Non-imaging tracking tools and method for hip replacement surgery

• US 20040102792A1
• Filed: 08/08/2003
• Published: 05/27/2004
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Kinamed Inc (VME Acquisition Corp)
• Original Assignee: Kinamed Inc (VME Acquisition Corp)
• Inventors: Carignan, Roger C., Sarin, Vineet Kumar, Bruce, Robert A., Pratt, William Ralph, Pratt, Clyde Ronald
• Granted Patent: US 8,002,772 B2
• Time in Patent Office: Days
• US Class Current: 606/151
• CPC Class Codes: A61B 17/1742 for the hip
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2034/102 Modelling of surgical devices, implants or prosthesis
• 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 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• 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 90/14 Fixators for body parts, e.g. skull clamps; Constructional details of fixators, e.g. pins
• CPC Class Codes: Y10T 24/44598 Threaded cylindrical rod and mating cavity

Abstract

The invention includes a method of determining a surgical patient'"'"'s pelvic position and inputting that position into a computer via a tracking system, suitable for use in navigating partial or total hip replacement surgery. The patient is first aligned with anatomical reference points in relation to corresponding locating features on a patient positioner. The positions of index features on the patient positioner are then acquired via a tracking system. Based on the positions of the index features and their known relationship to the locating features, the locations of the anatomical reference features are calculated and a pelvic plane is defined therefrom. The invention also includes a surgical tool for mounting a trackable target to a human bone, suitable for fixation to a human femur. This tool includes a removable bone clamp and a releasable coupling member, integrated with said removable bone clamp.

Claims

1. A method of determining a surgical patient'"'"'s pelvic position and inputting that position into a computer via a tracking system, suitable for use in navigating partial or total hip replacement surgery, comprising the steps of:

aligning the patient in relation to a patient positioning frame with pelvic anatomical features of the patient disposed in secure mechanical relationship with corresponding locating features on said positioning frame;

acquiring with a tracking system the positions of a plurality of index points, wherein each of said index points is respectively disposed at a previously known displacement relative to a corresponding one of said locating features; and

defining a pelvic plane by calculation from the acquired positions of said index points, said calculation including;

compensating for the previously known displacement of each said index point relative to its corresponding locating feature, thereby finding the locations of said locating features from the acquired positions of said index points; and

defining a plane from the calculated positions of the locating features.

2. The method of claim 1, wherein said pelvic anatomical features are the right Anterior Superior Iliac Spine (ASIS), the left ASIS, and the pubic symphysis;

and wherein said locating features comprise three locating features arranged to engage said right ASIS, left ASIS, and pubic symphysis respectively, such that said three locating features define the pelvic plane.

3. The method of claim 2, wherein said locating features include a retractable pubic indicator which is adjustable to palpate the patient'"'"'s pubic symphysis.

4. The method of claim 3, wherein said locating features further include at least one ASIS indicator concavity carried by a front support assembly of said patient positioning frame.

5. The method of claim 4, wherein said patient positioning frame further comprises a rear support assembly arranged adjustably to include the patient securely between said front support assembly and said rear support assembly.

6. The method of claim 3, wherein said step of acquiring with a tracking system the positions of a plurality of index points comprises:

touching said index points with an optically trackable probe;

calculating the position of said optically trackable probe while said probe is touching said index points; and

compensating for a known dimension and shape of said probe.

7. The method of claim 1, comprising the further steps:

fixing a trackable pelvic marker to the patient'"'"'s pelvis;

tracking the position and orientation of said trackable pelvic marker while said pelvic plane is fixed in relation to said patient positioning frame;

calculating a spatial relationship between the trackable pelvic marker and the defined pelvic plane;

releasing the patient'"'"'s pelvis from said patient positioning frame; and

tracking the pelvic plane indirectly by tracking the position and orientation of said trackable pelvic marker then applying a coordinate transformation to calculate the pelvic plane, from time to time.

8. The method of claim 7, wherein said trackable pelvic marker is fixed to the patient'"'"'s pelvis by a bone screw.

9. The method of claim 8, wherein said trackable pelvic marker comprises a marker with either reflective or active trackable optical targets.

10. A surgical tool for mounting a trackable target to a human bone, suitable for fixation to a human femur, comprising:

a removable bone clamp; and

a releasable coupling member, integrated with said removable bone clamp and arranged to mate with a compatible coupling member mounting the trackable target to establish a predetermined spatial relationship between said bone clamp and said trackable target;

wherein said coupling member comprises a releasable connection between said target and said bone clamp, to remove said trackable target;

and wherein said connection is capable of re-engaging in a re-engaged position which accurately recaptures said spatial relationship between the bone and said trackable target.

11. The surgical tool of claim 10, wherein said bone clamp includes an adjustable bracket having two opposable, pivotable jaws:

a first jaw pivotable about a first axis and a second jaw pivotable about a second axis.

12. The surgical tool of claim 11, wherein said first and second axes are substantially perpendicular.

13. The surgical tool of claim 12, wherein said bracket is adjustable by an adjustment screw.

14. The surgical tool of claim 12, wherein said pivotable jaws have at least one gripping feature adapted to grip the femur securely.

15. The surgical tool of claim 10, wherein said releasable coupling member comprises a first member of a dovetailed joint.

16. The surgical tool of claim 15, wherein said first member of said dovetailed joint is capable of mating with a complementary, second member to form a substantially solid joint with an exterior margin;

and further comprising a sleeve which is capable of surrounding and retaining said substantially solid joint, thus securing the joint in a repeatable, centered and assembled position

17. The surgical tool of claim 16, further comprising:

a compatible coupling member, having a trackable target mounted thereupon;

wherein said compatible coupling member includes said complementary second member of said dovetailed joint.

18. The surgical tool of claim 17, wherein one of said first and said complementary members of said dovetailed joint has a centering pin;

and wherein the other of said first and said complementary members of said dovetailed joint has a slot capable of receiving said centering pin.

19. The surgical tool of claim 17, wherein said first member of said dovetailed joint provides a first portion of a rotationally symmetrical solid;

and wherein said complementary member of said dovetailed joint provides a complementary portion of a rotationally symmetrical solid;

and wherein said solid joint, when assembled, has rotational symmetry about an axis.

20. The surgical tool of claim 19, wherein said first and complementary members together form a substantially solid joint which is generally cylindrical in exterior shape.

22. The surgical tool of claim 19, wherein said first and said complementary members together assemble to form a substantially solid joint which is at least partially conical in exterior shape.

23. The surgical tool according to claim 22, wherein said sleeve is arranged to slidably surround said dovetailed joint while causing said first and second members to tend toward a centered position;

said sleeve having an interior shape which snugly encloses the exterior shape of said dovetailed joint when said first and complementary members are assembled in a centered position.

21. The surgical tool of 20, wherein said sleeve is arranged to slidably engage said dovetailed joint while causing said first and second members to tend toward a centered position;

said sleeve having an interior shape which snugly encloses the exterior shape of said dovetailed joint when said first and complementary members are assembled in a centered position.