title: Contribution of fluid in bone extravascular matrix to strain-rate dependent stiffening of bone tissue - A poroelastic study.
abstract: Osteoporotic fractures represent an increasing cost to society, and its diagnosis methods based on bone density still lack accuracy in identifying risk of fracture. This is why a better understanding of mechanical behavior of bone tissue is of importance, especially when it comes to relating experimental observations to realistic physiological fall loading conditions. This study aims at exploring the stiffening effect of pore fluid in bone extravascular matrix subject to high strain rate loading that is more realistic to simulate a physiological fall. A computational approach is used, where bone tissue microstructure extracted from micro-CT images is modeled using finite elements. The solid phase of bone tissue is modeled as a poroelastic material, a porous matrix filled with fluid. When the extravascular matrix experiences certain volumetric deformation, the fluid in pores presents load carrying capacity, which consequently varies the apparent stiffness of bone tissue. It is shown that effects of fluid stiffening in bone can be significant, depending on the chosen material properties, the amount of volumetric strain in tissue and the loading rate with respect to hydraulic conductivity and drainage conditions. It is also shown that such stiffening effect is influenced by bone microstructure, and is more significant in cortical bone than in trabecular bone.
authors: Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom.
authors: Solenn
authors: S
authors: Le Pense
authors: Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom. Electronic address: y.chen@hw.ac.uk.
authors: Yuhang
authors: Y
authors: Chen
mesh_terms: D000058:Accidental Falls; D001696:Biomechanical Phenomena; D001857:Bone Matrix / Q000502:physiology*; D001842:Bone and Bones / Q000502:physiology*; D000071556:Cancellous Bone; D000071538:Cortical Bone; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D016062:Porosity; D013314:Stress, Mechanical
keywords: Bone mechanics; Hydraulic stiffening; Poroelasticity; Strain rate; Tissue microstructure