LAUSR

STUDY DESIGN Retrospective analysis of prospectively collected data. OBJECTIVE To investigate the effect of the approach of the TLIF (open vs. MIS) on reoperation rates due to ASD at 2 - 4 year follow up. SUMMARY OF BACKGROUND DATA Adjacent segment degeneration (ASDeg) is a complication of lumbar fusion surgery which may progress to adjacent segment disease (ASD) and cause debilitating postoperative pain potentially requiring additional operative management for relief. Minimally invasive (MIS) transforaminal lumbar interbody fusion surgery (TLIF) has been introduced to minimize this complication but the impact on ASD incidence is unclear. METHODS For a cohort of patients undergoing 1- or 2-level primary TLIF between 2013 and 2019, patient demographics and follow-up outcomes were collected and compared between patients who underwent open versus MIS TLIF using Mann Whitney U test, Fischer's exact test, and binary logistic regression. RESULTS 238 patients met inclusion criteria. There was a significant difference in revision rates due to ASD between MIS and open TLIFs at 2 (5.8% vs. 15.4%, P=0.021) and 3 (8% vs. 23.2%, P=0.03) year follow up, with open TLIFs demonstrating significantly higher revision rates. Surgical approach was the only independent predictor of reoperation rates at both 2 and 3 year follow ups (2-year P=0.009; 3-year P=0.011). CONCLUSION Open TLIF was found to have a significantly higher rate of reoperation due to ASD compared to the MIS approach. Additionally, surgical approach (MIS vs. Open) appears to be an independent predictor of reoperation rates.