Fig. 3.

a Burst fracture of L1 with 70% canal compromise and what appears to be a reverse cortical sign with the anterior cortex of the posterior wall facing anteriorly (the cut is at the inferior aspect of the pedicle and the foraminal level). b The sagittal reconstruction with the corresponding axial cuts show us that we are not dealing with a reverse cortical sign but it is the vertical depression of the inferior end plate into the comminuted vertebral body that mimics the flipped posterior wall cortex. The fragment is not separated from the vertebral body. c After posterior ligamentotaxis the retropulsed fragment in the canal has been significantly reduced confirming the integrity of the PLL