Neurophysiological monitoring during anterior cervical discectomy and fusion for ossification of the posterior longitudinal ligament

Objective: This study aimed to investigate the value of intraoperative neurophysiological monitoring (IONM) in anterior cervical spine discectomy with fusion (ACDF) for ossification of the posterior longitudinal ligament (OPLL). Methods: Patients who underwent multimodal IONM (transcranial electrical motor-evoked potentials [tcMEP], somatosensory-evoked potentials, and continuous electromyography) for ACDF from 2009 to 2019 were compared to historical controls from 2003 to 2009. The rates of postoperative neurological deficits, neurophysiological warnings, and their characteristics were analyzed. Results: Among 196 patients, postoperative neurological deficit rates were 3.79% and 14.06% in the IONM and historical control (non-IONM) groups, respectively (p