Artificial joint cup

Abstract

An artificial joint cup, in particular a hip joint cup, for implanting in a cavity in a bone. The joint cup is, in particular, substantially in the form of a spherical dome cup, having a convex outer surface and a concave inner surface. In addition, the joint cup comprises an outer diameter and an inner diameter. The ratio of the difference between the outer diameter and the inner diameter, in relation to the outer diameter, is in a range of between 0.5 and 0.07, preferably between 0.3 and 0.075, particularly preferably between 0.2 and 0.1. The joint cup is manufactured from a ceramic material, and the convex outer surface has a micro-structuring.

Claims

1. An artificial joint cup for implanting in a cavity in a bone having a convex outer surface and a concave inner surface, having an outer diameter and an inner diameter, wherein a ratio of a difference between the outer diameter and the inner diameter, in relation to the outer diameter, lies in a range of between 0.2 and 0.1, the joint cup is made of a ceramic material selected from the group consisting of titanium carbide ceramic, titanium oxycarbide ceramic, titanium nitride ceramic, titanium carbonitride ceramic, titanium aluminum nitride ceramic, titanium aluminum carbonitride ceramic, titanium zirconium nitride ceramic and silicon nitride ceramic, and the convex outer surface of the ceramic material has a macro-structuring comprising: a multiplicity of structure elements being delimited by depressions measuring form 0.3 mm to 3 mm, or a pore structure with a multiplicity of cavities that measure from 0.03 mm to 3 mm.

2. The joint cup as claimed in claim 1, wherein the concave inner surface forms a bearing surface for a joint ball that is to be received in the joint cup.

3. The joint cup as claimed in claim 1, wherein the concave inner surface forms a holding surface for an inner cup that is to be received in the joint cup.

4. The joint cup as claimed in claim 1, wherein the macro-structuring is suitable for inward growth of a trabecular structure of a bone.

5. The joint cup as claimed in claim 1, wherein depressions which separate structure elements in one row from each other, are arranged offset relative to each other in relation to depressions which separate structure elements in an adjacent row from each other.

6. The joint cup as claimed in claim 1, wherein the structure elements are shaped as cubes, pyramids, tetrahedrons, wedges or polyhedrons.

7. The joint cup as claimed in claim 1, wherein the ceramic material, from which the joint cup is manufactured, has osteoconductive properties.

8. The joint cup as claimed in claim 1, wherein the convex outer surface has an osteoconductive coating.

9. The joint cup as claimed in claim 8, wherein the osteoconductive coating is additionally osteointegrative.

10. The joint cup as claimed in claim 8, wherein the osteoconductive consists of an osteoconductive metal.

11. The joint cup as claimed in claim 10, wherein the osteoconductive coating consists of platinum or of an element of a second or third transition group.

12. The joint cup as claimed in claim 8, wherein the osteoconductive coating consists of hydroxyapatite or of an osteoconductive sintered oxide ceramic.

13. The joint cup as claimed in claim 8, wherein the ceramic material from which the joint cup is manufactured consists of a sintered oxide ceramic.

14. The joint cup as claimed in claim 1, wherein the osteoconductive coating has a micro-structuring comprising a pore structure with a multiplicity of cavities that measure from 0.003 mm to 0.3 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a plan view of a joint cup according to the invention;

(2) FIG. 2 shows a section through a joint cup according to FIG. 1;

(3) FIG. 3 shows a section through an alternative illustrative embodiment of a joint cup according to the invention;

(4) FIG. 4 shows a plan view of a joint cup according to the invention with spiral-shaped grooves;

(5) FIG. 5 shows a side view of a joint cup according to FIG. 4;

(6) FIG. 6 shows a perspective view of a further embodiment of a joint cup according to the invention;

(7) FIG. 7 shows a detailed view of the surface profile of a joint cup according to FIG. 6;

(8) FIG. 8 shows a plan view of a further embodiment of a joint cup according to the invention with spiral-shaped grooves running in opposite directions;

(9) FIG. 9 shows a side view of a joint cup according to FIG. 8;

(10) FIG. 10 shows a sectional image through a joint cup according to the invention with coating;

(11) FIG. 11 shows a sectional drawing through an alternative embodiment of a joint cup according to the invention with coating;

(12) FIG. 12 shows an enlarged detail of part of a sectional drawing through a joint cup according to FIG. 11;

(13) FIG. 13A diagrammatically shows a structure element in the shape of a cube;

(14) FIG. 13B diagrammatically shows a structure element in the shape of a pyramid;

(15) FIG. 13C diagrammatically shows a structure element in the shape of a polyhedron;

(16) FIG. 13D diagrammatically shows a structure element in the shape of a wedge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(17) FIG. 1 shows a plan view of a one-part joint socket 1 with a joint cup according to the invention. Here, the concave bearing surface 4 at the same time also forms the bearing surface 6 for a joint ball that is to be inserted into the joint socket 1.

(18) FIG. 2 shows a section through a one-part joint socket 1 with a joint cup 2 according to the invention as per FIG. 1. This joint cup is in the form of a spherical dome cup with a convex outer surface 3 and a concave bearing surface 4. The joint cup has an outer diameter (OD) and an inner diameter (ID).

(19) FIG. 3 shows a section through a multi-part joint socket 1 with a joint cup 2 according to the invention into which an inner cup 5 is inserted. This inner cup 5 is rigidly connected to the concave inner surface 4 of the joint cup 2 and forms a bearing surface 11 for a joint ball that is to be inserted into the joint socket 1.

(20) FIGS. 4 and 5 show a plan view and a side view of an illustrative embodiment of a joint cup 2 according to the invention. Here, the macro-structuring on the convex outer surface of the cup comprises a multiplicity of structure elements 7 which are delimited by depressions 8, in this case by spiral-shaped grooves.

(21) FIG. 6 shows a perspective view of an alternative embodiment of a joint socket 2 according to the invention. The surface profile of said joint socket 2 is shown enlarged in FIG. 7. It will be seen that the depressions 9, which separate the structure elements 7 in one row from each other, are arranged offset relative to each other in relation to depressions 10 which separate structure elements 7 in an adjacent row from each other.

(22) FIGS. 8 and 9 show a plan view and a side view of a further alternative embodiment of a joint socket 2 according to the invention. The depressions 11, which delimit the structure elements 7, are here formed by intersecting grooves with a mutually opposite pitch.

(23) FIG. 10 shows a part of a section through a joint socket 2 according to the invention with a smooth convex outer surface 3. The joint cup 2 depicted has the shape of a spherical dome cup. The convex outer surface 3 has an osteoconductive coating 12. By contrast, the concave bearing surface 4 is uncoated.

(24) FIG. 11 shows a part of a section through a further alternative illustrative embodiment of a joint cup 2 according to the invention. In this case, the joint cup has a macro-structured outer surface 3. This outer surface 3 is provided with an osteoconductive coating 12. By contrast, the concave inner surface 4 on the inside of the spherical dome cup is also uncoated here.

(25) FIG. 12 shows an enlarged detail of part of a section through a joint cup 2 according to the invention as per FIG. 11. It will be seen that an osteoconductive coating 12, which in turn has pores 13, is located on the structure elements 7 of the macro-structuring. By way of these pores, the surface can form a direct functional and structural union with the bone tissue.

(26) FIGS. 13A, 13B, 13C and 13D diagrammatically shown a structure element shaped as a cube, a pyramid, a polyhedron and wedge, respectively.