Unicondylar knee instrument system

• US 20060241639A1
• Filed: 01/23/2006
• Published: 10/26/2006
• Est. Priority Date: 04/18/2005
• Status: Active Grant

• Current Assignee: Arthrex Incorporated
• Original Assignee: Accin Corp.
• Inventors: Kvitnitsky, Mikhail, Kuczynski, John D.
• Granted Patent: US 7,601,154 B2
• Time in Patent Office: Days
• US Class Current: 606/88
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia

Abstract

The present invention provides for an apparatus for cutting a tibia, a stylus, an apparatus for cutting a femur, an apparatus for aligning a femoral cutting guide, and an ankle clamp in support of a unicondylar knee surgery. The present invention further provides for a method of preparing a femoral condyle of a femur for the implantation of a unicondylar femoral knee implant. The apparatus for cutting a tibia includes a unicondylar tibial resection guide that is adjustably connectable to a unicondylar tibial alignment guide and configured to operate concurrently with the tibial alignment guide. The apparatus for cutting a femur includes a spacer block and a cutting guide configured to operate concurrently with the spacer block.

Claims

1. An apparatus for cutting a tibia in support of a unicondylar knee surgery comprising:

a unicondylar tibial alignment guide having a tibia anchor; and

a unicondylar tibial resection guide adjustably connectable to the unicondylar tibial alignment guide and configured to operate concurrently with the unicondylar tibial alignment guide including;

an extended arm having at least one cutting guide surface; and

a tibial resection guide base connected to the extended arm.

2. The apparatus of claim 1, wherein the extended arm is the only element of the unicondylar tibial resection guide within a wound area.

3. The apparatus of claim 1, wherein the unicondylar tibial resection guide is adjustable in three degrees of freedom.

4. The apparatus of claim 3, wherein the three degrees of freedom include heaving, pitching, and rolling.

5. The apparatus of claim 1, wherein the overall thickness of the extended arm is about 1 to about 100 mm thick.

6. The apparatus of claim 1, wherein the overall thickness of the extended arm is about 2 to about 5 mm thick.

7. The apparatus of claim 1, wherein the unicondylar tibial alignment guide comprises at least two telescoping sections.

8. The apparatus of claim 1, further comprising a screw clamp connected to the tibial resection guide base attaching the unicondylar tibial resection guide to the unicondylar tibial alignment guide.

9. A tibial stylus for use in support of a unicondylar knee surgery comprising:

a tibial stylus pointer;

a member having an open top surface; and

a tibial stylus base having;

a posterior end configured to slidingly engage along the open top surface; and

an elongated anterior end connectable to the tibial stylus, configured such that the tibial stylus pointer moves along the anterior end of the tibial stylus base.

10. The tibial stylus of claim 9, wherein the member is a unicondylar tibial resection guide comprising:

an extended arm having at least one cutting surface; and

a tibial resection guide base connected to the extended arm.

11. The tibial stylus of claim 9, wherein the posterior end of the tibial stylus base is U-shaped.

12. An apparatus for cutting a femur in support of a unicondylar knee surgery comprising:

an instrument handle assembly including;

an elongated handle having a base; and

a spacer block removably connectable to the base; and

a unicondylar resection guide removeably connectable to the base and configured to operate concurrently with the spacer block including;

at least one channel for guiding a cutting tool; and

at least one opening for receiving a fixing element.

13. The apparatus of claim 12, wherein the unicondylar resection guide is slidingly and removably connectable to the base.

14. The apparatus of claim 12, wherein the spacer block and unicondylar resection guide are configured to operate independently of each other.

15. An apparatus for aligning a unicondylar femoral resection guide in support of a unicondylar knee surgery comprising:

an instrument handle assembly having a base; and

an alignment rod holder connected to the instrument handle assembly that slides substantially in the medial and lateral direction.

16. The apparatus of claim 15, further comprising a unicondylar resection guide removably connectable to the base.

17. The apparatus of claim 15, further comprising a unicondylar resection guide slidingly and removeably connectable to the base.

18. The apparatus of claim 15, further comprising a spacer block removably connectable to the base.

19. The apparatus of claim 15, wherein the alignment rod holder comprises:

a first alignment rod holder base having at least one substantially vertical passage;

a second alignment rod holder base having at least one substantially vertical passage; and

at least one dowel connecting the first and second alignment rod holder bases such that the first and second alignment rod holder bases slide within the instrument handle assembly in a substantially medial and lateral direction.

20. An ankle clamp for supporting an apparatus for cutting a tibia in support of a unicondylar knee surgery, comprising:

an ankle clamp base that includes a pair of base arms, each having a slot;

a pair of clamping arms, each having a slot and pivotably connected to the pair of base arms; and

a pair of springs, each respectively connecting the base arm and the clamping arm such that an opening force is provided to open the clamping arm.

21. The ankle clamp of claim 20, wherein the pair of springs, each respectively connecting the base arm and the clamping arm, provides a clamping force to close the clamping arm.

22. The ankle clamp of claim 20, wherein each one of the pair of springs are connected to a dowel, offset a predetermined distance from the pivotable connection of the clamping arms and base arms.

23. The ankle clamp of claim 20 further comprising a tibial alignment guide connected to the ankle clamp base.

24. A method of preparing a femoral condyle of a femur for the implantation of a unicondylar femoral knee implant comprising the steps of:

resecting a tibia;

determining a least affected site, wherein the site is a distal femoral condyle or a posterior femoral condyle;

positioning the knee such that the least affected site faces the tibia;

positioning a spacer block between the resected tibia and the least affected site;

determining an overall thickness for balancing the knee and resecting the femur to a thickness of a corresponding unicondylar femoral implant;

determining a spacer block and unicondylar femoral cutting block combination that equals the overall thickness when the knee is in extension; and

resecting the distal femoral condyle.