HIP IMPLANT SYSTEM

Abstract

A hip implant system includes an artificial acetabular cup and an artificial acetabular liner. The liner includes or consists of a metal or an alloy, and is coated at least in sections with a ceramic coating.

Claims

1. A hip implant system, comprising: an artificial acetabular cup; and an artificial acetabular liner comprising or consisting of a metal or an alloy, wherein the artificial acetabular liner is coated at least in sections with a ceramic coating.

2. The hip implant system according to claim 1, wherein only an outer face of the artificial acetabular liner or only an inner face of the artificial acetabular liner is coated at least in sections with the ceramic coating.

3. The hip implant system according to claim 1, wherein the artificial acetabular liner is coated fully with the ceramic coating.

4. The hip implant system according to claim 1, wherein the ceramic coating is constructed in a plurality of layers.

5. The hip implant system according to claim 1, wherein the ceramic coating comprises at least one non-oxide ceramic or consists at least of a non-oxide ceramic.

6. The hip implant system according to claim 1, wherein the ceramic coating comprises at least one chromium nitride layer, at least one chromium carbonitride layer, at least one chromium zirconium nitride layer and at least one zirconium nitride layer.

7. The hip implant system according to claim 1, wherein the ceramic coating comprises three chromium nitride layers, two chromium carbonitride layers, one chromium zirconium nitride layer and one zirconium nitride layer, or consists of the aforementioned layers.

8. The hip implant system according to claim 1, wherein the ceramic coating is formed as a multilayer layer system in which a first chromium nitride layer is covered by a first chromium carbonitride layer, the first chromium carbonitride layer is covered by a second chromium nitride layer, the second chromium nitride layer is covered by a second chromium carbonitride layer, the second chromium carbonitride layer is covered by a third chromium nitride layer the third chromium nitride layer is covered by a chromium zirconium nitride layer and the chromium zirconium nitride layer is covered by a zirconium nitride layer.

9. The hip implant system according to claim 7, wherein the zirconium nitride layer forms an outer cover layer of the ceramic coating.

10. The hip implant system according to claim 1, wherein the ceramic coating is formed directly on the artificial acetabular liner.

11. The hip implant system according to claim 1, wherein the ceramic coating has a thickness of from 0.5 μm to 10 μm.

12. The hip implant system according to claim 1, wherein an inner face of the artificial acetabular liner has a surface roughness of ≤0.5 μm; and/or an outer face of the artificial acetabular liner has a surface roughness of ≤1 μm; and/or the artificial acetabular liner has a wall thickness of from 2 mm to 3 mm; and/or the artificial acetabular liner has a cone angle θ of from 15° to 25°.

13. The hip implant system according to claim 1, wherein the artificial acetabular liner and the artificial acetabular cup are connected to one another with a friction fit in a joined state.

14. The hip implant system according to claim 1, wherein the alloy comprises cobalt and/or chromium.

15. The hip implant system according to claim 1, further comprising an artificial femoral liner and/or an artificial femoral head.

16. The hip implant system according to claim 1, wherein only a convex, conical or frustoconical outer face of the artificial acetabular liner or only a concave, conical or frustoconical inner face of the artificial acetabular liner is coated at least in sections with the ceramic coating.

17. The hip implant system according to claim 5, wherein the at least one non-oxide ceramic is selected from the group consisting of chromium nitride, chromium carbonitride, chromium zirconium nitride and zirconium nitride.

18. The hip implant system according to claim 7, wherein one of the chromium nitride layers is formed directly on the artificial acetabular liner.

19. The hip implant system according to claim 8, wherein the first chromium nitride layer is formed directly on the artificial acetabular liner.

20. The hip implant system according to claim 14, wherein the alloy containing cobalt and/or chromium is a cobalt-chromium-molybdenum alloy.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] FIG. 1 shows a schematic exploded representation of an embodiment of a hip implant system according to the invention,

[0061] FIG. 2 schematically shows an enlarged detail representation of a ceramic coating of a hip implant system according to the invention in a region A according to FIG. 1, and

[0062] FIG. 3 schematically shows an embodiment of a hip implant system according to the invention in the mounted or implanted state.

DETAILED DESCRIPTION

[0063] FIG. 1 schematically shows an embodiment of a hip implant system 1 according to the present invention.

