Acetabular cup

A method for replacing a hip joint, the method comprising:

• inserting an acetabular cup into a natural acetabulum, the acetabular cup comprising:
• a substantially hemispherical outer wall defining a first geometric center;
• and
• a substantially hemispherical socket defining a second geometric center displaced from the first geometric center;
• a cup rim extending between the substantially hemispherical outer wall and the substantially hemispherical socket, the cup rim defining a first relief;
• securing the acetabular cup into the natural acetabulum;
• and
• positioning a natural or prosthetic femoral head in the socket such that the natural or prosthetic femoral head is rotatable about the second geometric center to approximate natural hip motion, wherein inserting the acetabular cup into the natural acetabulum comprises positioning the first relief substantially posteriorly when inserted into the natural acetabulum.

A method for replacing a hip joint, the method comprising:

• inserting an acetabular cup into a natural acetabulum, the acetabular cup comprising:
• a substantially hemispherical outer wall defining a first geometric center;
• and
• a substantially hemispherical socket defining a second geometric center displaced from the first geometric center;
• a cup rim extending between the substantially hemispherical outer wall and the substantially hemispherical socket, the cup rim defining a first relief;
• securing the acetabular cup into the natural acetabulum;
• and
• positioning a natural or prosthetic femoral head in the socket such that the natural or prosthetic femoral head is rotatable about the second geometric center to approximate natural hip motion, wherein inserting the acetabular cup into the natural acetabulum comprises positioning the first relief substantially superiorly when inserted into the natural acetabulum.

A method for replacing a hip joint, the method comprising:

• inserting an acetabular cup into a natural acetabulum, the acetabular cup comprising:
• a substantially hemispherical outer wall defining a first geometric center;
• and
• a substantially hemispherical socket defining a second geometric center displaced from the first geometric center;
• a cup rim extending between the substantially hemispherical outer wall and the substantially hemispherical socket, the cup rim defining a first relief;
• securing the acetabular cup into the natural acetabulum;
• and
• positioning a natural or prosthetic femoral head in the socket such that the natural or prosthetic femoral head is rotatable about the second geometric center to approximate natural hip motion, wherein inserting the acetabular cup into the natural acetabulum comprises positioning the first relief substantially inferiorly when inserted into the natural acetabulum.

A method for replacing a hip joint, the method comprising:

• inserting an acetabular cup into a natural acetabulum, the acetabular cup comprising:
• a substantially hemispherical outer wall defining a first geometric center;
• a substantially hemispherical socket defining a second geometric center displaced from the first geometric center;
• a cup rim extending between the substantially hemispherical outer wall and the substantially hemispherical socket, the cup rim defining a first relief;
• securing the acetabular cup into the natural acetabulum;
• positioning a natural or prosthetic femoral head in the socket such that the natural or prosthetic femoral head is rotatable about the second geometric center to approximate natural hip motion;
• securing the acetabular cup into the natural acetabulum using a plurality of screws passing through a plurality of apertures sized and shaped to receive the plurality of screws;
• and
• wherein securing the acetabular cup into the natural acetabulum further comprises passing the plurality of screws through the plurality of apertures positioned on the first relief of the cup rim, wherein the apertures on the first relief are oriented non-parallel to an axis through the first geometric center of the outer wall perpendicular to a plane through the rim.

A method for replacing a hip joint comprising:

• inserting an acetabular cup into an acetabulum, the acetabular cup having a substantially hemispherical outer surface sized and shaped for implantation in the acetabulum, the substantially hemispherical outer surface having a first axis through a center of the outer surface perpendicular to a plane through a cup rim, the acetabular cup further comprising a socket having a part-spherical inner surface, the part spherical inner surface having an opening for receiving a natural or prosthetic femoral head, the socket having a second axis through a center of the part-spherical inner surface, the first and second axis being parallel, the second axis being offset from the first axis in a first direction, the acetabular cup rim surface extends outwardly in a second direction different than the first direction from a portion of a circumference of the opening of the socket inner surface towards the substantially hemispherical outer surface, the rim surface extending outwardly at a non 90° angle to the parallel first and second axis, a plurality of non-parallel apertures extending through both the rim surface and the substantially hemispherical outer surface, the socket and the rim surface located entirely within the substantially hemispherical outer surface;
• securing the acetabular cup into the natural acetabulum;
• and
• positioning a natural or prosthetic femoral head in the socket such that the natural or prosthetic femoral head is rotatable about the second geometric center to approximate natural hip motion.