Intervertebral implant

• US 5,755,798 A
• Filed: 10/25/1996
• Issued: 05/26/1998
• Est. Priority Date: 10/26/1995
• Status: Expired due to Fees

• Current Assignee: Artos Medizinische Produkte GmbH
• Original Assignee: Artos Medizinische Produkte GmbH
• Inventors: Papavero, Luca, Kranz, Curt, Steur, Gerd
• Primary Examiner(s): Prebilic, Paul B.
• Application Number:
  US08/736,802
• Time in Patent Office: 578 Days
• Field of Search: 623/17, 623/18, 623/20, 606/60, 606/61, 606/69, 606/70, 606/71, 606/53
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• 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 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30118 concentric circles
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30225 Flat cylinders, i.e. discs
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/3082 Grooves
• CPC Class Codes: A61F 2002/30909 Nets
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0021 square
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: Y10S 606/907 : Composed of particular material or coated

Abstract

An intervertebral implant for insertion between adjacent vertebrae. The implant includes a spacer having two end faces and defining a continuous hollow channel therein configured to receive natural bone substance; and flanges disposed on respective end faces of the spacer and extending in each respective end plane thereof for connection to the adjacent vertebrae. Each flange projects laterally beyond the spacer at at least one region of the spacer for reducing surface pressure exerted by the spacer on the vertebrae, at least one flange defining an aperture therein within a region of the hollow channel, the aperture being configured to receive a substrate therein for supporting the natural bone substance, the flanges further defining at least one perforation within a region thereof projecting laterally beyond the spacer through which the natural bone substance may grow along an outside region of the spacer.

Claims

1. An intervertebral implant for insertion between adjacent vertebrae comprising:

a spacer having two end faces and defining a continuous hollow channel therein adapted to receive natural bone substance;

flanges disposed on respective end faces of the spacer and extending in each respective end plane thereof for connection to the adjacent vertebrae, each flange projecting laterally beyond the spacer at at least one region of the spacer for reducing surface pressure exerted by the spacer on the vertebrae, at least one flange defining an aperture therein within a region of the hollow channel, the aperture being adapted to receive a substrate therein for supporting the natural bone substance, the flanges further defining at least one perforation within a region thereof projecting laterally beyond the spacer for receiving natural bone substance which may grow along an outside region of the spacer.

2. The implant according to claim 1, wherein the spacer has a substantially tubular shape and a substantially constant internal cross-section along a longitudinal direction thereof.

3. The implant according to claim 1, further comprising a substrate disposed in the aperture of the at least one flange.

4. The implant according to claim 3, wherein an internal cross section of the hollow channel is equal to or larger than an outer cross section of the substrate along a longitudinal direction of the spacer.

5. The implant according to claim 1, wherein an internal cross section of the hollow channel along a longitudinal direction of the spacer is substantially circular.

6. The implant according to claim 1, wherein the spacer is substantially rigid.

7. The implant according to claim 1, wherein the spacer has a resilience which largely corresponds to a resilience of the natural bone substance.

8. The implant according to claim 1, wherein the spacer defines at least one perforation facing in a radial direction for increasing a resilience thereof.

9. The implant according to claim 8, wherein the spacer is configured as a meshed cage for allowing the natural bone substance to grow into the cage.

10. The implant according to claim 1, wherein the flanges are substantially parallel to one another or at a slight angle with respect to one another to conform with a natural curvature of a vertebral column.

11. The implant according to claim 1, wherein the implant is made of a titanium or a titanium alloy.

12. The implant according to claim 3, wherein the substrate is made of a porous material.

13. The implant according to claim 3, wherein the substrate is made of a ceramics material burnt from bovine spongiosa.

14. The implant according to claim 3, wherein the substrate contains substances which promote bone growth.

15. The implant according to claim 1, wherein at least one of the flanges defines a surface profile on a side thereon facing a corresponding vertebra.

16. The implant according to claim 15, wherein the surface profile comprises a plurality of circumferentially extending grooves.

17. The implant according to claim 1, further comprising anchorage elements adapted to be fastened to the plates for positively connecting the plates to the vertebrae.

18. The implant according to claim 17, wherein the anchorage elements comprise bone screws.