Multiscale Approach to Understand the Multiphysics Phenomena in Bone Adaptation - Multiscale Computer Modeling in Biomechanics and Biomedical Engineering - page 62

Fig. 10 Reduced effective electro-diffusity of cations (solid line) and anions (dashed line)asa
function of the salinity (left, pore size of 10 nm) and the half-size of the pore (right, salinity of
0 : 01 M) (reproduced with permission from Kaiser et al. [ 59 ])
extravascular pores. Note that this experimental study brings up some fundamental
questions on the sign of the surface charge of the canalicular pores. Indeed, if this
charge is classically thought to be negative [ 3 ], such an anionic enrichment effect
would rather indicate a positively charged pore surface. In the concluding remarks
of this work, a possible explanation to this paradoxical observation is proposed.
5 Conclusion: Toward a New Paradigm of Bone Remodelling
The aim of this study was to offer new perspectives for in silico bone remodelling
representations. Based on a multiphysical hierarchical treatment of the phenomena
governing the tissue behaviour, this work quantitatively proved the accuracy of
common macroscopic bone tissue models. Nevertheless, qualitatively, it also puts
into relief the weakness of purely hydro-mechanical approaches when studying
remodelling signals at the cellular scale. Indeed, even if washed out at the tissue
level, the microscopic electro-chemical phenomena are visible in the neighbour-
hood of the cell.
Through this study, it was shown that the consequences of the microscopic
effects in the classical remodelling transduction scenarios may be considerable.
Since the key phenomena are located at the scale of the cell, it would be vain to
carry on working only at the organ scale. For instance, we stressed on the major
consequences on the shear stress of chemical fluxes occurring at the cellular scale.