Facet triangle spinal fixation device and method of use

• US 20050119657A1
• Filed: 09/10/2004
• Published: 06/02/2005
• Est. Priority Date: 10/28/2003
• Status: Active Grant

• Current Assignee: Pyramid Spine LLC
• Original Assignee: Pyramid Spine LLC
• Inventors: Goldsmith, Michael E.
• Granted Patent: US 7,591,837 B2
• Time in Patent Office: Days
• US Class Current: 606/915
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/707 Devices acting on, or attached to, a transverse process or rib; Tools therefor

Abstract

Provided is a one-piece device and method of use of the device to enable a surgeon to bilaterally secure two vertebrae together in a manner that increases the stability and strength of the connection over that previously known in the art. Also provided is a kit including the device and ancillary instrumentation to facilitate the method of the present invention.

Claims

1. A novel device for the fixation of two vertebra of a subject one to the other, the device comprising:

an elongated member having a longitudinal axis, said elongated member terminating at a first end of said longitudinal axis in a first terminal portion and terminating at a second end of said longitudinal axis at a second terminal portion;

a first securing portal defined within and passing through said first terminal portion and a second securing portal defined within and passing through said second terminal portion;

said elongated member being sized and configured to extend transversely across a first vertebra of a subject such that when said device is in use and fitted in said transverse relationship to said vertebra, said first securing portal will be positioned over a first facet of said first vertebra and said second securing portal will be positioned over a second facet of said vertebra;

a central portion of said elongated member connecting said first terminal portion to said second terminal portion;

said central portion being laterally displaced from said longitudinal axis so as to form an outward curvature in the central portion of said elongated member;

a first and a second securing member, each sized and configured to respectively pass partially through said first securing portal and said second securing portal and having sufficient length to also pass through a portion of bone of an adjacent first vertebra and a portion bone of an underlying second vertebra such that when in use, said first and second securing members serve to secure the device at both the first end and the second end of said elongated member to said first vertebra and said second underlying vertebra such that said first and second vertebra are secured one to the other.

2. The device according to claim 1, wherein said elongated member is of unitary construction.

3. The device according to claim 1, wherein said central portion is displaced caudally from said longitudinal axis of said device, said caudal displacement forming a twist angle of the device.

4. The device according to claim 3, wherein said twist angle is between 0-60 degrees.

5. The device according to claim 1, wherein said first terminal portion and said second terminal portion are each formed so as to be displaced away from the longitudinal axis of the elongated member in the same direction as the central portion is displaced from the longitudinal axis, said terminal portion displacement forming a foot plate angle of the device.

6. The device according to claim 1, wherein said first and second terminal portions of said elongated portion have a larger width dimension relative to the width dimension of the central portion of the elongated member.

7. The device according to claim 1, wherein said foot plate surface that is configured to be adjacent to the attachment surface of the vertebra is textured so as to improve device to bone contact and attachment security.

8. The device according to claim 1, wherein said first and second securing portals are configured at the outward facing side to have a spherical countersink that is complimentary in shape to the underside of the head of a securing member so as to facilitate angling of the securing member within the securing portal such that, when in use, the securing member can have a variable secure member entry angle into the underlying vertebral bone material.

9. The device according to claim 7, wherein said entry angle of the securing member can be varied up to 30 degrees without changing the position of the foot plate against the underlying vertebra.

10. The device according to claim 1, wherein said securing members are selected from the group consisting of common screws;

self-tapping screws, fully threaded cortical screws, partially threaded cortical screws, cancellous fully threaded screws, and partially threaded cancellous screws.

11. The device according to claim 1, wherein said volar aspect of said foot plates comprise splines to facilitate good contact with the underlying bone surface.

12. The device according to claim 1, further comprising a pair of retaining rings, each one of said pair of retaining rings being positioned radially around the inner circumference of a respective securing portal, said retaining ring serving to exert a retaining force on said securing member that is fully seated within the respective securing portal.

13. The device of claim 1, wherein said central portion angle is between 60 and 140 degrees.

14. The device of claim 1, wherein the foot plates have a volar surface of a type selected from the group consisting of smooth, grit-blasted, machine-textured, porous-coated, knurled, crosshatched, and provided with tines.

15. The device according to claim 1, wherein said foot plates have a wider dimension than said central portion of said device.

16. A method of treating a subject in need of treatment requiring fusion of at least one vertebra to another, the method comprising:

pre-surgical evaluation of vertebra conformation of said subject;

providing at least one device according to claim 1, said at least one device being sized and configured to be in conformity with said conformation of said at least one vertebra;

surgically exposing at least a portion of the dorsal aspect of said at least one vertebra;

attaching said device to said at least one vertebra such that said at least one vertebra is fixed to at least a portion of a second vertebra underlying said at least one vertebra.

17. A method of treating a subject in need of treatment requiring fusion of two or more vertebra to portions of corresponding underlying vertebra, the method comprising:

following the procedure of claim 16 for each of said two or more vertebra;

connecting the devices used for each of the two or more vertebra one to the other such that the respective device for each vertebra is fixed in position to the device of an adjacent vertebra.

18. The method of claim 17, wherein said connecting step is accomplished by use of at least one in-line connection member, a first end of said connection member being attached to a first device attached to a first vertebra and a second end of said connection member being attached to a second device attached to an adjacent vertebra.

19. The method of claim 18, wherein said at least one in-line connector is two connectors each positioned in an approximate parallel relationship one to the other, each being located on opposite sides of the spinal processes of the so connected adjacent vertebra.

20. A kit for use in a surgical procedure to fuse at least two adjacent vertebra, one to the other, the kit comprising:

at least one device according to claim 1, associated tools for said device, and a sterile package for said kit.

21. The kit according to claim 20, wherein said at least one device is a plurality of said devices of varying size and configuration.