Can the Weight-Bearing Capacity of the Femoral Neck be Estimated by Physical Measurements on the Greater Trochanter?

Early detection of mechanical weakening of the femoral neck would help to prevent fractures at this site which are the most serious clinical problem in osteoporosis. In the vicinity of the femoral neck, the greater trochanter is a superficial bone structure more easily accessible to in vivo measurements. The purpose of the present study was to evaluate the relation between the strength of the femoral neck and the composition of the trabecular tissue in the greater trochanter. Twenty-nine fresh human intact femora were examined. The relationship between the average shear stress in failure of the femoral neck (ASS) and the Ca concentration (CC), mineral density (BMD), and overall mass density (BD) of the greater trochanter was investigated. Linear stepwise regression analysis showed that the ASS of the femoral neck can be predicted from the BD, CC, and BMD of the trochanteric tissue, and their contribution to the estimation of the ASS was ranked in the above order. The linear function relating the ASS to these variables showed a highly significant multiple correlation ( R = 0.87, p < 0.001). Therefore in vivo measurements of the density and mineral content in the greater trochanter should be considered useful in assessing the risk of fracture of the femoral neck.