Participant-informed finite element models of the tibia-fibula complex from MRI: sensitivity to material property definition

Motivation: Finite element modeling could help us better understand the role of bone strain in stress fractures. MRI, the standard for diagnosis, characterizes geometry but not bone density. Goal(s): To evaluate the sensitivity of finite element model-estimated strain to the use of generic material properties. Approach: Finite element models of the tibia-fibula complex were created with heterogeneous (CT referent) or homogeneous (simulating MR) material properties. Errors in strain and percent changes across running stride length conditions were calculated. Results: Strains were substantially underestimated by models using homogeneous material properties, but relative changes in peak strain between and within individuals illustrated strong agreement. Impact: MRI can be used to explore relative changes in bone strain in healthy adults when CT is not available. This option improves the feasibility of using finite element modelling to study bone strain and will enable opportunistic studies.