Neurophysiological assessment of thoracic and cervical pedicle screw integrity.

Transpedicular instrumentation of the thoracic and cervical spine is technically more difficult than at lumbar levels because of narrower pedicles and less sensitive intraoperative fluoroscopic assessment. Furthermore, the potential implications of a misplaced screw are greater because of the close proximity of the spinal cord and vertebral artery. Real-time confirmation of correct pedicle screw placement in the operating room is therefore considered even more important, and this article reviews the availability, utility, and limitations of electrophysiologic testing techniques that can be used for this purpose.