Analysis of Trabecular Bone Multiaxial Failure Using Large Scale Computation

INTRODUCTION Multiaxial failure behavior of trabecular bone is important clinically since multiaxial loads occur in vivo, and are associated with hip fractures [1, 2] and implant loosening [3]. Knowledge of the multiaxial failure behavior of trabecular bone also has biological importance since it will enable whole bone finite element models [4] to accurately predict failure loads. To date, no complete multiaxial failure theory for trabecular bone has been developed, mainly due to difficulties involved in experimentally obtaining multiaxial failure data [5]. So far, theories like Tsai-Wu [5] and cellular solids [6] have been used and most recently, by making use of the high-resolution finite element method, a biaxial yield envelope for bovine trabecular bone was obtained [7]. These studies have provided insight into the multiaxial failure of trabecular bone, however, a complete failure criteria still remains unknown. The overall goal of this study was to address this issue computationally by making use of high-resolution finite element models. Specifically, our objectives were to: 1) determine the multiaxial failure envelope for one human trabecular bone specimen in 3-D strain space, and 2) determine the axial-shear behavior of the specimen.