不同体位下推拿旋转手法对颈椎间盘有限元模型应力分布的影响

Influence of Massage and Rotation Manipulation in Different Postures on Stress Distribution of Finite Element Model of Cervical Intervertebral Disc

目的探讨不同体位下推拿旋转手法对颈椎间盘有限元模型应力分布的影响,为其临床应用奠定基础。方法采集1例健康男性志愿者的CT和MRI数据,以逆向工程软件Geomagic Studio 12.0建立颈椎间盘有限元模型,并分别模拟前屈30°、中立位和后伸30°三个体位予以旋转推拿的力学载荷,Ansys 13.0软件计算不同体位的力学载荷下颈椎间盘有限元模型髓核应力分布和位移变化。结果本次研究建立颈椎C4/C6有限元模型,共包括19255个节点,96275个单元,C4/C5、C5/C6的屈曲、伸直、侧弯、旋转力矩与实验模型的符合程度相对满意。前屈30°、中立、后伸30°三种不同体位下,椎间盘的内在应力分布均集中在纤维环,髓内压变化幅度小于纤维环,但与纤维环变化趋势基本一致,髓核位移与髓内压变化基本一致。退变的椎间盘模型在静止生理状态时便有髓核位移情况,施加旋转手法后,髓内压和髓核位移均有所增大,其中C4/C5、C5/C6髓内压和髓核位移在后伸30°位时最小,其次是中立位,前屈30°位最大。结论颈椎间盘有限元模型分析结果支持后伸30°位时旋转手法对颈椎间盘髓核影响较小,安全性高。

Objective To explore the effects of massage rotation in different postures on stress distribution of finite element model of cervical intervertebral disc,so as to provide data evidence for itsclinical application.Methods CT and MRI data of a healthy male volunteer were recruited,and the finite element model of cervical intervertebral disc was established by reverse engineering software Geomagic Studio 12.0.The mechanical load of the rotary massage respectively at different cervical spine movement position was simulated and the stress distribution and displacement of nucleus pulposus was calculated and analyzed by Ansys13.0.Results In this study,the C4/C6 finite element model of cervical spine was established,including 19255 nodes,96275 units.And the compliance degree between the buckling,straightening,lateral bending and rotation moment of C4/C5 and C5/C6 was relatively satisfactory.In different movement positions,the internal stress distribution of intervertebral disc is all concentrated in the annulus.The magnitude of change of intramedullary pressure is smaller than that of the annulus,but it is basically consistent with the trend of change of the annulus,and the displacement of nucleus pulposus is basically consistent with the change of intramedullary pressure.The degenerative model of intervertebral disc has the displacement of nucleus pulposus in the static physiological state.After the application of rotation technique,both the intramedullary pressure and the displacement of nucleus pulposus were increased.The intramedullary pressure and displacement of both C4/C5 and C5/C6 got minimum value at the back stretch for 30 angular unit and got maximum value at the forward stretch for 30 angular unit.Conclusion The analysis results of finite element model of cervical intervertebral disc support that the massage rotation at the back stretch for 30 angular unit has little effect on the nucleus pulposus of cervical intervertebral disc.