Identification of fractures of the posterior elements of thoracolumbar vertebrae is important because these fractures render the spine unstable. Technically it is difficult to demonstrate the posterior elements on a supine lateral radiograph in patients with multiple injuries. Careful inspection of the posterior vertebral structures on the anteroposterior view will reveal valuable information. Three radiological signs--interpediculate widening, increased interspinal distance and the appearance of 'Chance' fractures--are discussed.