Insert for acetabular cup

1. An insert for an acetabular cup comprising an insertion body having an external surface shaped to be able to be coupled with a mating seating of said acetabular cup,

the insert comprising;

at least a friction element which is positioned on said external surface and is able to determine a predefined friction with the surface of said seating, so that, during use, said friction element prevents the relative rotation of said insertion body and said acetabular cup, wherein said friction element is positioned fixed on said external surface,

first clamping means able to keep the friction element solid with the insertion body,

wherein said external surface comprises at least a part, shaped for mating with said seating, with which said friction element is associated, wherein the first clamping means comprises a radial edge disposed transverse to an annular wall of said friction element, and a corresponding annular seating, made on said part, able to cooperate with the radial edge.

2. The insert as in claim 1 , wherein said part is shaped like a truncated cone.

3. The insert as in claim 1 , wherein said friction element is shaped like a ring, with a size compatible with said part of said external surface.

4. The insert as in claim 1 , comprising second clamping means able to prevent the reciprocal rotation of said friction element and said insertion body.

5. The insert as in claim 1 , comprising second clamping means able to prevent the reciprocal rotation of said friction element and said insertion body, wherein said second clamping means comprises at least a hollow, made on said annular wall of said friction element, and at least a corresponding block protruding from said part and able to cooperate with the hollow.

6. The insert as in claim 1 , comprising second clamping means able to prevent the reciprocal rotation of said friction element and said insertion body, wherein said second clamping means comprises at least a block protruding from said annular wall of said friction element, and at least a corresponding hollow made on said part and able to cooperate with the block.

7. The insert as in claim 1 , wherein said insertion body is made of a polymer material.

8. The insert as in claim 1 , wherein said friction element is made of the same material of which at least said seating of said acetabular cup is made.

9. The insert as in claim 8 , wherein said friction element is made of metal material.

10. The insert as in claim 9 , wherein said metal material is titanium-based.

11. The insert as in claim 9 , wherein said metal material is cobalt-based.

12. The insert as in claim 1 , wherein said seating is shaped to allow the fixed positioning of said friction element.

13. A method to stabilize the relative position of an insert of claim 1 for an acetabular cup and said acetabular cup, wherein said acetabular cup is provided with a seating and wherein said insert has an insertion body with an external surface shaped to be able to be coupled with said seating,

the insert comprising:

at least a friction element which is positioned on said external surface and is able to determine a predefined friction with the surface of said seating, so that, during use, said friction element prevents the relative rotation of said insertion body and said acetabular cup, wherein said friction element is positioned fixed on said external surface,

first clamping means able to keep the friction element solid with the insertion body,

wherein said external surface comprises at least a part, shaped for mating with said seating, with which said friction element is associated, wherein the first clamping means comprises a radial edge disposed transverse to an annular wall of said friction element, and a corresponding annular seating, made on said part, able to cooperate with the radial edge

comprising the following steps:

a first step comprising positioning the friction element on said external surface, said friction element being able to determine a predefined friction with said seating, so that, during use, said friction element prevents the relative rotation of said insertion body and said acetabular cup; and

a second step comprising positioning said insertion body, bearing said friction element, in said seating of said acetabular cup.

14. The insert as in claim 1 , wherein said insertion body is made of polyethylene.