OBJECTIVE: To measure the screw placement-related data by pelvic 3D CT reconstruction, so as to guide the screw placement and improve its accuracy.    

METHODS: Fifty patients with pelvic lesions or fractures admitted in Shandong Provincial Third Hospital from January 2013 to December 2016 were selected, and the pelvis was scanned with CT and then was reconstructed. The point A (the intersection of S₁ posterior sacral posterior wall and posterior superior iliac spine) was as the screw placement point, and three paths were measured on the point: posterior superior iliac spine path (AD path); anterior inferior iliac spine path (AC path); top of greater sciatic notch to the acetabular roof (AB path). On the plane of these three pathes, the section was made on the iliac bone, respectively; in each section, the channel for iliac nail was designed.

RESULTS AND CONCLUSION: (1) In the same path, there was no significant difference in the path length of the screw between male and female patients (P > 0.05). Paired t test showed that the diameter and length depth and angle of the screws were significantly different between AD and AC paths, AC and AD (P < 0.05). (2) There was no significant difference in the inclination angle of the spiral channel between male and female patients (P > 0.05). The inclination angle of the spiral channel and lateral angle at different paths showed significant difference between male and female patients (P < 0.05). (3) To conclude, 3D reconstruction of pelvis CT can be used to measure the length, diameter and angle of the iliac screw, and to guide the surgical treatment. 

中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程