Midline Ligamentum Flavum Cyst of Lumbar Spine.

Abstract

Ligamentum flavum cysts are thought to develop due to facet joint hypermobility; however, the etiology of these lesions is not completely elucidated. These cysts may lead to compressive pathologies of the spine requiring surgical intervention. We report the case of a 63-year-old male with chronic back pain and progressive neurogenic claudication for 6 months. He was found to have a ligamentum flavum cyst situated along the dorsal midline of the lumbar spinal canal contributing to spinal stenosis. The patient underwent a decompressive L4 laminectomy and en bloc excision of the ligamentum flavum cyst with complete resolution of his symptoms postoperatively. We suggest that chronic mechanical stress leads to degeneration of the ligamentum flavum and contributes directly to cyst formation.