Systems and methods for posterior dynamic stabilization of the spine

• US 20060084987A1
• Filed: 01/10/2005
• Published: 04/20/2006
• Est. Priority Date: 10/20/2004
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Kim, Daniel H.
• Granted Patent: US 7,998,175 B2
• Time in Patent Office: Days
• US Class Current: 606/258
• CPC Class Codes: A61B 17/686 Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/7004 with a cross-section which varies along its length A61B17/7019 takes precedence
• 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 17/7007 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit around the screw or hook heads
• CPC Class Codes: A61B 17/7011 Longitudinal element being non-straight, e.g. curved, angled or branched adjustable length longitudinal elements A61B17/7014; A61B17/7019 takes precedence, e.g. coil springs
• CPC Class Codes: A61B 17/7013 the shape of the element being adjustable before use adjustable length plates A61B17/7014
• CPC Class Codes: A61B 17/7023 with a pivot joint
• CPC Class Codes: A61B 17/7025 with a sliding joint
• CPC Class Codes: A61B 17/7026 with a part that is flexible due to its form
• CPC Class Codes: A61B 17/7028 the flexible part being a coil spring
• CPC Class Codes: A61B 17/7031 made wholly or partly of flexible material
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7041 with single longitudinal rod offset laterally from single row of screws or hooks A61B17/7044 takes precedence
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• 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 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2002/30624 Hinged joint, e.g. with transverse axle restricting the movement
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/448 comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants

Abstract

Systems and devices for dynamically stabilizing the spine are provided. The systems include a superior component for attachment to a superior vertebra of a spinal motion segment and an inferior component for attachment to an inferior vertebral of a spinal motion segment. The interconnection between the two components enables the spinal motion segment to move in a manner that mimics the natural motion of the spinal motion segment. Methods are also provided for stabilizing the spine and for implanting the subject systems.

Claims

1. A system for stabilizing at least one spinal motion segment comprising a superior vertebra and an inferior vertebra, the system comprising:

a superior component configured for attachment to the superior vertebra and having an apposition surface;

an inferior component configured for attachment to the inferior vertebra and having an apposition surface for engaging with the superior component apposition surface, wherein forward translation of the superior vertebra relative to the inferior vertebra is prevented; and

a spacer positioned between the two apposition surfaces, wherein the spacer maintains constant apposition between the two apposition surfaces.

2. The system of claim 1, wherein the spacer is bonded to both apposition surfaces.

3. The system of claim 1, wherein the spacer comprises at least two layers wherein a first layer is bonded to the superior apposition surface, the second layer is bonded to the inferior apposition surfaces and the first and second layers are bonded to each other.

4. The system of claim 1, wherein the spacer is secured between the two apposition surfaces by a pin which extends through the superior apposition surface, the spacer and the inferior apposition surface.

5. The system of claim 1, wherein the spacer is made of a compliant material wherein the spacer experiences a shearing motion upon movement of the vertebrae.

10. The system of claim 1, wherein the spacer is made of a compliant material wherein the spacer experiences a shearing motion upon movement of the vertebrae.

13. A method for stabilizing at least one spinal motion segment comprising a superior vertebra and an inferior vertebra, the method comprising:

providing the system of claim 1;

attaching the superior component to the superior vertebra;

attaching the inferior component to the inferior vertebra; and

maintaining substantial apposition between the apposition surfaces.

14. The method of claim 13, wherein the step of maintaining substantial apposition comprises bonding the apposition surfaces together.

15. The method of claim 13, wherein the step of maintaining comprises substantial apposition comprises securing the two surfaces together.

6. A system for stabilizing at least one spinal motion segment comprising a superior vertebra and an inferior vertebra, the system comprising:

a strut having a proximal end and a distal end;

a superior component configured for attachment to the superior vertebra and for adjustably receiving the proximal end of the strut wherein the length of a portion of the strut extending inferiorly of the superior component is adjustable;

an inferior component configured for attachment to the inferior vertebra and having a surface for engaging with the distal end of the strut, wherein forward translation of the superior vertebra relative to the inferior vertebra is prevented; and

a spacer positioned between the distal end of the strut and the engaging surface of the inferior component, wherein the spacer maintains constant apposition between the distal end of the strut and the engaging surface.

7. The system of claim 6, wherein the spacer is bonded to the distal end of the strut and to the engaging surface.

8. The system of claim 6, wherein the spacer comprises at least two layers wherein a first layer is bonded to the distal end of the strut, the second layer is bonded to the engaging surface and the first and second layers are bonded to each other.

9. The system of claim 6, wherein the spacer is secured between the distal end of the strut and the engaging surface of the inferior component by a pin which extends through the distal end of the strut, the spacer and the engaging surface.

11. A system for stabilizing at least one spinal motion segment comprising a superior vertebra and an inferior vertebra, the system comprising:

a superior component configured for attachment to the superior vertebra;

an inferior component configured for attachment to the inferior vertebra and for engaging with the superior component, wherein forward translation of the superior vertebra relative to the inferior vertebra is prevented;

means for attaching the superior component to the superior vertebra;

means for attaching the inferior component to the inferior vertebra; and

a damping element associated with at least one of the attachment means for dampening the torque undergone by the at least one attachment means.

12. The system of claim 11, wherein the damping element comprises a disk made of a polymer or a metal material.

16. A method for stabilizing at least one spinal motion segment comprising a superior vertebra and an inferior vertebra, the method comprising:

providing the system of claim 11;

attaching the superior component to the superior vertebra;

attaching the inferior component to the inferior vertebra; and

dampening any torque experienced by at least one of the superior and inferior components.