Hip-joint prosthesis
First Claim
1. A prosthesis comprising a ball head shaped to fit in an acetabulum, an elongated shaft shaped to fit in and between the two opposite sides of a medullary cavity of a femur, and a stem between and connecting said head to one end of said shaft, said shaft being curved in a plane and having a concave longitudinal edge and a convex longitudinal edge and said stem being inclined in said plane to the longitudinal axis of said shaft, said prosthesis being formed with:
- a laterally projecting shoulder engageable against a sawed-off end of a femur in whose medullary cavity said shaft is to be engaged;
an inner engagement surface on said concave edge adjacent said shoulder and engageable with one of said sides of a medullary cavity of said femur;
an outer engagement surface on said concave edge at the other end of said shaft and engageable with said one side of a medullary cavity of said femur;
an intermediate engagement surface on said convex edge between said inner and outer engagement surfaces and generally parallel to said outer engagement surface, said intermediate engagement surface being engageable with the other side of a medullary cavity of said femur; and
a connecting surface to each longitudinal side of and inclined to each of said engagement surfaces and adapted to lie out of contact with the sides of said medullary cavity.
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Accused Products
Abstract
A hip-joint prosthesis has a ball head shaped to fit in an acetabulum, an elongated shaft adapted to fit in and between two opposite sides of a medullary cavity of a femur, and a stem between and connecting the head to one end of the shaft. This shaft is curved in a plane and has a concave longitudinal edge and a convex longitudinal edge. A laterally projecting shoulder between the stem and the shank is engageable against a sawed-off end of a femur in whose medullary cavity the shaft is engaged. The shaft is formed on its concave edge at its two ends with inner and outer engagement surfaces of planar shape. Between these engagement surfaces on the convex side there is formed an intermediate engagement surface. When mounted in a femur the inner and outer engagement surfaces engage against one side of the medullary cavity and the intermediate engagement surface against the other for firm mounting of the shaft in the femur. Connecting surfaces incline relative to these engagement surfaces form the rest of the longitudinal edges of the shank and normally remain out of contact with the bone on which the prosthesis is mounted.
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Citations
14 Claims
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1. A prosthesis comprising a ball head shaped to fit in an acetabulum, an elongated shaft shaped to fit in and between the two opposite sides of a medullary cavity of a femur, and a stem between and connecting said head to one end of said shaft, said shaft being curved in a plane and having a concave longitudinal edge and a convex longitudinal edge and said stem being inclined in said plane to the longitudinal axis of said shaft, said prosthesis being formed with:
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a laterally projecting shoulder engageable against a sawed-off end of a femur in whose medullary cavity said shaft is to be engaged; an inner engagement surface on said concave edge adjacent said shoulder and engageable with one of said sides of a medullary cavity of said femur; an outer engagement surface on said concave edge at the other end of said shaft and engageable with said one side of a medullary cavity of said femur; an intermediate engagement surface on said convex edge between said inner and outer engagement surfaces and generally parallel to said outer engagement surface, said intermediate engagement surface being engageable with the other side of a medullary cavity of said femur; and a connecting surface to each longitudinal side of and inclined to each of said engagement surfaces and adapted to lie out of contact with the sides of said medullary cavity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification