ASYMMETRIC FORMATION OF PROSTHETIC COMPONENTS FOR THE MANIPULATION AND SUPPRESSION OF NATURAL FREQUENCIES
A hip joint prosthesis for implantation in the femur of a patient, wherein the shaft can be coupled with a ball head which in turn can be inserted rotatably in the hemispherical recess of a socket insert. To avoid squeaking the shaft is formed asymmetrically in its outer and/or inner geometry and/or material composition.
1 - 10 . (canceled)
11 . A shaft of a hip-joint prosthesis for implantation into the femur of a patient, wherein the shaft has a shaft axis and can be coupled with a ball head which in turn can be inserted in a rotatable manner in the hemispherical recess of a socket insert, wherein the shaft is formed asymmetrically for at least one of an outer geometry, an inner geometry or a material composition thereof.
12 . A shaft according to claim 11 , wherein the outer and inner geometry is configured asymmetrically in all three directions in space.
13 . A shaft according to claim 11 , wherein the shaft has recesses on its surface.
14 . A shaft according to claim 11 , wherein outer edges of cross-sectional areas are shaped asymmetrically.
15 . A shaft according to claim 11 , wherein the shaft is shaped discontinuously along the shaft axis.
16 . A shaft according to claim 11 , wherein the shaft has a through cross-bore.
17 . A shaft according to one of claims 1 to 6 , wherein the shaft has inner cavities of differing volume.
18 . A shaft according to claim 11 , wherein the shaft has longitudinal bores therein that can adjoin each other discontinuously.
19 . A shaft according to claim 11 having a connecting web, wherein bores of differing diameter are introduced in the connecting web.
20 . A shaft according to claim 11 , wherein at least one of rigidities, damping properties or material along the shaft axis are different.