Exoscope versus microscope in spine surgery: a meta-analysis based on procedure-specific subgroup analysis

Background Three-dimensional (3D) exoscopes have recently emerged as an alternative to the operating microscope (OM) in spine surgery, offering potential ergonomic and educational advantages. However, comparative evidence on surgical outcomes remains fragmented across different spinal pathologies and procedures,. With this work, we aim at comparing surgical and clinical outcomes of exoscopic versus microscopic spine surgery for degenerative conditions through a global meta-analysis, with procedure-specific subgroup analyses. Methods A systematic review and meta-analysis were conducted according to PRISMA guidelines. Comparative studies evaluating 3D exoscope versus microscope in spine surgery for degenerative conditions were included. Continuous outcomes (operative time, blood loss, length of stay, visual analogue scale [VAS] scores) were pooled using a random-effects inverse-variance model and expressed as mean differences (MD). Dichotomous outcomes (complications) were analyzed using Mantel–Haenszel odds ratios (OR). Heterogeneity was quantified with I² and τ² statistics. Subgroup analyses were performed by procedure (ACDF, MIS-TLIF, lumbar microdecompression/microdiscectomy), along with sensitivity analyses and meta-regressions when indicated. Results A total of 785 patients across 7 studies were included. No significant differences were found in operative time (MD − 5.9 min; 95% CI − 16.4 to + 4.7), complications (OR 0.83; 95% CI 0.53–1.30), length of stay (MD − 0.15 days; 95% CI − 0.84 to + 0.53), or postoperative VAS scores. Blood loss was slightly reduced with the exoscope (MD − 5.9 mL; 95% CI − 11.1 to − 0.6), although the clinical relevance appears negligible. Subgroup analyses showed consistent findings across ACDF, MIS-TLIF, and lumbar microdecompression. Conclusions Despite significant limitations, current literature supports the non-inferiority of exoscope to OM in spine surgery, with comparable surgical and clinical outcomes across procedures. Exoscopes may offer ergonomic and didactic advantages without increasing operative time, complications, or hospital stay. However, standardized quantification of performance in the former non-clinical domains is missing. Further high-quality randomized studies are needed to confirm these findings and define procedure-specific benefits.