Postoperative consequences of intraoperative neuromonitoring changes during cervical spine surgery

Background: Intraoperative neuromonitoring (IONM) is widely used in spine surgery to detect neurological injury. However, rising healthcare costs necessitate an evaluation of the value of IONM, given the added expense and time associated with its use. Here, we identified risk factors contributing to significant IONM changes during anterior versus posterior versus circumferential cervical surgery. Methods: This retrospective study at a Level I trauma center (2012–2016) involved 663 trauma patients with myelopathy or radiculopathy who underwent anterior, posterior, or circumferential cervical surgery utilizing IONM. We focused on when significant changes occurred during these procedures and correlated them with neurological outcomes. Results: Of the 663 patients, averaging 54.8 years of age, 51 (7.7%) patients developed statistically significant IONM changes; in descending order, they occurred during posterior (10.8% [27/249]), circumferential (9.1% [2/22]), and anterior (5.6% [22/392]) operations. Notably, 5 (9.8%) of the 51 patients developed new postoperative neurologic deficits; 4/5 (80%) occurred following posterior and 1 (20%) after an anterior cervical procedure. Conclusion: Of 663 patients, 51 (7.7%) patients developed statistically significant IONM changes that were most frequent (i.e., in descending order), following posterior (10.8% [27/249]), circumferential (9.1% [2/22]), and anterior (5.6% [22/392]) operations.