Is endoscopic technique an effective and safe alternative for lumbar interbody fusion? A systematic review and meta-analysis.

Study design: Systematic review; meta-analysis. Purpose: Lumbar degenerative disease is frequent and has a tremendous impact on patients' disability and quality-of-life. Open and minimally invasive procedures have been used to achieve adequate decompression and fusion. Endoscopic lumbar interbody fusion (Endo-LIF) is emerging as an alternative, trying to reduce morbidity, while achieving comparable to superior clinical outcomes. The aim of this work is to perform a systematic review and meta-analysis to investigate how Endo-LIF compares to open or minimally invasive procedures. Methods: Electronic databases (MEDLINE, Scopus, Web of Science, Cochrane) were systematically reviewed using the query: '(percutaneous OR endoscop*) AND (open OR minimal* invasive) AND lumbar AND fusion'. PRISMA guidelines were followed. Results: Twenty-seven articles were included (25 cohort study, 1 quasi-experimental study, and 1 randomized control trial; for meta-analytical results, only observational studies were considered). Endo-LIF conditioned longer operative time, with significantly lower blood loss, bedtime, and hospital length of stay. Early post-operative back pain favored endoscopic techniques. Endo-LIF and non-Endo-LIF minimally invasive surgery displayed comparable results for most back and leg pain or disability outcomes, despite Endo-LIF having been associated with higher disability at late follow-up (versus Open-LIF). No differences were found regarding fusion rates, cage subsidence, or adverse events. Definitive conclusions regarding fusion rate cannot be drawn due to low number of studies and unstandardized fusion definition. Conclusion: Endo-LIF is an effective and safe alternative to conventional lumbar interbody fusion procedures. Evidence shortcomings may be addressed, and future randomized control trials may be performed to compare techniques and to validate results.