Hip joint femoral component endoprosthesis with a lateral load-transferring support surface
AssigneeNew York University
InventorJoseph F. Fetto
Life of this patent
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Abstract
A femoral component of a hip endoprosthesis includes a lateral supporting wedge designed to be supported by the proximal lateral femur when in use. The wedge can be an integral part of the material of the femoral component or it can be placed on a standard component by cementing or preferably by a male/female socket fit. The lateral surface of the wedge forms an angle of about 10.degree.-20.degree. with the midline of the distal portion of the stem and has an anterior-posterior width of about 8-30 mm, preferably about 10-20 mm, and a medial-lateral extension of the lateral surface of the stem of at least 10 mm, preferably 10-30 mm.
Claims27
A femoral component of a hip endoprosthesis for implantation into the upper end of the medullary canal of a femur, said prosthesis comprising:
- a stem having a distal end, shaped and dimensioned for introduction into a medullary cavity of a femur, and a proximal end, said stem having a medial side on the side thereof intended to be adjacent to the medial side of the femur when in use and a lateral side on the side thereof intended to be adjacent to the lateral side of the femur when in use;
- a neck connected to and extending away from the proximal end of said stem, said neck being adapted to be connected to a head means for functioning as a femur head when in use;
- and
- a lateral support wedge integrally formed with or fixedly connected to said stem near the proximal end thereof, and being sized and shaped to extend the lateral side of said stem so as to form a lateral support surface which contacts the proximal lateral femoral cortex of the intertrochanteric region of the femur when in use, said lateral support surface forming an angle of 5.degree.-20.degree. with the midline of the distal portion of said stem and having a sufficient width to permit transfer of the force applied to the head means, when in use, onto the femur such that such contact will not damage the femur, said femoral component having no structure specifically designed to transfer load to the medial and central portions of the anterior and posterior intertrochanteric region of the femur when in use.
A femoral component of a hip endoprosthesis for implantation into the upper end of the medullary canal of a femur, said prosthesis comprising:
- a stem having a distal end, shaped and dimensioned for introduction into a medullary cavity of a femur, and a proximal end, said stem having a medial side on the side thereof intended to be adjacent to the medial side of the femur when in use and a lateral side on the side thereof intended to be adjacent to the lateral side of the femur when in use;
- a neck connected to and extending away from the proximal end of said stem, said neck being adapted to be connected to a head means for functioning as a femur head when in use;
- and
- a separate discrete lateral support wedge fixedly connected to said stem near the proximal end of said stem so as to extend the lateral side of said stem, when in use, so as to form a lateral support surface which contacts the proximal lateral femoral cortex in the intertrochanteric region of the femur, said lateral support surface having a sufficient width to permit transfer of the force applied to the head means, when in use, onto the femur such that such contact will not damage the femur.
A lateral support wedge connectable to the proximal end of the stem of a femoral component of a hip endoprosthesis implantable into the upper end of the medullary canal of a femur, said wedge being shaped so as to extend the lateral side of the stem of the femoral component, when in use, so as to form a lateral support surface which contacts the proximal lateral femoral cortex of the intertrochanteric region of the femur, said lateral support surface forming an angle of 5.degree.-20.degree. with the midline of the distal portion of the stem when connected thereto and having a sufficient width to permit redistribution of the force applied to the femoral component, when in use, onto the femur such that such contact will not damage the femur, said wedge having no structure specifically designed to transfer load to the medial and central portions of the anterior and posterior intertrochanteric region of the femur when in use.
Dependencies are inferred from the claim text.