EFFECT OF OSTEOCYTE-LACUNAE SHAPE AND DIRECTION ON THE FLUID FLOW BEHAVIOR IN OSTEON

In order to accurately describe the fluid flow in osteon, this study developed a method to describe the fluid anisotropic flow based on the density, shape and direction of lacunae. Firstly, the number and distribution of the bone canaliculi around the lacunae were calculated. Secondly, the permeability and porosity were estimated by using the calculated parameters and other microstructure data of bone tissue. Finally, the poroelastic finite element model of osteon was established according to the calculated parameters, and the influence of lacunae shape and direction on the fluid flow behavior in osteon under the axial displacement load was analyzed. The results showed that the lacunae shape and direction had a significant effect on the value and distribution of fluid pressure and velocity in osteon. For the range of parameters investigated, the influence of the lacunae shape on the maximum pressure and flow velocity in the same region of different osteon models can reach 86% and 18%, respectively, and the influence of the lacunae direction on that can reach 125% and 56%, respectively. In addition, the lacunae shape and direction had a great influence on the local pressure and velocity of a single osteon (up to 62% difference in fluid pressure between regions due to the influence of the lacunae shape, and up to 58% and 50% difference in fluid pressure and flow velocity due to the influence of the lacunae direction, respectively). The model showed that the lacunae shape and direction and the three-dimensional distribution of the canaliculus can determine the degree of anisotropy fluid flow in osteon. This study help to accurately quantify the anisotropic flow behavior of interstitial fluid of bone.