Fig. 3. Preoperative (A, B), postoperative (C) and 1-month follow-up (D) standard radiographs of a 78-year-old female patient with L4 degenerative lumbar spondylolisthesis. Postoperative standard radiographs show good reduction of spondylolisthesis as well as overt cage malposition (C). Standard radiographs, made 1 month postoperatively show significant loss of correction with cage subsidence (D).