The Influence of Bone Modulus-density Relationships on Two-dimensional Human Proximal Femur Remodeling Results

Abstract

Bone modulus-density relationships are important in the numerical simulation of bone remodeling process. This study aimed to investigate the influence of modulus-density relationships on the simulation results of two-dimensional human proximal femur remodeling process. Different combinations of modulus-density relationships (Young’s modulus E and apparent density) from previous researches were used to generate fourteen remodeling models. These models were grouped into cortical groups and trabecular groups. Models in one cortical group adopted the same cortical modulus-density relationship, and models in one trabecular group adopted the same trabecular modulus-density relationship. All models had the same initial density, remodeling parameters, and boundary conditions. A 300-day remodeling process simulation was performed for each model. At the end of remodeling, the apparent density distributions of all models were investigated. To quantify the consistency of the remodeling results from different models, degree of consistency based on Bland–Altman plot was proposed, which should be zero if remodeling results from two models are identical. The average degrees of consistency of all cortical groups were 0.274–0.294 (standard deviation 0.044–0.050), while that of trabecular groups were 0.028–0.046 (standard deviation 0.009–0.012). The results suggested that trabecular bone modulus-density relationships have a great impact on remodeling results and that the influence of cortical bone modulus-density relationships is not obvious. Further study regarding this matter needs to be implemented, and we strongly advise that sensitivity analysis of trabecular bone modulus-density relationship on numerical simulation results to be conducted for subject-specific bone remodeling study.