Perioperative Neurologic Complications in Adult Spinal Deformity Surgery: Incidence and Risk Factors in 564 Patients.

STUDY DESIGN: Prognostic study-case controlled.

OBJECTIVE: Describe the rate of neurologic complications in adult spinal deformity surgery and describe the effect of these complications on clinical outcomes.

SUMMARY OF BACKGROUND DATA: The incidence of neurologic complications and the risk factors for neurologic complications have not been reported in a large series of patients with adult spinal deformity (ASD). Existing series include a mixed patient cohort undergoing different types of spine surgery.

METHODS: Patients with ASD undergoing surgery between 2008 and 2014 were analyzed. Patients with neurologic complications were identified; demographics, operative details, and radiographic and clinical outcomes were compared. A subanalysis of those with surgical and nonsurgical (e.g., stroke) neurologic complications was performed. Statistical analysis included t tests or χ tests as appropriate and a multivariate analysis. A P value of less than 0.025 was considered significant.

RESULTS: A total of 564 patients met the inclusion criteria. The average age was 57 years. There were a total of 116 neurologic complications in 99 patients (17.6%). There were 88 surgical procedure-related neurologic complications in 77 patients (13.7%) and 28 nonsurgical neurologic complications in 28 patients (5.0%). The most common complications were radiculopathy (30%), motor deficits (22%), mental status changes (12%), and sensory deficits (12%). Revisions (odds ratio [OR] 1.7, 95% confidence interval [CI] 1.2-2.4) and interbody fusions (OR 2.1, 95% CI 1.4-3.2) were associated with an increased risk of neurologic complications. Decompression and osteotomies (including three-column osteotomies) did not increase the risk of neurologic complications. Patients with neurologic complications were not more likely to sustain other complications; however, they were more likely to undergo another operation during the follow-up period (OR 1.9, 95% CI 1.3-2.8).

CONCLUSION: The overall incidence of neurologic complications in ASD surgery was 17.6%. The incidence of surgical neurologic complications was 13.7%. There was a higher risk of neurologic complications in revision cases and in cases in which interbody fusion was required.

LEVEL OF EVIDENCE: 3.