侧卧位枕高与颈椎间盘应力关系的三维有限元分析

The relationship between pillow height and cervical intervertebral disc stress in lateral decubitus position by three-dimensional finite element analysis

目的 采用三维有限元法分析人体侧卧位状态下枕高与颈椎间盘应力的关系,为合理用枕提供依据.方法 对1名正常男性志愿者进行颈椎薄层CT扫描,联用医学图像处理软件Mimics、逆向工程软件Geomagic Studio、有限元软件MSC.Patran建立人体侧卧位枕高分别为10 cm（冠状面颈椎左侧屈）、17 cm（冠状面颈椎中立）、25 cm（冠状面颈椎右侧屈）3种条件下的全颈椎三维有限元模型,并进行分析运算.结果 冠状面颈椎近似中立位模型（枕高17 cm）的等效应力、最大主应力、最大剪应力均明显低于左侧屈或右侧区模型.结论 颈椎冠状面处于中立位可使颈椎间盘获得最佳应力分布状态.人体侧卧睡眠时,合理的枕高应是颈椎在冠状面处于中立位.

Objective To analyze the relationship between pillow height and cervical intervertebral disc stress in lateral decubitus position of the human body using three-dimensional finite element method,and to provide the basis for appropriate pillow selection.Methods A cervical spine CT scan was performed on a normal male volunteer.The medical 3D image reconstruction software （Mimics）,reverse engineering software （Geomagic Studio） and finite element software （MSC.Patran） were collectively used to establish three-dimensional finite element models of the whole cervical spine under three lateral decubitus conditions,includes pillow height of 10 cm （cervical spine leftward flexion）,17 cm （cervical spine neutral）,and 25 cm （cervical spine rightward flexion）.Moreover,the finite element analysis and calculation of the three models were conducted.Results The Von-Mises stress,maximal principal stress and maximum shear stress of the model in cervical spine neutral （pillow height=17 cm） were all significantly lower than those of the cervical spine lateral model.Conclusions When the cervical coronal plane is in neutral position,the cervical discs can achieve the best stress distribution state.In lateral decubitus position of the human body,a appropriate pillow height should make the cervical vertebrae in neutral position.