Patent ID: 6139582
Filing Date: 2000-10-31
Classification: A61F

Abstract:
An acetabular cup for implantation in an acetabulum of a patient, comprising;a shell component having a generally convex outer surface;a first plurality of rigid, spaced steps formed on a first portion of the outer surface of the shell component having crests extending in a first direction, the first plurality of steps being effective to engage bone for affixing the acetabular cup in the patient's acetabulum, the first plurality of steps extending from points on or near an equator of the convex outer surface of the shell component to points on or near the equator, at least one step in the first plurality of steps intersecting a plane that is generally parallel to the equator and equidistant to the equator and a pole of the shell component;a second plurality of rigid, spaced steps formed on a second portion of the outer surface of the shell component having crests extending in a second direction different from the first direction, the second plurality of steps being effective to engage bone for affixing the acetabular cup in the patient's acetabulum, the second plurality of steps extending from or near the equator of the convex outer surface of the shell component,said first and second sets of spaced steps being angled to normalize interface shear load caused by major joint loads during daily activity and resist superior and medial migration of the shell.