Localized damage in vertebral bone is most detrimental in regions of high strain energy density

It was hypothesized that damage to bone tissue would be mast detrimental to the structural integrity of the vertebral body if it occurred in regions w ith high strain energy density, and nor necessarily in regions of high or l ow trabecular bone apparent density, or in a particular anatomic location. The reduction in stiffness dice to localized damage was computed in 16 fini te element models of 10-mm-thick human vertebral sections. Statistical anal yses were performed to determine which characteristic at the damage locatio n strain energy density, apparent density, or anatomic location - best pred icted the corresponding stiffness reduction. There was a strong positive co rrelation between regional strain energy density and structural stiffness r eduction in all 16 vertebral sections for damage in the trabecular centrum (p < 0.05, r(2) = 0.43-0.93). By contrast, regional apparent density showed a significant negative correlation to stiffness reduction in only four of the sixteen bones (p < 0.05, r(2) = 0.47-0.58). While damage in different a natomic locations did lead to different reductions irt stiffness (p < 0.000 1, ANOVA), no single location was consistently the most critical location f or damage. Thus, knowledge of the characteristics of bone that determine st rain energy density distributions can provide an understanding of how damag e reduces whole bone mechanical properties. A patient-specific finite eleme nt model displaying a map of strain allergy density can help optimize surgi cal planning and reinforcement of bone in individuals with high fracture ri sk.