Endoscopic Lumbar Interbody Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Structured Debate and International Practice Patterns

Lumbar fusion has evolved from open transforaminal lumbar interbody fusion (TLIF) to minimally invasive TLIF (MIS-TLIF), the current minimally invasive benchmark. Endoscopic techniques, proven in discectomy and decompression, have been extended to fusion (uniportal endoscopic TLIF and biportal endoscopic TLIF), offering an alternative to MIS-TLIF. This structured debate-style review critically compares both techniques across 7 domains to clarify their respective roles in lumbar degenerative disease. It combined independent advocacy drafts with an international survey of 106 respondents across 35 countries, capturing procedural preferences and case-based reasoning. Using a prespecified 70% agreement threshold, domains were classified as domains with ≥70% panel agreement, whereas domains falling below this threshold were categorized as domains below the prespecified agreement threshold. This represents structured international survey agreement, not a formal Delphi process. Endoscopic fusion offers advantages in decreased blood loss, soft-tissue preservation, early postoperative back pain, and early recovery, with comparable mid-term clinical outcomes (long-term insufficiently established) to MIS-TLIF, which remains more reproducible and familiar. Complication rates are similar but technique-sensitive for endoscopic fusion. Panel responses favored endoscopic approaches for morbidity-related domains (soft-tissue preservation 89.6%, visualization 81.1%, recovery 74.5%), while fusion stability, short- to mid-term clinical outcomes, complications, and revision remained context-dependent without clear agreement. Endoscopic fusion is a credible option for selected single-level lumbar degenerative disease, offering perioperative advantages with comparable mid-term outcomes to MIS-TLIF; core endpoints, including fusion rate and revision rate, did not reach 70% panel agreement, even among endoscopy-favorable panelists. MIS-TLIF retains reproducibility advantages. The debate has shifted from feasibility to implementation, training standardization, cost-effectiveness, and long-term durability.