Poromechanical Stimulation of Bone Remodeling: A Continuum Micromechanics-Based Mathematical Model and Experimental Validation

Abstract

Bone tissue is a living biological entity. In particular, it is able to renew itself, which is key for maintaining its mechanical integrity necessary for fulfilling fundamental tasks such as providing protection of organs and facilitating locomotion. Moreover, bone is also able to accommodate to a long-term changing mechanical loading (as it may occur during exercise regimes, bedrest, or exposure to microgravity). The process responsible for accomplishing either task is termed bone remodeling, involving removal of mature bone tissue and subsequent formation of new bone tissue. Bone remodeling is driven by complex actions of biological cells and biochemical factors, and it is sensitive to the mechanical loads applied onto the skeleton. As for the latter, the exact mechanical stimulus, which is sensed and transduced into bone remodeling events, is still a matter of debate. In this paper, we study how hydrostatic pressure that occurs in the lacunar pore space of cortical bone (hosting osteocytes, thus the cells believed to be mainly responsible for triggering the mechanobiology of bone remodeling), accumulating due to (macroscopically applied) mechanical loading, is able to drive bone remodeling. For determination of the hydrostatic pressure, we make use of a micromechanics-based poroelasticity model. Finally, we compare simulation results with pertinent experimental and clinical data, in order to assess the role of the hydrostatic pressure in the lacunar pores for regulating bone remodeling. - See more at: http://ascelibrary.org/doi/10.1061/9780784412992.221#sthash.dBmohCVs.dpuf