Abstract
BACKGROUND CONTEXT: Full endoscopic lumbar interbody fusion (FELIF) is a minimally invasive alternative to open transforaminal lumbar interbody fusion (open-TLIF) for lumbar degenerative disease (LDD). This study aimed to compare 1-year outcomes of a modified trans-Kambin FELIF, termed Kambin Torpedo FELIF (KT-FELIF), with those of conventional open-TLIF. METHODS: In this retrospective cohort study, 76 patients with single-level LDD and bilateral symptoms underwent KT-FELIF (n=30) or open-TLIF (n=46) between January 2020 and January 2024. Patients with prior spinal surgery, multilevel disease, or incomplete follow-up imaging were excluded. Perioperative data, pain scores [visual analog scale (VAS)], radiologic outcomes, and complications were compared at ≥12-month follow-up. RESULTS: KT-FELIF showed significantly lower blood loss (72.00±62.00 mL vs. 173.91±134.37 mL, p<.01) and faster ambulation (1.37±0.49 vs. 2.30±0.81 days, p<.01) than conventional open-TLIF. Both groups showed significant VAS score improvement, but KT-FELIF offered better early pain relief (2 weeks and 6 months, p<.01). Fusion rates were similar (97% vs. 91%, p=.654), though open-TLIF had larger fusion mass (p=.005). KT-FELIF led to greater lumbar lordosis (p=.038) and spinal canal area gains (p=.002), while open-TLIF improved foraminal height more. Complication rates were comparable. CONCLUSIONS: KT-FELIF is a safe, effective, and less invasive alternative to open-TLIF for LDD with bilateral symptoms, offering benefits in blood loss, recovery time, and early pain relief, with comparable fusion and radiologic outcomes. Further long-term multicenter studies are warranted.