Thoracic scoliosis (AIS) posterior surgery complication

As treatment for adolescent idiopathic scoliosis (AIS) has evolved especially with more aggressive surgical correction, intraoperative neuromonitoring (IONM) has become critical part of the surgical procedure to ensure patient safety. One of the earliest techniques was the intraoperative wake-up test. While this had reportedly high sensitivity for detecting neurologic deficit, there were clear limitations to this technique as this defined gross motor function without detailed strength measurements. This promoted further research into other methods for monitoring and includes somatosensory-evoked potentials, transcranial motor-evoked potentials, neurogenic motor-evoked potentials, and electromyography. Combined IONM during spinal deformity correction is now the preferred method for detection and prevention of injury according to the Scoliosis Research Society. A thorough understanding of the basics of IONM is essential for any surgeon addressing AIS. This chapter reviews the history of neuromonitoring in spinal deformity surgery, focusing on the most common types of monitoring conducted today. It also reviews common causes for monitoring changes and recommended protocols for responding to changes.