Predicting ex vivo failure loads in human metatarsals using bone strength indices derived from volumetric quantitative computed tomography

BMD and geometric strength indices were strongly correlated to ultimate force measured by ex vivo 3-point bending. Geometric indices were more highly correlated to ultimate force than was BMD; bone thickness and density-weighted minimum section modulus had the highest individual correlations to ultimate force. Density-weighted geometric indices explained more variance than their binary analogs. Multiple regression analyses defined models that predicted 85-89% of variance in ultimate force in Met2 and Met3 using bone thickness and minimum section modulus in the mid-diaphysis. These results have implications for future in vivo imaging to non-invasively assess bone strength and metatarsal fracture risk.