FACET JOINT IMPLANT SIZING TOOL

• US 20080177311A1
• Filed: 10/30/2006
• Published: 07/24/2008
• Est. Priority Date: 10/30/2006
• Status: Abandoned Application

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: St. Francis Medical Technologies, Inc. (Medtronic Plc)
• Inventors: Mitchell, Steven T., Winslow, Charles J., Yerby, Scott A.
• Application Number:
  US11/554,401
• Publication Number:
  US 20080177311A1
• Time in Patent Office: Days
• US Class Current: 606/248
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/30471 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2220/0091 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type

Abstract

In an embodiment of the present invention, a tool resembles an implant for positioning within a cervical facet joint. The tool can be used for distracting and/or sizing the cervical facet joint and thereby distracting the cervical spine and increasing the area of the canals and openings through which the spinal cord and nerves must pass, and decreasing pressure on the spinal cord and/or nerve roots. The tool can be inserted laterally or posteriorly.

Claims

1. A tool comprising:

a spacer shaped similar to a cervical facet joint implant;

a handle; and

a pivot, wherein the distal end of the handle is connected with the proximal end of the spacer, allowing the base to pivot about the handle.

2. The tool of claim 1, wherein the spacer is adapted for sizing the cervical facet joint.

3. The tool of claim 2, where the thickness of the spacer varies among different spacers, wherein the said different spacers are used for sizing the cervical facet joint.

4. The tool of claim 1, further comprising a base, wherein the base contains one or more holes, where the holes are similar to holes in the cervical facet joint implant, wherein the proximal end of the base is connected to the handle, wherein the distal end of the base is connected with the proximal end of the spacer, allowing the spacer to pivot about the base.

5. The tool of claim 1, wherein the spacer is tapered to help the tool distract the facet joint.

6. The tool of claim 1, wherein the distal end of the joint spacer is rounded and is tapered in thickness to facilitate insertion into the cervical facet joint.

7. The tool of claim 1, wherein the spacer has one or more cleats adapted to be imbedded in the bone of the cervical facet joint.

8. A tool comprising:

a spacer;

a handle;

a pivot where the distal end of the handle is connected with the proximal end of the spacer allowing the spacer to pivot about the handle; and

a stop at the proximal end of the handle, the stop adapted to limit the insertion of the spacer.

9. The tool of claim 8, wherein the stop limits the rotation of the spacer relative to the handle.

10. A tool adapted to size a cervical facet joint in order to select a cervical facet joint implant for implanting in the cervical facet joint, said tool comprising:

a handle;

a spacer, wherein the spacer is shaped like a cervical artificial facet implant;

a pivot, the pivot connecting the proximal end of the spacer with the distal end of the handle; and

a stop at the proximal end of the base, the stop adapted to limit insertion of the spacer into the facet joint during sizing.

11. A method of sizing and or distracting a cervical facet joint comprising:

(a) accessing the cervical facet joint;

(b) selecting a tool, the tool having a spacer, a pivot, a handle and a stop, wherein the spacer pivots about the handle;

(c) inserting the tool into the cervical facet joint until the stop limits further insertion;

(d) pivoting the spacer away from the handle until it contacts the lamina;

(e) evaluating the fit of the tool, wherein evaluating includes evaluating the amount of distraction of the cervical facet joint;

(f) selecting one of a smaller and a larger tool depending on the measurement of step (e); and

(g) repeating steps (c)-(e) until a fit is found.

12. The method of claim 11, wherein the spacer is tapered, where in step (c) the tapering assists the tool distracting the facet joint.

13. The method as in claim 11, wherein the distal end of the spacer is rounded and is tapered in thickness, where in step (c) the tapering and roundedness facilitate insertion into the cervical facet joint.

14. The method as in claim 11, where the thickness of the spacer varies among different tools, where in steps (c)-(e) different tools are used for sizing the cervical facet joint.

15. The method of claim 11, wherein the spacer has one or more cleats, where in step (d) the cleats are adapted to be imbedded in the bone of the cervical facet joint to assist pivoting.

16. The method of claim 11, wherein the stop limits the rotation of the spacer relative to the handle.

17. The method of claim 11, wherein the tool further comprises a base, wherein the base contains one or more holes, where the one or more holes are similar to one or more holes in a cervical facet joint implant, where step (e) further comprises checking the position of the one or more holes in the base on the facet joint.