CT数字重建技术测量经骶椎后方骶髂关节螺钉固定应用解剖参数

目的 测量经骶椎后方骶髂关节螺钉（sacroiliac screw passing the back of sacrum，SISPTBOS）固定的相关解剖参数，为临床应用提供依据。 方法 分析32例骨盆正常的成人三维CT重建图像，观察SISPTBOS钉道范围，采用CT数字重建技术模拟植入SISPTBOS，测量钉道有关解剖参数，包括钉道长度（L）、进针点与S1上关节中央的距离（M1）、出针点与髋臼后上缘的距离（M2）、前倾角（e）、外倾角（f）、矢状面安全角（a）、冠状面安全角（b）、矢状面钉道最小直径（d1）和冠状面钉道最小直径（d2）。 结果 钉道内侧壁为弓状线，外侧壁为椎管后外侧壁和髂骨外层，下壁为S1骶孔与坐骨切迹的连线，上壁为骶骨翼斜坡、骶髂关节表面和大骨盆底部。L为（11.90±1.62） cm，M1为（2.07±1.40） mm，M2为（4.78±2.57） mm，e为（57.97±4.28）°，f为（54.89±5.13）°，a为（11.45±2.73）°，b为（7.46±1.34）°，d1为（8.57 ± 0.99）mm，d2为（6.75±0.84） mm。男女比较，仅e和f存在显著性差异（P<0.05）。 结论 可选择直径5.0~6.0 mm、长度9~10 cm螺钉作为SISPTBOS固定。该通道植入螺钉可行，较为安全。

Measurement of applied anatomical parameters of sacroiliac screw passing the back of sacrum by CT digital reconstruction technique

Objective To measure the anatomical parameters of the innovative sacroiliac screw-sacroiliac screw passing the back of sacrum(SISPTBOS), so as to provide basis for clinical application. Methods The 3D CT reconstruction images of 32 cases of normal adult pelvis were analyzed to observe the range of SISPTBOS channel, by simulating placement of SISPTBOS, measuring the anatomical parameters including the length of the screw channel（L), the distance between the insertion point and the center of superior articular process of S1(M1), the distance between the exit point and the superior- posterior border of actabulium(M2), the anteversion angle between the central axis and the line parallel to the upper endplate of S1(e), the outward angle(f), the safety angle in the sagittal plane(a), the safety angle in the coronal plane(b), the minimum diameter in the sagittal plane(d1) and the minimum diameter in the coronal plane(d2). Results The medial boundary of the screw canal was the inner wall of the arcuate line. The lateral boundary was the posterior-lateral walls of the spinal canal of S1 and the ilium, the lower boundary was the line between the sacral hole of S1 and the ischial notch, the upper boundary was the sacral slope, surface of sacroiliac joint, and the bottom of the true pelvis. L was (11.90±1.62) cm, M1 was ((2.07±1.40) mm, M2 was (4.78±2.57) mm, e was (57.97±4.28) °, f was (54.89±5.13) °, a was (11.45±2.73) °, b was (7.46±1.34) °, d1 was (8.57±0.99)mm and d2 was (6.75±0.84) mm. There were significant differences in the anteversion angle between the central axis and the line parallel to the upper endplate of S1 (e) and the outward angle(f) between males and females (P<0.05). Conclusions Implanting of the SISPTBOS is feasible and safe, which may be selected by using screws with a diameter of 5.0 to 6.0 mm and a length of 9 to10 cm.