COMPONENTS FOR FUSING VERTEBRAL BODIES

Abstract

The invention relates to components for fusing vertebral bodies and to methods for the production and use thereof.

Claims

1. A component for fusing vertebral bodies, wherein the component is made from a porous, multi-surface body which has an edge with sealed region on at least one surface.

2. The component according to claim 1, wherein the component is made from a porous, multi-surface body which in each case has a sealed region on at least one surface on two opposing edges.

3. The component according one of the preceding claims, to claim 1, wherein the component is made from a porous, multi-surface body which has an edge with a circumferential sealed region on at least one surface.

4. The component according to claim 1, wherein the component is made from a porous, multi-surface body which has edges with sealed regions on two mutually opposing surfaces.

5. The component according to claim 1, wherein the component is made from a porous, multi-surface body which in each case has edges with a circumferential sealed region on two mutually opposing surfaces.

6. The component according to claim 1, wherein the porous, multi-surface body is made from porous ceramic.

7. The component according to claim 1, wherein the porous, multi-surface body is made from porous ceramic and permits large elastic elongations.

8. The component according to claim 1, wherein the sealed region is made from densely sintered ceramic.

9. The component according to claim 1, wherein the sealed region is made from densely sintered ceramic with high mechanical stability.

10. The component according to claim 1, wherein the material for the ceramic is chosen from the group consisting of aluminum oxide, zirconium oxide or mixed ceramics based on those mentioned above.

11. The component according to claim 1, wherein the material for the ceramic is chosen from zirconium-oxide-reinforced materials (ZTA, zirconia-toughened alumina).

12. The component according to claim 1, wherein the material for the ceramic is tetragonally stabilized zirconium oxide.

13. The component according to claim 14, wherein the material for the ceramic is yttrium-, cerium- or gadolinium-stabilized zirconium oxide.

14. The component according to claim 1, wherein the material for the porous ceramic is chosen from the group consisting of aluminum oxide, zirconium oxide or mixed ceramics based on those mentioned above, wherein the material additionally contains a bioactive substance by means of which the ceramic is bioactivated.

15. The component according to claim 1, wherein the bioactivation is carried out by a bioactive substance based on calcium phosphate, by a glass-like substance or by a phosphating layer.

16. The component according to claim 17, wherein the bioactive substance is based on calcium phosphate, hydroxylapatite or tricalcium phosphate (TCP).

17. The component according to claim 17, wherein the glass-like substance is a bioglass with the designation 45S5, which contains SiO.sub.2 (silicon dioxide), CaO (calcium oxide), Na.sub.2O (sodium superoxide) and P.sub.2O.sub.5 (phosphorus pentoxide).

18. The component according to claim 1, wherein the effective macroscopic modulus of elasticity of the porous inner region (second region) is <100 GPa.

19. The component according to claim 1, wherein the sealed region has a 4-point bending strength in the range from approximately 500 to 2000 MPa, preferably 700 to 1500 MPa.

20. The component according to claim 1, wherein the material for the porous ceramic consists of a zirconium-oxide-based material with a compressive strength of >10 MPa.

21. The component according to claim 1, wherein the material of the sealed region has a compressive strength which is at least a factor 10 higher than the porous region.

22. The component according to claim 1, wherein the porous ceramic has the following parameters: a pore size between 100 and 1000 μm, a porosity between 75 and 85% v/v, and an interconnectivity of the pores.

23. The component according to one of the preceding claims, characterized in that the geometry of the component is matched to the anatomy of the human vertebral body.

24. A method for producing the component according to claim 1, wherein production is carried out using template techniques/forming techniques, direct foaming methods or freeze-foaming methods.

25. The method for producing the component according to claim 24, wherein the edge regions (edges) of the porous ceramic are sealed in a second step by infiltration with a ceramic slurry.

Description

[0045] In a first variant according to the invention, the first region is formed in two parts, wherein, in each case, one part of the first region circumferentially encompasses the mechanically sensitive edge regions of the face surfaces of the second region according to FIGS. 1 and 2.

[0046] The two circumferential parts of the first region are securely connected to the porous second region, for example sintered together. However, the two parts of the first region have no connection to one another.

[0047] According to the invention, the mechanical compliance of the component is therefore provided by the porous second region, wherein the mechanically sensitive edge regions of monolithic, solid and circumferential second ceramic are protected.

[0048] In addition, in this variant according to the invention, the second porous region as a whole is offset inwards and is thus protected from the two parts of the first region in the manner of a protector.

[0049] According to the invention, the two parts of the first region can also have structures, for example cutouts, holes with/without thread or grooves, which enable the engagement of an instrument for safe handling, in particular during implantation.

[0050] According to the invention, the interface with the instrument therefore extends primarily over the stable first region.

[0051] In the same way, the first region of the component according to the invention constitutes the primary interface with the two end plates of the adjacent vertebral bodies, which, by means of suitable structures such as serrations, edges or pyramid-shaped elevations for example, ensure optimum primary stability.

