摘要
目的建立上颈椎的有限元模型(C0-C3),对Hangman骨折的常见致伤暴力进行应力分析。方法选取一名健康成年男性例行体检CT资料,以层厚0.6mm进行连续颈部扫描得到的断层数据图片,导入到医学三维重建软件MIMICS中进行处理,得到模型的表面,以LIS格式导入到ANSYS软件中,生成三维实体,并确定单元类型赋予材料属性。得到上颈椎模型骨性结构的实体。依据文献资料及参考CT结果对上颈椎软组织进行建模。通过对上颈椎有限元模型加载前屈、后伸、压缩、牵张暴力的方法模拟临床上常见的导致Hangman骨折的暴力作用方式,对加载结果进行分析研究,探讨Hangman骨折的损伤机制。结果①在纵向牵张载荷作用下,寰椎前部、寰枢外侧关节、C2-3椎体间、C2-3小关节、C3椎板棘突部分所受应力较为集中,枢椎峡部未见明显应力集中;②在纵向压缩载荷作用下,应力由上颈椎前上到后下部逐渐降低,其中应力最大处位于寰椎前弓,其次为寰枢关节、枢椎椎体、C3椎体,而枢椎以下的后柱结构所受应力相对较小;③在过伸力矩作用下,寰椎侧块、侧块与后弓交界部、寰椎后弓结节;枢椎上关节面、峡部、下关节突部分以及前纵韧带是应力集中的部位;④在过屈力矩作用下,上颈椎前部、枕寰关节、后弓、寰椎后弓结节:枢椎棘突、峡部、下关节突为应力相对集中处。结论过伸和过屈暴力应是导致Hangman骨折的两个主要的致伤机制,而轴向牵张和压缩暴力不直接导致枢椎峡部应力增大,不是主要的致伤力。
Objective To develop finite element model of upper cervical spine （Compared with C0- C3 ）, Force loads inducing Hangman＇s fracture were applied to the model to analyzing the stress distribution. Methods We obtained the CT data from a healthy adult man for the regularly health examination. Then his cervical spine was scanned by 0.6 mm thickness without any interval. Then the CT images were inputted to the Mimics software and product a 3D surface image of C0-C3 by selecting image, preconditioning and remeshing tools. The 3D image was inputted to the ANSYS with LIS format and became a 3D entity, And the element type and material properties were defined at the same time. The soft tissue of cervical spine were modeled according to literature. Force loads including flexion, extension, compression and tension were applied on the occiput to elucidate which load scenarios could result in Hangman＇s Fracture. Results ① Under tension load, higher stress was occurred in foreside of ring, atlanto-axial articulation, C2-3 disc, C2-3 facet joint and C3 spinosus. ②Under compression load, higher stress was occurred in foreside of ring, atlanto-axial articulation, C2-3 disc. The posterior parts had lower stress. ③ Under extension load, higher stress was occurred in lateral mass and posterior arch of the ring, facet articulation and pars interarticularis of the axis. ④Under flexion load, higher stress was occurred in the anterior parts of the model, atlanto-occipital articulation, posterior arch of the ring, inferior facet articulation and pars interarticularis of the axis. Conclusions Forces of excessive flexion and ex- tension were the main casual mechanisms leading to Hangman＇s Fracture. Whereas forces of compression and tension werent the main casual mechanisms but they were the accessorial causes.
出处
《中国现代药物应用》
2008年第15期9-11,共3页
Chinese Journal of Modern Drug Application
