枢椎后路峡部螺钉固定的相关影像学测量

目的：通过CT测量探讨枢椎峡部螺钉固定技术的安全性和可行性。方法：收集2016年1月至2019年12月进行全颈椎CT检查的137例结构完整的上颈椎CT数据，其中男71例，女66例；年龄22~65（41.8±17.4）岁。通过Mimics19.0软件测量峡部螺钉技术相关的解剖学数据，包括峡部宽度、峡部垂直长度、峡部垂直高度、峡部螺钉通道长度、峡部螺钉通道头倾角度。并分析各项指标之间的相关性。结果：枢椎峡部宽度（9.05±1.63） mm，垂直长度（11.21±1.43） mm，垂直高度（17.53±2.93） mm。螺钉通道长度为（19.07±3.20） mm。峡部螺钉通道长度>14 mm的占94.53%，14~16 mm的占82.12%，16~18 mm的占63.14%，18~20 mm的占39.78%。螺钉通道的头倾角度为30°~68°，平均（46.06±8.06）°。螺钉通道长度和头倾角度呈高度正相关（r=0.965，P=0.000）。峡部垂直长度和螺钉通道长度，峡部垂直长度和螺钉的头倾角度之间都呈轻度正相关（r=0.240，P=0.000；r=0.163，P=0.007）。峡部宽度和螺钉通道长度，峡部宽度和螺钉通道的头倾角度之间都呈中度负相关（r=-0.333，P=0.000；r=-0.380，P=0.000）。结论：进行枢椎后路峡部螺钉固定安全、可靠，比枢椎后路椎弓根螺钉固定具有更大的适用范围，可以作为椎弓根螺钉的替代选择。

Imaging measurement for the posterior pars interarticularis screw fixation on axis

Objective: To explore the safety and feasibility of posterior pars interarticularis screw fixation on axis by CT measurement.Methods: The CT data of 137 patients with complete upper cervical spine who underwent full cervical spine CT examination from January 2016 to December 2019 were collected, including 71 males and 66 females, aged from 22 to 65 years old with an average of (41.8±17.4) years old. Mimics 19.0 software was used to measure anatomical data related to the pars interarticularis screw, including the pars width, pars vertical length, pars vertical height, length of pars screw trajectory, upward inclination angle of pars screw trajectory. And the correlation between each index was analyzed.Results: The axis pars has an average width of(9.05±1.63) mm, an average vertical length of(11.21±1.43) mm, and an average vertical height of (17.53±2.93) mm. The mean length of pars screw trajectory was(19.07±3.20) mm. Regarding to the length of pars screw trajectory, 94.53% of pars measured more than 14 mm, 82.12% of pars measured at 14-16 mm, 63.14% of pars measured at 16-18 mm, 39.78% of pars measured at 18-20 mm. The upward inclination angle of pars screw was 30°-68° with an average of(46.06±8.06) °. There was a highly positive correlation between the length of screw trajectory and upward inclination angle(r=0.965, P=0.000). The vertical length of pars was weakly positively correlated with length of screw trajectory and upward inclination angle(r=0.240, P=0.000;r=0.163, P=0.007). Pars width was moderately negative correlated with length of scrwe trajectory and upward inclination angle(r=-0.333, P=0.000;r=-0.380, P=0.000).Conclusion: The posterior pars interarticularis screw fixation is safe and reliable. It has a more wider applicability than pedicle screw fixation and can be used as an alternative to pedicle screws.