title: Intraoperative neuromonitoring in single-level spinal procedures: a retrospective propensity score-matched analysis in a national longitudinal database.
abstract: METHODS
  Retrospective propensity score-matched analysis on a national database (MarketScan) between 2006 and 2010.
  
  
  OBJECTIVE
  To compare rates of neurological deficits after elective single-level spinal procedures with and without intraoperative neuromonitoring, as well as associated payment differences and geographic variance.
  
  
  BACKGROUND
  Intraoperative neurophysiologic monitoring is a technique that may contribute to avoiding permanent neurological injury during some spine surgery procedures. However, it is unclear whether all patients undergoing spine surgery benefit from neuromonitoring.
  
  
  METHODS
  An identified 85,640 patients underwent single-level spinal procedures including anterior cervical discectomy and fusion (ACDF), lumbar fusion, lumbar laminectomy, or lumbar discectomy. Neuromonitoring was identified with appropriate Current Procedural Terminology (CPT) codes. Cohorts were balanced on baseline comorbidities and procedure characteristics using propensity score matching. Trauma and spinal tumors cases were excluded.
  
  
  RESULTS
  Patients (12.66%) received neuromonitoring intraoperatively. Lumbar laminectomies had reduced 30-day neurological complication rate with neuromonitoring (0.0% vs. 1.18%, P=0.002). Neuromonitoring did not correlate 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%). With the addition of neuromonitoring, payments for ACDFs increased 16.24% ($3842), lumbar fusions 7.84% ($3540), lumbar laminectomies 24.33% ($3704), and lumbar discectomies 22.54% ($2859). Significant geographic variation was evident. Some states had no recorded single-level spinal cases with concurrent neuromonitoring. Rates for ACDFs and lumbar fusions, laminectomies, and discectomies ranged as high as 61%, 58%, 22%, and 21%, respectively.
  
  
  CONCLUSIONS
  With intraoperative neurological monitoring in single-level procedures, neurological complications were decreased only among lumbar laminectomies. No difference was observed in ACDFs, lumbar fusions, or lumbar discectomies. There was a significant increase in total payments associated with the index procedure and hospitalization. We demonstrate significant geographic variation in neuromonitoring.
  
  
  METHODS
  3.
authors.affiliation: From the Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Cole
authors.forename: Anand
authors.initials: A
authors.lastname: Veeravagu
authors.forename: Michael
authors.initials: M
authors.lastname: Zhang
authors.forename: Alexander
authors.initials: A
authors.lastname: Li
authors.forename: John K
authors.initials: JK
authors.lastname: Ratliff
mesh_terms: D016208:Databases, Factual / Q000639:trends; D017586:Diskectomy / Q000009:adverse effects* / Q000639:trends; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects* / Q000639:trends; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery*; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods* / Q000639:trends; D057216:Propensity Score; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects* / Q000639:trends; D014481:United States / Q000453:epidemiology