[0064] The hip implant system 1 comprises an artificial acetabular cup 10 and an artificial acetabular liner 20 which can be inserted into the artificial acetabular cup 10. The hip implant system 1 may furthermore comprise an artificial femoral liner 30 and in particular an artificial femoral head 40.

[0065] The artificial acetabular cup 10 is preferably at least in sections, in particular only in sections, or fully configured in the form of a spherical shell segment. Preferably, the artificial acetabular cup 10 comprises an at least in sections convex outer face 12 and an at least in sections concave inner face 14, which are respectively bounded by a circumferential edge 16, 17 of the artificial acetabular cup 10. In this case, the at least in sections concave inner face 14 and the circumferential edge 16 form an at least in sections concavely configured reception region 18 for the artificial acetabular liner 20.

[0066] The artificial acetabular cup 10 is preferably made from a biocompatible metal, for example titanium. In order to achieve sufficient osseointegration and in particular secondary stability, an open-pored titanium or hydroxyapatite coating may be formed on the at least in sections convexly configured outer side of the artificial acetabular cup 10.

[0067] The artificial acetabular liner 20 is likewise preferably at least in sections, in particular only in sections, or fully configured in the form of a spherical shell segment. Preferably, the artificial acetabular liner 20 comprises an at least in sections convex outer face 22 and an at least in sections concave inner or glide face 24, which are respectively bounded by a circumferential edge 26, 27 of the artificial acetabular liner 20. In this case, the at least in sections concave inner or glide face 24 and the circumferential edge 26 form an at least in sections concavely configured reception region 28 for the artificial femoral liner 30.

[0068] The at least in sections convex outer face 22 of the artificial acetabular liner 20 preferably has a surface roughness Ra of ≤1 μm, preferably ≤0.6 μm. In this way, optimization of the interlocking of the at least in sections convex outer face 22 with the at least in sections concave inner face 14 of the artificial acetabular cup 10 may be achieved advantageously.

[0069] The at least in sections concave inner or glide face 24 of the artificial acetabular liner 20 preferably has a surface roughness Ra of ≤0.5 μm, preferably ≤0.05 μm. In this way, optimized interlocking of the at least in sections concave inner or glide face 24 with an outer or glide face of the artificial femoral liner 30 may be achieved particularly advantageously.

[0070] Furthermore, the artificial acetabular liner 20 and the artificial acetabular cup 10 are clamped, preferably conically clamped, to one another in a mounted state.

[0071] The artificial acetabular liner 20 consists of an alloy containing cobalt and/or chromium, preferably a cobalt-chromium-molybdenum alloy.

[0072] The artificial acetabular liner 20 is at least in sections, in particular only in sections, or fully coated or provided with a ceramic coating 50. The ceramic coating preferably comprises chromium nitride (CrN), chromium carbonitride (CrCN), chromium zirconium nitride (CrZrN) and zirconium nitride (ZrN). In particular, the ceramic coating 50 may consist of the aforementioned ceramic materials.

[0073] Particularly preferably, the ceramic coating 50 comprises at least one chromium nitride layer (CrN layer), in particular (only) one or a plurality of chromium nitride layers, for example two or three chromium nitride layers, and/or at least one chromium carbonitride layer (CrCN layer), in particular (only) one or a plurality of chromium carbonitride layers, for example two chromium carbonitride layers, and/or at least one chromium zirconium nitride layer (CrZrN layer), in particular (only) one or a plurality of chromium zirconium nitride layers, and/or at least one zirconium nitride layer (ZrN layer), in particular (only) one or a plurality of zirconium nitride layers. The ceramic coating 50 may, in particular, consist of one or more of the aforementioned layers or of all the aforementioned layers.

[0074] Preferably, the ceramic coating 50 has a thickness of from 0.5 μm to 10 μm.

[0075] In an uncoated state, the artificial acetabular liner 20 may furthermore have, in particular, a wall thickness of from 2 mm to 3 mm.

[0076] By the ceramic coating 50, in vivo release of cobalt ions and/or chromium ions into surrounding patient tissue advantageously may be reduced or even entirely avoided. This in turn reduces the risk of postsurgical complications, particularly in the form of infections. As a result, the risk of a postsurgical reintervention may therefore be significantly reduced.

