At each intersegmental level the ligamentum flavum is a paired structure being represented symmetrically on both sides.
In the neck region the ligaments are thin, but broad and long; they are thicker in the thoracic region, and thickest in the lumbar region.
Arises from the lower half of the anterior surface of the lamina above and attaches to the posterior surface and upper margin of the lamina below.
On each side the ligament divides into a medial and lateral portion. The medial portion passes to the back of the next lower lamina. The lateral portion passes in front of the fact joint where it attaches to the anterior aspect of the inferior and superior articular processes and forms the anterior capsule. The most lateral fibres extend beyond the superior articular process to the pedicle below.
Their marked elasticity serves to preserve the upright posture, and to assist the vertebral column in resuming it after flexion. It resists excess separation of adjacent vertebral lamina and prevents buckling of the ligament into the spinal canal during extension, which would cause canal compression.
The lateral portion prevents the anterior capsule of the facet joint being nipped within the joint cavity during movement.
The body goes through several changes as a person ages. Some of these changes occur because of the continued wear that is placed on the body over long periods of time. The neck and back are especially susceptible to these changes since they are responsible for supporting the majority of the body’s weight and movements. Over time, the ligamentum flavum can lose strength and elasticity, causing it to thicken and buckle towards the spinal column. When this happens, a patient can develop spinal stenosis (or a narrowing of the spinal canal), a sometimes painful condition. If the ligamentum flavum buckles to the point that it impinges a spinal nerve, a patient may experience the following symptoms of spinal stenosis:
- Localized pain
- Radiating pain (depending on the location of the spinal stenosis, the pain could radiate into the shoulders, arms, ribs or legs)
Hypertrophy of this ligament may cause spinal stenosis because it lies in the posterior portion of the vertebral canal. increased expression of TIMP-2 in ligamentum flavum fibroblasts is associated with fibrosis and hypertrophy of the ligamentum flavum in patients with spinal stenosis.
Many causes of neck and back pain are directly related to the ligamentum flavum. Though the anatomy of the spine is quite complex, treating conditions that affect it does not have to be.
The combination of MRI and computed tomography seems the most useful for the precise diagnosis of OLF.
- Nikolai Bogduk. Chapter 4: Ligaments of the lumbar spine In: Clinical Anatomy of the Lumbar Spine and Sacrum. Elsevier.
- J Bone Joint Surg Am. 2005 Dec;87(12):2750-7. Hypertrophy of ligamentum flavum in lumbar spinal stenosis associated with increased proteinase inhibitor concentration.
- Neuroradiology 1990, Volume 32, Issue 1, pp 38-42. Neuroradiological examination of thoracic radiculo-myelopathy due to ossification of the ligamentum flavum