Osteotomy procedure

• US 20040106926A1
• Filed: 12/02/2002
• Published: 06/03/2004
• Est. Priority Date: 12/02/2002
• Status: Active Grant

• Current Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Original Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Inventors: Pinzuti, Jean-Baptiste, Leitner, Francois
• Granted Patent: US 7,318,827 B2
• Time in Patent Office: Days
• US Class Current: 606/87
• CPC Class Codes: A61B 17/142 with reciprocating saw blades, e.g. with cutting edges at the distal end of the saw blades
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/152 for removing a wedge-shaped piece of bone
• CPC Class Codes: A61B 17/1703 using imaging means, e.g. by X-rays
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2068 using pointers, e.g. pointers having reference marks for determining coordinates of body points
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

An osteotomy resection procedure for removing a wedge from a bone utilizing a localization device. The localization device being used to track reference points associated with the bone, track surgical instruments, perform calculations to determine a resection angle for the wedge, and assist a surgeon in performing the procedure.

Claims

1. A method for removing a wedge from a bone to reshape said bone, wherein, prior to removing said wedge, said bone extends between a first position corresponding to a first end of said bone and a second position corresponding to a second end of said bone and wherein, after removing said wedge, said second end of said bone is relocated to a third position such that a desired correction angle is produced between a first vector extending from the first position to the second position and a second vector extending from the first position to the third position, said method comprising the steps of:

performing a first cut into the bone, said first cut having a depth;

determining a pivot point within the bone, said pivot point located within said first cut;

calculating a resection angle at said pivot point for the wedge with respect to said first cut to produce the desired correction angle; and

performing a second cut into the bone, said second cut made with respect to said first cut at said resection angle and extending to at least about said pivot point, said first and second cuts defining the wedge.

2. The method of claim 1, wherein the step of calculating said resection angle is performed by a localization device.

3. The method of claim 1, further comprising:

determining the first and second positions corresponding to the ends of the bone with a localization device.

4. The method of claim 1, wherein said calculating step comprises at least the steps of:

determining the location of the third position with reference to the first position; and

calculating said resection angle based on said pivot point, the second position, and the third position.

5. The method of claim 4, wherein said step of calculating the resection angle comprises at least the step of solving the equation:

6. The method of claim 4, wherein said step of determining the location of the third position comprises at least the step of solving the equation:

A′

=K+KA cos(α

)+KA^ortho sin(α

);

where A′

is the third position, K is the first position, KA is a vector extending from the first position to the second position, KA^ortho is a vector of equal magnitude and orthogonal to KA, and a is the desired correction angle.

7. The method of claim 6, wherein said step of calculating the resection angle comprises at least the step of solving the equation:

8. The method of claim 1, wherein said step of performing said first cut comprises at least the steps of:

obtaining reference points associated with the bone using a localization device;

attaching to the bone a first cut cutting jig having a guide, said cutting jig capable of receiving a marker for use by the localization device in orienting said guide with respect to the bone; and

inserting a saw having a cutting tip into said guide for making said first cut, said saw capable of receiving a marker for use by the localization device in tracking said cutting tip with respect to the bone; and

displaying a representation indication the position of said cutting tip with respect to the bone during the cutting of the bone to provide visual assistance for performing said first cut.

9. The method of claim 8, wherein said attaching step comprises at least the step of:

navigating said first cut cutting jig with the localization device so that said guide is positioned to guide said saw at approximately 45 degrees to the first vector.

10. The method of claim 8, wherein said attaching step comprises at least the step of:

navigating said first cut cutting jig with the localization device so that said guide is positioned to guide said saw at approximately 90 degrees to the first vector.

11. The method of claim 8, wherein said step of performing said second cut comprises at least the steps of:

attaching to the bone a second cut cutting jig having a guide, said second cut cutting jig capable of receiving a marker for use by the localization device in orienting said second cut cutting jig guide with respect to the bone, said second cut cutting jig being navigated using the localization device so that said second cut may be performed such that said second cut will intersect said first cut at said pivot point at the resection angle with respect to said first cut; and

inserting a second saw having a cutting tip into said second cut cutting jig guide for making said second cut, said saw capable of receiving a marker for use by the localization device in orienting said cutting tip with respect to the bone; and

displaying a representation indicating the position of the cutting tip with respect to the bone during the cutting of the bone to provide visual assistance for performing said second cut.

12. The method of claim 1, wherein said step of determining said pivot point comprises at least the steps of:

inserting a check blade fully into said first cut, said check blade having a marker so that it may be tracked by a localization device;

observing said marker on said check blade with said localization device to determine the depth of said first cut;

recording a location corresponding to the depth of said first cut with said localization device; and

selecting the recorded location of said first cut as said pivot point.

13. A method for removing a wedge from a bone to reshape said bone, wherein, prior to removing said wedge, said bone extends between a first position corresponding to a first end of said bone and a second position corresponding to a second end of said bone and wherein, after removing said wedge, said second end of said bone is relocated to a third position such that a desired correction angle is produced between a first vector extending from the first position to the second position and a second vector extending from the first position to the third position, said method comprising the step of:

calculating a resection angle for the wedge at a pivot point within the bone that will produce the desired correction angle when the wedge is removed from the bone.

14. The method of claim 13, wherein said step of calculating the resection angle is performed by a localization device.

15. The method of claim 13, further comprising:

determining the first and second positions corresponding to the ends of the bone with a localization device.

16. The method of claim 13, wherein said calculating step comprises at least the steps of:

determining the location of the third position with respect to the first position; and

calculating said resection angle based on said pivot point, the second position, and the third position.

