Trabecular Bone Adaptation: An Experimental and Computational Investigation

Bone mechanical properties are influenced by its complex microstructure which when disrupted, compromises bone function and increases fracture risk. This thesis explored trabecular bone adaptation to mechanical loading using ex vivo experimental and computational approaches. The effects of mesh density, element formulation, and heterogeneous material grouping on human trabecular bone micro finite element (μFE) models were quantified. Finer mesh resolutions (20 μm) yielded more accurate predictions but required higher computational resources. Both voxel- and geometry-based μFE models showed strong correlations (R² ≥ 0.8) with measured apparent elastic modulus, confirming their accuracy in predicting bone mechanics. Geometry-based models provided higher accuracy, while voxel-based models yielded more precise predictions. The ex vivo experiment found high strain magnitude and low strain rate were insufficient to stimulate trabecular bone formation. A custom-made algorithm was developed to simulate trabecular bone surface adaptation in response to mechanical loading and compared against the experiment. Although the predicted change in stiffness did not align with the ex vivo measurements, several valuable insights on structural contributions to trabecular bone adaptation in response to mechanical stimuli were discovered: 1. adaptation was specimen specific; 2. formation and resorption occurred simultaneously throughout the bone core; 3. tissue elastic modulus and thickness changed in a heterogeneous manner; and, 4. peak stress was reduced through bone adaptation. The contributions of this thesis advance the understanding of trabecular bone mechanical behaviour and its adaptation to mechanical loading, offering a promising framework for future applications in bone health research and the development of personalized therapeutic strategies.