Orthotropic properties of cancellous bone modelled as parameterized cellular material

Area of Science:

• Biomechanics
• Materials Science
• Computational Biology

Background:

• Accurate analysis of bone tissue stresses, strains, and adaptive remodeling necessitates detailed knowledge of cancellous bone's constitutive properties and microstructural relationships.
• Homogenization techniques applied to equivalent trabecular microstructures offer a promising approach for this analysis.

Purpose of the Study:

• To derive parameterized orthotropic constitutive models of cancellous bone.
• To establish relationships between microstructural parameters and the resulting mechanical properties.

Main Methods:

• Utilized finite element analysis (FEA) on repeatable microstructure cells based on a space-filling dodecahedron.
• Developed a structured mesh generator to create 3D models for arbitrary shape parameter sets.
• Performed static numerical tests and determined elastic orthotropic stiffness matrix coefficients.

Main Results:

• Tabularized functions correlating elastic constants with four shape parameters were generated.
• These coefficients were further correlated with apparent density and principal fabric tensor values.
• The derived models showed good agreement with micro-FE data from actual cancellous bone specimens.

Conclusions:

• Parameterized orthotropic constitutive models derived from FEA of trabecular microstructures are effective for predicting cancellous bone properties.
• The models, parameterized by shape, can represent diverse bone microstructures and their mechanical behavior.
• This approach provides a robust framework for analyzing bone mechanics and simulating adaptive remodeling.