Bone remodeling simulation methods and its applications based on finite element analysis and topology optimization

Abstract

Bone is capable of adapting to external loads by reorganizing its architecture as well as mass. This metabolic process is called bone remodeling or adaptation. Since the 1970s, researchers in the field have been attempting to propose a mathematical model that can capture this complex process. Homeostasis-based phenomenological models have been widely used for bone remodeling simulation on the biological foundation. As an alternative, optimization-based simulations have been recently studied to express time-dependent bone remodeling phenomenon. In this paper, we proposed a novel optimization-based method for age-related bone remodeling by introducing two parameters in the optimization formulation. The proposed method was validated through a bone specimen in comparison with the relevant data in the literature. It was then applied to human proximal femur to simulate age-related changes in trabecular bone in the age span of 20 to 60 years. A quantitative comparison was made in terms of BV/TV. Other morphological indices, Tb.N and DA, were also in line with the data in the literature. Further in-depth studies would enhance the predictive capability of the proposed method and thus contribute to the development of patient-specific model.Computational bone remodeling simulation has been widely studied and markedly evolved to predict trabecular architecture alteration under various load conditions. Subject-specific simulation, however, still remains to be further investigated. The bottleneck has been the determination of physiological loads for a subject-specific bone specimen. In the field, several inverse load estimation algorithms have been proposed to estimate “unknown” loads with the information on the “known” bone density distribution (or bone architecture). Shifting the current paradigm of load estimation, we may estimate local loads for the region of interest (ROI) with the given global loads. In the finite element method, a technique called ‘substructuring’ h...