Abstract: A cementless femoral hip stem component. The hip stem component includes an elongate stem, a proximal body, and a collar disposed on the proximal body and extending outward therefrom in a sideways direction to form a ledge. The proximal body defines at least a majority of a frustoconical shape. The ledge formed by the collar includes a tapered undersurface, beneath which extends the proximal body. The tapered undersurface of the ledge and the proximal body extend in different directions and thereby cooperatively define a double-flared contact surface configured to enable subsidable engagement of said double-flared contact surface with the femur at two different rates of subsidence within the femur. An abrupt, male corner is formed by the stem and the proximal body and is sufficiently abrupt to provide enhanced bone ingrowth stimulation.

Abstract: A cementless femoral hip stem component. The hip stem component includes an elongate stem, a proximal body, and a collar disposed on the proximal body and extending outward therefrom in a sideways direction to form a ledge. The proximal body defines at least a majority of a frustoconical shape. The ledge formed by the collar includes a tapered undersurface, beneath which extends the proximal body. The tapered undersurface of the ledge and the proximal body extend in different directions and thereby cooperatively define a double-flared contact surface configured to enable subsidable engagement of said double-flared contact surface with the femur at two different rates of subsidence within the femur. An abrupt, male corner is formed by the stem and the proximal body and is sufficiently abrupt to provide enhanced bone ingrowth stimulation.

Abstract: A cementless femoral hip stem component. The hip stem component includes an elongate stem, a proximal body, and a collar disposed on the proximal body and extending outward therefrom in a sideways direction to form a ledge. The proximal body defines at least a majority of a frustoconical shape. The ledge formed by the collar includes a tapered undersurface, beneath which extends the proximal body. The tapered undersurface of the ledge and the proximal body extend in different directions and thereby cooperatively define a double-flared contact surface configured to enable subsidable engagement of said double-flared contact surface with the femur at two different rates of subsidence within the femur. An abrupt, male corner is formed by the stem and the proximal body and is sufficiently abrupt to provide enhanced bone ingrowth stimulation.

Abstract: A cementless femoral hip stem component includes an elongate stem having opposing distal and proximal sections. The proximal section includes a conical stem surface which terminates in a proximal end. A collar having a conical undersurface extends laterally outward from the proximal end of the stem. The proximal conical stem portion and the conical undersurface of the collar cooperatively define a unitary double-cone contact surface to allow the collar to subsidably engage with external cortical bone in tandem with the proximal conical stem subsidably engaging with the internal femoral canal.

Abstract: A modular hip stem prosthesis including a separate and interchangeable stem piece and proximal shoulder piece. Coronal and sagittal slots are formed in a rounded distal end of the stem in a substantially right-angle orientation. A neck member extends angularly outward from the shoulder piece and is configured to receive a spherical hip ball for insertion into the hip socket. The proximal shoulder piece includes a cylindrical projection for insertion into an axial bore formed in an upper end of the stem. An annular lip is formed in side walls defining the axial bore, and a distal end of the cylindrical projection abuts the lip when it is inserted into the bore. Radial teeth are formed on a distal end of the cylindrical projection and mate with compatible teeth formed on the annular lip to thereby render the shoulder piece removably mountable onto the stem. A locking screw securely joins the shoulder piece with the stem.