颈椎拔伸旋转手法内在应力的实时监测

Real-time monitor of intra-stress distribution in cervical spine during cervical rotatory manipulation

目的研究颈椎拔伸旋转手法内在应力的分布特点。方法应用有限元分析软件在颈椎CT片基础上逐步重建C3/4～C6/7颈椎模型并网格化。将颈椎拔伸旋转手法分解后的各项力学参数代入模型进行计算分析,即时显示手法作用时模型内在应力的变化。结果拔伸过程,模型应力集中的区域及大小呈由大减少再增大的趋势,应力主要在C3/4关节突关节;拇指向左推C4棘突过程中,C4棘突的左下部、根部、棘突左侧根部与椎弓根结合处先后出现应力集中,最大应力为9.627kPa;颈椎向右旋转40°的过程中,C3～6双侧关节突关节,C4～6的椎弓、棘突根部、二者结合处及椎体侧方等都先后出现应力集中,右侧C3/4关节突关节应力最大,为363.6kPa。颈椎快速返回中立位,模型应力集中的区域及大小均快速减少。结论颈椎拔伸旋转手法下的颈椎有其独特的应力变化规律。关节突关节在颈椎活动中承受主要应力。右旋40°时模型所受压力最大,但不会损伤正常颈椎骨性结构。

Objective To explore the characters of intra-stress distribution in cervical spine during cervical rotatory manipulation（CRM）.Methods A 3D finite element model of C3/4～C6/7 was set up through software systems handling normal C3～C7 CT images.The decomposed mechanic parameters of CRM were analyzed by the finite element system.The changes of intra-stress distribution in model were displayed simultaneously during simulating manipulation.Results The size and region of stress suffered cervical model gradually decreased,and then increased gradually during pulling manipulation.The regions of stress concentration were mainly in C3/4 zygapophyseak joints.With increased thrust in C4 spinous process turning to the left,left bottom and root of C4 spinous process,combination area in left bottom and vertebral of pedicle C4 spinous process appeared stress concentration in turn,with the greatest stress of 9.627 kpa.In the process of cervical spine turning and right rotating about 40°,bilateral C3～C6 zygapophyseak joints,C4～C6 vertebral arch,the root of C4～C6 spinous process and the lateral side of C4～C6 vertebral body appeared stress concentration in turn,with the greatest stress of 363.6kpa in right of C3/4 zygapophyseak joints.The size and the region of stress suffered model reduced quickly at the stage of quickly returning to neutral position.Conclusions Cervical spine has its unique characters of intra-stress distribution under the CRM.Zygapophyseak joints suffer the major stress during the cervical spine movement.Model suffered the greatest stress under right rotation with 40°,but it did not injure the normal structrue of cervical spine.