A retrolisthesis is a posterior displacement of one vertebral body with respect to the adjacent vertebrae to a degree less than a luxation (dislocation). Clinically speaking, retrolisthesis is the opposite of spondylolisthesis (anterior displacement of one vertebral body on the subjacent vertebral body). In the past this clinical pathology was also called a "retrospondylolisthesis". Retrolistheses are most easily diagnosed on lateral x-ray views of the spine. Views, where care has been taken to expose for a true lateral view without any rotation, offer the best diagnostic quality...