Characterization of Fracture Resistance and Robustness in Network-Based Models of Bone*

Trabecular bone is a soft, lightweight bone organized as a web of struts and rods (trabeculae) found inside load-bearing bones (i.e. femur, spine). With the onset of bone diseases like osteoporosis, trabeculae erode, leading to increased fracture risk. Studies show that osteoporosis’ diagnostic marker, bone mineral density (BMD), does not correlate well with fracture resistance. Structural properties of trabecular bone are needed to fully determine fracture risk. We are developing a network-based model of trabecular bone to create network graphs from human bone images, with weighted links representing trabeculae and nodes representing branch points. These graphs allow for the use of network metrics to characterize trabecular structure. By converting the links to beams, we also create finite element beam models to study the mechanical properties of trabecular bone. By finding correlations between bone’s structural and mechanical properties, we will identify mesoscale markers for bone strength that complement BMD and help to distinguish between healthy and osteoporotic bone.