HOEFTLEDPROTES.

摘要

A total hip joint prosthesis has a ball, replacing the ball of the hip joint ball and socket, affixed to the femur by a stem. Stem stress is reduced by providing a rounded cross-section of the stem truncated along the lateral side in the critical section subject to greatest cyclic loading. The stem is of controlled low flexibility so that when the bone cement and stem composite structure is in place, the bone is subject to a maximum percent of normal stress from bending moments. By virtue of the truncated shape and its size relative to the bone cavity, stress in the stem is minimized when the stem alone carries the load.