Safe Ligamentum Flavum Resection via Osteotomy in Biportal Endoscopic Spine Surgery: A Surgical Technical Note With a Case Presentation

Endoscopic spine surgery (ESS) provides minimally invasive treatment options for a wide range of degenerative spinal disorders. However, performing a safe decompressive laminectomy, which is an essential and foundational step in ESS, can be challenging for novice surgeons, especially due to the risk of iatrogenic dural injury during flavectomy. This video article introduces the “crescent osteotomy” technique, which employs a mallet and chisel for controlled, anatomically precise resection of the ligamentum flavum. Although this approach has been adopted by some surgeons, it offers a straightforward and safe method that allows for effective additional laminectomy while facilitating easier flavectomy. The technique intentionally preserves the ligamentum flavum as a protective layer during the critical decompression phase. By doing so, the method reduces the likelihood of accidental dural tears and prevents unnecessary facet violation, making it particularly advantageous for beginning ESS surgeons. A representative case involving an 85-year-old man with L4–5 central stenosis and gait disturbance illustrates its effectiveness, with excellent postoperative neurological recovery and pain relief. The crescent osteotomy technique thus represents a feasible, efficient, and safe surgical option that enhances intraoperative control and optimizes clinical outcomes in ESS.