INVESTIGATION ON LOADING-INDUCED FLUID FLOW IN OSTEOGENESIS IMPERFECTA BONE

摘要

Osteogenesis Imperfecta (OI) is a genetic bone disorder which is typically characterized by brittle bones with frequent fractures. It is also known as brittle bone disease. Surgical procedure is one of the ways adopted by clinicians for the management of OI. In recent years, it has however become clear that physical activity is equally important for managing OI in both children and adults. Exogenous mechanical stimulation e.g. prophylactic exercises may be useful in improving the bone mass and strength of OI bones as loading-induced mechanical components e.g. normal strain and canalicular fluid flow stimulate remodeling activities. Several studies have characterized the strain environment in OI bones, whereas, very few studies attempted to characterize the canalicular fluid flow. In the present study, we anticipate that canalicular fluid flow reduces in OI bone as compared to healthy bone under physiological loading. This work accordingly computes the canalicular fluid distribution in the single osteon model of OI and controlormal bones subjected to normal physiological loadings. A transversely isotropic poroelastic model of osteon is developed. Loading is applied in accordance with gait cycles reported for OI and healthy bones. Fluid distribution patterns computed for OI and healthy bones are compared at different time-points of stance phase of the gait cycle. A significant reduction in fluid flow is observed in case of OI bone as compared to healthy bone. This clearly indicates that improvements in physical activities or exercises can be designed to enhance the level of canalicular fluid flow to initiate possible osteogenic activities and the bone.