The placing of pedicular screws under fluoroscopic control is the most common technique as it is both reproducible and accessible. It is a two dimensional imaging technique. The profile incidence at the level of the spine is mostly used to spot the vertebral pedicle and the direction of the screw in the sagittal plane. However, there is no real control of the direction of the pedicular screw in the horizontal or frontal plane. The screw malposition rate is less important than with the 'free hand' technique but remains none of the less significant. Furthermore, fluoroscopy is an irradiating imaging technique, both for the patient and the staff.