目的建立C1-7全颈椎三维有限元模型,研究其在颈部肌肉作用下颈椎牵引的生物力学特性,为临床颈椎牵引的治疗提供参考。方法建立正常颈椎的三维非线性有限元模型,在此基础上结合临床颈椎牵引的方法,利用生物力学分析软件进行建模仿真,在牵引重量一定的情况下,用后伸0°、10°、20°、30°、40°进行牵引,获得关节力和肌肉力,筛选合适的关节力和肌肉力对颈椎模型进行有限元分析。结果颈椎后伸牵引过程中,在肌肉力的作用下,颈椎椎体、椎间盘、钩椎关节的平均最大等效应力分别增加4.86、1.79、0.69MPa,颈椎椎体的平均最大相对位移在矢状轴、垂直轴方向上分别增加5.53、0.63mm。颈椎后伸牵引的生物力学特性与文献中的有限元分析结果相近。结论颈部肌肉对颈椎各椎体、椎间盘以及钩椎关节应力及位移的增加具有较大的促进作用。临床上行颈椎后伸牵引时,应考虑到颈部肌肉的作用,牵引角度不宜过大,推荐0°~20°是颈椎牵引初期相对安全的角度范围。
Objective To establish a three-dimensional (3 D) finite element model of cervical vertebrae ( C1-'7), and study its biomechanical properties under muscle force by cervical traction, so as to provide references for clinical treatment. Methods On the basis of nonlinear finite element model of normal cervical vertebrae and com- bined with clinical traction methods, cervical traction at the extension angle of 0°, 10°, 20°, 30°, 40° under the same traction weight, was simulated by finite element analysis (FEA) software to obtain and select the joint force and muscle force that were appropriate for FEA on the model. Results In the process of cervical extension by traction, under the muscle force, the average maximum equivalent stress of cervical vertebrae, intervertebral disc and uncovertebral joints increased by 4.86, 1.79, 0.69 MPa, respectively, and the average maximum relative displacement of cervical vertebrae in sagittal and vertical axis direction increased by 11.1,l. 26 mm, respective- ly. The biomechanical properties of cervical traction were similar to the FEA results reported in the literature. Conclusions Neck muscles play an active role in promoting the stress and displacement of cervical vertebrae, in- tervertebral discs and uncovertebral joints and it should be taken into consideration when performing cervical trac- tion in clinic. In addition, the traction angle should not be too large: 0°-20° is generally recommended as a rela- tively safe angle range at the initial stage.