Reliability of magnetic resonance imaging in detecting posterior ligament complex injury in thoracolumbar spinal fractures

Study design. Prospective study of patients with thoracolumbar spinal fractures, Objectives. To assess the reliability of magnetic resonance imaging (MRI) for posterior ligament complex injury in thoracolumbar spinal fractures. Summary of Background Data. Some researchers have studied posterior ligament complex injury in spinal fracture using MRI. However, most did not evaluate the findings of MRI compared with operative findings. Methods. Thirty-four patients with thoracolumbar spinal fracture were evaluated by palpation of the interspinous gap, plain radiography, and MRI before operation. In addition to conventional MRI sequences, a fat-suppressed T2-weighted sagittal sequence was performed. Surgery was performed by a posterior approach. During the operation, posterior ligament complex injury was carefully examined. Results. A wide interspinous gap was palpated in 14 and was found in 21 patients on plain radiography. Magnetic resonance imaging raised suspicion of injury to the posterior ligament complex in 30 patients. According to interpretation of MRI, injury to the supraspinous ligament was suspected in 27 patients, the interspinous ligament in 30 patients, and the ligamentum flavum in 9 patients. There were 28 supraspinous ligament injuries, 29 interspinous ligament injuries, and 7 ligamentum flavum injuries in operative findings. There was a significant relation between MRI interpretation and operative findings. Conclusion. A fat-suppressed T2-weighted sagittal sequence of MRI was a highly sensitive, specific, and accurate method of evaluating posterior ligament complex injury. Based on the results of this study, a fat-suppressed T2-weighted sagittal sequence of MRIs is recommended for the accurate evaluation of posterior ligament complex injury and would be helpful in the selection of treatment options.