MECHANICAL AXIS ALIGNMENT USING MRI IMAGING

• US 20100099977A1
• Filed: 10/22/2008
• Published: 04/22/2010
• Est. Priority Date: 10/22/2008
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Hershberger, Troy W.
• Granted Patent: US 9,730,616 B2
• Time in Patent Office: Days
• US Class Current: 600/414
• CPC Class Codes: A61B 17/151 for corrective osteotomy
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 2090/067 for measuring angles
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/103 Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes A61B5/08 takes precedence; measuring aids for tailors A41H1/00; measuring instruments specially adapted for dentistry A61C19/04
• CPC Class Codes: A61B 5/1071 measuring angles, e.g. using goniometers A61B5/1123 takes precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 6/00 Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment instruments measuring radiation intensity for application in the field of nuclear medicine, e.g. in vivo counting, G01T1/161; apparatus for taking X-ray photographs G03B42/02
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies

Abstract

A method of imaging a body part includes locating a first, second and third anatomical reference area. The third anatomical reference area is disposed generally between the first and second anatomical reference areas. Furthermore, the method includes positioning a first member of a reference tool relative to the first anatomical reference area, positioning a second member of the reference tool relative to the second anatomical reference area, and a pivotal coupling member relative to the third anatomical reference area. The pivotal coupling member pivotally couples the first and second members of the reference tool. In addition, the method includes imaging a target area of the body part to produce an image. The image includes the target area of the body part and the first and second members. The first member indicates a first axis of the body part, and the second member indicates a second axis of the body part.

Claims

1. A method of imaging a body part comprising:

locating a first anatomical reference area of the body part;

locating a second anatomical reference area of the body part;

locating a third anatomical reference area of the body part, the third anatomical reference area disposed generally between the first and second anatomical reference areas;

positioning a first member of a reference tool relative to the first anatomical reference area;

positioning a second member of the reference tool relative to the second anatomical reference area;

positioning a pivotal coupling member relative to the third anatomical reference area, the pivotal coupling member pivotally coupling the first and second members of the reference tool; and

imaging a target area of the body part to produce an image, the image including the target area of the body part and at least a portion of the first and second members, the at least a portion of the first member indicating a first axis of the body part in the image, and the at least a portion of the second member indicating a second axis of the body part in the image.

2. The method of claim 1, wherein locating the first anatomical reference area comprises locating an approximate center of a femoral head.

3. The method of claim 2, wherein locating an approximate center of the femoral head comprises mathematically calculating the approximate center of the femoral head based on anatomical measurements of a pelvis.

4. The method of claim 1, wherein locating the second anatomical reference area comprises locating an approximate center of an ankle joint.

5. The method of claim 1, wherein locating the third anatomical reference area comprises locating an approximate center of a knee joint.

6. The method of claim 1, further comprising positioning an imaging coil over the body part.

7. The method of claim 1, further comprising generating a cut guide for surgically cutting the body part along a cutting direction based on the image.

8. The method of claim 7, wherein the cutting direction is approximately perpendicular to the first axis of the body part.

9. The method of claim 1, wherein the target area includes the third anatomical reference area and excludes the first and second anatomical reference areas.

10. The method of claim 1, wherein imaging the target area of the body part comprises at least one of Magnetic Resonance Imaging (MRI), computed tomography (CT), X-ray and fluoroscopy of the target area of the body part.

11. A reference tool for indicating anatomical features of a body part, the reference tool comprising:

a first member positionable relative to a first anatomical reference area of the body part;

a second member positionable relative to a second anatomical reference area of the body part; and

a pivotable coupling member pivotally coupling the first member and the second member, the pivotable coupling member locatable relative to a third reference point of the body part disposed generally between the first and second anatomical reference areas, the first member and the second member being detectable on an image of a target area of the body part such that the first member indicates a first axis of the body part in the image and the second member indicates a second axis of the body part in the image.

12. The reference tool of claim 11, wherein the first member and the second member each have a substantially straight axis.

13. The reference tool of claim 11, wherein the pivotable coupling member is at least one of a ball joint and a hinge that pivotally couples the first and second members.

14. The reference tool of claim 11, wherein the first member, the second member, and the pivotable coupling member are made out of a non-magnetic material.

15. The reference tool of claim 11, wherein at least one of the first and second members has an adjustable length.

16. The reference tool of claim 11, further comprising a scale that is operably coupled to one of the first and second members to indicate a distance between the pivotal coupling member and an end of the one of the first and second members.

17. A method of imaging a knee joint of a leg comprising:

locating an approximate center of a femoral head of the leg;

locating an approximate center of an ankle joint of the leg;

locating an approximate center of a knee joint of the leg;

positioning a pivotal coupling member over the approximate center of the knee joint of the leg, the pivotal coupling member pivotally coupling a first and a second member of a reference tool;

pivoting the first member of the reference tool to position the first member over the approximate center of the femoral head;

pivoting the second member of the reference tool to position the second member over the approximate center of the ankle joint; and

imaging the knee joint to produce an image of the knee joint and at least a portion of the first and second members, the at least a portion of the first member indicating a mechanical axis of the leg in the image, and the at least a portion of the second member indicating a tibial axis of the leg in the image.

18. The method of claim 17, wherein the image includes the knee joint and excludes the femoral head and the ankle joint.

19. The method of claim 17, further comprising identifying a joint line of the leg.

20. The method of claim 17, further comprising positioning a distal end of the first member of the reference tool over the approximate center of the femoral head.

21. The method of claim 17, further comprising positioning a distal end of the second member over the approximate center of the ankle joint.

22. The method of claim 17, further comprising extending a length of at least one of the first and second member.

23. The method of claim 22, further comprising measuring an approximate distance between the center of the knee joint and at least one of the center of the ankle joint and the center of the knee joint

24. A method of imaging a body part comprising:

locating a first anatomical reference area of the body part;

locating a second anatomical reference area of the body part;

positioning a first member of a reference tool relative to the first anatomical reference area;

positioning a second member of the reference tool relative to the second anatomical reference area, the second member disposed at a positive angle relative to the first member; and

imaging a target area of the body part to produce an image, the image including the target area of the body part and at least a portion of the first and second members, the at least a portion of the first member indicating a first axis of the body part in the image, and the at least a portion of the second member indicating a second axis of the body part in the image.

25. The method of claim 24 further comprising locating a third anatomical reference area of the body part, the third anatomical reference area disposed generally between the first and second anatomical reference areas, and positioning a pivotal coupling member relative to the third anatomical reference area, the pivotal coupling member pivotally coupling the first and second members of the reference tool.