SYSTEM FOR POSITIONING A CUTTING GUIDE IN KNEE SURGERY

• US 20120259342A1
• Filed: 06/15/2012
• Published: 10/11/2012
• Est. Priority Date: 10/30/2008
• Status: Active Grant

• Current Assignee: Synvasive Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Synvasive Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Fisher, Michael G., Haight, Michael, Beckers, Leo, Chana, Barjinder Singh
• Granted Patent: US 9,439,656 B2
• Time in Patent Office: Days
• US Class Current: 606/88
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 2017/0268 for the knee
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/4666 for measuring force, pressure or mechanical tension

Abstract

A system is provided for positioning a cutting guide on a femur of a knee to make a cut along a distal end of the femur during knee surgery. The system may generally include an adjustable femoral attachment member configured to attach to a cut distal end of the femur, a cutting guide removably attachable to the femoral attachment member and configured to guide a surgical saw to make an additional cut on the distal end of the femur, and a force sensor for positioning between the femoral attachment member and a proximal end of a tibia of the knee. The force sensor may include a medial portion for sensing a medial force in the knee and a lateral portion for sensing a lateral force in the knee.

Claims

1. A system for positioning a cutting guide on a femur of a knee to make a cut along a distal end of the femur during a surgical procedure on the knee, the system comprising:

an adjustable femoral attachment member configured to attach to a cut distal end of the femur, the femoral attachment member comprising;

a medial elevator for increasing an amount of space between a medial portion of the femoral attachment member and the cut distal end of the femur;

a lateral elevator for creating space between a lateral portion of the femoral attachment member and the cut distal end of the femur; and

a single adjustment member configured to adjust both the medial and lateral elevators;

a cutting guide removably attachable to the femoral attachment member and configured to guide a surgical saw to make an additional cut on the distal end of the femur; and

a force sensor for positioning between the femoral attachment member and a proximal end of a tibia of the knee, wherein the force sensor comprises a medial portion for sensing a medial force in the knee and a lateral portion for sensing a lateral force in the knee.

2. A system as in claim 1, further comprising an insert for positioning between the force sensor and the femoral attachment member in the knee.

3. A system as in claim 1, further comprising multiple pins for attaching the cutting guide to the femur.

4. A system as in claim 1, further comprising multiple screws for attaching the femoral attachment member to the femur.

5. A system as in claim 4, wherein the femoral attachment member comprises at least two screw holes on a distal-facing surface for accepting the screws.

6. A system as in claim 5, further comprising an indicator on the distal-facing surface for indicating an angle of resection to which the cutting guide has been adjusted.

7. A system as in claim 1, further comprising an adjustment device for adjusting the femoral attachment member.

8. A system as in claim 7, wherein the adjustment device comprises a wrench configured to turn the adjustment member in one direction to adjust the medial elevator and in an opposite direction to adjust the lateral elevator.

9. A system as in claim 1, further comprising a slide member removably coupled with the cutting guide so that the cutting guide and slide member can slide onto the femoral attachment member to contact an anterior side of the femur.

10. A system as in claim 1, wherein the femoral attachment member is configured to be attached to the cut distal end of the femur while the knee is in flexion.

11. A system as in claim 10, wherein the femoral attachment member is configured to remain attached to the cut distal end of the femur while the knee is moved from flexion to extension.

12. A system as in claim 1, further comprising a display coupled with the sensor and configured to display a first indicator representing the medial force and a second indicator representing the lateral force.

13. A method for positioning a cutting guide on a femur of a knee to make a cut along a distal end of the femur during a surgical procedure on the knee, the method comprising:

attaching an adjustable femoral attachment member with a cut distal end of the femur;

positioning a force sensor on a cut proximal end of a tibia of the knee;

attaching the cutting guide to the femoral attachment member;

adjusting the femoral attachment member, using a single adjustment member of the femoral attachment member, to elevate at least one of a medial side and a lateral side of the femoral attachment member relative to the cut distal end of the femur to approximately balance medial and lateral forces displayed on a display coupled with the sensor, wherein adjusting the femoral attachment member changes a position of the cutting guide relative to the femur; and

attaching the cutting guide to the femur.

14. A method as in claim 13, wherein attaching the femoral attachment member comprises advancing two screws through holes in the attachment member and into the cut distal end of the femur while the knee is in flexion.

15. A method as in claim 14, further comprising positioning an insert between the force sensor and the femoral attachment member.

16. A method as in claim 14, further comprising moving the knee into extension while the femoral attachment member remains attached to the femur and before adjusting the femoral attachment member.

17. A method as in claim 16, wherein the cutting guide is attached to the femur while the knee is in extension.

18. A method as in claim 17, wherein attaching the cutting guide comprises pinning the cutting guide to the femur using multiple pins.

19. A method as in claim 17, further comprising moving the knee back into flexion after the cutting guide is attached.

20. A method as in claim 19, further comprising viewing a resection angle indicator on a distal surface of the femoral attachment member while the knee is in flexion, wherein the resection angle indicator indicates approximately an angle of resection of the distal femur based on a position of the cutting guide.

