Intervertebral implant

• US 20090192614A1
• Filed: 01/21/2009
• Published: 07/30/2009
• Est. Priority Date: 01/25/2008
• Status: Active Grant

• Current Assignee: Aesculap AG (Lonza Group AG)
• Original Assignee: Aesculap AG (Lonza Group AG)
• Inventors: Wagner, Cecile, Beger, Jens, Haas, Alexander
• Granted Patent: US 8,021,424 B2
• Time in Patent Office: Days
• US Class Current: 623/17.15
• 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 2002/30075 swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30242 spherical
• CPC Class Codes: A61F 2002/30245 Partial spheres
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/30537 adjustable
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30647 Joints made of two toroidal rings engaged together
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30889 Arcuate pegs
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2210/0061 swellable
• CPC Class Codes: A61F 2230/0019 rectangular
• CPC Class Codes: A61F 2230/0065 toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0071 spherical
• CPC Class Codes: A61F 2230/0082 parallelepipedal
• CPC Class Codes: A61F 2250/0004 adjustable

Abstract

In order, in an intervertebral implant having a core made of a swellable material and having a vertebral-body locating face on its top and/or bottom side, which is connected to the swellable core, to reduce the shearing forces between the swellable core and the vertebral-body locating face during swelling of the swellable core, it is proposed that the vertebral-body locating face comprises a plurality of support elements, which are respectively anchored adjacent to one another and individually in the core, and a plurality of mutually separate locating elements, which are disposed adjacent to one another and outside of the core and which are carried by the support elements and are movable relative to one another in the plane of the vertebral-body locating face.

Claims

1. Intervertebral implant having a core made of a swellable material and having a vertebral-body locating face on its top and/or bottom side, which is connected to the swellable core, wherein the vertebral-body locating face comprises a plurality of support elements, which are respectively anchored adjacent to one another and individually in the core, and a plurality of mutually separate locating elements, which are disposed adjacent to one another and outside of the core and which are carried by the support elements and are movable relative to one another in the plane of the vertebral-body locating face.

2. Intervertebral implant according to claim 1, wherein in each case a support element and a locating element are permanently connected to one another.

3. Intervertebral implant according to claim 2, wherein in each case a support element and a locating element are of an integral construction.

4. Intervertebral implant according to claim 3, wherein the support elements are spheres, which are partially embedded in the core and of which the part projecting from the core forms in each case a locating element.

5. Intervertebral implant according to claim 1 wherein the support element comprises a foot, which extends into the core with a widened portion.

6. Intervertebral implant according to claim 5, wherein the widened portion has the shape of a sphere.

7. Intervertebral implant according to claim 1, wherein the locating element is of a plate-shaped configuration.

8. Intervertebral implant according to claim 1, wherein all of the locating elements lie in one plane.

9. Intervertebral implant according to claim 1, wherein the locating elements in the non-swollen state of the core lie adjacent to one another without an overlap.

10. Intervertebral implant according to claim 1, wherein the locating elements in the non-swollen state of the core lie adjacent to one another so as to mutually overlap in an edge region.

11. Intervertebral implant according to claim 10, wherein the locating elements are bevelled in the edge region of mutual overlap in the non-swollen state of the core.

12. Intervertebral implant according to claim 1, wherein mutually adjacent support elements and/or locating elements are connected to one another by means of a limiting element, which during the swelling of the core allows but limits a moving of the support elements and/or locating elements apart from one another.

13. Intervertebral implant according to claim 12, wherein the limiting element is of an annular configuration and in each case surrounds two mutually adjacent support elements and/or locating elements.

14. Intervertebral implant according to claim 12, wherein the support element and/or the locating element have an eye-shaped portion, through which the limiting element engages.

15. Intervertebral implant according to claim 12, wherein all of the mutually adjacent support elements and/or locating elements in a row are connected to one another by means of limiting elements.

16. Intervertebral implant according to claim 15, wherein support elements and/or locating elements from mutually adjacent rows are additionally connected to one another by means of limiting elements.

17. Intervertebral implant according to claim 1, wherein the support elements and the locating elements at their sides facing one another are of an eye-shaped configuration and engage around one another in this eye-shaped region.

18. Intervertebral implant according to claim 1, wherein the support elements and the locating elements at their sides facing one another are of an eye-shaped configuration and are connected to one another in this eye-shaped region by limiting elements so as to be movable up to a maximum distance apart from one another.

19. Intervertebral implant according to claim 17, wherein the eye-shaped region is formed by the lateral faces of a three-dimensional body composed of rod-shaped edge elements.

20. Intervertebral implant according to claim 19, wherein the three-dimensional body is a cube.

21. Intervertebral implant according to claim 1, wherein disposed between the locating elements are fixing projections, which are displaceable transversely of the plane of the vertebral-body locating face and which are displaceable from a normal position, in which they do not project beyond the locating elements, into a fixing position, in which they project beyond the locating elements, and wherein for displacement of the fixing projections drive elements are provided, which can be activated by the movement of the support elements and/or the locating elements apart from one another during the swelling of the core.

22. Intervertebral implant according to claim 21, wherein the drive element comprises diverging locating faces for tension members, which are held in each case on a support element and/or locating element and, when the support elements and/or locating elements move apart from one another, slide along the locating faces in such a way that the drive element is displaced in the direction of the vertebral-body locating face.

23. Intervertebral implant according to claim 22, wherein the locating faces are formed by the limbs of a triangular drive element.

24. Intervertebral implant according claim 21, wherein the drive element takes the form of a limiting element that allows the support elements and/or locating elements to move up to a maximum spacing apart from one another.