Thoracolumbar Burst Fractures: Two “New” Plain Film Signs with C.T. Correlation

The authors describe two “new” signs of fragment retropulsion in burst fractures, seen on the lateral plain radiograph ‐ the “posterior bow” (PB) and the “vanishing line” (VL). Their accuracy for detection of retropulsion compared to CT scanning was retrospectively assessed in 49 patients with significant thoracolumbar injuries. Overall accuracy is good but depends on high standards of radiography and careful interpretation. The major reasons for error were poor plain films and injuries above Til. The signs may be valuable if CT is not available or if the patient's medical status makes scanning difficult. They may be useful for assessing canal size on follow‐up films. In certain instances CT scanning may be unnecessary ‐ if plain films show the exact extent of retropulsion, if a fracture‐dislocation is of the Chance or flexion‐distraction type, and if patients are neurological‐ly intact or completely paraplegic but are clinically stable.