“…A quite common scenario in percutaneous iliosacral screwing is unconscious manipulation of the guide-wire in a wrong direction [16]. Graves and Routt [20] have reported that current standard inlet and outlet images are not based on orthogonal coordinates, and therefore any starting point and aim changes made by moving perpendicular to the C-arm beam will not preclude the trajectory changing on both inlet and outlet views. With the use of orthogonal intracutaneous K-wires, which indicate up, down, cranial and caudal, it is easy to match the position of the sacrum with the image of the sacrum by simply rotating the image on the screen.…”