Finite element analysis of mid-diaphyseal transverse fracture based on cortical bone heterogeneity

The failure of bone may cause from accumulation of micro cracks, and will affect the micro structure features. The composition in cortical bone can be in the composite structure which has variety in material properties and play a role to macroscopic fracture behavior of whole bone structure. The composition in bone can be demonstrated as heterogeneous material properties which considered as constituents of osteon, cement line, interstitial matrix and Haversian canal. It is hypothesize that linear stress interaction exist and growth to intensify the interaction between constituents. This paper presents a finite cortical bone model based on continuum mechanics theory to identify the linear elastic interaction between four constituents and evaluate its model based on the standard analytical model for brittle fracture. Finite element method is employed to calculate the interaction fracture parameter, stress intensity factor (SIF) and energy release rate for four anatomical positions in cortical bone which are posterior, anterior, medial and lateral are considered due to different variability of bone properties. The results demonstrates the highest value of SIFs at posterior cortex and found lowest at lateral cortex. It is identified that numerical data is in good agreement with analytical model for brittle fracture.