Inter-cervical facet joint implant with locking screw system

• US 8,128,660 B2
• Filed: 12/14/2005
• Issued: 03/06/2012
• Est. Priority Date: 12/13/2004
• Status: Expired due to Fees

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: Kyphon SARL (Medtronic Plc)
• Inventors: Mitchell, Steven T., Winslow, Charles J., Zucherman, James F., Hsu, Ken Y.
• Primary Examiner(s): Barrett, Thomas C.
• Assistant Examiner(s): ARAJ, MICHAEL J
• Application Number:
  US11/304,437
• Publication Number:
  US 20060241597A1
• Time in Patent Office: 2,274 Days
• Field of Search: 606/60, 606246-249, 623 1711- 1716
• 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 2/44 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
• 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 2/4657 : Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• 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 adapted that address ailments of the spine, the implant including:

a facet joint spacer that is adapted to be inserted in a facet joint;

an anchoring plate adapted to be secured to a vertebra, the anchoring plate having a first recess sized and shaped to receive a portion of the facet joint spacer, wherein when the portion of the facet joint spacer is received in the first recess an articulation joint is formed between the facet joint spacer and the anchoring plate such that the facet joint spacer is pivotally connected with the anchoring plate;

a bone screw that is disposed through the anchoring plate and is adapted to secure the anchoring plate to the vertebra;

a locking screw having an asymmetric head and a shaft, the asymmetric head being fixedly attached to the shaft such that the asymmetric head rotates with rotation of the shaft, the asymmetric head defining an engagement portion that holds the bone screw in place in the anchoring plate and a disengagement portion substantially opposing the engagement portion that allows the bone screw to be removed from the anchoring plate;

wherein said locking screw has a first position that causes the engagement portion to be positioned closer to the bone screw than the disengagement portion in order to hold the bone screw in the anchoring plate and a second position that causes the disengagement portion to be positioned closer to the bone screw than the engagement portion to allow the bone screw to be removed from the anchoring plate, the locking screw being coupled to the anchoring plate while in the first and second positions.

2. The implant of claim 1 wherein said engagement portion and disengagement portion define an outer perimeter of the asymmetrical head.

3. The implant of claim 2 wherein said head includes a cut-out that allows the bone screw to be removed from the anchoring plate.

4. The implant of claim 3 wherein said cut-out is concave.

5. The implant of claim 3 wherein said cut-out is crescent shaped.

6. The implant of claim 1 wherein said locking screw includes a head with a concave portion and a convex portion.

7. The implant of claim 1 wherein the bone screw is received in a second recess in the anchoring plate and the locking screw is received in a third recess of the anchoring plate.

8. The implant of claim 7 wherein the second recess that received the bone screw is off-set from the third recess that receives the locking screw.

9. The implant of claim 7 wherein the second recess that receives the bone screw is below the third recess that received the locking screw.

10. The implant of claim 7 wherein the third recess that receives the locking screw cuts into the second recess that receives the bone screw.

11. The implant of claim 1 wherein said facet joint spacer is pivotably connected with the anchoring plate.

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

a first anchoring plate that is adapted to be fixedly associated with a first vertebra;

a second anchoring plate that is adapted to be fixedly associated with a second vertebra;

a facet joint spacer connected with the first anchoring plate and the second anchoring plate, the facet joint spacer adapted to be positioned in a facet joint, wherein at least one of the first and second anchoring plates has a first recess sized and shaped to receive a portion of the facet joint spacer, wherein when the portion of the facet joint spacer is received in the first recess an articulation joint is formed between the facet joint spacer and the one of the first and second anchoring plates having the first recess such that the facet joint spacer is pivotally connected with the one of the first and second anchoring plates having the first recess;

a first bone screw that is disposed through a second recess in the first anchoring plate and is adapted to secure the first anchoring plate to the first vertebra;

a second bone screw that is disposed through the second anchoring plate and is adapted to secure the second anchoring plate to the second vertebra;

a locking screw having an asymmetric head and a shaft, the asymmetric head being fixedly attached to the shaft such that the asymmetric head rotates with rotation of the shaft, the asymmetric;

wherein said locking screw has a first position that locks the first bone screw in the first anchoring plate and a second position that allows the bone screw to be removed from the anchoring plate, the locking screw being coupled to the anchoring plate while in the first and second positions.

13. The implant of claim 12 wherein said locking screw has an asymmetrical head.

14. The implant of claim 13 wherein said head includes a cut-out that allows the bone screw to be removed from the anchoring plate.

15. The implant of claim 14 wherein said cut-out is concave.

16. The implant of claim 14 wherein said cut-out is crescent shaped.

17. The implant of claim 12 wherein said locking screw includes a head with a concave portion and a convex portion.

18. The implant of claim 12 wherein the first bone screw is received in the second recess in the anchoring plate and the locking screw is received in a third recess of the anchoring plate.

19. The implant of claim 18, wherein the second recess that received the first bone screw is off-set from the third recess that receives the locking screw.

20. The implant of claim 18 wherein the second recess that receives the first bone screw is below the third recess that received the locking screw.

21. The implant of claim 18 wherein the third recess that receives the locking screw cuts into the second recess that receives the first bone screw.

22. A facet joint implant adapted that address ailments of the spine, the implant including:

a facet joint spacer that is adapted to be inserted in a facet joint;

an anchoring plate having a recess sized and shaped to receive a portion of the facet joint spacer, the anchoring plate adapted to be secured to a vertebra;

wherein when the portion of the facet joint spacer is received in the recess an articulation joint is formed between the facet joint spacer and the anchoring plate such that the facet joint spacer is pivotally connected with the anchoring plate;

a bone screw that is disposed through an aperture in the anchoring plate and is adapted to secure the anchoring plate to the vertebra;

a locking screw having an asymmetric head and a shaft, the asymmetric head being fixedly attached to the shaft such that the asymmetric head rotates with rotation of the shaft, the asymmetric head defining an engagement portion that holds the bone screw in place in the anchoring plate and a disengagement portion substantially opposing the engagement portion that allows the bone screw to be removed from the anchoring plate;

wherein said locking screw has a first position that holds the bone screw positioned in the aperture in the anchoring plate by positioning the engagement portion over the aperture and a second position that allows the bone screw to be removed from the aperture in the anchoring plate by positioning the disengagement portion closer to the bone screw than the engagement portion, the locking screw being coupled to the anchoring plate while in the first and second positions.