PAIRWISE STRENGTH RELATIONSHIPS OF CORTICAL AND CANCELLOUS BONE IN HUMAN FEMUR - AN AUTOPSY STUDY

To analyze the mechanical properties of cortical and cancellous bone i n the femur and relate them to bone mineral, we retrieved 14 pairs of femurs from elderly subjects at autopsy. Bone mineral was measured by quantitative single-energy computed tomography. Significant associatio ns were found between two types of cortical bone mechanical tests, thr ee-point bending and pullout of screw, one performed on the right and the other on the left femur. Similarly, pairwise associations were fou nd between the mechanical tests of cancellous bone, punch and cube com pression, one performed on the right and the other on the left femur. Also, all mechanical tests correlated with bone mineral as determined by quantitative single-energy computed tomography. In general, bone ma ss measures correlated better with bone strength than did bone density measures. However, the cortical and cancellous bone mechanical proper ties were not interrelated, which suggests a separate regulation of th e strength of these two types of bone. Bone mineral may not only have importance for the occurrence of fractures; it should be considered as an important factor in the fixation of fragile bone.