Hip prosthesis

An acetabular implant comprising an elongated anchor having a first end disposed within and mechanically substantially immovably fixed to a portion of a pelvic bone of a patient and a free end extending in a generally downward direction into an acetabular cavity defined by the pelvis, the anchor being substantially aligned with the pectineal line of the pelvis;

• an acetabular cup disposed within the cavity and having a fixation hole spaced from an edge of the cup and aligned with the anchor, the free end of the anchor extending into the hole;
• a screw member disposed within the fixation hole, threadably engaging the anchor and demountably fixing the cup to the anchor, the cup having an exterior shape selected so that it generates a press-fit with the acetabular cavity, a portion of an exterior surface of the cup surrounding the hole extending over less than the entire exterior surface so that the portion is at least partially spaced from the cup edge, the portion being porous to facilitate bone ingrowth into such portion;
• a remainder of the exterior cup surface being spaced from the hole and substantially smooth to inhibit bone ingrowth;
• and a liner constructed of a material having a relatively low coefficient of friction disposed within the cup and defining a generally semi-spherically shaped acetabular socket engaging a ball member connected with the patient's femur.

A femoral implant adapted to be mechanically fixed to a femur with a pressfit between the implant and the femur comprising an intertrochanteric body adapted to be forced into an upwardly open intertrochanteric cavity previously formed proximate an upper end of the femur to correspond in shape to the shape of the body so as to establish intimate, pressfit contact between the body and the cavity, the body defining generally opposite and spaced apart anterior and posterior sides and generally opposite, spaced apart lateral and medial sides, a spacing between the lateral and medial sides decreasing in a generally downward direction, the body further defining an interior load transferring surface which is contiguous with at least one side, disposed generally below said one side and angularly inclined relative to said one side so as to face generally downwardly and being adapted to intimately contact a correspondingly formed surface of the femur for the transmission of compressive forces between the body and the femur via the load transferring surface, at least the interior loading surface including a porous area for promoting bone ingrowth when in contact with living bone;

• a neck protruding from the body and oriented to extend in a generally upward and medial direction;
• and a ball attached to the neck and formed to be movably disposed within a generally semi-spherical acetabular socket.

A femoral hip implant comprising an elongated stem disposed in a medullary cavity of a femur, the stem having a substantially smooth surface to inhibit bone ingrowth and extending upwardly towards an intertrochanteric cavity defined by walls of the femur and previously formed at an upper end of the femur;

• an intertrochanteric body integrally constructed with and disposed generally above the stem, tightly engaging walls defining the intertrochanteric cavity to thereby mechanically fix the body to the femur and having an anterior side and an opposite, spaced apart posterior side, a lateral side and an opposing, spaced apart medial side, the body further defining first and second spaced apart interior load transferring surfaces contiguous with the stem, the anterior side and the posterior side, respectively, and being angularly inclined relative to anterior and posterior sides, each interior load transferring surface facing generally downwardly and sloping generally downwardly in the medial direction at an angle of about 70.degree. relative to longitudinal axis of the stem, at least the load transferring surface of the body being porous and in intimate contact with bone tissue to promote bone ingrowth into the porous sides and the surfaces;
• a neck extending upwardly from the body in a generally medial direction;
• and a ball immovably attached to the neck and movably disposed within a generally spherical acetabular socket on the patient's pelvis.

A prosthetic hip for a patient comprising an acetabular cavity including a generally semispherical acetabular cup including a fixation hole spaced from an edge of the cup and positioned so that the hole can be substantially aligned with the pectineal line of the patient when the cup is implanted in the cavity, a portion of an exterior surface of the cup being porous to promote bone ingrowth upon implantation of the cup, the portion of the exterior cup surface extending over at least a part of the hole, a remainder of the exterior surface of the cup which is spaced from the hole being substantially smooth, and an elongated anchor insertable through the hole into the pelvis for mechanically fixing the cup to the pelvis, the anchor including means for engaging the cup and applying a force to the cup in the direction of the anchor to thereby firmly seat the cup in the cavity, and a femoral implant for implantation in a femur including an intertrochanteric body adapted to be forced into an upwardly open intertrochanteric cavity previously formed proximate an upper end of the femur to correspond in shape and size to the body so as to tightly engage the body and thereby mechanically fix the body to the femur, the body defining generally opposite and spaced apart anterior and posterior sides and generally opposite, spaced apart lateral and medial sides, a spacing between the lateral and medial sides decreasing in a generally downward direction, the body further defining an interior load transferring surface which is contiguous with at least one side, angularly inclined relative to said at least one side and generally downwardly facing for the transmission of compressive forces between the interior load transferring surface and a correspondingly shaped and positioned surface of the femur, the sides and the interior loading surface including porous areas for promoting bone ingrowth when in contact with living bone;

• a neck protruding from the body and oriented to extend in a generally upward and medial direction;
• and a ball attached to the neck and formed to be movably disposed within and cooperate with the acetabular implant.

A procedure for the implantation of a femoral hip joint component comprising the steps of:

• (a) resecting the head and neck of a femur to expose the interior thereof;
• (b) shaping an intertrochanteric, upwardly open cavity in the femur which has substantially parallel, spaced apart anterior and interior sides, a lateral side and a spaced apart medial side and load transmitting, generally upwardly facing interior load transferring ledges at a lower end of the anterior and posterior sides which are angularly inclined relative thereto;
• (c) providing a femoral implant which includes an intertrochanteric body having anterior and posterior sides, a lateral side and a medial side, and interior load transferring surfaces for the transmission of compressive forces to the ledges which face generally downwardly and are contiguous with a lower end of the anterior and posterior sides, the sides and the interior load transferring surfaces being shaped complementary to the corresponding sides and the ledges of the cavity and dimensioned to tightly engage the intertrochanteric cavity, the femoral implant further including a downwardly extending, elongated stem;
• (d) inserting the femoral implant into the femur by extending the stem into the medullary cavity and pressing the intertrochanteric body into the intertrochanteric cavity to tightly seat the former in the latter whereby a compressive force applied to the femur and the implant is transmitted via the interengaged ledges and surfaces;
• (e) promoting the ingrowth of bone at an area where the body contacts the bone tissue;
• (f) inhibiting the ingrowth of bone over substantially full length of the stem;
• and
• (g) providing a ball on the femoral implant for placement into an acetabular socket.