FINITE ELEMENT ANALYSIS OF CANCELLOUS BONE

A variety of pathologies exist which increase the likelihood of bone fracture. Present methods for determining the fracture risk of a specific patient are based exclusively on the amount of bone present. While the quantity of bone tissue is correlated with strength, it neglects to account for bone’s intricate microarchitecture. To assess the effect of bone quality on strength, a methodology was developed for the structural analysis of cancellous bone biopsies. Thirty biopsies were selected from a pre-existing biopsy bank, and scanned using a SCANCO µCT-40 at a resolution of 30 microns. Cortical bone was removed from the resulting three-dimensional geometry, and the remaining cancellous bone was meshed with solid tetrahedral elements. A linear static uniaxial compression test was performed using ANSYS v14.0 to determine the apparent-level Young’s modulus. The maximum von Mises stress was also investigated, but showed poor convergence with increased mesh density. Consistent with the methodology of Pistoia et al., the failure load was assumed to occur when 2% of the bone volume exceeded 7000 µstrain. The results of the finite element analysis compared favorably with known values for cancellous bone strength