Finite Element Analysis Of Thoracolumbar Compression Fractures Treated With Resetting Bed At Different Heights

Objective:Using three-dimensional medical image visualization and medical finite element analysis method of reverse engineering, and with the help of MIMICS software, establishing three-dimensional finite element model of the T11-L3vertebral body. On the basis of the model, discussing the stress mechanism of thoracic and lumbar vertebral compression fracture, simulating the treatment process of the bed bracket resetting, analyzing the distribution of stress and displacement change in the process of reduction of vertebral fractures in different part, to explore the best reduction and displacement of fracture of vertebral body.Methods:Recruiting a healthy male volunteer, giving him64slice spiral CT scans. The data output in DICOM format and stored into the disk, importing the data into three-dimensional medical reconstruction software MIMICS for processing, to generate the three-dimensional graphic, determine the element type, and give material properties. Then importing the entity model into ANSYS12finite element software, generating the three-dimensional finite element model of generation of thoracic and lumbar spine. After validate the model, give the boundary constraints, then load the model, establishing the thoracic and lumbar vertebral compression fracture model. Analyzing the stress distribution of vertebral body of thoracolumbar compression fracture and the stress mechanism. Based on the finite element model of thoracolumbar vertebral compression fractures, simulating the treatment process of the bed bracket resetting, analyzing the distribution of stress and displacement change of different parts of the injured vertebra in the process of reduction, to explore the optimal stress points and vertebral fracture force size.Results:1.The Three dimensional finite element model of thoracolumbar basically accord with the biomechanical characteristics of the normal human, including5208triangular shell elements,238743tetrahedron elements, a total of58738nodes, which can be used for biomechanical studies of thoracic and lumbar vertebrae.2. After validating the model, simulating the treatment process.in the reset process, the optimal stress point is located in the injured vertebral spinous process peak,the best displacement is10cm. It plays an important role in the mechanism of injury of L1vertebral compression fractures, provides adequate theoretical basis of Reduction bed bracket in treatment of thoracolumbar vertebral compression fractures, and facilitates the clinical application.Conclusion:The establishment of thoracolumbar three-dimensional finite element model contains five vertebrae,4discs, corresponding ligaments and other structures of T11-L3. Applied load of the model, power from small to large, model to obtain the range of movement from big to small, finally tends to be stable, showing the nonlinear mechanical behavior. The finite element model L1vertebral compression fractures also shows the nonlinear mechanical behavior of structure. Fracture model in different hyperextension protection applying reset shows different restoration effect after loading. When hyperextension fulcrum in the injured vertebral spines point, the displacement change is most obvious, the mechanics characteristics of each part of the vertebral body is most stable, and when10cm vertebral reset has the best effect.