Introduction: Intraoperative neurophysiologic monitoring is a technique that is both sensitive and specific for nervous injury during spine surgery. In procedures involving trauma or with an otherwise high risk of significant nervous injury, intraoperative neuromonitoring can be helpful in improving long-term outcomes. However, it is unclear if all patients undergoing spine surgery benefit from neuromonitoring.

Methods: We performed a retrospective analysis on a national database (Thomson Reuters MarketScan). Between 2006 and 2010, an identified 85,640 patients underwent single level spinal procedures including anterior cervical discectomy and fusion (ACDF), lumbar fusion, lumbar laminectomy, or lumbar discectomy. Concurrent neuromonitoring was identified with the CPT codes 95940, 95941, or 95920. Cohorts for each of the four procedural categories were balanced on baseline comorbidities and procedure characteristics using propensity score matching.

Results: Overall, 10,844 (12.66%) patients received neuromonitoring intraoperatively. Regardless of neuromonitoring status, the 30-day overall complication rates did not significantly differ among monitored and unmonitored patients. When neurological complications were examined specifically, only lumbar laminectomies had reduced 30-day neurological complication rate with neuromonitoring (0.0% vs 1.18%, p < 0.0024). Neuromonitoring did not correlate significantly with reduced intraoperative neurological complications in ACDFs (0.09% vs 0.13%), lumbar fusions (0.32% vs 0.58%), or lumbar discectomy (1.24% vs. 0.91%). The 30-day readmission rate was higher for patients undergoing lumbar discectomies with neuromonitoring than those without (4.29% vs 3.34%, OR 1.29, p < 0.0451). For patients who underwent lumbar fusion, reoperation was more frequent when neuromonitoring was involved (6.52% vs 4.85%, OR 1.13, p < .0015), but did not differ among other procedures. With the addition of neuromonitoring, payments for ACDFs increased 16.24% ($17,244 vs $16,105), lumbar fusions 7.84% ($28,678 vs $29,009), lumbar laminectomies 24.33% ($16,729 vs $19,199), and lumbar discectomies 22.54% ($10,549 vs $12,449).

Conclusions: In a national database study of propensity score matched patients undergoing single level spinal procedures without and without intraoperative neuromonitoring, intraoperative neurological complications were only noted to be decreased among lumbar laminectomies. Among all procedures, there was a significant increase in total payments associated with the index procedure and subsequent hospitalization.

Patient Care: This analysis provides a retrospective analysis of the unclear utility of neuromonitoring in single level spinal procedures. We also outline the increased payments associated with neuromonitoring.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the overall rates of neuromonitoring usage in single level spinal procedures 2) Describe the comparative neurological complication rates in single level procedures with and without neuromonitoring 3) Identify the increased payment amounts associated with neuromonitoring.

References: Hilibrand AS, Schwartz DM, Sethuraman V, Vaccaro AR, Albert TJ. Comparison of transcranial electric motor and somatosensory evoked potential monitoring during cervical spine surgery. The Journal of bone and joint surgery American volume. 2004;86-a(6):1248-53. Eggspuehler A, Sutter MA, Grob D, Jeszenszky D, Porchet F, Dvorak J. Multimodal intraoperative monitoring (MIOM) during cervical spine surgical procedures in 246 patients. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2007;16 Suppl 2:S209-15. Bose B, Sestokas AK, Schwartz DM. Neurophysiological monitoring of spinal cord function during instrumented anterior cervical fusion. The spine journal : official journal of the North American Spine Society. 2004;4(2):202-7. Fehlings MG, Brodke DS, C. ND, D. JR. The evidence for intraoperative neurophysiological monitroing in spine surgery: does it make a difference. Spine. 2010;35(95):S37-S46. Kelleher MO, Tan G, Sarjeant R, Fehlings MG. Predictive value of intraoperative neurophysiological monitoring during cervical spine surgery: a prospective analysis of 1055 consecutive patients. Journal of neurosurgery Spine. 2008;8(3):215-21. Li F, Gorji R, Allott G, Modes K, Lunn R, Yang ZJ. The usefulness of intraoperative neurophysiological monitoring in cervical spine surgery: a retrospective analysis of 200 consecutive patients. J Neurosurg Anesthesiol. 2012;24(3):185-90. Ney JP, van der Goes DN, Watanabe JH. Cost-benefit analysis: intraoperative neurophysiological monitoring in spinal surgeries. J Clin Neurophysiol. 2013;30(3):280-6.