Definition:
The Posterior Ligamentous Complex (PLC) refers to a group of ligaments and soft tissues that stabilize the posterior aspect of the spinal column. PLC integrity is critical for maintaining spinal stability, especially after trauma.
Components of the PLC:
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Facet joint capsules
Function:
Provides posterior tension band support to resist flexion, rotation, and shear forces.
Helps maintain alignment of the vertebrae.
Prevents instability and progressive deformity after spinal trauma.
Clinical Significance:
Loss of PLC integrity is a key criterion in the Thoracolumbar Injury Classification and Severity Score (TLICS).
MRI is the gold standard for assessing PLC injury.
Disruption may necessitate surgical stabilization even in the absence of neurological deficits or vertebral collapse.
Imaging Findings Suggestive of PLC Injury:
Increased interspinous distance on X-ray or CT.
High signal in ligaments on T2/STIR MRI.
Facet dislocation or widening.
Kyphotic angulation.
Related Concepts: