Plain X-ray images of the LSS AP (A), lateral (B), and axial (C) MSCT images showing a 5.4 mm medial violation of the L4 screw (measured by subtraction of 1.23 cm in Figure D from 1.77 cm in Figure C), plain X-ray images of the LSS AP (E) and lateral (F) after revision, and examination of the intraoperative medial wall of the pedicle and ensuring that no wall placed the screw. Therefore, there is no need for postoperative MSCT.