Population-based, three-dimensional analysis of age- and sex-related femur shaft geometry differences

This study analyzed age- and sex-related differences in femur shaft geometry, focusing on bowing and width. Using three-dimensional skeletonization of computed tomography (CT) images from 1400 participants, the researchers found that femoral bowing and femur width increased with age, particularly in women. The medullary canal widened significantly in women after 50 years but not in men. CT images were processed using AVIEW Modeler software to create 3D models of the femur, facilitating a detailed comparison of geometric parameters by age and sex. Results showed that men had longer femurs and larger outer diameters, while women had smaller radii of curvature (ROC). ROC decreased by 19.4% in men and 23.6% in women from ages 20 to 89, and femur width increased by 11.4% in men and 24.5% in women over their lifetimes. These findings highlight significant age- and sex-related changes in femur geometry, with implications for understanding fragility fractures.