Finite Element Modeling And Analysis Of Personalized Scoliosis

Scoliosis,also commonly called scoliosis,refers to a spinal deformity in which multiple vertebrae on the human spine deviate from the midline of the sacrum in the coronal plane to the side,forming a spinal deformity in which the spine is bent and deformed on the coronal plane.Its pathological changes and spatial structure are very complicated.Adolescents and children are the most susceptible to scoliosis,and domestic and foreign studies have reported that the incidence rate is 1.06% ～ 13.60%.Scoliosis has seriously endangered human health.Because scoliosis affects the appearance of patients,it affects the patient’s psychology and affects the quality of life of the patient.Clinically,there are generally two treatment options for patients with scoliosis: non-surgical treatment and surgical treatment.Regardless of the treatment of scoliosis,the study of spinal kinematics analysis and spinal orthopedic biomechanics is the focus.In order to explore the kinematic characteristics of the human spine and the correction effect of the corrective force under different working conditions when correcting scoliosis,this study mainly conducts two aspects of research work.On the one hand,the Vicon motion capture system was used to explore the effects of different actions.The movement of the normal human spine.On the other hand,a case of idiopathic scoliosis is selected to establish a finite element model of the scoliosis,and simulate and analyze it with finite element analysis software.The specific research content includes:(1)Through the Vicon motion capture system,the motion data of the human spine in front and back flexion and extension,left and right lateral flexion,and left and right rotation are collected,and the kinematic data collected by Vicon is exported,and the spine is obtained through data processing software processing and analysis.The displacement,velocity,acceleration of some segments and the angle and angular velocity changes of the C7-T6-T11 line.(2)A patient with idiopathic scoliosis was select,and used medical image modeling software and finite element analysis software(Mimics,3-matic,Hypermesh,Abaqus)to establish a personalized idiopathic spine based on its CT scan image Convex finite element model.The model contains all vertebrae and intervertebral discs,ribs and costal cartilage,and six kinds of ligaments between the vertebrae.(3)The validity of part of the model was verified through the following three aspects:(1)The Cobb angle of the scoliosis finite element model was compared with the Cobb angle of the X-ray image of the patient in the supine position;The data is compared,(3)The T1-T4,T12-L2,and L4-L5 segment models are set to be consistent with the experimental conditions of other scholars,and the simulation results are compared with the experimental results of other scholars.(4)Applied corrective force to the model at different positions,studied the stress and displacement distribution of the spine under different working conditions,explore the corrective effect of the corrective force at different positions on the model,and then selected the best corrective effect to apply the corrective force The corrective force of different magnitudes is applied to the position of,and the relationship between the corrective force and the Cobb angle change is explored.Through kinematics data acquisition,processing and analysis,and finite element modeling simulation and analysis,the following conclusions can be obtained:(1)Through the analysis of the motion capture results of different actions,it is found that for the C7-T6-T11 included angle on the spine,there are two obvious wave crests in the cross-section,the angle changes of the front and rear flexion and extension and the left and right scoliosis;in the vector On the morphological plane,the angle change is greatest when rotating left and right,and there are two obvious troughs;on the coronal plane,the angle change is the biggest when rotating left and right,and the angle changes during flexion and extension and lateral bending are relatively small.(2)The analysis of the six movements of spine movement found that the angular velocity of the C7-T6-T11 included angle in any one movement cycle is greater than the angular velocity on the sagittal and coronal planes,and the angular velocity on the coronal plane is the smallest.(3)Through the research of the position of corrective force application,it is found that the closer the position of corrective force is applied,the better the correction effect of scoliosis vertebral body.For the same corrective force,when the corrective force is loaded on the ribs,the stress of the vertebral body is the largest,and when the corrective force is loaded directly on the vertebral body,the stress of the intervertebral disc and the stress of the ligaments are the largest,especially on the outer soft tissues.The stress of each part is smaller than the stress generated by directly loading the corrective force on the vertebral body and ribs,and the displacement of other spine tissue components is also greater than the displacement generated when the corrective force is directly loaded on the vertebral body and ribs.(4)Load different corrective forces on the T8 vertebral body.The displacement,stress and intervertebral disc stress of the vertebral body gradually increase with the increase of the corrective force.The position of the maximum vertebral body stress is on the T2 vertebral body.The position of the maximum stress is on the intervertebral disc between T1 and T2,and the Cobb angle of the spine increases gradually with the increase of the correction force,and there is a certain linear relationship between the two,the correlation coefficient is 5.24*10-3 °/N.The research results in this study provide a reliable biomechanical basis for understanding the kinematic characteristics of normal spine,studying and analyzing the stress and correction law of scoliosis spine under the action of correcting force,and it also provides a reliable biomechanical basis for clinical correction of idiopathic scoliosis.Provide certain biomechanics guidance and reference.