====== Posterior Ligamentous Complex (PLC) Integrity ======

**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:**
  * **Spinal instability**
  * **Thoracolumbar burst fractures**
  * **Flexion-distraction injuries**