Fig. 3

Intraoperative fluoroscopic lateral (a), inlet (b), and outlet (c) views demonstrating the position of the contralateral guidewire was satisfactory. The first cannula guided the starting point of the guidewire and the other cannula guided the exiting point (d). The point-to-point coaxial guide apparatus was installed and locked (e). A longer guidewire was inserted into the screw corridor along the trajectory directed by the cannulas (f). The position of the longer guidewire can be verified by progressive fluoroscopic evaluation (g, h). When the guidewire exited the contralateral iliac cortex, we inserted into the transiliac-transsacral screw over the guidewire (i)