Impact of Intraoperative Monitoring During Elective Complex Spinal Fusions (≥4 Levels) on 30-Day Complication and Readmission Rates: A Single-Institutional Study of 643 Adult Patients with Spinal Deformity

Objective The aim of this study is to determine if there are differences in 30-day postoperative complication and readmission rates between patients with spinal deformity undergoing complex spinal fusion with and without intraoperative monitoring (IOM). Methods The medical records of 643 adult patients with spine deformity undergoing elective complex spinal fusion (≥4 levels) at a major academic institution from 2005 to 2015 were reviewed. We identified 122 cases (19%) that involved IOM including electromyography, somatosensory evoked potential, and/or transcranial motor evoked potential and 521 (81%) that did not (IOM, n = 122; no-IOM, n = 521). The primary outcome investigated was the rate of 30-day postoperative complications and readmission. Results Patient demographics and comorbidities were similar between both groups, including age, gender, body mass index, and smoking status. IOM cases had significantly increased operative time (IOM, 360.9 ± 153.8 minutes vs. no-IOM, 290.3 ± 127.1 minutes; P < 0.0001), with no differences in the incidences of spinal cord injury, nerve injury, and durotomy. Both cohorts had similar postoperative complications and length of hospital stay, with the no-IOM cohort having a greater incidence of intensive care unit transfer (no-IOM, 27.1% vs. IOM, 16.1%, P = 0.015). There was no significant difference in 30-day readmission between the cohorts (IOM, 8.2% vs. no-IOM, 12.3%; P = 0.27) or differences in sensorimotor deficits. Although the overall 30-day complication rate trended to be higher in the no-IOM cohort, these factors were not attributed to IOM use. Conclusions Our study suggests that the use of IOM may not have a significant impact on overall surgical outcomes and 30-day readmission rates.