The Relationship between Femoral Morphotype and Femoral Component Design

Abstract

The shape of the femoral canal is variable, much more so than most contemporary designs of femoral components would suggest or can accommodate. In the face of this variability, line-to-line or surface-to-surface contact is not expected between the cementless implant and much of the endosteal surface. It is also apparent that changes in implant design are still needed if the normal biomechanics of the hip joint are to be restored in each patient and if component fixation is to be optimized. Most cementless components aim to achieve proximal load transfer to the femoral canal. However, increasing clinical evidence suggests that distal filling of the femur is also necessary to minimize the incidence of postoperative symptoms, particularly in revision procedures. If this is indeed the case, more accommodating designs of femoral components are needed that will permit proximal and distal fitting at the femoral canal so that stable fixation may be achieved regardless of variations in bone geometry.