Finite Element Model Construction And Analysis Of Mild Adolescent Idiopathic Scoliosis In Adolescents

BackgroundAdolescent idiopathic scoliosis(AIS)is the most common spinal deformity that occurs in adolescence.Motion treatments have been found to be effective on AIS,whereas their mechanisms were still unknown and no consensus has been reached.The biomechanical study of scoliosis has been carried out for many years by using three-dimensional finite element analysis technique.This technology can overcome the limitations of traditional experimental methods that require a large number of specimens,complex data processing,and has become a good method for studying the scoliosis.However,the current three-dimensional finite element analysis for AIS is mainly for severe patients,and there is no three-dimensional finite element analysis specifically for mild AIS patients.ObjectiveThe purpose of this study is to establish a three-dimensional finite element model of mild AIS patients,verify the model,and perform finite element analysis.Method1.We obtain thin-layer CT data from the sixth cervical vertebrae to the fifth lumbar vertebrae of a mild AIS patient,and construct a three-dimensional finite element model of the AIS patient by establishing a bone model,boundary modification,and grid division,and verify the model.2.The three-dimensional finite element model of the AIS patient was analyzed by Ansys analysis software.The stress changes of the model were simulated under six movements of forward flexion,backward extension,left flexion,right flexion,left rotation and right rotation.3.Combined with the anatomical characteristics of the spine and the deformity types of the patient with scoliosis,the stress distribution of the mild AIS patient was analyzed.Result and Conclusion1.A three-dimensional finite element model of the mild AIS patient has been established.2.The validity of the model has been verified from two aspects of geometry and mechanics.3.The displacement of the sixth cervical vertebra changed the most during the right flexion,and the displacement value was 105.26mm.4.The stress of the whole spine was the largest when the right rotation was carried out,the stress of the sixth cervical vertebrae was the largest at flexion and extension,the stress of the second thoracic vertebrae was the largest at static and left and right flexion,the stress of the third thoracic vertebrae was the highest when the left rotation was done,and the stress of the seventh cervical vertebrae was the largest when the right rotation was done.During static and forward flexion,the stress of the 2nd and 3rd thoracic intervertebral disc was the highest,the stress of the 3rd and 4th thoracic intervertebral disc was the highest when backward extension,the stress of the sixth and seventh cervical intervertebral disc was the highest when left and right flexion and right rotation,and the stress of 4th and 5th thoracic intervertebral disc was the largest when left rotation.