Patent ID: 7044974

Claim:
A hip prosthesis comprising: an acetabular liner including a hemispherical convex back and a face opposite the hemispherical convex back, the hemispherical convex back defining a polar region, a concave bearing surface extending into the liner through the face toward the polar region, a screw thread spiraling around a portion of the hemispherical convex back, the screw thread having a thread crest and a thread root, the thread crest following a spherical profile as it spirals around the hemispherical convex back toward the polar region; and an acetabular shell including a hemispherical cavity for receiving the convex back the hemispherical cavity having a polar region, a screw thread spiraling around a portion of the cavity, the screw thread having a thread root following a spherical profile as it spirals around the cavity toward the polar region, the thread root being engageable with the thread crest of the liner screw thread.