Facet joint replacement

• US 8,333,789 B2
• Filed: 04/17/2008
• Issued: 12/18/2012
• Est. Priority Date: 01/10/2007
• Status: Active Grant

• Current Assignee: Globus Medical, Inc.
• Original Assignee: Gmedelaware 2 LLC (Globus Medical, Inc.)
• Inventors: Triplett, Daniel J, Helgerson, Joel R., Fauth, Andrew R., Skinlo, David M.
• Primary Examiner(s): Willse, David H.
• Application Number:
  US12/104,855
• Publication Number:
  US 20080221622A1
• Time in Patent Office: 1,706 Days
• Field of Search: 606/247, 606/248, 606/278
• 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;

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 is operably attached to an attachment mechanism, wherein the attachment mechanism comprises an expandable member, a shell over the expandable member, and a locking nut that is actuatable to move the attachment mechanism from an adjustable configuration to a locked configuration, wherein the locking nut is directly in contact with the expandable member; and

a crosslink operably attached to the inferior strut, wherein the orientations of the second end, the inferior articular surface, and the crosslink are all adjustable relative to each other until a locked configuration in which the second end, the inferior articular surface, and the crosslink are rigidly secured to each other.

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.

5. The system of claim 1, wherein the attachment mechanism further comprises a split sphere positioned within a split ring, the split sphere comprising a bore;

wherein the split sphere is polyaxially rotatable within the split ring when the attachment mechanism is in the adjustable configuration, and is rigidly secured relative to the split ring when the attachment mechanism is in the locked configuration;

wherein the bore is sized to slidably receive the crosslink when the attachment mechanism is in the adjustable configuration, and is sized to rigidly grip the crosslink when the attachment mechanism is in the locked configuration.

6. The system of claim 1, wherein the attachment mechanism, in the adjustable configuration, further permits relative translation between the second end, the inferior articular surface, and the crosslink.

7. 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 is operably attached to an attachment mechanism comprising a split ring shaped to receive a crosslink; and

wherein the attachment mechanism comprises an expandable member, a shell over the expandable member, and a locking nut having an adjustable configuration, wherein the locking nut is directly in contact with the expandable member in which relative rotation and/or translation is permitted between the split ring and the crosslink, and a locked configuration in which the split ring is compressed such that the split ring is rigidly secured to the crosslink.

8. The system of claim 7, wherein the attachment mechanism comprises a split sphere positioned within the split ring, the split sphere comprising a bore;

wherein the split sphere is polyaxially rotatable within the split ring when the attachment mechanism is in the adjustable configuration, and is rigidly secured relative to the split ring when the attachment mechanism is in the locked configuration;

wherein the bore is sized to slidably receive the crosslink when the attachment mechanism is in the adjustable configuration, and is sized to rigidly grip the crosslink when the attachment mechanism is in the locked configuration.