LEG ALIGNMENT APPARATUS AND METHOD

• US 20150238202A1
• Filed: 09/27/2013
• Published: 08/27/2015
• Est. Priority Date: 10/03/2012
• Status: Abandoned Application

• Current Assignee: Corin Limited (Corin Medical Ltd. /Management/)
• Original Assignee: Corin Limited (Corin Medical Ltd. /Management/)
• Inventors: Collins, Simon, Bellemans, Johan, Victor, Jan Maria Karel, Sabharwal, Harsimran, Sutcliffe, Andrew Craig, Girotti, Gianluca, Elmslie, Ian James
• Application Number:
  US14/433,040
• Publication Number:
  US 20150238202A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 2090/067 for measuring angles

Abstract

Leg alignment apparatus for use in total arthroplasty of left and right knees, comprises an intramedullary rod, a femoral body for location on or adjacent to an anterior surface of a femur, and a support element which extends or is extendable from the femoral body to the intramedullary rod for holding the femoral body stationary or substantially stationary relative to the intramedullary rod. A condylar locator which is pivotable relative to the femoral body and which is seatable on a distal end of the femur is also provided, along with a soft-tissue tensioning element to apply a separation between the femur and the tibia, and a varus/valgus indicator to indicate an angular alignment of the knee based on the intramedullary rod and the soft-tissue tensioning element. A method of determining a distal end resection position for a femur at a knee joint is also provided.

Claims

1. Leg alignment apparatus for use in total arthroplasty of left and right knees, the apparatus comprising an intramedullary rod, a femoral body which locates on or adjacent to an anterior surface of a femur, a support element which extends or is extendable from the femoral body to the intramedullary rod which holds the femoral body stationary or substantially stationary relative to the intramedullary rod, a condylar locator which is pivotable relative to the femoral body and which is seatable on a distal end of the femur, a soft-tissue tensioning element to apply a separation between the femur and the tibia, and a varus/valgus indicator to indicate an angular alignment of the knee based on the intramedullary rod and the soft-tissue tensioning element.

2. Leg alignment apparatus as claimed in claim 1, wherein the soft-tissue tensioning element is able to apply a linear separation between the femur and the tibia.

3. Leg alignment apparatus as claimed in claim 1, wherein the condylar locator is seatable on a distal end of at least one of medial and lateral condyles.

5. Leg alignment apparatus as claimed in claim 1, wherein the varus/valgus indicator is able to indicate an angular deviation of the knee from neutral alignment.

6. Leg alignment apparatus as claimed in claim 1, wherein the soft-tissue tensioning element and the femoral body are pivotably interconnected or interconnectable.

7. Leg alignment apparatus as claimed in claim 6, wherein the soft-tissue tensioning element includes a soft-tissue tensioning connector which is pivotably mounted on the femoral body.

9. Leg alignment apparatus as claimed in claim 1, wherein the condylar locator includes medial and/or lateral elongate condylar platforms.

12. Leg alignment apparatus (12) as claimed in claim 1, wherein the soft-tissue tensioning element includes at least one shim element which distracts a tibia and femur.

13. Leg alignment apparatus as claimed in claim 1, wherein the condylar locator includes a ligament tension indicator which is pivotable relative to the soft-tissue tensioning element.

15. Leg alignment apparatus as claimed in claim 1, further comprising a cutting-jig guide or a cutting jig which is movable relative to the femoral body and in unison with the condylar locator, so that a predetermined amount of bone is resectable from a distal end of the femur based on the most prominent femoral distal condyle.

17. Leg alignment apparatus as claimed in claim 1, wherein the support element is integrally formed as one-piece with the intramedullary rod, and is angularly-offset relative to the longitudinal axis of the intramedullary rod, so as to project in a direction of an anterior surface of a femur.

4. (canceled)

8. (canceled)

10. (canceled)

11. (canceled)

14. (canceled)

16. (canceled)

18. (canceled)

19. (canceled)

20. A method of determining a distal end resection position for a femur at a knee joint, the method comprising the steps of:

a] prior to distal resection and with a leg in extension, providing a separation between a tibia and femur of the knee joint;

b] with the leg still in extension and the separation of step a] applied, determining angular alignment of the knee based on an intramedullary rod extending along a femoral anatomical axis and/or a condylar plane and the separation between the tibia and femur; and

c] determining a position of distal resection from a condylar plane of the femur.

21. The method as claimed in claim 20, further comprising a step d] prior to step a] of resecting a proximal end of the tibia perpendicularly or substantially perpendicularly to the tibial mechanical axis in a coronal plane and in a range of zero to ten degree posterior slope in the sagittal plane.

24. The method as claimed in claim 20, further comprising a step e] between steps b] and c] of releasing soft tissue spanning between the femur and the tibia to set a required said angular alignment or neutral alignment.

25. The method as claimed in claim 24, wherein, in step e], once the said determined angular alignment or neutral alignment is achieved, the said alignment is locked in place.

26. The method as claimed in claim 25, wherein, prior to step e], the said angular alignment is predetermined and locked in place, and the releasing of soft tissue in step e] causes movement of the condylar plane relative to the tibia.

27. The method as claimed in claim 20, wherein, in step c], the position of the distal femoral resection is set based on the most prominent femoral distal condyle.

28. The method as claimed in claim 20, wherein, in step c], at least one cutting guide locator is formed on an anterior surface of a distal end portion of the femur.

29. The method as claimed in claim 28, wherein the cutting guide locator is a predetermined set distance from a most prominent femoral distal condyle, so that a same predetermined set amount of bone is always resectable from a distal end of the femur.

30. The method as claimed in claim 20, wherein, in step a cutting jig is located on a distal end portion of the femur which guides a cutter during distal resection of the femur.

31. The method as claimed in claim 20, further comprising a step f] subsequent to step c] of placing the leg in flexion, providing a linear separation between the tibia and femur of the knee joint, and further resecting a distal end portion of the femur relative to a medial posterior condyle of the femur so as to set femoral rotation.

22. (canceled)

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34. (canceled)