There are many methods used to estimate the undamaged effective (apparent) moduli of cancellous bone as a function of bone volume fraction (BV/TV), mean intercept length (MIL), and other image based average microstructural measures. The MIL and BV/TV are both only functions of the cancellous microstructure and, therefore, cannot directly account for damage induced changes in the intrinsic trabecular hard tissue mechanical properties. Using a nonlinear finite element (FE) approximation for the degradation of effective modulus as a function of applied effective compressive strain, we demonstrate that a measurement of the directional tortuosity of undamaged trabecular hard tissue strongly predicts directional effective modulus (r2 > 0.90) and directional effective modulus degradation (r2 > 0.65). This novel measure of cancellous bone directional tortuosity has the potential for development into an anisotropic approach for calculating effective mechanical properties as a function of trabecular level material damage applicable to understanding how tissue microstructure and intrinsic hard tissue moduli interact to determine cancellous bone quality.
Directional Tortuosity as a Predictor of Modulus Damage for Vertebral Cancellous Bone
Manuscript received June 30, 2014; final manuscript received November 17, 2014; accepted manuscript posted November 20, 2014; published online December 10, 2014. Assoc. Editor: Ara Nazarian.
Fyhrie, D. P., and Zauel, R. (January 1, 2015). "Directional Tortuosity as a Predictor of Modulus Damage for Vertebral Cancellous Bone." ASME. J Biomech Eng. January 2015; 137(1): 011007. https://doi.org/10.1115/1.4029177
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