Optimizing Lumbar Interbody Fusion: A Technical Note on Biportal Endoscopic Transforaminal Lumbar Interbody Fusion with Dual Cage Strategy

Objective: This study presents a technical note on Unilateral Biportal Endoscopic Transforaminal Lumbar Interbody Fusion (UBE-TLIF) using dual cages, focusing on its potential to enhance fusion rates and minimize cage subsidence. Background: TLIF is a well-established treatment for lumbar degenerative conditions, yet traditional and minimally invasive approaches are limited by narrow working corridors, reduced disc space visualization, and increased risk of pseudoarthrosis and subsidence. The biportal endoscopic approach offers superior visualization and decompression capabilities. Incorporating dual cages into this technique may further optimize biomechanical stability and fusion success. Materials and Methods: We describe a stepwise surgical technique of UBE-TLIF with dual cage insertion, emphasizing radical discectomy, meticulous endplate preparation under direct endoscopic vision, and the strategic bone graft packing. Cages were placed in a parallel configuration to maximize footprint and minimize endplate stress. Fusion construct integrity and cage positioning were confirmed intraoperatively through fluoroscopy. Discussion: The dual cage configuration allowed for enhanced load distribution and greater bone graft volume within the disc space. The technique facilitated anterior cage placement, potentially restoring lumbar lordosis while preserving bony endplate integrity. Conclusion: UBE-TLIF with dual cages is a novel, minimally invasive technique that combines the advantages of endoscopic visualization and better bony endplate preparation with enhanced biomechanical stability. The technique addresses the limitations of conventional TLIF by enabling radical discectomy, optimal cage positioning, and greater graft volume, thereby improving the likelihood of successful fusion and reducing subsidence risk.