17. The method of claim 16, wherein said step of calculating said resection angle comprises at least the step of solving the equation:

18. The method of claim 16, wherein said step of determining the location of the third position comprises at least the step of solving the equation:

A′

=K+KA cos(α

)+KA^ortho sin(α

);

where A′

is the third position, K is the first position, KA is a vector extending from the first position to the second position, KA^ortho is a vector of equal magnitude and orthogonal to KA, and a is the desired correction angle.

19. The method of claim 18, wherein said step of calculating said resection angle comprises at least the step of solving the equation:

20. A method for removing a wedge from a bone extending between a first joint and a second joint to reshape said bone, said first joint coupling said bone on a first end to a first body and said second joint coupling said bone on a second end to a second body, said method comprising the steps of:

determining the center of the first joint to obtain a first position;

determining the center of the second joint to obtain a second position;

performing a first cut into the bone, said first cut having a depth;

determining a pivot point within the bone, said pivot point located at the depth of said first cut;

calculating a resection angle for the wedge with respect to said first cut based on said pivot point, said first and second determined positions, and the desired correction angle, wherein, prior to removing the wedge, the bone extends between said first position and said second position and wherein, after removing the wedge, the second end of the bone is relocated to a third position such that a desired correction angle is produced between a first vector extending from said first position to said second position and a second vector extending from said first position to said third position; and

performing a second cut into the bone at said resection angle, said second cut extending to at least about said pivot point, said first and second cuts defining the wedge.

21. The method of claim 20, wherein said steps of determining the center of the first and second joints and calculating the resection angle are performed using a localization device.

22. The method of claim 20, wherein the bone is a femur, the first joint is a knee, the second joint is a hip joint, the first body is a tibia, and the second body is a hip bone.

23. The method of claim 20, wherein the bone is a tibia, the first joint is a knee, the second joint is an ankle, the first body is a femur, and the second body is a foot.

24. The method of claim 20, wherein said step of determining said pivot point comprises at least the steps of:

inserting a check blade fully into said first cut, said check blade having a marker so that it may be tracked by a localization device;

observing said marker on said check blade with said localization device to determine the depth of said first cut;

recording a location corresponding to the depth of said first cut with said localization device; and

selecting the recorded location of said first cut as said pivot point.

25. The method of claim 20, wherein said calculating step comprises at least the steps of:

determining the location of said third position with reference to said first position; and

calculating said resection angle based on said pivot point, said second position, and said third position.

26. The method of claim 25, wherein said step of calculating said resection angle comprises at least the step of solving the equation:

27. The method of claim 25, wherein said step of determining the location of said the third position comprises at least the step of solving the equation:

A′

=K+KA cos(α

)+KA^ortho sin(α

);

where A′

is said third position, K is said first position, KA is a vector extending from said first position to said second position, KA^ortho is a vector of equal magnitude and orthogonal to KA, and a is said desired correction angle.

28. The method of claim 27, wherein said step of calculating said resection angle comprises at least the step of solving the equation:

29. A computer program product for removing a wedge from a bone, said computer program product comprising:

computer readable program code embodied in a computer readable medium, the computer readable program code comprising at least;

computer readable program code for calculating a resection angle for the wedge at a pivot point within the bone that will produce a desired correction angle when the wedge is removed from the bone.

30. The computer program product of claim 29, wherein said computer readable program code is for use in a localization device, said localization device providing information identifying a first position corresponding to a first end of said bone and a second position corresponding to a second end of said bone prior to removing the wedge and wherein, after removing the wedge, said second end of said bone is relocated to a third position such that the desired correction angle is produced between a first vector extending from the first position to the second position and a second vector extending from the first position to the third position.

31. The product of claim 30, wherein said computer readable program code for calculating said resection angle comprises at least computer readable program code for solving the equation:

32. The product of claim 30, wherein said computer readable program code further comprises at least:

computer readable program code for determining;

A′

=K+KA cos(α

)+KA^ortho sin(α

);

where A′

is the third position, K is the first position, KA is a vector extending from the first position to the second position, KA^ortho is a vector of equal magnitude and orthogonal to KA, and a is the desired correction angle.

33. The product of claim 32, wherein said computer readable program code for calculating said resection angle comprises at least computer readable program code for solving the equation:

34. A localization device for use in an osteotomy procedure to remove a wedge from a bone by making two cuts in the bone to reshape said bone, wherein, prior to removing said wedge, said bone extends between a first position corresponding to a first end of said bone and a second position corresponding to a second end of said bone and wherein, after removing said wedge, said second end of said bone is relocated to a third position such that a desired correction angle is produced between a first vector extending from the first position to the second position and a second vector extending from the first position to the third position, said device comprising:

sensors for sensing information corresponding to the locations of markers associated with one or more of the bone and surgical instruments;

a computer coupled to said sensors for tracking the markers;

means for determining a pivot point within the first cut in the bone;

means for calculating a resection angle for making the second cut relative to the first cut that will produce the desired correction angle when the wedge is removed from the bone.

35. The localization device of claim 34, further comprising:

means for guiding the second cut relative to the first cut so as to produce the calculated resection angle.

36. The localization device of claim 35, wherein said guiding means comprises at least:

a visual display coupled to said computer for guiding a surgeon during the osteotomy procedure.

37. The localization device of claim 34, wherein said means for calculating said resection angle comprises at least means for solving the equation:

38. The localization device of claim 34, wherein said means for calculating said resection angle comprises at least means for determining

A′

=K+KA cos(α

)+KA^ortho sin(α

);

where A′

is the third position, K is the first position, KA is a vector extending from the first position to the second position, KA^ortho is a vector of equal magnitude and orthogonal to KA, and a is the desired correction angle.

39. The localization device of claim 38, wherein said means for calculating said resection angle further comprises at least means for solving the equation: