Fig. 1

L4 DLS in a patient treated with L4 laminectomy and posterolateral fusion. Because of leg pain, she underwent revision surgery (ab). Postoperative X-ray showed screw displacement. c Postoperative X-ray showed that the screw was corrected and the pain improved. d L4-L5 disc height narrowing and posterolateral fusion were observed at the 48-month follow-up