Medical vs MicroCT based Finite Element Analysis : Exploring the Influence of Bone Heterogeneity and Bone Geometry

A comprehensive investigation into the direct comparison of medical-CT and μCT-based FEA regarding the impact of bone heterogeneity and geometry is lacking. Therefore, in this study, the impact of bone heterogeneity and bone geometry in FEA for the evaluation of uncemented prostheses is demonstrated. The comparison between three different material models and two different CT scan technologies (medical-CT and μCT) was conducted by evaluating the FEA models at a given ROI under the same loading conditions. The inclusion of bone heterogeneity led to a 20.57 ± 7.37% and 24.07 ± 15.07% reduction in material stiffness for μCT and medical-CT, respectively, resulting in less stress concentration in heterogeneous material models compared to homogeneous material models. Despite the similar Von-Mises stress and peak stresses between the medical-CT and μCT-based FE models, the contours of the stress and the location of the peak values differed due to the differences in geometries and material heterogeneity between the scans. This potential discrepancy could lead to an incorrect indication of load transfer characteristics based on the medical-CT-based FEA of uncemented prostheses.Clinical Relevance-The accuracy of FEA results depends on the precise construction of bone geometry and density estimation from CT scans. Therefore, this study demonstrated the effect of bone heterogeneity and bone geometry in FEA, leading to a more informed and careful consideration of the selection of material models and bone geometry, particularly when trabecular mechanics play an important role, as in uncemented prostheses.