Patent ID: 7771485

Claim:
A ball joint or cap for an artificial hip joint that is suitable for carrying out a rotating or pivoting motion in an artificial hip joint socket having a surface, wherein the surface comprises three areas: a polar area that is smooth and without depressions; an intermediate area between the smooth polar area and approximately an equator of the ball joint or cap, the intermediate area comprising recessed depressions, each depression having a hole width between 1.0 mm to 3.0 mm, and a base edge area that is adjacent to the intermediate area in the direction of a base edge of the ball joint or cap, the base edge area having recessed depressions, the depressions having hole widths that become increasingly smaller the closer the depression is to the base edge, wherein the hole widths are between 0.5 mm and 1.0 mm; wherein the recessed depressions are regularly placed on the surface and do not have interconnecting channels between them.