Interspinous Ligament (Lumbar) Detail

ligamentum interspinale lumbale detail

The lumbar interspinous ligaments fill the space between adjacent lumbar spinous processes, connecting the inferior surface of one spinous process to the superior surface of the adjacent one. They are thicker and better developed in the lumbar spine than thoracic.

Region: Lower Back

Biomechanics

Function & Actions

Resist lumbar flexion by limiting spinous process separation, form part of the posterior tension band that must be reconstructed after posterior lumbar approaches, and are the tissue compressed by interspinous spacer devices in lumbar spinal stenosis treatment.

Clinical Relevance

Clinical Notes

Interspinous ligament disruption (white line sign or interpsinous widening on lateral X-ray) indicates posterior ligamentous complex injury and an unstable lumbar fracture pattern. Interspinous spacer devices (X-Stop, Superion) are implanted between lumbar spinous processes, requiring intact interspinous ligaments for device containment.

Pathology

Common Injuries & Conditions

Posterior Ligamentous Complex Injury — Interspinous Widening

Interspinous ligament disruption producing widening on lateral lumbar radiograph, indicating an unstable posterior ligamentous complex injury requiring posterior instrumented fusion.

Interspinous Spacer Device Placement

Interspinous process devices implanted for lumbar spinal stenosis use the interspinous ligament as the posterior boundary — intact ligament is required for device stability and containment.