Fig. 4.

Limitations to intraoperative verification of correct screw placement after anterior vertebral body replacement of C3 with plating and percutaneous posterior transpedicular instrumentation of C2 to C4. a Axial view of multiplanar reconstruction obtained by isocentric C-arm (three-dimensional fluoroscopy). The poor image quality caused by metal artifacts allowed no evaluation of screw position. b A postoperative CT scan demonstrated a critical lateral pedicle wall perforation of the right screw in C4 with encroachment of the vertebral foramen (left side of the image)