Comparison of index-level reoperation-free survival and complication rates between endoscopic and conventional transforaminal lumbar interbody fusion: a retrospective comparative study in Korea.

Abstract

Retrospective comparative study. To compare index-level reoperation-free survival and implant-related complication rates between patients undergoing endoscopic transforaminal lumbar interbody fusion (ETLIF) and conventional open transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spine disorders. ETLIF is a popular minimally invasive alternative to conventional TLIF for degenerative lumbar spine disorders; however, there are concerns regarding its long-term durability and the risk of reoperation compared with the established open TLIF. We retrospectively analyzed clinicodemographic characteristics (including bone mineral density), operative parameters, and implant-related complications of 199 patients who underwent lumbar interbody fusion at two spine centers (ETLIF: n=97; TLIF: n=102). Kaplan-Meier survival analysis and Cox proportional hazards modeling were used to evaluate index-level reoperation rates. Statistical significance was set at p <0.05. The ETLIF group had a significantly higher rate of index-level reoperation (7.2% vs. 1.0%, p =0.017), longer operative time (182 minutes vs. 162 minutes, p =0.014), and shorter follow-up duration (23.5 months vs. 37.2 months, p=0.001) than the open TLIF group. Kaplan-Meier analysis demonstrated a progressive decline in reoperation-free survival in the ETLIF group, whereas the TLIF group maintained 98.9% survival at 24 months. Cox regression revealed a hazard ratio of 8.34 (95% confidence interval, 1.36-22.20) for ETLIF. Although the ETLIF group showed slightly higher rates of screw loosening, infection, and implant breakage, between-group differences were not statistically significant. ETLIF was associated with a higher incidence and risk of early index-level reoperation compared to open TLIF, highlighting the need for careful monitoring of initial construct stability in endoscopic fusion. Further studies are required to verify these observations and their clinical implications.