Methods: 22 pelvis specimens of native adults were studied, a total of 44 sacroiliac joint anthropometric measurement were performed on 22 cadaveric pelvises to determine the shape of S_1 pedicle transverse section, the optimal entry point for iliosacral screw on the outer table of the posterolateral ilium, the direction of screw, and the dista.

Improving the automation of the process of needle insertion can reduce the operator’s man-made factors such as skill level requirements, improve the accuracy and efficiency of needle insertion, and minimize the injuries of patient\'s organs and major vascular.