Spinal implant and method of use

• US 7,267,687 B2
• Filed: 09/24/2002
• Issued: 09/11/2007
• Est. Priority Date: 10/02/2001
• Status: Expired due to Term

• Current Assignee: REX Medical LP
• Original Assignee: REX Medical LP
• Inventors: McGuckin, James F. Jr.
• Primary Examiner(s): Pellegrino; Brian E.
• Application Number:
  US10/253,446
• Publication Number:
  US 20030199979A1
• Time in Patent Office: 1,813 Days
• Field of Search: 623/17.11, 623/17.12, 623/17.16, 623/1.18, 623/1.19, 623/2.36, 623/2.37, 606/61, 606/99
• US Class Current: 623/17.11
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/00557 inflatable A61B2017/22051 takes precedence
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 2017/0256 for the spine
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/444 for replacing the nucleus pulposus
• 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 2210/0014 using shape memory or superelastic materials, e.g. nitinol

Abstract

A spinal implant having a smaller transverse cross-sectional dimension in the radially compressed configuration than in a first expanded configuration and a more linear configuration in the second delivery configuration than in the first curved configuration. The implant assumes the radially compressed configuration and second delivery configuration during delivery to the disc space and assumes the first curved configuration and first expanded configuration upon placement within the disc space. The implant further moves towards the radially compressed configuration once implanted in response to a load placed on the implant by the vertebral bodies.

Claims

1. A spinal implant having first and second axially spaced end portions and an intermediate portion between the first and second end portions, the first and second end portions defining first and second surfaces defining upper and lower flat surfaces, the implant composed of shape memory material further having a first shape memorized expanded configuration, a first shaped memorized curved non-linear placement configuration wherein it is C-shaped in configuration when implanted wherein the first and second end portions are angled with respect to a longitudinal axis of the intermediate portion and extend towards each other, a second radially compressed configuration, and a second delivery configuration wherein the first and second end portions face away from each other and the end portions lie along a longitudinal axis of the implant which passes through the intermediate portion, the implant further having a C-shaped transverse cross-section smaller in transverse cross-sectional dimension in the radially compressed configuration than in the first expanded configuration and having a more linear configuration in the second delivery configuration than in the first curved configuration, the implant assuming the second radially compressed configuration and second delivery configuration during delivery to the disc space and assuming the first curved configuration and first expanded configuration upon placement within the disc space, the implant further moving towards the radially compressed configuration once implanted in response to a load placed on the implant by the vertebral bodies, in the delivery configuration the first and second end portions are spaced apart a first distance and in the first curved C-shaped placement configuration the first and second end portions are spaced apart a second distance less than the first distance and the implant is adapted to extend circumferentially along the periphery of the disc space in the C-shaped configuration wherein the implant has both a transverse C-shaped configuration and a C-shape defined with respect to a longitudinal axis of the implant when implanted.

2. The spinal implant of claim 1, wherein the C-shaped transverse configuration is a substantially rectangular transverse cross section forming the first and second flat surfaces.

3. The spinal implant of claim 1, further comprising an insert material contained within the implant.

4. The spinal implant of claim 3, wherein the insert material is contained within the implant by a tongue and groove arrangement.

5. The spinal implant of claim 1, further comprising an insert material contained within the implant.

6. The spinal implant of claim 5, wherein the insert material is contained within the implant by a tongue and groove arrangement.

7. The spinal implant of claim 1, wherein an outer surface of the implant is roughened to enhance bone ingrowth.

8. The spinal implant of claim 1, wherein the implant includes a plurality of openings in an outer surface to enhance flexibility.

9. The spinal implant of claim 1, wherein the implant includes a plurality of grooves in an outer surface to enhance flexibility.

10. The spinal implant of claim 1, wherein in the placement configuration some transverse cross sections of the implant lie in non-parallel planes.

11. The spinal implant of claim 1, wherein in the placement configuration the first and second end portions each have an end surface lying in a plane parallel to a longitudinal axis of the spine.

12. A spinal implant having a substantially cylindrical hollow housing composed of shape memory material and having first and second axially spaced end portions and an intermediate portion defining upper and lower flat vertebral engaging surfaces between the first and second end portions, the housing having a shape memorized non-linear configuration for placement forming a C-shape with respect to a longitudinal axis extending through the center of the implant wherein the first and second end portions extend at an angle to a longitudinal axis of the intermediate portion, the housing being C-shaped in transverse cross-section and being radially compressible from a first configuration to a second configuration by the vertebral bodies in response to a load placed on the housing and returning to its first configuration upon removal of the load, in the delivery configuration the longitudinal axis extending through the intermediate portion passes through the end portions and in the C-shaped placement configuration top and bottom surfaces of the first and second end portions provide compressible vertebral engaging surfaces and the implant is adapted to extend along the periphery of the disc space in the C-shaped configuration wherein the implant has both a transverse C-shaped configuration and a C-shape defined with respect to a longitudinal axis of the implant when implanted.

13. The spinal implant of claim 12, further comprising a filler material disposed within the outer housing such that the filler material assumes a non-linear configuration for placement such that a first end portion and a second end portion of the filler material extend at an angle to a longitudinal axis of an intermediate portion of the filler material.

14. The spinal implant of claim 13, wherein the filler material is retained by a tongue and groove arrangement.

15. The spinal implant of claim 12, wherein the outer support contains a roughened surface to enhance bone ingrowth.

16. The spinal implant of claim 12, wherein in the placement configuration transverse cross sections of the implant are at varying angles to a plane containing a longitudinal axis of the spine.

17. The spinal implant of claim 12, wherein in the placement configuration the end portions have an end surface lying in a plane parallel to a longitudinal axis of the spine.