Model Simplification Of The Spine And Finite-element Analysis In Condition Of Internal Force

Scoliosis is a3D spinal deformity that is a segment of spinal of human body occurs lateral bending and accompanying with the spinal's rotation. Adolescent Idiopathic Scoliosis (unknown cause) takes in the highest proportion of Scoliosis, whose pathological and orthodontic treatment are always one of concerned hot issues by scholars and experts of medical profession and labor community. Based on the above-mentioned premise, the biomechanical characteristics of spine is studied through establishing the spine3D simplified model and Finite-element model of spinal of human body in this paper. Thus, it will provide the reliable basis for analyzing the pathogenesis of adolescent idiopathic scoliosis and the optimization of orthodontic treatment.It is proposed to built a method of simplified model about the spinal structure of human body in this paper. This model mainly contains the human body's spine of vertebrae (including the small joint), disc, joint capsule, etc. Which are counted as mechanical parts and are combined as a unit according to a certain assembly relationship in the process of establishment. Then, the established model imported into Workbench of analysis module of ANSYS. And, which is carried on preliminary treatment so as to build Finite-element model that is imported into ANSYS to make analysis. The studied internal force is the force of the spine's deformation due to the pathological change of disc and joint capsule to cause the change of structure, shape, size and position in this paper.The conclusion shows that:1. In the process of researching the deformation of spine caused by damage of joint capsule, some results are found. When the small joints stands internal force at any one place, the spinal generally produce a certain degree of axial compression (along the Z axis) and rear extension of the spine's section. When the left and right sides stands the force with the different size and the asymmetric direction, spinal appeares reverse phenomenon and tiny migration. This shows that, because of the right and left little joint under nonequilibrium forces, thus causes the torsion of vertebral body, which is one of reasons of causing the shift of spinal (side protruding).2. The internal force are uneven which is impacted by the pathological change of disc, the whole spine will not only occurres axial compression deformation, but also more importantly occurres scoliosis and rear extension of right and left protruding so as to make original physiology bend curvature of human body spinal to occur the change, even the normal direction also changed. In addition, the vertebral's lower surface has the largest torsional angle where the biggest deviant occur. Thus we can speculate that:when vertebral bear internal force which is caused by disc lesions, because of the inhomogeneity of the force, the overall spinal happened all kinds of deformations that hard to predict, including compression, side protruding, extension and reverse, etc. And idiopathic scoliosis is also composited by all sorts of deformations that hard to predict, so disc disease may be one of the important causes which is causing scoliosis.Researched content and conclusion of this paper will provide a certain help for analyzing the pathogenesis to adolescent idiopathic scoliosis (AIS), and provide related reference for medicine clinical operation.