[Three-dimensional computed tomography analysis and clinical application of sacroiliac screw placement]

Zhonghua Wai Ke Za Zhi. 2018 Mar 1;56(3):201-205. doi: 10.3760/cma.j.issn.0529-5815.2018.03.007.
[Article in Chinese]

Abstract

Objective: To evaluate the possibility of transverse sacroiliac screw placement in different segments of the sacrum. Methods: Data of 80 pelvic CT scans (slice thickness ≤1.0 mm) archived in CT department of the Third Hospital of Hebei Medical University from September 2016 to October 2017 were retrospectively collected. Mimics software was used to rebuild the pelvis three-dimensional model. According to whether the sacral 1(S(1)) segment could place the transverse sacroiliac screws or not, all the sacrums were divided into normal group (n=55) and dysmorphic group (n=25). Simulation the S(1), sacral 2(S(2)) transverse sacroiliac screw placement in 3-Matic software. Analysis whether there was any difference in maximum diameter and length of S(2) transverse sacroiliac screw between the normal group and the dysmorphic group. The pelvic CT data of the dysmorphic group were measured, and the optimal tilt angle and length of the oblique S(1) screw were obtained. The feasibility of transverse sacroiliac screw insertion in sacral 3(S(3)) segment was evaluated.t-test, rank sum test, and χ(2) test was used to analyze data, respectively. Results: In the dysmorphic group, the largest diameter of the S(1) transverse screw was (4.9±1.6)mm, and the normal group was (13.6±3.6)mm (t=-15.07, P=0.00). In the dysmorphic group, the largest diameter of S(2) transverse screw was (13.8±3.0)mm, and was (12.4±2.2)mm in the normal group(t=2.11, P=0.04). There was no significant difference in the length of S(2) transverse sacroiliac screw between the two groups (t=0.47, P=0.64). In the dysmorphic group, the anterior vertebral height of S(1) was (23.1±4.0)mm, which was significantly higher than that of the normal group ((14.1±4.2)mm)(t=9.01, P=0.00). The angle of S(1)S(2) in the dysmorphic group was 10.9°(3.8°, 17.6°), which was significantly larger than that of the normal group (2.0°(1.0°, 2.0°) (Z=-4.03, P=0.00). In the dysmorphic group, the incline angle of the oblique S(1) sacroiliac screw was (35.6±6.2)°, the anteversion angle was (37.2±4.4)°, and the mean screw length was (90.2±4.7)mm. In the dysmorphic group, the placement rate of S(3) transverse sacroiliac screw was 48.0%, and that of the normal sacral group was 9.1%. Conclusions: There is often dysmorphic in the sacrum in patients with large S(1) anterior vertebral height and S(1)S(2) angle. Sacral dysmorphic patients with posterior pelvic ring injury may be treated with S(1) pedicle oblique sacroiliac screws. S(3) transverse sacroiliac screws should be carefully placed, especially for the absence of sacral dysmorphic in patients.

目的:探讨不同节段骶骨置入骶髂关节横行螺钉的可能性。 方法:回顾性收集2016年9月至2017年10月在河北医科大学第三医院接受骨盆CT扫描的80例患者的CT原始数据(层厚≤1.0 mm)。采用Mimics软件重建骨盆三维模型。根据S(1)节段是否可横行置入骶髂螺钉,将入组资料分为骶骨正常组(n=55)和骶骨变异组(n=25)。在3-Matic软件中模拟S(1)、S(2)横行骶髂螺钉置入过程。分析骶骨正常组和骶骨变异组骶骨可置入S(2)横行骶髂螺钉的最大直径及长度有无区别。测量骶骨变异组骨盆CT资料,得出沿S(1)椎弓根置入骶髂螺钉时螺钉的最佳倾斜角度及长度。评估S(3)节段置入横行骶髂螺钉的可行性。计量资料的比较采用t检验或秩和检验进行分析;计数资料的比较采用χ(2)检验进行分析。 结果:骶骨变异组S(1)最大横行骨通道直径为(4.9±1.6)mm,骶骨正常组为(13.6±3.6)mm,两组差异有统计学意义(t=-15.07,P=0.00);骶骨变异组S(2)最大横行骨通道直径为(13.8±3.0)mm,骶骨正常组为(12.4±2.2)mm,两组差异有统计学意义(t=2.11,P=0.04)。骶骨变异组和骶骨正常组S(2)可通过横行骶髂螺钉的长度分别为(137.1±8.8)mm和(136.2±7.9)mm,差异无统计学意义(t=0.47,P=0.64)。骶骨变异组S(1)椎体前缘高度为(23.1±4.0)mm,高于骶骨正常组的(14.1±4.2)mm(t=9.01,P=0.00)。骶骨变异组的S(1)S(2)夹角为10.9°(3.8°,17.6°),大于骶骨正常组的2.0°(1.0°,2.0°)(Z=-4.03,P=0.00)。骶骨变异组S(1)斜型骶髂螺钉的头倾角度为(35.6±6.2)°,前倾角度为(37.2±4.4)°,可置入的螺钉长度为(90.2±4.7)mm。骶骨变异组的S(3)横行骶髂螺钉置入率为48.0%,骶骨正常组的S(3)横行螺钉的置入率为9.1%。 结论: S(1)前缘高和S(1)S(2)夹角较大的患者通常存在骶骨变异,骶骨变异的骨盆后环损伤患者可考虑置入S(1)椎弓根斜行骶髂螺钉。S(3)横行骶髂螺钉应谨慎置入,尤其是对于骶骨无变异的患者。.

Keywords: Dysmorphic; Imaging, three-dimensional; S(1) transverse iliosacral screw; Sacrum.

MeSH terms

  • Bone Screws*
  • Fracture Fixation, Internal*
  • Humans
  • Pelvis
  • Retrospective Studies
  • Sacroiliac Joint* / diagnostic imaging
  • Sacroiliac Joint* / injuries
  • Sacroiliac Joint* / surgery
  • Sacrum*
  • Tomography, X-Ray Computed