Intervertebral fusion implant

• US 5,658,337 A
• Filed: 04/17/1996
• Issued: 08/19/1997
• Est. Priority Date: 05/23/1994
• Status: Expired due to Term

• Current Assignee: Zimmer Spine, Inc. (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Spine-Tech, Inc. (Sulzer Medica)
• Inventors: Kohrs, Douglas W., Yuan, Hansen A., Stassen, David W.
• Primary Examiner(s): CLARKE, ROBERT A
• Application Number:
  US08/633,297
• Time in Patent Office: 489 Days
• Field of Search: 623/17, 606/60, 606/61
• US Class Current: 623/17.11
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30146 octagonal
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30789 perpendicular with respect to each other
• CPC Class Codes: A61F 2002/30858 Threads interrupted by grooves or sidewalls, e.g. flat sidewalls
• CPC Class Codes: A61F 2002/30868 Square, rectangular or rhomboidal threads
• CPC Class Codes: A61F 2002/30879 Ribs
• CPC Class Codes: A61F 2002/30883 dovetail-shaped
• 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 2002/4627 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 2230/0017 Angular shapes
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0082 : parallelepipedal

Abstract

A intervertebral fusion implant includes first and second bearing surfaces which oppose cortical bone upon insertion of the implant into a bore formed between two vertebrae. The implant includes first and second ridges which extend from the bearing surface. The ridges extend through the cortical bone into cancellous bone. The ridges are provided with openings formed through the ridges. The openings are in communication with the interior of the implant.

Claims

1. An implant for facilitating intervertebral fusion between opposing vertebrae, said implant comprising:

a hollow implant body having a generally parallelepiped configuration with longitudinal edges;

a plurality of generally linear and separate anchor segments disposed at said longitudinal edges and said anchor segments spaced from one another by unthreaded areas on surfaces of said body between said longitudinal edges;

said anchor segments cooperating to define a helical pattern;

said body having at least two diametrically opposed sides with openings formed through each of said sides in communication with an interior of said implant body.

12. The implant according to any of claims 2 or 1 wherein said anchor segments are thread segments.

2. An implant for facilitating intervertebral fusion between opposing vertebrae;

said implant comprising;

an implant body having a first bearing surface and a second bearing surface, each of said first and second bearing surfaces extending generally parallel to one another and on opposite sides of a longitudinal axis of said body;

a first ridge extending from said first bearing surface;

a second ridge extending from said second bearing surface;

a first opening formed through said first ridge in communication with said interior;

a second opening formed through said second ridge in communication with said interior; and

a plurality of anchor segments disposed on opposite sides of said first and second ridges with said plurality of anchor segments defining a helix pattern.

3. The implant according to claim 2 wherein said first and second bearing surfaces and first and second ridges are sized for said first and second bearing surface to oppose cortical bone of end plates of opposing vertebrae and with said ridges sized to extend beyond said cortical bone and be in communication with cancellous bone of said vertebrae.

4. The implant according to claim 2 comprising first and second side walls extending between said first and second bearing surfaces.

5. The implant according to claim 4 comprising first and second bores formed through said first and second side walls with first and second bores in communication with said interior.

6. The implant according to claim 4 wherein said side walls are concave along their longitudinal axis.

7. The implant according to claim 6 comprising first and second bores formed through said side walls with said first and second bores in communication with said interior.

8. The implant according to claim 7 wherein said implant is selected for placement within a bore formed between opposing vertebra with said bore having a predetermined radius, said anchor segments separated by valleys with a radial line from said longitudinal axis to said valleys being substantially equal to a said radius of said bore.

9. The implant according to claim 4 wherein said side walls are substantially solid throughout their surface area.

10. The implant according to claim 2 wherein said body is providing with a leading edge having a taper with a cross-sectional area of said body at said leading edge being smaller than a cross sectional area of said body away from said leading edge.

11. The implant according to claim 2 wherein said side walls and said bearing walls are concave along said longitudinal dimension.

13. An implant for facilitating intervertebral fusion between opposing vertebrae;

said implant comprising;

an implant body having a first bearing surface and a second bearing surface, each of said first and second bearing surfaces extending generally parallel to one another and on opposite sides of a longitudinal axis of said body;

a first ridge extending from said first bearing surface;

a second ridge extending from said second bearing surface;

a first opening formed through said first ridge in communication with said interior;

a second opening formed through said second ridge in communication with said interior;

first and second side walls extending between said first and second bearing surfaces;

said side walls are concave along their longitudinal axis; and

said side walls are substantially solid through their surface area.