Quantification and material modelling of the localized non-bone regions in the trabecular architecture of the sacrum

Simulating fractures using CT-based bone models enables personalized treatment. However, most commercially-available applications only use bone mineral density (BMD) to calculate Young's modulus, solely considering the mineralized phase. Our methodology maps sacral region material properties by: (1) segmenting bone into mineralized / non-mineralized volumes, (2) calculating mineralized region Young's modulus via BMD approach and non-mineralized region modulus via volume fraction, and (3) generating a FE mesh with material mapping. This enables stress field analysis and Young's modulus approximation for low Hounsfield values. Considering the internal composition of bone is crucial for improving patient-specific FE models and assessing pelvic fractures.