Transforaminal Endoscopic Versus Open Lumbar Foraminotomy for Lumbar Foraminal Stenosis: Comparative Two-Year Outcomes and Technical Considerations for Complete Endoscopic Decompression.

Background/Objectives: Transforaminal endoscopic lumbar foraminotomy (TELF) is increasingly used for lumbar foraminal stenosis, but direct comparisons with open lumbar foraminotomy remain limited. We compared 2-year clinical and perioperative outcomes between the procedures. Methods: We retrospectively reviewed consecutive patients who underwent single-level TELF or open lumbar foraminotomy between January 2020 and January 2024. The primary outcome was the change in leg-pain visual analog scale (VAS) score from baseline to 24 months. Results: Of 159 eligible patients, 147 completed 2-year follow-up (TELF, n = 72; open, n = 75). Improvement in leg-pain VAS score was 5.93 ± 1.60 points after TELF and 5.57 ± 1.44 points after open foraminotomy (mean difference, 0.36; 95% confidence interval, -0.14 to 0.85; p = 0.157). Two-year pain, disability, modified MacNab, complication, and reoperation outcomes did not differ significantly. TELF was associated with a shorter operative time (59.80 ± 15.37 vs. 81.20 ± 21.65 min), hospital stay (1.93 ± 0.68 vs. 6.84 ± 2.85 days), and return-to-work interval among patients who returned to work (3.91 ± 1.20 vs. 8.71 ± 2.45 weeks; all p < 0.001). Conclusions: TELF and open lumbar foraminotomy showed similar observed 2-year clinical outcomes, whereas the TELF treatment pathway was associated with faster perioperative recovery. These observational differences should not be interpreted as equivalence or as effects of surgical technique alone. Complete removal of the medial tip of the superior articular process is presented as a technical consideration for adequate foraminal decompression during TELF; its independent effect on outcomes was not evaluated.