Knowledge of the elastic and failure properties of trabecular tissue enables high-resolution finite element models to predict apparent level behavior of whole specimens of trabecular bone. These calibrated models can then be used to perform a large number of computational experiments that address complex behavior, such as multiaxial failure. This eliminates the infeasible alternative, namely, determining the material constants experimentally which would require a prohibitively large number of human bone specimens due to variations in architecture and density. Cortical bone mechanical properties have been used to model trabecular tissue in generic numerical studies [I]. Recently it was found that the use of cortical like behavior in high-resolution nonlinear finite element models resulted in excellent prediction of apparent level yield behavior [2]. It was also shown that the trabecular tissue yield strains, higher in compression than tension, were homogenous between specimens. Therefore, using experimental data to obtain effective mechanical properties of computational models results in a powerful tool to explore the multiaxial yield properties of trabecular bone. The overall goal of this study was to obtain effective elastic and yield properties of trabecular tissue from the human femoral neck using a combined experimental-computational approach. This is the initial step in a larger study to develop a multiaxial failure criterion for human trabecular bone. Specifically the objectives were: 1) to calibrate the effective tissue elastic modulus for each specimen, 2) to investigate the sensitivity of computed apparent yield strains to the assumed tissue yield strains and 3) to calibrate the effective tissue tensile and compressive yield strains for each specimen.
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