ARTICULATING FACET FUSION SCREW

• US 20080255618A1
• Filed: 04/13/2007
• Published: 10/16/2008
• Est. Priority Date: 04/13/2007
• Status: Active Grant

• Current Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Inventors: Mickiewicz, Christopher, Fisher, Michael Alan
• Granted Patent: US 8,043,334 B2
• Time in Patent Office: Days
• US Class Current: 606/247
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/863 with thread interrupted or changing its form along shank, other than constant taper
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable, resorptive for implantable prostheses A61F2210/0004
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone

Abstract

A spinal implant is provided having an elongate member with a longitudinal axis and threads extending over at least a portion of the outer surface thereof. The implant includes a stabilization feature associated with the elongate member that is selectively configurable between a delivery configuration and a deployed configuration in which the stabilization feature is oriented at an angle with respect to the longitudinal axis of the elongate member. Also, at least a portion of the implant can include a fusion-promoting bioactive material. In another aspect, the invention includes methods for providing stabilization within a facet joint by delivery of an articulating intra-facet screw.

Claims

1. A spinal implant, comprising:

an elongate member having a longitudinal axis and threads extending over at least a portion of the outer surface thereof, and

a stabilization feature associated with the elongate member that is selectively configurable between a delivery configuration and a deployed configuration in which the stabilization feature is oriented at an angle with respect to the longitudinal axis of the elongate member.

2. The implant of claim 1, wherein the stabilization feature is coupled to the elongate member by a joint that is configured to allow the stabilization feature to move between the delivery configuration and the deployed configuration.

3. The implant of claim 2, wherein the joint is selected from the group consisting of a pivot, a hinge, and a flexing-point.

4. The implant of claim 1, wherein the stabilization feature comprises an articulating member pivotably connected to a proximal portion of the elongate member.

5. The implant of claim 4, wherein the articulating member includes motion resisting plates extending over at least a portion of an exterior surface thereof and configured to provide frictional opposition to motion in the deployed configuration.

6. The implant of claim 1, wherein the stabilization feature comprises two distinct articulating members pivotably connected to a proximal portion of the elongate member and which are capable of rotating relative to one another in the deployed configuration.

7. The implant of claim 1, wherein the stabilization feature comprises at least one prong which is substantially recessed within the elongate member in the delivery configuration.

8. The implant of claim 7, further comprising an actuator effective to move the at least one prong to the deployed configuration in which the at least one prong extends from the elongate member at an angle relative to the longitudinal axis of the elongate member.

9. The implant of claim 8, wherein a lumen formed within the elongate member is configured to receive the actuator which is effective to move the at least one prong to the deployed configuration.

10. The implant of claim 1, wherein the stabilization feature is an expanding sleeve that is positioned over at least a portion of an outer surface of the elongate member, the sleeve having proximal and distal ends, and at least one hinged arm located between the proximal and distal ends.

11. The implant of claim 10, wherein an actuation member is mated to the implant proximal to the proximal end of the sleeve, and distal movement of the actuation member is effective to compress the sleeve and move the hinged arm to an expanded configuration.

12. The implant of claim 11, wherein the sleeve is not expanded in the delivery configuration and is expanded in the deployed configuration.

13. The implant of claim 11, wherein the actuation member is a nut threadably mated to the elongate member.

14. The implant of claim 1, wherein the implant includes a fusion-promoting bioactive material.

15. The implant of claim 14, wherein the fusion-promoting bioactive material is selected from the group consisting of cortical allograft bone and bioceramic-loaded bioabsorbable material.

16. A method for facet joint fixation and fusion, comprising:

surgically delivering at least one implant to a facet joint in an intrafacet orientation, the implant having at least one selectively deployable stabilization feature formed therein; and

deploying the stabilization feature such that it extends from the implant to engage a bony surface of the facet joint to oppose the natural motion of the facet joint.

17. The method of claim 16, wherein delivering the implant includes inserting a threaded distal tip of the implant into the facet joint so that it assumes a non-linear trajectory and follows a curvilinear pathway to embed in the bony surface of the facet joint.

18. The method of claim 16, wherein deploying the stabilization feature includes re-orienting a proximal portion of the implant relative to the embedded tip.

19. The method of claim 16, wherein deploying the stabilization feature includes bifurcating two distinct articulating portions of a proximal or distal portion of the implant, allowing them to rotate relative to one another.

20. The method of claim 16, wherein deploying the stabilization feature includes protracting at least one prong recessed within the implant so as to embed the at least one prong in the bony surface of the facet joint.

21. The method of claim 20, wherein protracting the at least one prong includes moving the at least one prong distally through the lumen so that it follows a predefined pathway to protrude through an opening in the implant.

22. The method of claim 16, wherein deploying the stabilization feature includes compressing an expandable sleeve distally, thereby causing a hinged arm of the sleeve to extend outwards from the implant to engage the bony surface of the facet joint.

23. The method of claim 16, wherein the surgically delivering step is performed in a minimally invasive procedure.

24. The method of claim 16, wherein deploying the stabilization feature includes inserting the implant in osteoporotic bone using a threaded fit so as to prevent retraction or pull-out of the implant.