ARTIFICIAL CEMENTLESS HIP PROSTHESIS STEM

摘要

It is intended to eliminate not only the shear stress concentration occurring at the distal end of a stem but also the shear stress concentration at the proximal end thereof so that a load applied on the hip prosthesis is focused in the proximal part for transmitting the same to the normal site and narrowing the variation width of the stress distribution. An artificial cementless hip prosthesis stem which comprises an inner construct (7) receiving a load applied to the hip prosthesis and an outer construct (8) transmitting the load from the inner construct to the femur (1). The former construct has an inner body (7B) transferring the load to a neck part (7A). The latter construct has a bell mouth-shaped outer body (8A) surrounding the inner body (7B) and opening toward the bone edge and a leg part (8B) extending toward the bone marrow cavity. The torsional rigidity given to the distal end and the proximal end of the outer body (8A) and the leg part (8B) is regulated lower than the torsional rigidity given to the intermediate position (18) in the outer body (8A).