Physiological Loading-induced Interstitial Fluid Dynamics in Osteon of Osteogenesis Imperfecta Bone
Abstract Osteogenesis Imperfecta (OI), also known as 'brittle bone disease', is a genetic bone disorder. OI bones experience frequent fractures. It is observed physical activity is equally beneficial in reducing OI bone fractures in both children and adults as mechanical stimulation improves bone mass and strength. Loading-induced mechanical strain and interstitial fluid flow stimulates bone remodeling activities. Several studies have characterized strain environment in OI bones, whereas, a very few studies attempted to characterize the interstitial fluid flow. OI significantly affect bone microarchitecture. Thus, the present study anticipates that canalicular fluid flow reduces in OI bone in comparison to healthy bone in response to physiological loading due to altered poromechanical properties. Hence, this work attempts to understand the canalicular fluid distribution in the single osteon model of OI and healthy bones. A poromechanical model of osteon is developed to compute pore-pressure and interstitial fluid flow as a function of gait loading pattern reported for OI and healthy subjects. Fluid distribution patterns are compared at different time-points of stance phase of the gait cycle. It is observed that fluid flow significantly reduces in OI bone. Additionally, flow is more static than dynamic in OI osteon in comparison to healthy subjects. The present work attempts to identify the plausible explanation behind low mechano-transduction capability of OI bone. This work may further be extended in designing better biomechanical strategies to enhance fluid flow in order to improve osteogenic activities in OI bone.