Three ways of inserting the anteroinferior iliac spine channel screws: a computer simulation comparison / 中华创伤骨科杂志

ABSTRACT

Objective To compare the safely between 3 ways of inserting the anteroinferior iliac spine channel screws using computer simulation.Methods The spiral pelvic CT data of 100 patients were collected who had sought medical treatment at General Hospital of The Northern Theater Command from October 2017 to October 2018.They were 61 males and 39 females,aged from 20 to 60 years (average,47.5 years).The data were imported into Mimics (Materi-alise,Belgium) software to create three-dimensional models of the pelvis.The pelvic modeling data were then imported into 3-Matic (Materi-alise,Belgium) software for post-processing.Three cylinders with a diameter of 6.7 mm were created,taking the anteroinferior iliac spine as the entry point and taking the posterosuperior iliac spine,the posteroinferior iliac spine and the midpoint between the 2 spines as the 3 exit points.The insertion of anteroinferior iliac spine channel screws was simulated to observe the screw penetration.Results In the channel from the anteroinferior iliac spine to the posterosuperior iliac spine,penetration occurred in 41 cases out of the medial ilium and in 2 cases out of the lateral ilium,giving a penetration rate of 43％ (43/100);in the channel from the anteroinferior iliac spine to the midpoint between the 2 spines,penetration occurred in 16 cases out of the medial ilium and in 2 cases out of the lateral ilium,giving a penetration rate of 18％ (18/100);in the channel from the anteroinferior iliac spine to the posteroinferior iliac spine,penetration occurred in 6 cases out of the medial ilium,in 2 cases out of the lateral ilium,in 60 cases out of the greater sciatic notch and in 8 cases out of both the medial ilium and greater sciatic notch,giving a penetration rate of 76％ (76/100).There were significant differences between the 3 ways of insertion in the screw penetration (x2 =68.219,P ＜ 0.001).The rate of screw penetration in the channel from the anteroinferior iliac spine to the posteroinferior iliac spine was significantly higher than that in the channel from the anteroinferior iliac spine to the posterosuperior iliac spine which was significantly higher than that in the channel from the anteroinferior iliac spine to the midpoint between the 2 spines (P ＜ 0.05).Conclusions The channel from the anteroinferior iliac spine to the midpoint between the posterosuperior iliac spine and the posteroinferior iliac spine may lead to a lower rate of screw penetration while the channel from the anteroinferior iliac spine to the posteroinferior iliac spine may lead to a higher rate of screw penetration.