Fig. 2From: Accuracy of pedicle screw placement in the thoracic and lumbosacral spines using O-arm-based navigation versus conventional freehand techniqueA 59-year-old woman presented with lumbar and lower extremities pain for 3 years. a–c Preoperative spinal radiography and magnetic resonance imaging (MRI) showed lumbar spondylolisthesis and disc herniation. d–f Images of the navigation screen. g–i Images of the O-arm screen obtained from the second intraoperative O-arm scan. j, k Images of the O-arm screen obtained from the third intraoperative O-arm scan. l Postoperative MRIBack to article page