Postoperative Neurological Complications Following Revision Spine Surgery: A State Inpatient Database Analysis

Background Postoperative neurological complications after spine surgery can result in increased mortality and morbidity. Despite the introduction of new spinal implants and surgical technology, reoperation rates have remained stable over recent years. Understanding the reasons for revision (refusion) surgery and the risk of neurological complications can assist in developing more effective screening protocols for repeat surgeries and early detection of potential neurological complications.

Methods This study was designed and conducted as a retrospective cohort study. The primary objective of this study was to evaluate whether revision spine surgery increased the risk of postoperative neurological deficits. A secondary objective of the study was to analyze whether deficits following repeat spine surgery increased morbidity and mortality. Data on revision spine procedures were extracted from the California State Inpatient Database for years 2008 to 2011. Patients who developed postoperative neurological deficits were then subdivided into causative procedure: revision anterior cervical discectomy and fusion, revision posterior cervical fusion, and revision thoracolumbar fusion. These data were then used to calculate the total incidence of postoperative neurological deficits following each type of procedure. The impact of neurological deficits on in-hospital morbidity following revision procedures was also calculated.

Results Revision procedures accounted for 5.84% of all spine procedures in a total of 7645 patients. Among these patients, 67 patients (0.88%) developed a postoperative neurological deficit with an adjusted odds ratio of 1.56 (95% CI, 1.20–2.00, P < .05). When using individuals with no neurological deficit as the reference group, the odds of morbidity were 5.3 (95% CI, 3.15–9.00, P < .05) in those who sustained neurological deficit following revision procedure.

Conclusions/Clinical Relevance This study exposes the increased risk of postoperative neurological complications in revision spine surgeries. In response, further studies are needed to evaluate the use of intraoperative neurophysiological monitoring to reduce this risk.