 Using a 20-degree caudad-cephalad trajectory as well as 10-degree lateral-to-medial direction, the trajectory was completed in 8 mm increments, this was subsequently sounded in all four quadrants to make sure that there was no violation of the pedicle wall of the trajectory. 
Using a 20 - degree caudad - cephalad trajectory as well as 10 - degree lateral - to - medial direction , the trajectory was completed in 8 mm increments , this was subsequently sounded in all four quadrants to make sure that there was no violation of the pedicle wall of the trajectory .