The value of CT and MRI in the classification and surgical decision-making among spine surgeons in thoracolumbar spinal injuries.

Abstract

Although imaging has a major role in evaluation and management of thoracolumbar spinal trauma by spine surgeons, the exact role of computed tomography (CT) and magnetic resonance imaging (MRI) in addition to radiographs for fracture classification and surgical decision-making is unclear. Spine surgeons (n=41) from around the world classified 30 thoracolumbar fractures. The cases were presented in a three-step approach: first plain radiographs, followed by CT and MRI images. Surgeons were asked to classify according to the AOSpine classification system and choose management in each of the three steps. Surgeons correctly classified 43.4% of fractures with plain radiographs alone; after, additionally, evaluating CT and MRI images, this percentage increased by further 18.2 and 2.2%, respectively. AO type A fractures were identified in 51.7% of fractures with radiographs, while the number of type B fractures increased after CT and MRI. The number of type C fractures diagnosed was constant across the three steps. Agreement between radiographs and CT was fair for A-type (k=0.31), poor for B-type (k=0.19), but it was excellent between CT and MRI (k>0.87). CT and MRI had similar sensitivity in identifying fracture subtypes except that MRI had a higher sensitivity (56.5%) for B2 fractures (p<0.001). The need for surgical fixation was deemed present in 72% based on radiographs alone and increased to 81.7% with CT images (p<0.0001). The assessment for need of surgery did not change after an MRI (p=0.77). For accurate classification, radiographs alone were insufficient except for C-type injuries. CT is mandatory for accurately classifying thoracolumbar fractures. Though MRI did confer a modest gain in sensitivity in B2 injuries, the study does not support the need for routine MRI in patients for classification, assessing instability or need for surgery.