Poroelastic Model of Trabecular Bone in Uniaxial Strain Conditions

Abstract

A one-dimensional poroelastic model of trabecular bone was developed to investigate the fluid effect on the mechanical behavior at the continuum level. The poroelastic properties were determined based upon an assumed drained Poisson's ratio of 0.3 and experimental results reported in the literature. Even though the free escape of the fluid through the loading end was allowed during deformation, model predictions showed that the pore pressure generated within trabecular bone would cause significant variations in total stress. The total stress increase resulted in a stiffening of trabecular bone, which supports the concept of hydraulic stiffening that has been advocated by several investigators. Model predictions showed a good agreement to the mechanical behaviors of trabecular bone specimens with marrow in situ in a uniaxial strain condition observed in previous studies. These results support the hypothesis that trabecular bone is poroelastic and the fluid effect on the mechanical behavior at the continnum level is significant. Thus, the incorporation of the fluid effect in future studies is recommended to improve our understanding of mechanical behavior of trabecular bone.