Tsutomu Inaoka MD, Presenter: Nothing to Disclose

Kenjirou Ohashi MD, Abstract Co-Author: Nothing to Disclose

Georges Yousef El-Khoury MD, Abstract Co-Author: Nothing to Disclose

Kevin Staley Berbaum PhD, Abstract Co-Author: Nothing to Disclose

To assess the significance of MRI findings in sagittal-slice fractures (anterior fracture-dislocation) of the thoracic spine and correlate these findings with the neurologic outcomes.

Of 228 patients with thoracic spine fractures, 35 patients (15%) had sagittal-slice fractures by MDCT. 20 patients (15 men and 5 women; mean age, 37.3 years) were imaged by MRI. Mechanism of injury included MVA (n=10), fall (n=5), and others (n=5). Two MSK radiologists reviewed the images independently and disagreements were reconciled by consensus. The fracture level and displacement, presence of epidural/paravertebral hematoma, disk injuries, cord injuries, dural tear, ligamentous injuries, and other soft-tissue injuries were recorded. Fracture displacement was measured by the distance between the vertebrae. Neurologic deficit was assessed at presentation and at follow-up. We compared the MRI findings between the patients with and without permanent neurologic deficit.

The dislocation occurred commonly at T3/4 (n=3), T6/7 (n=3), and T12/L1 (n=3) levels. 15/20(75%) of the patients had neurologic deficit at presentation. 13/20 (65%) had permanent neurologic deficit. On MRI, 19/20 (95%) had epidural/paravertebral hematoma, 18/20 (90%) had disk injuries, 19/20 (95%) had ligamentous injuries, 16/20 (80%) had cord injuries, 7/20 (35%) had dural tear, and 16/20 (80%) had other soft-tissue injuries. There was no significant difference in the incidences of MRI findings between patients with and without permanent neurologic deficit (P>0.05). There was no significant difference in the degree of vertebral displacement (p=0.34) between the patients with and without permanent neurologic deficit.

Sagittal-slice fractures of the thoracic spine are high energy injuries. These fractures are frequently associated with neurologic deficit. MRI findings of ligamentous and cord injuries are frequently present regardless of the patients' neurologic outcomes. This is likely because the sagittal-slice injury is a dynamic event where the maximum canal stenosis and cord injury occur at the time of the impact and the final position of the displaced vertebrae do not reflect what happened at the time of the injury.

Sagittal-slice fractures are frequently associated with neurologic deficit. MRI clearly showed the ligamentous and cord injuries; however the MRI findings are not good predictors of neurologic status.

Inaoka, T, Ohashi, K, El-Khoury, G, Berbaum, K, Sagittal-slice Fractures (Anterior Fracture-Dislocation) of the Thoracic Spine: MRI Findings and Neurologic Outcomes.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6008810.html