Misdiagnosis of Thoracolumbar Posterior Ligamentous Complex Injuries and Use of Radiographic Parameter Correlations to Improve Detection Accuracy.

Retrospective study. To evaluate radiological parameters as indicators for posterior ligamentous complex (PLC) injuries in the case of limited availability of magnetic resonance imaging. Traumatic thoracolumbar spinal fractures with PLC injuries can be misdiagnosed on X-rays or computed tomography scans. This study aimed to retrospectively assess unrecognized PLC injuries and evaluate radiographic parameters as indicators of PLC injuries requiring surgery. In total, 314 patients with type A and type B2 fractures who underwent surgical treatment between 2001 and 2010 were included. The frequency of misdiagnosis was reassessed, and radiographic parameters were evaluated and correlated. The average age of the patients was 51.8 years. There were 225 type A3/A4 and 89 type B2 fractures; 39 of the type B2 fractures (43.8%) had been misdiagnosed as type A fractures. Type B fractures presented with a significantly higher kyphotic wedge angle and Cobb angle and a lower sagittal index (SI) than type A fractures. In addition, the normalized interspinous distance was higher in type B2 fractures. The significant mathematical indicators for PLC injuries were as follows: Cobb angle+kyphotic wedge angle >29°; Cobb angle2 >170°; and vertebral angle/SI >25. The results demonstrated that PLC injuries are frequently misdiagnosed. Correlations between certain radiological parameters associated with PLC injuries can be useful indicators of the presence of such injuries requiring surgery.