Abstract
In this study a multiβscale mechanoβregulation model was developed in order to investigate the mechanobiology of trabecular fracture healing in vertebral bodies. A macroβscale finite element model of the spinal segment L3βL4βL5, including a mild wedge fracture in the body of the L4 vertebra, was used to determine the boundary conditions acting on a microβscale finite element model simulating a portion of fractured trabecular bone. The microβscale model, in turn, was utilized to predict the local patterns of tissue differentiation within the fracture gap and then how the equivalent mechanical properties of the macroβscale model change with time. The patterns of tissue differentiation predicted by the model appeared consistent with those observed in vivo. Bone formation occurred primarily through endochondral ossification. New woven bone was predicted to occupy the majority of the space within the fracture site approximately 7β8 weeks after the fracture event. Remodeling of cancellous bone architecture was then predicted, with complete new trabeculae forming due to bridging of the microcallus between the remnant trabeculae. Β© 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:433β443, 2011