[0052] According to the invention, the connection of the two regions can be made by joining in the green state and subsequent co-sintering, thus resulting in a substance-to-substance bond.

[0053] In principle, according to the invention, any kind of shape in the green according to the prior art is suitable for ensuring a connection of the two regions. In particular, the porous second region can be foamed directly in the two monolithic sub-regions, which are arranged in a special mold.

[0054] Naturally, instead of being made from ceramic, such an implant can also be produced from other materials which are suitable for implantation purposes, for example metals and metal wires made from titanium. However, several of the advantages listed above then no longer apply, such as fewer artifacts in the imaging, the general non-toxicity and others. The same also applies to the next variant.

[0055] In a second variant according to the invention according to FIGS. 3 and 4, the sensitive edge regions of the porous ceramic of the second region are infiltrated with a ceramic slurry in the green state. As a result of the infiltration, these regions are sealed. A substance-to-substance bond, with which the mechanically sensitive regions of the fusion component are protected, is formed in the subsequent sintering.

[0056] According to the invention, in particular rapid prototyping methods according to the prior art are suitable for this variant, as these enable the implant to be built up step-by-step and the two regions according to the invention can be formed independently of one another.

[0057] In particular, according to the invention, specific gradients in the porosity or other porous structures can also be set up or produced with this method in order to specifically match the elastic characteristics of the ceramic component to the mechanical requirements of the bone growth.

[0058] In particular, the invention includes a component for fusing vertebral bodies, wherein the component is made from a porous, multi-surface body which has an edge with sealed region on at least one surface.

[0059] In a preferred embodiment, the component consisting of the porous, multi-surface body in each case has a sealed region on at least one surface on two opposing edges.

[0060] In a further preferred embodiment, the component consisting of the porous, multi-surface body has an edge with a circumferential sealed region on at least one surface.

[0061] In a further preferred embodiment, the component consisting of the porous, multi-surface body has edges with sealed regions on two mutually opposing surfaces.

[0062] In a further preferred embodiment, the component consisting of the porous, multi-surface body in each case has edges with a circumferential sealed region on two mutually opposing surfaces.

[0063] In a further preferred embodiment, the component consisting of the porous, multi-surface body is made of porous ceramic.

[0064] In a further preferred embodiment, the component consisting of the porous, multi-surface body is made of porous ceramic and permits large elastic elongations.

[0065] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the sealed region is made of densely sintered ceramic.

[0066] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the sealed region is made of densely sintered ceramic with high mechanical stability.

[0067] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the material for the ceramic is chosen from the group consisting of aluminum oxide, zirconium oxide or mixed ceramics based on those mentioned above.

[0068] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the material for the ceramic is chosen from zirconium-oxide-reinforced materials (ZTA, zirconia-toughened alumina).

[0069] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the workpiece for the ceramic is tetragonally stabilized zirconium oxide.

[0070] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the workpiece for the ceramic is yttrium-, cerium- or gadolinium-stabilized zirconium oxide.

[0071] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the material for the porous ceramic is chosen from the group consisting of aluminum oxide, zirconium oxide or mixed ceramics based on those mentioned above, wherein the material additionally contains a bioactive substance by means of which the ceramic is bioactivated.

[0072] In a further preferred embodiment of the porous, multi-surface body, the bioactivation is carried out by a bioactive substance based on calcium phosphate, by a glass-like substance or by a phosphating layer.

[0073] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the bioactive substance is based on calcium phosphate, hydroxylapatite or tricalcium phosphate (TCP).

[0074] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the glass-like substance is a bioglass with the designation 45S5, which contains SiO2 (silicon dioxide), CaO (calcium oxide), Na2O (sodium superoxide) and P2O5 (phosphorus pentoxide).

[0075] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the effective macroscopic modulus of elasticity of the porous inner region (second region) is <100 GPa.

[0076] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the sealed region has a 4-point bending strength in the range from approximately 500 to 2000 MPa, preferably 700 to 1500 MPa.

[0077] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the material for the porous ceramic consists of a zirconium-oxide-based material with a compressive strength of >10 MPa.

[0078] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the material of the sealed region has a compressive strength which is at least a factor 10 higher than the porous region.

[0079] In a further preferred embodiment of the component consisting of the porous, multi-surface body, the porous ceramic has the following parameters: [0080] a pore size between 100 and 1000 μm, [0081] a porosity between 75 and 85% v/v, and [0082] an interconnectivity of the pores.

[0083] In a further preferred embodiment, the geometry of the component is matched to the anatomy of the human vertebral body.

[0084] The method for producing the component according to the invention consisting of the porous, multi-surface body includes the use of template techniques/forming techniques, direct foaming methods or freeze-foaming methods.

[0085] In a preferred embodiment of the method, the edge regions (edges) of the porous ceramic are sealed in a second step by infiltration with a ceramic slurry.