Effect of intraspecimen spatial variation in tissue mineral density on the apparent stiffness of trabecular bone.

This study investigated the effects of intraspecimen variations in tissue mineral density (TMD) on the apparent-level stiffness of human trabecular bone. High-resolution finite element (FE) models were created for each of 12 human trabecular bone specimens, using both microcomputed tomography (mu CT) and "gold-standard" synchrotron radiation mu CT (SR mu CT) data. Our results confirm that incorporating TMD spatial variation reduces the calculated apparent stiffness compared to homogeneous TMD models. This effect exists for both mu CT- and SR mu CT-based FE models, but is exaggerated in mu CT-based models. This study provides a direct comparison of mu CT to SR mu CT data and is thereby able to conclude that the influence of including TMD heterogeneity is overestimated in mu CT-based models.