Thoracolumbar burst fractures: evaluation with MR imaging.

PURPOSE

To determine the frequency of posterior ligamentous injury that occurs in patients with thoracolumbar burst fractures and to correlate ligamentous disruption with radiographic appearance.

MATERIALS AND METHODS

Magnetic resonance (MR) imaging examinations of 21 patients with 25 thoracolumbar burst fractures were retrospectively evaluated to determine spinal ligament integrity. Radiographic and computed tomographic (CT) examinations were evaluated for interpediculate widening, midsagittal canal narrowing, posterior element fractures, and kyphosis; a radiographic assessment of posterior ligamentous integrity was made. These findings were then correlated with the status of the spinal ligaments.

RESULTS

The patients were divided into two groups on the basis of the status of their supraspinous ligament (SSL). Six patients had disrupted SSLs, and 15 had intact SSLs. Radiographic and CT findings did not correlate with supraspinous ligament disruption. Radiographic indicators of posterior ligamentous disruption were present in only 33% of patients with SSL disruption.

CONCLUSION

SSL disruption is a frequent occurrence in patients with burst fractures. No radiographic features of burst fractures correlate with SSL disruption, and radiographic signs of posterior ligamentous disruption are insensitive.