OBJECTIVE Minimally invasive spine surgery can minimize damage to normal anatomical structures. Recently, fully endoscopic spine surgeries have been attempted for lumbar fusion surgery. In this study, the authors performed a percutaneous unilateral biportal endoscopic (UBE) technique as a minimally invasive surgery for lumbar fusion. The purpose of this study is to present the UBE technique of fully endoscopic lumbar interbody fusion (LIF) and to analyze the clinical results. METHODS Patients who were to undergo single-level fusion surgery from L3-4 to L5-S1 were enrolled. Two channels (endoscopic portal and working portal) were used for endoscopic lumbar fusion surgery. All patients underwent follow-up for more than 12 months. Demographic characteristics, diagnosis, operative time, and estimated blood loss were evaluated. MRI was performed on postoperative Day 2. Clinical evaluations (visual analog scale [VAS] for the leg and Oswestry Disability Index [ODI] scores) were performed preoperatively and during the follow-up period. RESULTS A total of 69 patients (24 men and 45 women) were enrolled in this study. The mean follow-up period was 13.5 months. Postoperative MRI revealed optimal direct neural decompression after fully endoscopic fusion surgery. VAS and ODI scores significantly improved after the surgery. There was no postoperative neurological deterioration. CONCLUSIONS Fully endoscopic LIF using the UBE technique may represent an alternative minimally invasive LIF surgery for the treatment of degenerative lumbar disease. Long-term follow-up and larger clinical studies are needed to validate the clinical and radiological results of this surgery.
Keywords: ALIF = anterior lumbar interbody fusion; LLIF = lateral LIF; ODI = Oswestry Disability Index; TLIF = transforaminal LIF; UBE = unilateral biportal endoscopic; VAS = visual analog scale; endoscopy; fusion surgery; lumbar; minimally invasive surgery.