Microstructural analysis of porcine skull bone subjected to impact loading

Skull fracture can be a complex process involving various types of bone microstructure. Finite element analysis of the microscopic architecture in the bone allows for a controlled evaluation of the stress wave interactions, micro-crack growth, propagation and eventual coalescence of trabecular fracture. In this paper, the microstructure and mechanics of small-volume sections of a 6-month-old Gottingen Minipig skull were analyzed. MicroCT scans were used to generate finite element models. Various computational methods were investigated for modeling the intricacies contained within the porous microstructure of the trabecular bone. Pores were explicitly meshed in one method, whereas in the second, a mesh was created from a microCT image-informed mapping algorithm that mapped the trabecular porosity from an image stack to a solid volume mesh of the model. From here, all models were subject to uniaxial compression simulations. The output of the simulations allowed for a detailed understanding of the failure mechanics of the skull structure and allowed for comparison between the methods. Fracture typically occurs in the weakest areas where the bone is highly porous and forms a fracture surface throughout the material, which causes the bone to collapse upon itself.