Prediction of cortical bone elastic constants by a two-level micromechanical model using a generalized...

Area of Science:

• Biomechanics
• Materials Science
• Orthopedics

Background:

• Cortical bone exhibits complex microstructures, including Haversian canals and lamellae, influencing its mechanical properties.
• Transversely isotropic elasticity is a key characteristic of cortical bone, affected by porosity.
• Understanding bone mechanics is crucial for addressing skeletal injuries like femoral neck fractures.

Purpose of the Study:

• To develop a two-level micromechanical model for predicting the elastic properties of cortical bone.
• To investigate the influence of microstructural features and porosity on bone elasticity.
• To assess the model's agreement with experimental data and its utility in fracture analysis.

Main Methods:

• A generalized self-consistent method was employed to create a two-level micromechanical model.
• The first level modeled an osteon as a two-phase composite (Haversian canals in lamellar matrix).
• The second level treated osteons and resorption cavities as inclusions within interstitial lamellar matrix.

Main Results:

• The model successfully predicted the transversely isotropic elasticity of human femoral cortical bone concerning porosity.
• Model predictions showed good agreement with experimental data.
• Discrepancies between model and experimental data were noted, potentially due to variations in microstructural properties.

Conclusions:

• The developed micromechanical model provides valuable insights into cortical bone elasticity.
• The model is useful for understanding the role of porosity in femoral neck fracture mechanics.
• Further refinement may account for variability in microstructural elastic properties.