Facet joint replacement

• US 8,353,933 B2
• Filed: 04/17/2008
• Issued: 01/15/2013
• Est. Priority Date: 04/17/2007
• Status: Active Grant

• Current Assignee: Globus Medical, Inc.
• Original Assignee: Gmedelaware 2 LLC (Globus Medical, Inc.)
• Inventors: Triplett, Daniel J., Fauth, Andrew R., Skinlo, David M., Goble, E. Marlowe, Gerbec, Daniel E., Helgerson, Joel R
• Primary Examiner(s): Stewart, Alvin
• Assistant Examiner(s): PALMER, JAMES W
• Application Number:
  US12/104,726
• Publication Number:
  US 20080275507A1
• Time in Patent Office: 1,734 Days
• Field of Search: 606/246, 606/248, 606/249, 606/250, 606/251, 606/252, 606/253, 606254-264, 606/247, 606/313
• US Class Current: 606/247
• CPC Class Codes: A61B 17/7005 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit in the screw or hook heads
• CPC Class Codes: A61B 17/7035 Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other
• CPC Class Codes: A61B 17/704 the longitudinal element passing through a ball-joint in the screw head
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/7067 Devices bearing against one or more spinous processes and also attached to another part of the spine; Tools therefor
• CPC Class Codes: A61B 17/707 Devices acting on, or attached to, a transverse process or rib; Tools therefor
• CPC Class Codes: A61B 2017/7073 with intervertebral connecting element crossing an imaginary spinal median surface
• CPC Class Codes: A61F 2/0095 Packages or dispensers for prostheses or other implants for intraocular lenses A61F2/1691; for dental surgery A61C19/02
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• 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 2002/30481 using a locking clip
• CPC Class Codes: A61F 2002/30495 using a locking ring
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30522 releasable, e.g. using a releasable ratchet
• CPC Class Codes: A61F 2002/30537 adjustable
• CPC Class Codes: A61F 2002/3054 : about a connection axis or implantation axis for selecting any one of a plurality of radial orientations between two modular parts, e.g. Morse taper connections, at discrete positions, angular positions or continuous positions
• CPC Class Codes: A61F 2002/3055 : for adjusting length
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30649 : Ball-and-socket joints
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30884 : Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/449 : comprising multiple spinal implants located in different intervertebral spaces or in different vertebrae
• 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 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• 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 2250/0004 : adjustable
• CPC Class Codes: A61F 2250/0007 : for adjusting length
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

A facet joint replacement system includes an inferior implant with an inferior articular surface, and a superior implant with a superior articular surface. The inferior implant may comprise an inferior strut, and a polyaxially adjustable, lockable mechanism which couples the inferior articular surface with a first end of the inferior strut. A second end of the inferior strut may be secured to a polyaxially adjustable, lockable fixation assembly securable in a vertebra. The first end of the inferior strut may be post-shaped, and the second end ring-shaped, and vice versa. The superior implant may be secured to a polyaxially adjustable lockable fixation assembly securable in a vertebra. Inferior and superior implants may be implanted individually, paired on one lateral vertebral side, bi-laterally, and/or in multiple vertebral levels. A crosslink may be secured to one implant and extend across a vertebral sagittal plane to a second implant. A clip may align the articular surfaces during implantation.

Claims

1. A system for replacing at least a portion of a natural facet joint that controls motion between a first vertebra and a second vertebra, the system comprising:

a fixation member implantable in a pedicle of the second vertebra; and

an inferior facet joint implant comprising;

an inferior articular surface shaped to replace a natural inferior articular surface of the second vertebra;

an inferior strut comprising a first end and a second end, wherein the first end is securable to the fixation member; and

an attachment mechanism comprising an adjustable configuration in which the inferior articular surface is connected to the second end in such a manner that permits relative rotation between the inferior articular surface and the second end about three orthogonal axes, and a locked configuration in which the inferior articular surface is rigidly secured to the second end, wherein the attachment mechanism further comprises an expandable member and a nut configured to urge expansion of the expandable member, wherein the attachment mechanism and inferior strut are simultaneously locked by actuating the nut.

