Intravoxel bone micromechanics for microCT-based finite element simulations

Area of Science:

• Computational Biomechanics
• Materials Science
• Biomedical Engineering

Background:

• Micro-Finite Element (micro-FE) simulations are crucial in biomechanics.
• Accurate material property assignment remains a challenge, often relying on empirical relationships.

Purpose of the Study:

• To develop a method for deriving voxel-specific elastic properties for bone tissue.
• To assess the impact of heterogeneous versus homogeneous material properties on micro-FE simulation outcomes.

Main Methods:

• Derived voxel-specific volume fractions of mineral, collagen, and water from X-ray attenuation data.
• Utilized a micromechanics model to compute voxel-specific stiffness tensors.
• Compared micro-FE simulation results of a mouse femur using heterogeneous versus homogeneous properties.

Main Results:

• Heterogeneous properties led to more accurate organ stiffness estimations compared to homogeneous properties.
• Simulations revealed significant tensile normal stresses in the mouse femur neck.
• These findings may explain morphological differences between mouse and human femur necks.

Conclusions:

• The proposed method provides a more accurate way to assign material properties in micro-FE analysis of bone.
• Understanding voxel-specific mechanical behavior is essential for accurate biomechanical simulations.
• The study offers insights into the mechanical loading and morphology of the femur neck.