Ligamentum flavum

The ligamentum flava are paired ligaments which run between adjacent laminae of the vertebral bodies and are present from C2/3 to the sacrum. Above the C2/3 level the equivalent structures are known as the posterior atlanto-occipital membrane (between the base of skull and C1) and the posterior atlantoaxial membrane (between C1 and C2). The ligamentum flava form part of the posterior ligamentous complex of the vertebral column.

Gross anatomy

• paired, yellowish, elastic ligament
• forms part of the posterior border of the spinal canal
• relatively thin in the cervical spine, progressively becoming thickest in the lumbar spine
• broad base along the lamina from the facet joints to base of the spinous process
• attaches from the front of the upper lamina to the back of the lower lamina
• in the lumbar region, it runs laterally, covering the anterior aspect of the facet joints. 

Relations

• anterolateral: intervertebral foramen and contents (spinal nerve roots, segmental arteries, recurrent meningeal nerves, communicating veins between internal and external venous plexus)
• anteromedial: spinal cord and meninges
• posterolateral: lamina, facet joints
• posteromedial: spinous process, interspinous ligament, venous connection between internal and external vertebral venous plexuses

Innervation

• superficial: medial branch of dorsal roots of spinal nerves
• deep: sinuvertebral nerves (recurrent meningeal nerves)

History and etymology

'Flavum' is Latin for 'yellow', referring to the colour of the ligament.

Related pathology

• ligamentum flavum cysts
• ossification of the ligamentum flavum
• ligamentum flavum hypertrophy