CAS bone reference and less invasive installation method thereof

• US 20040068260A1
• Filed: 10/04/2002
• Published: 04/08/2004
• Est. Priority Date: 10/04/2002
• Status: Active Grant

• Current Assignee: ORTHOsoft ULC. (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Orthosoft Inc. (Zimmer Biomet Holdings, Inc.)
• Inventors: Cossette, Sebastien, Jansen, Herbert, Chouinard, Benoit
• Granted Patent: US 6,856,828 B2
• Time in Patent Office: Days
• US Class Current: 606/63
• CPC Class Codes: A61B 17/3496 Protecting sleeves or inner probes; Retractable tips for protecting body piercing guide needles A61M25/0612
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone
• CPC Class Codes: A61B 2090/08021 of the patient or his organs
• CPC Class Codes: A61B 2090/3916 Bone tissue
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 2090/3987 Applicators for implanting markers
• 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

A surgical bone reference assembly is communicable with an image guided surgical system such that position and movement of a bone element are monitorable. A bone anchor member comprises a trackable member and teeth engageable with the bone element. The trackable member comprises a detectable element adapted to be located and tracked in three dimensional space by the image guided surgical system, thereby defining position and movement of the trackable member. A protective guide member is used with the bone anchor member such that the bone anchor member is insertable through soft tissue covering the bone element without causing significant damage thereto. The bone anchor member is engageable with the bone element, such that the teeth are forced into engagement with the bone element and the bone anchor member is fastenable to the bone element in a fixed relation thereto.

Claims

1. A method for monitoring position and movement of a bone element using an image guided surgical system, comprising the steps of:

providing a bone reference assembly comprising a toothed bone anchor member and a trackable member, the trackable member comprising a detectable element adapted to be located and tracked in three dimensional space by the image guided surgical system, thereby defining position and movement of the trackable member;

inserting a protective guide member through soft tissue covering the bone element using a proximal end adapted for gradual separation of the soft tissue so as not to cause significant damage thereto, such that the proximal end is substantially adjacent the bone element, the protective guide member being sized to receive at least the toothed bone anchor member therein;

using the protective guide member to guide the toothed bone anchor member into direct engagement with the bone element;

engaging the toothed bone anchor member to the bone element such that the bone reference assembly is in a fixed position relative to the bone element;

performing a registration of the bone element; and

locating and tracking the bone element using the image guided surgical system.

2. The method as defined in claim 1, further comprising adjusting the trackable member, linked to the toothed bone anchor member by an adjustable articulated support, into a desired position and orientation relative to sensing elements of the image guided surgical system.

3. The method as defined in claim 2, wherein adjusting the trackable member further comprises adjusting a joint of the articulated support.

4. The method as defined in claim 3, further comprising locking the joint of the articulated support such that the trackable member is fixed in the desired position relative to the bone anchor member.

5. The method as defined in claim 3, further comprising adjusting at least two independent, lockable joints of the articulated support.

6. The method as defined in claim 1, further comprising inserting the toothed bone anchor member through a sleeve portion of the protective guide member.

7. The method as defined in claim 6, further comprising inserting a surgical screw through a central aperture in the toothed bone anchor member, a proximal end of the screw being adapted to be fastened to the bone element.

8. The method as defined in claim 7, further comprising engaging a nut on a distal end of the screw and tightening the nut thereon until the nut engages the bone anchor member, the bone anchor member being thereby fixed on the surgical screw between the nut and the bone element.

9. The method as defined in claim 1, wherein inserting the protective guide member further comprises using an insertion probe having the substantially blunt and conical proximal end.

10. The method as defined in claim 9, further comprising engaging the protective guide member to the insertion probe prior to inserting it through the soft tissue, detaching the probe member from the protective guide member once the protective guide member is in place, and removing the probe member.

11. The method as defined in claim 1, wherein the step of performing the registration comprises acquiring a number of points on a surface of the bone element.

12. The method as defined in claim 11, wherein the step of performing the registration comprises matching the points to a corresponding surface of a computer stored representation of the bone element.

13. The method as defined in claim 12, wherein the computer stored representation is created by generating a three dimensional computer model of the bone element from a computed tomography scan.

14. The method as defined in claim 1, wherein the step of performing the registration comprises matching reference artifacts from a two-dimensional fluoroscopic image of the bone element to the location of the reference artifacts at the time the fluoroscope image was taken, the position and orientation of the reference artifacts being determined by the image guided surgical system.

15. The method as defined in claim 11, wherein the points are acquired by digitizing landmarks on the surface of the bone element, and registration of the bone element further comprises using the points to build an anatomic reference model of the bone element.

16. A surgical bone reference assembly communicable with an image guided surgical system such that position and movement of a bone element are monitorable, the bone reference assembly comprising:

a bone anchor member comprising a trackable member and teeth engageable with the bone element, the trackable member comprising a detectable element adapted to be located and tracked in three dimensional space by the image guided surgical system, thereby defining position and movement of the trackable member; and

a protective guide member for use with the bone anchor member such that the bone anchor member is insertable through soft tissue covering the bone element without causing significant damage thereto;

the bone anchor member being engageable with the bone element, such that the teeth are forced into engagement with the bone element and the bone anchor member is fastenable to the bone element in a fixed relation thereto.

17. The bone reference assembly as defined in claim 16, wherein the protective guide member comprises a sleeve member.

18. The bone reference assembly as defined in claim 17, wherein the sleeve member is cylindrical and the bone anchor member comprises a substantially tubular portion insertable within the sleeve member.

19. The bone reference assembly as defined in claim 18, wherein the substantially tubular portion comprises the teeth near a proximal end thereof.

20. The bone reference assembly as defined in claim 16, wherein the sleeve member is removably engageable about a probe, adapted for inserting the sleeve member through the soft tissue without causing significant damage thereto.

21. The bone reference assembly as defined in claim 20, wherein the probe comprises a substantially blunt conical tip adapted for gradually separating the soft tissue without causing significant damage thereto.

22. The bone reference assembly as defined in claim 16, wherein the trackable member is linked to the bone anchor member by an adjustable articulated support, permitting variable positioning of the trackable member and being lockable to fix the trackable member in position relative to the bone anchor member.

23. The bone reference assembly as defined in claim 22, wherein the articulated support permits at least two degrees of freedom of the trackable member relative to the bone anchor member.

24. The bone reference assembly as defined in claim 23, wherein the articulated support comprises at least two independent joints.

25. The bone reference assembly as defined in claim 24, wherein the independent joints comprise lockable, rotational joints.

26. The bone reference assembly as define in claim 22, wherein the articulated support permits selective positioning of the trackable member relative to the bone anchor member between predetermined fixed positions.

27. The bone reference assembly as defined in claim 17, further comprising a surgical screw for fastening the bone anchor member to the bone element, the substantially tubular portion of the bone anchor member being adapted to receive the surgical screw therethrough.