Lower Neurological Risk with Anterior Operations Compared to Posterior Operations for Thoracic Disc Herniations: Analysis of 697 Patients.

STUDY DESIGN Retrospective cohort study. OBJECTIVE Compare rates of post-operative neural deficits between surgical approaches for thoracic disc herniations (TDHs). SUMMARY OF BACKGROUND DATA Anterior and posterior approaches for TDH carry high reported neurological risk, albeit comparative risk is not well defined. METHODS Health Care Utilization Project (HCUP) state inpatient databases (NY, FL, CA; 2005-2014) were queried for patients who underwent TDH operation. Demographics, operative details, surgical approach, neural injury, length of stay (LOS), and discharge location were assessed. Multivariate linear regression was used to determine relative risk of neural deficit and SNF discharge. RESULTS 697 patients (mean age 52.0 years, 194 institutions) met inclusion. Majority of operations were elective (76.0%) and 1-2 levels (80.5%). Overall neural injury rate was 9.0%. Anterior operations had significantly lower rates of neural injury compared to posterior operations on univariate analysis (4.6% v. 11.4%; p < 0.01). All multi-level operations had similarly high rates of neural injury. On multivariate analysis, posterior approaches (RR 1.78; p = 0.12) and combined approaches (RR 2.15; p = 0.17) had higher neural risk compared to anterior approaches after controlling for younger age, higher CCI, and non-elective admissions. Combined approaches had similar neural injury rates (13.8%) to posterior operations (11.4%) and significantly longer LOS and SNF discharges compared to single approaches. Neural deficit was associated with discharge to SNF (With = 87.3%; Without = 23.7%; p < 0.01) and increased LOS (With = 12.5 days; Without = 6.9 days; p < 0.01). CONCLUSION Overall rate of neural deficit after operation for TDH was 9.0%. While anterior approach was associated with a lower neural injury rate, this association was confounded by age, CCI, and admission type. After correcting for these confounders, a non-significant trend remained that favored the anterior approach. Neural deficit was associated with increased LOS and discharge to SNF post-operatively.Level of Evidence: 4.