2. The system of claim 1, wherein the first end comprises a post adjustably securable to the fixation member through the use of a second attachment mechanism coupled to the fixation member.

3. The system of claim 1, wherein the first end comprises a ring adjustably securable to the fixation member through the use of a second attachment mechanism coupled to the fixation member.

4. The system of claim 1, wherein the second end comprises a ring, wherein the attachment mechanism comprises:

a compressible member positionable at least partially within the ring; and

a locking member configured to be actuated relative to the compressible member to urge compression of the compressible member;

wherein, in response to compression of the compressible member, an interior wall of a cavity of the compressible member exerts force against a rounded surface fixedly connected to the inferior articular surface to restrict rotation of the inferior articular surface relative to the ring to provide the locked configuration.

5. The system of claim 4, wherein the compressible member comprises a conical portion and a threaded post, wherein the locking member comprises a nut configured to threadably engage the threaded post such that tightening of the nut on the threaded post urges the conical portion through the ring to cause compression of the conical portion.

6. The system of claim 1, wherein the second end comprises a post, wherein the attachment mechanism and

wherein, in response to expansion of the expandable member, a perimeter of the expandable member exerts force against an interior surface of the cavity to restrict rotation of the expandable member relative to the inferior articular surface to provide the locked configuration.

7. The system of claim 6, wherein the locking member comprises a conical expander and a threaded post and the attachment mechanism further comprises a nut configured to threadably engage the threaded post such that tightening of the nut on the threaded post draws the conical expander through an interior of the expandable member to urge expansion of the expandable member.

8. The system of claim 1, wherein the attachment mechanism, in the adjustable configuration, further permits relative translation between the inferior articular surface and the second end along at least one axis.

9. The system of claim 1, wherein the second end comprises a crosslink receiver connectable to a crosslink crossing a sagittal plane of the first and second vertebrae, wherein when the attachment mechanism, in the adjustable configuration, permits adjustment of the relative orientation independently of an orientation of the crosslink.

10. A system for replacing at least a portion of a natural facet joint that controls motion between a first vertebra and a second vertebra, the system comprising:

a fixation member implantable in a pedicle of the second vertebra; and

an inferior facet joint implant comprising;

an inferior articular surface shaped to replace a natural inferior articular surface of the second vertebra;

an inferior strut comprising a first end and a second end, wherein the first end is securable to the fixation member and the second end comprises a crosslink receiver connectable to a crosslink crossing a sagittal plane of the first and second vertebrae; and

an attachment mechanism comprising an adjustable configuration in which the inferior articular surface is adjustably connected to the second end independently of an orientation of the crosslink, and a locked configuration in which the inferior articular surface is rigidly secured to the second end, wherein the attachment mechanism further comprises an expandable member and a nut configured to urge expansion of the expandable member, wherein the attachment mechanism and inferior strut are simultaneously locked by actuating the nut.

11. The system of claim 10, wherein the first end comprises a post adjustably securable to the fixation member through the use of a second attachment mechanism coupled to the fixation member.

12. The system of claim 10, wherein the first end comprises a ring adjustably securable to the fixation member through the use of a second attachment mechanism coupled to the fixation member.

13. The system of claim 10, wherein the second end comprises a ring, wherein the attachment mechanism comprises:

a compressible member positionable at least partially within the ring; and

a locking member configured to be actuated relative to the compressible member to urge compression of the compressible member;

wherein, in response to compression of the compressible member, an interior wall of a cavity of the compressible member exerts force against a rounded surface fixedly connected to the inferior articular surface to restrict rotation of the inferior articular surface relative to the ring to provide the locked configuration.

14. The system of claim 13, wherein the compressible member comprises a conical portion and a threaded post, wherein the locking member comprises a nut configured to threadably engage the threaded post such that tightening of the nut on the threaded post urges the conical portion through the ring to cause compression of the conical portion.

