Simulation study on parameter dependence of dynamic osteocyte response under low-magnitude high-frequency vibration.

The dynamic response mechanism of osteocytes to whole-body low-amplitude high-frequency vibration (LMHFV) is investigated using numerical simulation. In this study, a finite element model of a single bone lacuna-osteocyte incorporating the cytoskeleton was established. The vibration parameter dependence characteristics (acceleration amplitude (a), frequency (f)) of the dynamic osteocyte response under LMHFV were simulated. The results demonstrate that the alternating positive and negative liquid pressure acted on the osteocyte under LMHFV protocols (0.01 g-0.05 g, 30 Hz) (g=gravitational acceleration, 1 g = 9.8 m/s) and the fluid shear stress increase with the acceleration amplitude. Additionally, the absolute values of positive and negative liquid pressure are relatively higher in the parameters range (0.026 g-0.038 g, 30 Hz). The von Mises stress extreme value of the microtubules presents a non-linear variation with increasing vibration parameters. Moreover, cytoskeletons can generate higher stress under vibration protocols (0.02 g-0.03 g, 30-45 Hz), thus facilitating the transmission of mechanical signals while satisfying the mechanical strength conditions compared to other reasonable vibration parameter range (0.01 g-0.05 g, 30-45 Hz). In summary, LMHFV with appropriate parameters can improve the mechanical microenvironment of osteocytes and enhance cell bioactivity to some extent.