacer elements, the first femoral spacer element having a thickness of 1 mm, the second femoral spacer element having a thickness of 2 mm, and the third femoral spacer element having a thickness of 3 mm.

7. The assembly of claim 3 , wherein the convexly shaped surface includes attachment mechanisms for connection to one of the plurality of femoral spacer elements.

8. A tibial resection guide assembly, comprising:
an elongate rod;
a tibial resection guide mounted to the elongate rod between first and second ends thereof and having a resection guide surface; and
a referencing member slidably mounted to the first end of the elongate rod, the referencing member having a proximal facing surface for contacting a distal femur and a distal facing surface having a first convex portion for contacting a proximal tibia, the proximal facing surface having a plurality of projections extending therefrom for receipt in respective openings within the distal femur.

9. The assembly of claim 8 , further comprising a spacer element having proximal and distal surfaces defining a thickness therebetween.

10. The assembly of claim 9 , wherein the distal surface of the referencing member includes an attachment mechanism, and the spacer element includes a connection member extending from the proximal surface thereof and configured to connect to the attachment mechanism such that the distal surface of the spacer element is offset from the distal surface of the referencing member.

11. The assembly of claim 10 , wherein the attachment mechanism is located within the first convex portion.

12. The assembly of claim 9 , wherein the thickness of the spacer element is one of 1 mm, 2 mm, and 3 mm.

13. The assembly of claim 9 , wherein the referencing member includes a second convex portion for contacting a proximal tibia, and the first and second convex portions are separated by a space.

14. The assembly of claim 8 , wherein the first end of the elongate rod includes a hollow guide configured to slidingly receive an extension of the referencing member.

15. A tibial resection guide assembly, comprising:
an elongate rod;
a tibial resection guide adjustably mounted to the elongate rod and having a resection guide surface; and
a referencing member having a body adjustably mounted to the elongate rod, the body having a proximal surface and a distal convex surface defining a thickness of the referencing member, wherein the proximal surface is planar and includes a peg member extending therefrom for receipt within an opening of a distal femur.

16. The assembly of claim 15 , further comprising a spacer element connectable to the distal convex surface.

17. The assembly of claim 16 , wherein the spacer element includes proximal and distal surfaces defining a thickness therebetween, and when the spacer element is connected to the distal convex surface of the referencing member, the thickness of the referencing member is increased by an amount substantially equal to the thickness of the spacer element.

18. The assembly of claim 17 , wherein the thickness of the spacer element is one of 1 mm, 2 mm, and 3 mm.

Assignees

• Howmedica Osteonics Corp

Inventors

• Axelson Jr Stuart L
• Soliman Mohamed
• Ferko Michael C
• Simes Jr Robert Frederick
• Howell james h

Classifications

• A61F2/4684

  Trial or dummy prostheses · CPC title

• A61B17/154

  for preparing bone for knee prosthesis · CPC title

• A61B17/155 Primary

  Cutting femur · CPC title

• A61B17/157 Primary

  Cutting tibia · CPC title

• A61B17/15

  Guides therefor · CPC title