Inter-cervical facet implant and method

• US 20060149289A1
• Filed: 02/08/2005
• Published: 07/06/2006
• Est. Priority Date: 12/13/2004
• Status: Abandoned Application

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: St. Francis Medical Technologies, Inc. (Medtronic Plc)
• Inventors: Flynn, John J., Mitchell, Steven T., Zucherman, James F., Winslow, Charles J., Hsu, Ken Y., Yerby, Scott A.
• Application Number:
  US11/053,346
• Publication Number:
  US 20060149289A1
• Time in Patent Office: Days
• US Class Current: 606/102
• CPC Class Codes: A61B 17/562 Implants for placement in joint gaps without restricting joint motion, e.g. to reduce arthritic pain
• CPC Class Codes: A61B 17/7007 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit around the screw or hook heads
• CPC Class Codes: A61B 17/701 Longitudinal elements with a non-circular, e.g. rectangular, cross-section A61B17/7005, A61B17/7007 take precedence
• CPC Class Codes: A61B 17/7022 Tethers, i.e. longitudinal elements capable of transmitting tension only, e.g. straps, sutures or cables A61B17/702 takes precedence
• CPC Class Codes: A61B 17/7028 the flexible part being a coil spring
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/7071 Implants for expanding or repairing the vertebral arch or wedged between laminae or pedicles; Tools therefor
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• 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

Abstract

Systems and method in accordance with the embodiments of the present invention can include an implant for positioning within a cervical facet joint for distracting the cervical spine, thereby 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 implant can be inserted laterally or posteriorly.

Claims

1. A tool for sizing 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;

an interfacet sizer, the interfacet sizer having a rounded distal end and a proximal end and connected with the handle at the proximal end; and

a stop at the proximal end of the interfacet sizer, the stop adapted to prevent over-insertion of the interfacet sizer during sizing.

2. The tool as in claim 1 wherein the distal end of the interfacet sizer is tapered in thickness to facilitate insertion into the cervical facet joint to be sized.

3. The tool as in claim 1 wherein the interfacet sizer is angled obliquely from a longitudinal axis of the handle.

4. The tool as in claim 1 wherein the interfacet sizer can have a uniform thickness that is variable among different of said tools for sizing the cervical facet joint.

5. The tool as in claim 1 wherein the interfacet sizer can have a variable length among different said tools for sizing the cervical facet joint.

6. The tool as in claim 1 wherein the interfacet sizer can have a variable width among different said tools for sizing the cervical facet joint.

7. The tool as in claim 1 wherein the stop is shaped like a ridge.

8. The tool as in claim 1 wherein the interfacet sizer is shaped like an artificial facet joint.

9. A tool for sizing 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;

an interfacet sizer, the interfacet sizer having a rounded, tapered distal end to facilitate insertion of the interfacet sizer into the cervical facet joint, and a proximal end connected with the handle; and

a stop placed at the proximal end of the interfacet sizer, the stop adapted to prevent over-insertion of the tool during sizing,

wherein the interfacet sizer is shaped like an artificial facet joint.

10. A method of sizing a cervical facet joint with a sizing tool to select a cervical facet joint implant to implant in the cervical facet joint, the method comprising the steps of:

accessing the cervical facet joint;

selecting a first sizing tool, the sizing tool having a distal rounded head with a tapered tip, the tapered tip to facilitate insertion, and the head variable in size from one sizing tool to another;

inserting the first sizing tool into the cervical facet joint until a stop on the first sizing tool prevents further insertion;

evaluating the fit of the fist sizing tool and the amount of distraction of the cervical facet joint from insertion of the sizing tool; and

considering an implant based on the evaluating step.

11. The method as in claim 10 wherein the method further comprises:

repeating the selecting, inserting, and evaluating steps with at least another sizing tool of a different dimension until achieving a desired amount of distraction with at least one of the first sizing tool and the another sizing tool of the different dimension.

12. The method as in claim 10 wherein the considering step further comprises choosing an implant with substantially the same dimensions as the sizing tool achieving the desired amount of distraction.