FRACTURE HEALING SIMULATION REGULATED BY FORCE AND OXYGEN

Abstract

According to the mechanical conditions of fracture fixation and the oxygen levels in the tissues, a simulation model of fracture healing process was built to describe the relationship among mechanical stability, oxygen levels in tissues and tissue differentiation during the second fracture healing. Different from the previous simulation model, in this paper, we took the three-dimensional model as the research object, solved the mechanical stimulation by finite element method, established the partial differential equation to solve the spatial and temporal variation of the oxygen in tissues. The process of tissue differentiation was described by fuzzy control method. The initial stage of fracture healing, intramembranous ossification, chondrogenesis, cartilage calcification and endochondral ossification during the fracture healing process were simulated, and the properties of tissue materials were continuously updated to complete the iterative process. The simulation program of fracture healing process was independently developed in Eclipse environment, and the simulation results were compared with experimental data and those of other fracture healing simulation models to verify the simulation program in this paper. Finally, the processes of transverse fracture healing in rats with different axial stability under normoxic, hypoxic and hyperoxic conditions was simulated, and the effects of different tissue oxygen levels and interosseous stabilities on fracture healing were analyzed. It is concluded by simulation that the delayed healing or non-union of bone will occur when in state of tissue hypoxia or interosseous instability, normal healing will occur when in state of tissue normoxia, and the healing will be accelerated when in state of tissue hyperoxia.