下颈椎后路3种固定技术的拔出强度研究

Pull-out strength of posterior lower cervical screws inserted by three fixation techniques

目的评价下颈椎后路侧块螺钉、椎弓根螺钉、经关节螺钉3种固定方法的拔出强度。方法6具新鲜颈椎尸体标本(C3～C7),分别用侧块螺钉Roy-Camille法(LMS)、椎弓根螺钉(TPS)和经关节螺钉植入法(TAS)拧入螺钉,使用万能材料实验机,以100、200、300、400、500、600N分级加载,以18mm/min加载速度进行螺钉拔出实验,测试其最大拔出力、最大拔出能量。结果LMS最大拔出力为(426±38)N,最大拔出能量为(5.26±0.39)J;TPS最大拔出力为(502±42)N,最大拔出能量为(7.18±0.67)J;TAS最大拔出力为(482±40)N,最大拔出能量为(6.68±0.47)J。LMS的最大拔出力和最大拔出能量均小于TPS和TAS(P<0.05),而TPS和TAS之间相近,差异无统计学意义(P>0.05)。结论经关节螺钉拔出强度优于侧块螺钉,而椎弓根螺钉拔出强度最大。

Objective To evaluate the pull-out strength of posterior lower cervical screws inserted by three fixation Techniques.Methods Six fresh cervical spine samples（C3～C7） were implanted with screws using lateral mass screw Roy-camille technique,pedicle screw technique and transarticular screw technique,respectively.The screw pull-out testing was carried out at the load of 100,200,300,400,500 and 600N and the speed of 18 mm/min on the experiment machine.The maximum pull-out strength and pull-out energy were tested.Results The maximum pull-out strength was（426±38）N for lateral mass screw,（502±42）N for pedicle screw,（482±40）N for transarticular screw;The maximum pull-out energy was（5.26±0.39）J for lateral mass screw,（7.18±0.67）for pedicle screw,（6.68±0.47）J for transarticular screw.The maximum pull-out strength and pull-out energy of lateral mass screw were less than pedicle screw and transarticular screw（P〈0.05）.The pull-out strength and pull-out energy of the pedicle screw and the transarticular screw were equal.Conclusions The transarticular screw technique provides stronger fixation than the lateral mass screw technique,and the pedicle screw technique is the strongest.