21. A method as in claim 13, wherein attaching the cutting guide to the femoral attachment member comprises sliding the cutting guide, attached to a slide member, onto the femoral attachment member until the cutting guide contacts a cut anterior surface of the femur.

22. A method as in claim 21, further comprising, before attaching the cutting guide to the femoral attachment member, attaching the slide member to the cutting guide.

23. A method as in claim 22, wherein attaching the slide member to the cutting guide comprises tightening a first screw using an adjustment device, and wherein adjusting the femoral adjustment member comprises turning a second screw using the same adjustment device.

24. A method as in claim 13, further comprising, before attaching the femoral adjustment member, making initial cuts on the distal end of the femur, an anterior side of the femur and a posterior side of the femur.

25. A method as in claim 13, wherein the single adjustment member comprises a screw, and wherein adjusting the femoral adjustment member comprises using an adjustment device to turn the screw in a first direction to adjust the medial side of the adjustment member and in a second direction to adjust the lateral side of the adjustment member.

26. A method as in claim 13, further comprising:

removing the femoral attachment member from the femur and the sensor from the tibia; and

cutting the distal end of the femur, using the attached cutting guide.

27. A method as in claim 26, further comprising removing a slide member attached to the cutting guide before cutting the distal end of the femur.

28. A method for making a cut on a distal end of a femur during a surgical procedure on a knee, the method comprising:

attaching an adjustable femoral attachment member with the distal end of the femur on which initial distal, anterior and posterior cuts have previously been made, while the knee is in flexion;

positioning a force sensor coupled with an insert on a cut proximal end of a tibia of the knee;

sliding a cutting guide onto the femoral attachment member until it contacts a cut anterior side of the femur;

tightening the cutting guide onto the femoral attachment member;

moving the knee into extension;

adjusting the femoral attachment member, using a single adjustment member of the femoral attachment member, to balance medial and lateral forces displayed on a display coupled with the sensor, wherein adjusting the femoral attachment member changes a position of the cutting guide relative to the femur;

attaching the cutting guide to the femur;

moving the knee into flexion;

removing the femoral attachment member from the femur; and

making the cut on the distal end of the femur, using the cutting guide.

29. A method as in claim 28, wherein adjusting the femoral attachment member comprises turning the single adjustment member using an adjustment device in at least one of a first direction, to adjust the medial force, and a second direction, to adjust the lateral force.

30. A method as in claim 29, wherein tightening the cutting guide comprises using the adjustment device to tighten a screw attaching the cutting guide to the femoral attachment member.

31. A method as in claim 28, wherein sliding the cutting guide onto the femoral attachment member comprises sliding a slide member attached to the cutting guide along the femoral attachment member, wherein the method further comprises removing the slide member from the cutting guide before making the cut on the distal end of the femur.

32. A method as in claim 28, further comprising viewing a resection angle indicator on the femoral attachment member after moving the knee into flexion to approximate a resection angle before making the cut.

33. A method as in claim 28, further comprising removing the sensor and the insert from the tibia before making the cut on the distal end of the femur.

34. A device for positioning a cutting guide on a femur of a knee during a surgical procedure on the knee, the device comprising:

a stationary femoral member that attaches to a cut distal end of the femur;

an adjustable femoral member moveably attached to the stationary femoral member;

a medial elevator for creating space between the stationary and adjustable femoral members closer to a medial edge of the device than a lateral edge of the device;

a lateral elevator for creating space between the stationary and adjustable femoral members closer to the lateral edge of the device than the medial edge of the device; and

a single adjustment member configured to adjust both the medial and lateral elevators.

35. A device as in claim 34, further comprising a cutting guide removably attachable to the adjustable femoral member and configured to guide a surgical saw to make an additional cut on the distal end of the femur.

36. A device as in claim 34, further comprising a force sensor for positioning between the adjustable femoral member and a proximal end of a tibia of the knee, wherein the force sensor comprises a medial portion for sensing a medial force in the knee and a lateral portion for sensing a lateral force in the knee.

37. A device as in claim 36, further comprising a display coupled with the sensor and configured to display a first indicator representing the medial force and a second indicator representing the lateral force.

38. A device as in claim 36, further comprising an insert for positioning between the force sensor and the femoral attachment member in the knee.

39. A device as in claim 34, further comprising multiple screws for attaching the stationary femoral member to the femur.

40. A device as in claim 34, further comprising an indicator on a distal-facing surface of the adjustable femoral member for indicating an angle of resection to which the cutting guide has been adjusted.

41. A device as in claim 34, further comprising an adjustment device for adjusting the medial and lateral elevators via the single adjustment member.

42. A device as in claim 41, wherein the adjustment device comprises a wrench configured to turn the adjustment member in one direction to adjust the medial elevator and in an opposite direction to adjust the lateral elevator.

43. A device as in claim 34, wherein the single adjustment member comprises a sliding portion that slides in a first direction to elevate the medial elevator and in a second, opposite direction to elevate the lateral elevator.

44. A device as in claim 34, wherein the device is configured to be attached to the cut distal end of the femur while the knee is in flexion.

45. A device as in claim 44, wherein the femoral attachment member is configured to remain attached to the cut distal end of the femur while the knee is moved from flexion to extension.