Dynamic permeability of the lacunar–canalicular system in human cortical bone

A new method for the experimental determination of the permeability of a small sample of a fluid-saturated hierarchically structured porous material is described and applied to the determination of the lacunar–canalicular permeability ( K LC ) in bone. The interest in the permeability of the lacunar–canalicular pore system (LCS) is due to the fact that the LCS is considered to be the site of bone mechanotransduction due to the loading-driven fluid flow over cellular structures. The permeability of this space has been estimated to be anywhere from 10 - 17 to 10 - 25 m 2 . However, the vascular pore system and LCS are intertwined, rendering the permeability of the much smaller-dimensioned LCS challenging to measure. In this study, we report a combined experimental and analytical approach that allowed the accurate determination of the K LC to be on the order of 10 - 22 m 2 for human osteonal bone. It was found that the K LC has a linear dependence on loading frequency, decreasing at a rate of 2 × 10 - 24 m 2 /Hz from 1 to 100 Hz, and using the proposed model, the porosity alone was able to explain 86 % of the K LC variability.