15. The system of claim 10, wherein the second end comprises a post, wherein the attachment mechanism comprises:

an expandable member positionable at least partially within a cavity proximate the inferior articular surface; and

a locking member configured to be actuated relative to the expandable member to urge expansion of the expandable member;

wherein, in response to expansion of the expandable member, a perimeter of the expandable member exerts force against an interior surface of the cavity to restrict rotation of the expandable member relative to the inferior articular surface to provide the locked configuration.

16. The system of claim 15, wherein the locking member comprises a conical expander and a threaded post and the attachment mechanism further comprises a nut configured to threadably engage the threaded post such that tightening of the nut on the threaded post draws the conical expander through an interior of the expandable member to urge expansion of the expandable member.

17. The system of claim 10, wherein the crosslink receiver comprises a collar through which the crosslink is insertable, the system further comprising a second attachment mechanism configured to secure the collar to the crosslink at any of a plurality of relative orientations between the collar and the crosslink about at least two orthogonal axes.

18. A system for replacing at least a portion of a natural facet joint that controls motion between a first vertebra and a second vertebra, the system comprising:

a left fixation member implantable in a left pedicle of the second vertebra;

a right fixation member implantable in a right pedicle of the second vertebra;

a left inferior facet joint implant comprising;

a left inferior articular surface shaped to replace a natural left inferior articular surface of the second vertebra;

a left inferior strut comprising a first end and a second end, wherein the first end is securable to the fixation member; and

a left attachment mechanism; and

a right inferior facet joint implant comprising;

a right inferior articular surface shaped to replace a natural right inferior articular surface of the second vertebra;

a left inferior strut comprising a first end and a second end, wherein the first end is securable to the right fixation member; and

a right attachment mechanism;

wherein each attachment mechanism comprises an adjustable configuration in which the corresponding inferior articular surface is connected to the corresponding second end in such a manner that permits relative rotation between the corresponding inferior articular surface and the corresponding second end about three orthogonal axes, and a locked configuration in which the corresponding inferior articular surface is rigidly secured to the corresponding second end, wherein each attachment mechanism further comprises an expandable member and a nut configured to urge expansion of the expandable member, wherein each attachment mechanism and their respective strut are simultaneously locked by actuating a nut.

19. The system of claim 18, wherein each second end comprises a ring, wherein each attachment mechanism comprises:

a compressible member positionable at least partially within the ring; and

a locking member configured to be actuated relative to the compressible member to urge compression of the compressible member;

wherein, in response to compression of the compressible member, an interior wall of a cavity of the compressible member exerts force against a rounded surface fixedly connected to the inferior articular surface to restrict rotation of the inferior articular surface relative to the ring to provide the locked configuration;

wherein the compressible member comprises a conical portion and a threaded post, wherein the locking member comprises a nut configured to threadably engage the threaded post such that tightening of the nut on the threaded post urges the conical portion through the ring to cause compression of the conical portion

wherein each of the first ends comprises a post adjustably securable to the corresponding fixation member.

20. The system of claim 19, wherein each second end comprises a post, wherein each attachment mechanism comprises:

an expandable member positionable at least partially within a cavity proximate the inferior articular surface; and

a locking member configured to be actuated relative to the expandable member to urge expansion of the expandable member;

wherein, in response to expansion of the expandable member, a perimeter of the expandable member exerts force against an interior surface of the cavity to restrict rotation of the expandable member relative to the inferior articular surface to provide the locked configuration;

wherein the locking member comprises a conical expander and a threaded post and the attachment mechanism further comprises a nut configured to threadably engage the threaded post such that tightening of the nut on the threaded post draws the conical expander through an interior of the expandable member to urge expansion of the expandable member;

wherein each of the first ends comprises a ring adjustably securable to the corresponding fixation member.

21. The system of claim 19, further comprising:

a left superior facet joint implant securable to a left pedicle of the first vertebra, the left superior facet joint implant comprising a left superior articular surface;

a right superior facet joint implant securable to a right pedicle of the first vertebra, the right superior facet joint implant comprising a right superior articular surface;

wherein, when all of the facet joint implants are secured to the corresponding pedicles, the left superior articular surface is positioned to articulate with the left inferior articular surface and the right superior articular surface is positioned to articulate with the right inferior articular surface.