[0077] The artificial femoral liner 30 is likewise preferably at least in sections, in particular only in sections, or fully configured in the form of a spherical shell segment. Preferably, the artificial femoral liner 30 has an at least in sections convex outer or glide face 32 and an at least in sections concave inner or glide face 34, which are respectively bounded by a circumferential edge 36, 37 of the artificial femoral liner 30. In this case, the at least in sections concave inner or glide face 34 and the circumferential edge 36 form an at least in sections concavely configured reception region 38 for the artificial femoral head 40.

[0078] Preferably, the at least in sections concave inner or glide face 24 of the artificial acetabular liner 20 and the at least in sections convex outer or glide face 32 of the artificial femoral liner 30 form a ball-and-socket joint after implantation of the hip implant system 1.

[0079] The artificial femoral liner 30 consists of a plastic, preferably polyethylene, in particular ultrahigh molecular weight polyethylene, and optionally an antioxidant. The antioxidant may, for example, be vitamin E.

[0080] The artificial femoral head 40 is preferably configured spherically or partially spherically or (likewise) at least in sections in the form of a spherical shell segment. The artificial femoral head 40 comprises a reception region 48 for receiving an artificial femoral stem, in particular for receiving a preferably cylindrical or conical section of an artificial femoral stem. The reception region 48 is preferably configured as an indentation having a circular or non-circular cross section. For example, the indentation may have a rectangular cross section.

[0081] Preferably, the at least in sections concave inner or glide face 34 of the artificial femoral liner 30 and an at least in sections convex outer or glide face 42 of the artificial femoral head 40 form a so-called cotyloid joint. Such a cotyloid joint is distinguished in that the at least in sections convexly configured outer or glide face 42 of the artificial femoral head 40 is gripped beyond its equator 43 by the at least in sections concavely configured inner or glide face 34 of the artificial femoral liner 30, so that these components of the hip implant system 1 are prevented from falling out of one another.

[0082] FIG. 2 schematically shows an enlarged detail representation of a preferred ceramic coating 50 according to the invention in a region A on the at least in sections convex outer face 22 of the artificial acetabular liner 20 according to FIG. 1.

[0083] The ceramic coating 50 is configured as a multilayer layer system having the following layer sequence on the at least in sections convex outer face 22 of the artificial acetabular liner 20:

[0084] The at least in sections convex outer face 22 is covered directly by a first chromium nitride layer 15a. The first chromium nitride layer 15a is covered directly by a first chromium carbonitride layer 15b. The first chromium carbonitride layer 15b is covered directly by a second chromium nitride layer 15c. The second chromium nitride layer 15c is covered directly by a second chromium carbonitride layer 15d. The second chromium carbonitride layer 15d is covered directly by a third chromium nitride layer 15e. The third chromium nitride layer 15e is covered directly by a chromium zirconium nitride layer 15f. The chromium zirconium nitride layer 15f is covered directly by a zirconium nitride layer 15g, which at the same time constitutes the cover layer of the ceramic coating 50. Alternatively, the third chromium nitride layer 15e may be covered directly by a cover layer of zirconium nitride (not represented).

[0085] Alternatively, an intermediate layer, for example made of zirconium, a zirconium alloy or a ceramic containing zirconium, may be formed between the artificial acetabular liner and the ceramic coating 50 (not represented).

[0086] FIG. 3 shows an embodiment of a hip implant system 1 in a mounted or implanted state.

[0087] The hip implant system comprises an artificial acetabular cup 10, an artificial acetabular liner 20, an artificial femoral liner 30, an artificial femoral head 40 and an artificial femoral stem 60.

[0088] The artificial acetabular liner 20 is coated at least in sections, in particular only in sections, or fully with a ceramic coating 50. The artificial acetabular liner 20 may in particular have a cone angle θ of from 15° to 25°, in particular 16° to 21°. Advantageously, high clamping forces may therefore be produced between the artificial acetabular liner 20 and the artificial acetabular cup 10 in the joined state.

[0089] The artificial femoral stem 60 is inserted by means of a cylindrical or conical section 61 into the artificial femoral head 40.

[0090] In respect of further features and advantages of the hip implant system 1, in particular the artificial acetabular cup 10, the artificial acetabular liner 20, the artificial femoral liner 30, the artificial femoral head 40, the ceramic coating 50 and the artificial femoral stem 60, full reference is made to the descriptions relating to FIGS. 1 and 2. The features and advantages insofar as they are described there also apply correspondingly for the hip implant system 1 represented in FIG. 3.