不同体位下颈椎旋转手法对颈椎间盘位移和内在应力的影响

Effect of Cervical Rotatory Manipulation on Displacement and Intra-stress of Cervical Disc in Different Positions

目的利用三维有限元模拟颈椎在前屈、中立、后伸三种体位下行颈椎旋转手法,探讨该手法在不同体位下对颈椎间盘位移和内在应力的影响。方法 2016年11月对1例25岁健康成年女性志愿者的颈椎进行CT扫描成像,应用Mimics 10.01、Geomagic Studio、Solidworks 14.0等软件建立颈椎C5-6实体CAD模型,然后将模型导入Ansys Workbench 14.5软件进行有效性验证及手法模拟。在颈椎前屈、中立、后伸三种体位下进行手法分解,把各项力学参数代入三维有限元模型进行计算分析。即时显示手法作用时颈椎间盘的位移和内在应力的变化。结果在三种体位下,纤维环旋转对侧的后部均出现向前回缩变形,前屈位最大,中立位次之,后伸位最小;纤维环旋转侧的后部均出现向后膨出变形,前屈位最小,中立位次之,后伸位最大;椎间盘内在应力在三种体位下分别集中于旋转对侧后部、旋转对侧和旋转侧后部,其中前屈位最大,后伸位次之,中立位最小。结论从椎间盘安全性角度出发,颈椎旋转手法治疗神经根型颈椎病时,建议向健侧旋转,体位首选中立位,若疗效欠佳再考虑使用前屈位。颈椎管狭窄的患者不宜使用颈椎旋转手法治疗。

Objective To simulate the cervical rotatory manipulation(CRM)in flexion,neutral and extension positions using three-dimensional finite element,so as to investigate the effect of this manipulation on the displacement and intra-stress of cervical disc in different positions.Methods By using the method of reverse engineering with Mimics10.01,Geomagic Studio and Solidworks14.0,a three-dimensional geometric CAD model of C5-6was developed from the CT scan images of a normal adult female aged25years.The model was imported into Ansys Workbench14.5,and a three-dimensional finite element model was verified and simulated the CRM.The CRM was decomposed by principium of manipulation in flexion,neutral and extension,respectively.The parameter of mechanics was analyzed with the finite element system.The change of displacement and intra-stress distribution in cervical disc simultaneous were displayed during simulating the manipulation.Results The posterior part of opposite rotary side of annulus fibers was all retracted,and the displacement was toward anterior,maximal in flexion position,followed as neutral position and minimal in extension position.In the meantime,the posterior part of the rotary side of annulus fibers was expanded into posterior,minimal in flexion position,followed as neutral position and maximal in extension position.The intra-stress in cervical disc was focused on posterior part of opposite rotary side,opposite rotary side and posterior part of the rotary side in flexion position,neutral position and extension position,respectively,maximal in flexion position,followed as extension position and minimal in neutral position.Conclusion To treat with cervical spondylotic radiculopathy in the perspective of safety of cervical disc,the CRM should rotate to the unaffected side,first in neutral position,second in flexion position if with poor efficacy.Patients with cervical spinal stenosis should not be treated with the CRM.