Inter-cervical facet implant with surface enhancements

• US 8,172,877 B2
• Filed: 12/14/2005
• Issued: 05/08/2012
• Est. Priority Date: 12/13/2004
• Status: Expired due to Fees

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: Kyphon SARL (Medtronic Plc)
• Inventors: Winslow, Charles J., Zucherman, James F., Hsu, Ken Y., Mitchell, Steven T.
• Primary Examiner(s): Ramana, Anu
• Application Number:
  US11/304,404
• Publication Number:
  US 20060247632A1
• Time in Patent Office: 2,337 Days
• Field of Search: 606/246, 606/247, 606/248, 606/249
• 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 sized and shaped for insertion into a facet joint formed between a superior facet and an inferior facet, the facet joint spacer having a superior surface and an opposing inferior surface such that the superior surface is sized to engage the inferior facet and the inferior surface is sized to engage the superior facet when the facet joint spacer is inserted into the facet joint;

an anchoring plate sized and configured to be anchored to a lamina of a vertebra when the facet joint spacer is disposed in the facet joint;

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

at least one protrusion extending from one of the superior and inferior surfaces of the facet joint spacer such that when the facet joint spacer is inserted into the facet joint between the superior and inferior surface the at least one protrusion engages one of the superior and inferior facets to retain the facet joint spacer in the facet joint.

2. 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.

3. 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.

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

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

6. 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 he bone screw such that the facet joint spacer is adapted to be retained in the facet joint.

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

a facet joint spacer sized and shaped for insertion into a facet joint formed between a superior facet and an inferior facet, the facet joint spacer having a superior surface and an opposing inferior surface such that the superior surface is sized to engage the inferior facet and the inferior surface is sized to engage the superior facet when the facet joint spacer is inserted into the facet joint;

an anchoring plate sized and configured to be anchored to a lamina of a vertebra when the facet joint spacer is disposed in the 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

at least one protrusion extending from the inferior surface of the facet joint spacer, the at least one protrusion has a length which is less than the thickness between the superior surface and the inferior surface of the facet joint spacer, wherein when the facet joint spacer is inserted into the facet joint between the superior and inferior surface the at least one protrusion engages one of the superior facet to retain the facet joint spacer in the facet Joint.

8. The implant of claim 7 wherein the inferior surface is roughened.

9. The implant of claim 7 wherein the inferior surface is roughened and

the superior surface is smooth.

10. The implant of claim 7 wherein the at least one protrusion points in a direction opposite to a direction of insertion of the facet joint spacer into a facet joint.