The proximal femur--a second look at rational of implant design

Twenty five pairs (50 bones) of cadaveric femora were studied morphologically and radio logically using standardized techniques to obtain anthropometric data to evaluate the applicability of internationally designed implant and to generate a database for proximal femur to help in design for future implant if these were found unsuitable.

femoral head diameter, femoral neck diameter, diameter of proximal femur, canal width at above and below lesser trochanter and 7.5 cm below lower margin of lesser trochanter, endosteal and extracortical width, isthmus position from lesser trochanter, femoral neck anteversion, neck shaft angle and intramedullary axis of femur. The mean +/- SD of these values were calculated. These values were compared with those reported in the literature for Hong Kong Chinese, Caucasians and were found to be different. The implant designed for western population should be used judiciously and facture implant designed should be specific for (ours) bones. We found the pyriformis fossa is usually not in line with the intramedullary axis. Thus antegrade itramedullary nailing portal should be anterior and lateral to pyriformis fossa.