Mechanical Analysis And Application Of Human Lumbar Spine Based On Finite Element Method

With the development of science and technology,studying the mechanical behavior of normal lumbar vertebrae under external load,mastering the pathogenesis of degenerative lumbar vertebrae,and comparing the treatment effects of different surgical procedures on lumbar vertebrae have become one of the important research directions of biomechanics.In this paper,we first study the main methods of establishing the three-dimensional model of the lumbar vertebrae and the constitutive models of the lumbar segments.On the basis of this,we optimize the method of establishing the lumbar vertebra 3D model and the constitutive model of the intervertebral disc by reverse modeling.In-depth research was carried out to establish a reliable lumbar finite element model,and the model was simulated by the finite element method.Further,this model was used to study the effect of lumbar degeneration on the mechanical behavior of lumbar segments,and the effects of different interbody fusion cages on the mechanical behavior of lumbar segments were compared.This study can be divided into three main parts:In the first part,based on image processing technology,a three-dimensional model of lumbar vertebrae was established.The constitutive model and boundary conditions of lumbar tissue structure in traditional theory were studied.Finally,the reliability of finite element model was verified.The results show that:(1)The finite element model can truly reflect the activity of lumbar vertebrae under various working conditions;(2)The values of intervertebral disc pressure and medical experiment results obtained by finite element model are very different.In the second part,the method of establishing the three-dimensional model of lumbar vertebrae is optimized by reverse modeling technique.The superelastic constitutive model is used to optimize the finite element model established by traditional theory,and the finite element mesh method is further studied.Finally,the finite element model is applied.The reliability is verified.In the third part,the optimized lumbar finite element model is applied to study the mechanical behavior of degenerative lumbar vertebrae and evaluate the surgical results.Aiming at the two cases of osteoporosis and intervertebral disc bulging,the corresponding finite element model of degenerative lumbar vertebrae was established.The surgical model of peek and titanium alloy was established for intervertebral cages with different materials.