Inter-cervical facet implant with surface enhancements

• US 20060247632A1
• Filed: 12/14/2005
• Published: 11/02/2006
• Est. Priority Date: 12/13/2004
• Status: Active Grant

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: St. Francis Medical Technologies, Inc. (Medtronic Plc)
• Inventors: Mitchell, Steven T., Zucherman, James F., Winslow, Charles J., Hsu, Ken Y.
• Granted Patent: US 8,172,877 B2
• Time in Patent Office: Days
• US Class Current: 606/247
• CPC Class Codes: A61B 17/025 Joint distractors
• 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 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/7001 Screws or hooks combined with longitudinal elements which do not contact vertebrae A61B17/7058 takes 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 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• 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 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• CPC Class Codes: A61B 17/8635 Tips of screws
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4684 : Trial or dummy prostheses
• CPC Class Codes: A61F 2002/30079 : magnetic
• CPC Class Codes: A61F 2002/30092 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/3013 : figure-"8"- or hourglass-shaped
• CPC Class Codes: A61F 2002/30176 : V-shaped
• CPC Class Codes: A61F 2002/30308 : banana-shaped
• CPC Class Codes: A61F 2002/30378 : Spherically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30383 : made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30462 : retained or tied with a rope, string, thread, wire or cable
• 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 2002/30517 : using a locking plate
• CPC Class Codes: A61F 2002/30528 : Means for limiting said movement
• CPC Class Codes: A61F 2002/30538 : for adjusting angular orientation
• CPC Class Codes: A61F 2002/30563 : having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30566 : Helical springs
• CPC Class Codes: A61F 2002/30578 : having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30601 : telescopic
• CPC Class Codes: A61F 2002/30639 : having rolling elements between both articulating surfaces
• CPC Class Codes: A61F 2002/30708 : Means for distinguishing between left-sided and right-sided devices, Sets comprising both left-sided and right-sided prosthetic parts
• CPC Class Codes: A61F 2002/30769 : madreporic
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30878 : with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4661 : for measuring thickness
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/009 : magnetic
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2220/0091 : connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2230/001 : Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0054 : V-shaped
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0084 : Means for distinguishing between left-sided and right-sided devices; Sets comprising both left-sided and right-sided prosthetic parts
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: A61F 2310/00976 : Coating or prosthesis-covering structure made of proteins or of polypeptides, e.g. of bone morphogenic proteins BMP or of transforming growth factors TGF

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 facet joint implant that addresses ailments of the spine, the implant comprising:

a facet joint spacer adapted to be inserted into a facet joint;

an anchoring plate;

an articulation joint connecting the anchoring plate to the facet joint; and

at least one protrusion extending from the facet joint spacer which is adapted to retain the artificial joint in the facet joint.

2. The implant of claim 1 wherein:

said facet joint spacer has a superior surface and an inferior surface;

the superior surface is adapted to be positioned adjacent to an inferior facet of a facet joint;

the inferior surface is adapted to be positioned adjacent to a superior facet of a facet joint; and

the at least one protrusion extends from the inferior surface and is adapted to engage the superior facet.

3. The implant of claim 1 wherein:

said facet joint spacer has a superior surface and an inferior surface; and

the at least one protrusion extends from the inferior surface.

4. The implant of claim 3 wherein:

a plurality of protrusions extend from the inferior surface.

5. The implant of claim 1 wherein:

the at least one protrusion points away from a direction of insertion of the facet joint spacer into a facet joint.

6. The implant of claim 3 including at least one protrusion extending from the superior surface.

7. The implant of claim 1 wherein said at least one protrusion has a length that is less than a thickness of the facet joint spacer.

8. The implant of claim 3 wherein a thickness is defined between the superior surface and the inferior surface and the protrusion has a length which is less than the thickness between the superior surface and the interior surface.

9. The implant of claim 1 wherein said anchoring plate includes a side that is adapted to be placed adjacent to the spine and wherein at least another protrusion extends from said side.

10. The implant of claim 9 wherein said anchoring plate has a thickness and the at least another protrusion has a length that is less than the thickness of the at least another protrusion.

11. The implant of claim 1 wherein at least one of the facet joint spacer and the protrusion has a roughened surface.

12. The implant of claim 3 wherein said inferior surface is roughened.

13. The implant of claim 3 wherein said inferior surface is roughened surface and the superior surface smooth and is adapted to allow an inferior facet to slide relative to the superior surface.

14. The implant of claim 1, wherein the direction articulation joint is a hinge.

15. The implant of claim 1, wherein the articulation joint is a ball and socket joint.

16. The implant of claim 1, further comprising:

a locking screw;

a bone screw;

a retaining plate; and

wherein;

the locking screw holds the retaining plate against the bone screw such that the facet joint spacer is adapted to be retained in the facet joint.

17. A facet joint implant that addresses ailments of the spine,

the implant comprising:

an anchoring plate;

an facet joint spacer adapted to be inserted into a facet joint;

an articulation joint connecting the anchoring plate and the facet joint spacer;

wherein the facet joint spacer includes a superior surface and an inferior surface, with the inferior surface adapted to be positioned adjacent a superior facet of a facet joint;

wherein a thickness is defined between the superior surface and the inferior surface; and

a plurality of protrusions extending from the inferior surface of the facet joint spacer; and

where said protrusions extend from the inferior surface a distance that is less than the thickness of the facet joint spacer.

18. The implant of claim 17 wherein the inferior surface is roughened.

19. The implant of claim 17 wherein the inferior surface is roughened and the superior surface is smooth.

20. The implant of claim 17 wherein the protrusion points in a direction opposite to a direction of insertion of the facet joint spacer into a facet joint.