Fig. 1

a–i The step-by-step illustrations in procedures of PSRF. a the site of anterior inferior iliac spine (AIIS) and the pubis symphysis including its centerline were marked. b the AIIS was explored after the blunt dissection was taken between the space of the sartorius and the iliopsoas followed by drawing the sartorius outward. c the starting point was selected at the lateral one-third side of the AIIS, and the bony corridor was created by the pedicle finder. d, e the pedicle screw with the diameter of 7 mm and the length of 80 mm was inserted with the suitable depth in the outward tilt angle of 30° as well as the backward tilt angle of 20°. f 2-cm incision was positioned over the pubic tubercle. g pedicle screw with the diameter of 6.5 mm and the length of 50 mm was placed in appropriate depth under the X-ray fluoroscopy. h three pedicle screws were fixed and then a titanium rod with 6 mm diameter was curved according to the shape of anterior ring. i long hemostat was used to make the corridor superficial to the fascia from the incision from bilateral AIIS to the pubic tubercle, then the titanium rod was placed through the corridor passing below the sartorius and the front of medial iliopsoas. And then, it was connected to these three pedicle screws head