We wanted to evaluate the MRI features and their diagnostic accuracy for SSL injury in the thoracolumbar spine.

From December 2003 to June 2006, among 42 surgically treated patients with spinal fracture, the 35 patients who underwent MRI and who were surgically evaluated for SSL injury were included in this study. The sagittal MR images were evaluated for the presence of SSL injury and its level, location and distraction gap, the level and compression ratio of the fractured body, and the presence of ISL or yellow ligament injury and posterior osseous fracture. The sensitivity, specificity and accuracy of MRI were calculated. The distraction gap of the SSL and the compression ratio of the fractured body or posterior osseous fracture were statistically analyzed.

Thirty-one among the 33 patients with surgically confirmed SSL injury were diagnosed on MRI. SSL injury was mostly seen at the thoracolumbar junction and near the upper spinous process. The mean distraction gap was 4.3 mm. The level of the fractured body was most commonly in the lower vertebra of the injured SSL level and the mean compression ratio was 21.8%. Combined SSL, ISL and yellow ligament injury were mostly seen. The sensitivity, specificity and accuracy were 93.9%, 50% and 91.4%, respectively. There was a statistically significant difference of the distraction gap of the injured SSL depending on the presence of posterior osseous fracture.

MRI is an accurate modality for evaluating SSL injury and the associated findings.