Biportal Endoscopic Resection of a Ligamentum Flavum Cyst: A Technical Note

ABSTRACT The biportal endoscopic technique, known as unilateral biportal endoscopy (UBE), has emerged as an effective minimally invasive approach for managing various spinal disorders. This report presents the first documented use of UBE for resection of a ligamentum flavum cyst—a rare, benign lesion associated with spinal canal stenosis. A 74-year-old female patient with severe neurogenic claudication and S1 nerve root compression secondary to an L4-L5 ligamentum flavum cyst underwent UBE-guided decompression and cyst removal. The procedure was performed under general anesthesia using two 1-cm portals for the endoscope and surgical instruments, allowing precise dissection and visualization. The cyst was resected with minimal tissue disruption, and complete decompression of neural elements was confirmed. Postoperatively, the patient experienced full resolution of symptoms, with VAS scores dropping to 0 and Oswestry Disability Index improving from 60% to 15%. Histopathological analysis confirmed the diagnosis. The technique offers clear advantages over uniportal approaches, primarily due to independent control of the camera and instruments, which enhances maneuverability and reduces dural injury risk. Furthermore, UBE combines the benefits of microsurgical accuracy with reduced invasiveness, allowing faster recovery and minimal scarring. The approach proved safe, effective, and technically feasible for treating ligamentum flavum cysts, reinforcing its potential role in managing degenerative lumbar conditions and spinal stenosis. This case highlights the applicability of biportal endoscopy as a valuable tool in modern spine surgery. Level of Evidence III; Study of nonconsecutive patients; without consistently applied.