Physiological Loading-Induced Interstitial Fluid Dynamics in Osteon of Osteogenesis Imperfecta Bone

Area of Science:

• Biomedical Engineering
• Orthopedics
• Mechanobiology

Background:

• Osteogenesis imperfecta (OI), or brittle bone disease, is a genetic disorder characterized by frequent bone fractures.
• While mechanical stimulation from physical activity benefits OI bone health, the underlying fluid dynamics are poorly understood.
• OI alters bone micro-architecture, impacting its mechanical properties and cellular responses.

Purpose of the Study:

• To investigate and compare canalicular fluid flow in osteons of OI and healthy bone under physiological loading.
• To determine if altered poromechanical properties in OI bone reduce interstitial fluid flow.
• To identify mechanisms behind diminished mechanotransduction in OI bone.

Main Methods:

• Development of a poromechanical model of a single osteon.
• Simulation of pore-pressure and interstitial fluid flow using gait loading patterns for OI and healthy subjects.
• Comparison of fluid distribution patterns during the stance phase of the gait cycle.

Main Results:

• Interstitial fluid flow is significantly reduced in OI bone compared to healthy bone.
• Fluid flow in OI osteons is more static and less dynamic than in healthy osteons.
• The study identified a plausible explanation for the reduced mechanotransduction in OI bone.

Conclusions:

• Altered poromechanical properties in OI bone lead to diminished canalicular fluid flow.
• Reduced fluid flow may underlie the impaired mechanotransduction and weakened bone structure in OI.
• Findings suggest potential for biomechanical therapies to enhance fluid flow and improve osteogenic activity in OI.