Anterior Two Fusion Cage For Treatment Of Thoracolumbar Burst Fracture With Finite Element Analysis Of The Early Postoperative

Objective:(1)To establish three kinds of three-dimensional finite element models of normal spinal thoracic and lumbar vertebrae(T12-L2),subtotal corpectomy cylinder mesh cage reconstruction,and posterior 1/3 corpectomy rectangle cage reconstruction.(2)The validity of the finite element model was verified by comparing the past three dimensional finite element analysis and in vitro biomechanical study.(3)Comparative analysis using three-dimensional finite element method,the traditional anterior subtotal corpectomy cylinder mesh cage reconstruction and posterior 1/3 corpectomy rectangle cage reconstruction for the treatment of thoracolumbar burst fracture early postoperative stability,endplate interfacial stress and stress distribution in plants.Methods:(1)Select 1 healthy adult male volunteers,through the examination to exclude spine related diseases.Access the DICOM format file by useing of the spiral CT scanning of thoracolumbar segment T12-L2;three-dimensional reconstruction by Mimics 17 and the reverse engineering software Geomagic Studio 13.0,obtained the IGES file into ANSYS software;further improve the intervertebral disc and ligaments,The finite element model of normal T12-L1 segment is established(model A).(2)Based on the finite element model of normal thoracic lumbar,thoracic and lumbar vertebrae simulation for anterior decompression and internal fixation,respectively establish subtotal corpectomy cylinder mesh cage reconstruction of three-dimensional finite element model and posterior 1/3 corpectomy rectangle cage reconstruction of three-dimensional finite element model.(3)In ANSYS software,Constrained L2 vertebral inferior surface and inferior articular process,500N preload was applied above T12,the upper surface of T12 vertebral body was 400N,and the upper articular process was 100N;Additional moment of motion is 7.5N/m,to simulate the movement of flexion,extension,left and right lateral bending,left and right rotation and axial compression,validity of the three dimensional finite element model was verified,and The stability of two models,the stress near the endplate and the stress in the plant were compared.Results:(1)This experiment successfully established normal human thoracolumbar spine(T12-L2)three-dimensional finite element model,and previous research activities similar to that model,a three-dimensional finite element model established in this study method is accurate and reliable,the model can be used to further study.(2)Comparison of three dimensional finite element model of the subtotal corpectomy cylinder mesh cage reconstruction and the three-dimensional finite element model of the posterior 1/3 corpectomy rectangle cage reconstruction,The stability of the two models is similar,and the stability of the spinal column can be maintained after the reconstruction of the two kinds of fusion devices;Under different conditions,the peak value of the inner plant and the adjacent endplate surface of the three dimensional finite element model of the subtotal corpectomy cylinder mesh cage reconstruction was higher than Three dimensional finite element model of the posterior 1/3 corpectomy rectangle cage reconstruction.Conclusion:(1)In this study,we use Mimics,Geomagic Studio,ANSYS and other software to quickly establish the three-dimensional finite element model of human thoracolumbar spine(T12-L2).The validity verification shows that the model can be used for further simulation analysis of Biomechanics.(2)To maintain the stability of the spine,the posterior 1/3 corpectomy rectangle cage reconstruction with the same effect as subtotal corpectomy cylinder mesh cage reconstruction.(3)After using a new rectangular fusion device to reconstructive,the peak value of the stress of the adjacent vertebral endplate and the inner plant decreased,which is a better fusion device.