Navigation-Assisted Unilateral Biportal Endoscopic Decompression of Far-Out Compression in Bertolotti Syndrome: A Technical Note

Far-out compression in Bertolotti syndrome is a recognized cause of chronic low back pain associated with lumbosacral transitional vertebrae and may present with extraforaminal nerve root compression. We present a technical note demonstrating navigation-assisted unilateral biportal endoscopic (UBE) decompression in a patient with bilateral far-out stenosis and right-sided pseudoarticulation. Real-time navigation facilitated accurate docking, foraminotomy, nerve root identification, and complete pseudoarticulation resection while preserving the facet joint. Postoperatively, the patient had substantial pain relief and functional recovery. The visual analogue scale score for pain decreased from 9 preoperatively to 5 on postoperative day 1 and to 1 at the 3-month follow-up. This video highlights the technical workflow and advantages of navigation-assisted UBE for complex transitional anatomy with combined foraminal compression and pseudoarticulation.