In Silico Modeling of a Bone Repair Strategy Combining an Osteoconductive Biomaterial with a Mechanical Stimulation Re- habilitation Program

Bone repair in case of major defects remains a problem poorly solved by conventional techniques. Many researches are currently carried out in tissue engineering, using in vivo models on animals or in vitro on cell cultures, to understand and guide the mechanisms of bone repair and consolidation. New osteoconductive and osteoinductive biomaterials are developed to promote bone formation. Moreover, there is a lot of evidence on the importance of the mechanical stimulation of bone cells in the process of bone repair. Nevertheless, the mechanical environment proposed to cells within a porous biomaterial is difficult to estimate. And more importantly, in the follow-up of a patient treated for bone fracture, there is no precise management of mechanical stimulation during the rehabilitation phase with the setting up of an adapted program and the use of modern measuring tools. To study the influence of mechanical stimulation during rehabilitation and prior to complex in vivo experiments, the use of theoretical and numerical mechanobiological models of bone repair could be an alternative. Here tissue formation and differentiation were predicted in a porous poly-lactic acid biomaterial and a hydrogel membrane filling a large bone defect in a human tibial diaphysis. We identified optimal loading case promoting the differentiation of tissue into mature bone in the diaphysis defect. We indicated that the rehabilitation program should be adapted to reproduce this optimal mechanical stimulation. Taking advantage of the growth of the simulation means and by a greater synergy with the experimental models, the numerical modeling of the bone consolidation can constitute a complementary tool for the benefit of patients.