Fig. 3From: Safe surgical corridor for iliosacral screw placement in unstable pelvic fractures: a computed-tomography-guided validation study of the “triangulation method”Rectangular plane coordinate system The plane cartesian coordinate system is established in the plane where the three points, namely, the greater trochanter, the ASIS, and the SEP, are located ASIS, anterior superior iliac spine; SEP, skin entry pointBack to article page