Analog Of Cervical Kyphosis By Finite Element Method

Backgroud: The cervical kyphosis is the progressive curvature malformation of cervial spine, it can affect the normal cervial spine function of children and adult. The cause of most of patients with cervical kyphosis is iatrogeic injury, postlaminectomy cervical kyphosis is main cause of this malformation, In a few of patient, the cause of this malformation is idiopathic. In literatures, The studies on the cause of cervical kyphosis has been focused on postlaminectomy cervical kyphosis, the cause of idiopathic cervical spine is known little and very few of study has been done in literatures.Objective: In this study, we reconstruct and analyze the postlaminestomy cervical spine model with finite element method, we evaluate the affect of laminectomy on cervical spine curvature, analyze the role of the gravitative center of head, the elastic modulus of cervical intervertebral disc and ligaments on maintenance the curvature of cervical spine after laminectomy, and want to clarity the reason of great difference of morbidity of cervical kyphosis between children and adult after laminectomy. In this study, we also reconstruct and analyze the cervical spine model with finite element method. The cerviacl spine model include the cervical vertebras, posterior arch, spinous process, intervertebral disc, anterior and posterior longitudinal ligaments, capsular ligament, ligamentum flavum, interspinous and supraspinous ligaments. We also analyze the role of the gravitative center of head, the elastic modulus of cervical intervertebral disc and ligaments on maintenance the curvature of cervical spine, and want to find the possible causes that cause the idiopathic cervical kyphosis. at the final of this study, we report the operational methods and the effect of patients with cervical kyphosis, and rudimental discuss how to treat the cervical kyphosis. Methods: In this study, the highly resolution pictures of cervical spinal cross section were used as data to reconstruct the three-dimensional cervical spine models, which the interval distance of lays is lmm. This study reconstruct two cervical spine models, the completely cervical spine model include the base of skull, the superior part of first thoracic vertebra and all construction of cervical spine, such as the cervical vertebras,posterior arch, spinous process, intervertebral disc, anterior and posterior longitudinal ligaments, capsular ligament, ligamentum flavum, interspinous and supraspinous ligaments. The second cervical spine model is postlaminectmy cervical spine model, it include all the structions of the completely cervical spine model except the vertebral lamina, spinous process, the ligamentum flavum ,the interspinous and supraspinous ligament from the second to the seventh cervical spine. We defined the finite element and elastic modulus of the structions of cervical spine according the literatures. With the postlaminectomy cervical spine model and finite element software ansys6.1, we study the affect of laminectomy to the curvature of cervical spine, analyze the curvature change of cervical spine under the antedisplacement of gravitative center of head, the change of elastic modulus of intervertebral disc and ligament. With the completely cervical spine and finite element software ansys6.1, we study the curvature change of cervical spine under the antedisplacement of gravitative center of head, the change of elastic modulus of intervertebral disc and ligament. We simulate the cervical spine by changing the position of gravitative center of head, the elastic modulus of intervertebral disc and ligaments. 14 patients with idiopathic cervical kyphosis were all treated with operation, include the anterior decompression, interbody fusion and/or anterior plate fixation, the average follow-up period was 12 months (ranging 6-15 months). Results: The results of finite element analysis show:1 Normal cervical spine can maintenance normal physical lordosis under multi-load, after multi-load, the cervical lordosis slight increase.2 The physical lordosis of postlaminectom...