Quantitative Load Dependency Analysis of Local Trabecular Bone Microstructure to Understand the Spatial Characteristics in the Synthetic Proximal Femur

SIMPLE SUMMARY: This research aims to quantitatively analyze the trabecular bone microstructure in the synthetic proximal femur based on the region of interest (ROI) to better understand the spatial characteristics under various loading conditions. For this purpose, the load dependencies of twelve ROIs were evaluated under seven different loading conditions. According to the analysis, bone microstructures in the metaphysis and global model depended on multiple loads, whereas those in the epiphysis depended on single or double loads. These findings showed that a specific ROI primarily depends on specific loading conditions. This study provides the foundation for future local bone reconstruction utilizing only specific loads with high load dependency as well as a basis for further studies to validate the actual bone structure. ABSTRACT: Analysis of the dependency of the trabecular structure on loading conditions is essential for understanding and predicting bone structure formation. Although previous studies have investigated the relationship between loads and structural adaptations, there is a need for an in-depth analysis of this relationship based on the bone region and load specifics. In this study, the load dependency of the trabecular bone microstructure for twelve regions of interest (ROIs) in the synthetic proximal femur was quantitatively analyzed to understand the spatial characteristics under seven different loading conditions. To investigate the load dependency, a quantitative measure, called the load dependency score (LDS), was established based on the statistics of the strain energy density (SED) distribution. The results showed that for the global model and epiphysis ROIs, bone microstructures relied on the multiple-loading condition, whereas the structures in the metaphysis depended on single or double loads. These results demonstrate that a given ROI is predominantly dependent on a particular loading condition. The results confirm that the dependency analysis of the load effects for ROIs should be performed both qualitatively and quantitatively.