The Finite Element Analysis Research About The Dislocation Pedicle Screw Systems Fixed Method Of Lumbar Vertebral Fracture

【Objective】:1. To master the use of spiral CT picture in lumbar pedicle screw fixation system toestablish the finite element model for.2. Lumbar pedicle screw internal fixation system for biomechanical experimentsprovide a three-dimensional finite element model, based on the analysis of differentloads, the screw connecting rod stress distribution.3. For vertebral fracture internal fixation provides the reference for the selection of.【Methods】:1. Image: A volunteers were chosen, with Toshiba Aquilion ONE320row spiral CTon lumbar continuous horizontal scanning, image processing and preservation inCT-V station.2. Model: CT scanned data into the computer, with the help of mimicsl03Dreconstruction, established lumbar geometric model, simulation L2lumbar fracturegeometry model. The use of Abaqus10、Solidworks software, lumbar spine, pediclescrew system establishment of finite element model. Simulation of L1-L3、L1-L2-L3,L1-L3-L4vertebral pedicle screw fixation finite element model, importAbaqus10software for load analysis.3. Loading and calculation: In the L1axis pressure is applied to the surface and on thebasis of applying forward, backward, lateral, axial10Nm moment simulation humanstanding, flexion, extension, lateral bending, torsion action. The results of qualitativeobservation: the stress distribution map display; calculation of screw and rod averageVon Mises stress and the values were subjected to statistical analysis.【Results】:1. This experiment using Mimics, Solidworks and finite element software Abaqus ofnormal lumbar spinal three-dimensional model. 2. From the model of the lumbar motion relative to the normal model compared eachoperation model of activity decreased to different degrees, in which L1-L3-L4fixedmodel activity decreased significantly, other two kinds of operation schemes oflumbar activity decreased to the level of basic level.3. Model L1-L2-L3and model L1-L3-L4in standing, lateral bending, flexion thisthree condition screw stress had no significant difference, but in extension and torsioncondition in the two condition model screw stress has significant difference. ModelL1-L2-L3and model L1-L3, the two models under different conditions with the screwof the stress had significant difference. Model L1-L3-L4and model L1-L3, only theextension state screw stress had significant difference.4. From the operation scheme of screws for the mean and variance of comparison, ineach case the average stress are L1-L3model, L1-L3-L4model, L1-L2-L3modelminimum.【Conclusion】:1. Using320row helical CT scanning image, the use of Mimics, Solidworks and finiteelement software Abaqus to establish finite element model of lumbar spine method isconvenient, accurate, and other advantages, at the same time, the method ofexperimental materials demand less, experimental high repeatability, the greatestdegree of conservation of experiment resources.2. In this experiment the lumbar spine fixation model activity were lower than normal,L1-L3-L4this operation for lumbar activity limitation is the most serious.3. Model L1-L2-L3screw the smallest stress, stress the most excellent in dispersion.L1-L3model of average stress almost reached the L1-L2-L3model of a times, stressfluctuation is larger, the screws on stress concentration situation serious.