国人成人经第1及第2骶椎骶髂骨螺钉置钉钉道差异的CT测量

Assessing difference between S1 and S2 alar-iliac screw placement by computed tomography in Chinese adults population

目的对国人经第1第2骶椎骶髂(sacral alar-iliac,SAI)螺钉固定钉道各参数进行CT测量,比较S1AI和S2AI螺钉钉道解剖参数差异。方法随机选取2015年4-10月本院影像归档和通信系统中60例骨骼发育成熟且骨盆正常国人的三维计算机断层扫描(3DCT)重建数据进行分析。S1和S2骶髂骨螺钉钉道参数中最大长度和宽度的轨迹通过旋转并截取三维骨盆获得。对长度和角度参数进行评估和比较。结果 S1AI置钉较S2AI置钉尾向倾角大,男性平均增加约26°,女性平均增加约24°[男性S1(57.25±4.37)°vs S2(31.02±7.43)°,女性S1(58.61±5.11)°vs S2(34.16±6.02)°;P<0.05];外倾稍小,男性、女性皆平均减少2°[男性S1(38.14±3.10)°vs S2(40.25±2.84)°,女性S1(37.24±2.96°)vs S2(39.25±2.64°);P<0.05];最长钉道长度:男性S1(119.46±3.77)mm vs S2(120.04±6.52)mm(P=0.551),女性S1(108.21±5.24)mm vs S2(109.47±4.63)mm(P=0.434);骶骨内钉道长度:男性S1(43.12±4.63)mm vs S2(35.75±5.03)mm(P<0.05),女性S1(39.73±5.85)mm vs S2(32.16±5.28)mm(P<0.05);髂骨内宽度:男性S1(22.05±4.91)mm vs S2(21.49±3.22)mm(P=0.672),女性S1(16.93±2.12)mm vs S2(15.35±2.71)mm(P=0.366);骨皮质距离:男性S1(9.42±2.41)mm vs S2(9.01±2.33)mm(P=0.352),女性S1(5.92±1.48)mm vs S2(6.34±1.26)mm(P=0.837)。S1AI与S2AI的入钉点比较,距皮肤距离、距中线距离、距髂后上棘距离均有统计学差异。结论国人成人骨盆存在最佳骶髂骨螺钉置钉钉道时,S1AI及S2AI螺钉均具有可行性。S1AI螺钉较S2AI螺钉置钉角度尾向倾角男性平均增加约26°,女性平均增加约24°,外倾稍小,男性女性皆平均减少2°,最长置钉长度基本相同,S1AI的入钉点距皮肤和髂后上棘更深,距中线稍远。临床操作中应注意S1和S2骶髂骨螺钉置钉角度、钉道长度及入钉点的差异。

Objective To assess the radiographic parameters of S1 and S2 sacral alar iliac（SAI） screws in Chinese adults population and compare the parameters of S1-AI and S2-AI techniques. Methods Three dimensional computed tomography（3DCT） reconstructions of 60 randomly selected Chinese skeletally mature patients with normal pelvis in our hospital from April to October in 2015 were analyzed. Trajectories of S1 AI and S2 AI techniques with maximal length and width were obtained by manipulating and rotating the 3D pelvis. The length and angulation parameters were evaluated and compared. Results Based on the ideal trajectory, the parameters of S1 AI and S2 AI technique were shown as follows： the S1 AI trajectories were more caudal than S2 AI trajectories with average sagittal angulation increasing 26° in male and 24° in female. The sagittal angulation was [（57.25±4.37）°（S1） vs（31.02±7.43）°（S2）, P〈0.05] in male and [（58.61±5.11）°（S1） vs（34.16±6.02）°（S2）, P 0.05] in female. The lateral angulation of S1 AI trajectories was 2° less than that of S2 AI trajectories on average, which was [（38.14±3.10）°（S1） vs（40.25±2.84）°（S2）, P 0.05] in male and [（37.24±2.96）°（S1） vs（39.25±2.64）°（S2）, P 0.05] in female. The maximal length of trajectories was [（119.46±3.77） mm（S1） vs（120.04±6.52） mm（S2）, P=0.551] in male, and [（108.21±5.24） mm（S1） vs（109.47±4.63） mm（S2）, P=0.434] in female. The length of sacroiliac screws in male was [（43.12±4.63） mm（S1） vs（35.75±5.03） mm（S2）, P 0.05], and [（39.73±5.85） mm（S1） vs（32.16±5.28） mm（S2）, P 0.05] in female, and the width of it was [（22.05±4.91） mm（S1） vs（21.49±3.22） mm（S2）, P=0.672] in male and [（16.93±2.12） mm（S1） vs（15.35±2.71） mm（S2）, P=0.366] in female. The distance to cortical bone was [（9.42±2.41） mm（S1） vs（9.01±2.33） mm（S2）, P=0.352] in male and [（5.92±1.48） mm（S1） vs（6.34±1.26） mm（S2）, P=0.837] in female. There were significant differences in the distance from screw entrance point to skin, median line and spina iliaca posterior superior between S1 AI and S2 AI technique. Conclusion The application of S1 AI and S2 AI screws into the sacrum and ilium of Chinese adult population is feasible along with the angle and length of ideal trajectory. The S1 AI trajectories are more caudal than S2 AI trajectories with average sagittal angulation increasing 26° in male and 24° in female, and the lateral angulation of S1 AI trajectories is 2° less than that of S2 AI trajectories on average. The maximal lengthes of trajectories are almost the same, while the distance from screw entrance point to skin and spina iliaca posterior superior of S1 AI is much deeper, and the distance from screw entrance point to median line is longer. Differences between S1 AI and S2 AI ideal trajectories should be noticed in operation.