OBJECTIVEMinimally 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.METHODSPatients 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.RESULTSA 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.CONCLUSIONSFully 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.

OBJECTIVE The use of conventional uniportal spinal endoscopic decompression surgery for lumbar spinal stenosis can be limited by technical difficulties and a restricted field of vision. The purpose of this study is to describe the technique for percutaneous biportal endoscopic decompression (PBED) for lumbar spinal stenosis and analysis of clinical postoperative results. METHODS The authors performed a unilateral laminotomy with bilateral foraminal decompression using a unilateral biportal endoscopic system in patients with single-level lumbar stenosis. The authors enrolled only patients who underwent follow-up for longer than 12 months after PBED. Fifty-eight patients were enrolled in this study. This approach was based on 2 portals: one portal was used for continuous irrigation and endoscopic viewing and the other portal was used to manipulate the instruments used in the decompression procedures. Clinical parameters such as the Oswestry Disability Index (ODI), Macnab criteria, and postoperative complications were analyzed. RESULTS Neural decompression was effectively performed in all enrolled patients. The mean ODI was significantly lower after PBED. Of 58 patients, 47 (81.0%) had a good or excellent result according to the Macnab criteria. Postoperative ODI and visual analog scale scores were significantly improved compared with preoperative values. CONCLUSIONS From a surgical point of view, percutaneous biportal endoscopy is very similar to microscopic spinal surgery, permitting good visualization of the contralateral sublaminar and medial foraminal areas. The authors suggest that the PBED, which is a minimally invasive procedure, is an alternative treatment option for degenerative lumbar stenosis.