Influence of Osteocyte Lacunar-Canalicular Morphology and Network Architecture on Osteocyte Mechanosensitivity

The goal of this review is to summarize recent findings related to modifications in osteocyte lacunar and canalicular morphology due to physiological and pathological conditions. In addition, this review aims to outline how these modifications may influence the local mechanical environment of osteocytes and their mechanosensitivity.

Reduction in lacunar density with age and increasing lacunar size with lactation are confirmed in multiple studies in human and murine bone. There is also evidence of a reduction in canalicular density, length, and branching, as well as increasing sphericity and smaller lacunae with aging and disease. However, while some studies have found modifications in lacunar density, size, shape, and orientation, as well as canalicular density, length, and size due to specific physiological and pathological conditions, others have not observed any differences. Recent finite element models provide insights into how observed modifications in the lacunar-canalicular network (lacunar and canalicular density) and lacunar-canalicular morphology (lacunar area/volume, shape, and orientation as well as canalicular diameter and length) may influence the fluid flow and local strains around the lacunar-canalicular network and modify the local mechanical environment of osteocytes. Modifications in the lacunar-canalicular network morphology may lead to significant changes in the strains received by osteocytes and may influence bone's response to mechanical stimulation as osteocytes are the primary mechanosensing bone cells. Further experimental and computational studies will continue to improve our understanding of the relationship between lacunar-canalicular network morphology and osteocyte mechanosensitivity.