Axial Stress Promotion Tibial Fracture Healing After External Fixation By Three-dimensional Finite Element Analysis Study

Objective:(1)we aimed to set up the mathematical,computer-based model of tibial fracture healing after external fixation using finite element analysis of the bones to simulate the process of bone healing.(2)Three dimensional finite element simulate the progress fracture healing under different loading frequency and magnitude of axial stress,and trying to define the optimum magnitude and frequency combination.Methods:(1)The two-dimensional computed tomography(CT)image dataset was obtained by scanning a heathy volunteer's tibial.The image data transfer DICOM format.Three-dimensional model(3D)of tibia was reconstructed from CT image using 3D model reconstruction software(Minics).A 1.5-mm transverse tibial fracture with a external callus was simulated in CAD software,A unilateral external fixator with three pins was modelled and inserted in the the tibia.Mimics software Remesh module was used to generate and optimize meshes for the tibia and all fixator.The cortical bone and fixator volumetric elements was 195525,81502 respectively.The number of callus volumetric elements was 50491.(2)The regional material properties of the callus and bone,and the boundary conditions were assigned.The following mechanical parameters were tested: Loading was performed at one of five frequencies(0.5,1.0,1.5,2.0,3.0 Hz)and one of five load magnitudes(100,150,200,250,300N).An iterative procedure was developed to simulate tissue differentiation during fracture healing.The results of observation: bone callus internal stress and strain and displacement of the fragment in tibial fracture healing process,callus cell number changes of fracture displacement and tissue Simulation view of the predicted healing patterns over time.Results:(1)3D finite element model was built to simulate the healing process of tibial fracture.The callus stress,strain and displacement in fragment of tibial fracture was calculated through FEA.(2)In terms of callus difference time,200 N and 1Hz parametric of combination difference in mature bone tissue was 7 weeks,the time was shortest.Conclusions: 200 N and 1Hz the optimal parameter combination was obtained,andprovided a theoretical basis for clinical individual promotion tibial fracture healing...