Patent ID: 7572295

Claim:
An acetabular implant for use in a hip joint prosthesis, the implant comprising: a body portion comprising a polycarbonate polyurethane having a durometer hardness of approximately 80 Shore A, the body portion comprising: a substantially semispherical inner articulating surface defining a socket sized to receive a head portion of a femoral component of the hip joint prosthesis; and an outer engagement surface having an annular protrusion extending outwardly from the outer engagement surface, the annular protrusion being resiliently deformable for snap-fit engagement with a corresponding recess, wherein the annular protrusion includes an upper surface portion that interfaces with the outer engagement surface at a first angle and a lower surface portion that interfaces with the outer engagement surface at a second angle, the second angle being less than the first angle; and a deformation control element comprising a polymer having a durometer hardness of approximately 70 Shore D and positioned entirely within the body portion between the inner articulating surface and the outer engagement surface, wherein the deformation control element comprises a generally semispherical shape with a plurality of cutouts therein, wherein the plurality of cutouts are shaped to define a plurality of flaps, the flaps having an increased thickness adjacent the boundary extending between the inner articulating surface and the outer engagement surface, and wherein the deformation control element limits outward deformation of the body portion and allows inward deformation of the body portion; wherein the annular protrusion of the outer engagement surface defines a maximum diameter of the implant that is less than a maximum diameter of the implant at a boundary of the implant extending between the inner articulating surface and the outer engagement surface.