Lumbosacral spine lateral view X-ray shows

(A) Spondylisthesis# Spondylolisthesis is the forward displacement of a vertebra, especially the fifth lumbar vertebra, most commonly occurring after a break or fracture. Backward displacement is referred to as retrolisthesis.> Variant "listhesis," resulting from division of this compound word, is sometimes applied in conjunction with scoliosis. These "slips" occur most commonly in the lumbar spine. Spondylolysis (a defect or fracture of the pars interarticularis of the vertebral arch-appears as Scotty dog sign or Scottish terrier sign in oblique view X-Ray) is the most common cause of spondylolisthesis, which should not be confused with a slipped disc, in which one of the spinal discs in between the vertebrae has ruptured.> Hangman's fracture is a specific type of spondylolisthesis where the C2 vertebra is displaced anteriorly relative to the C3 vertebra due to fractures of the C2 vertebra's pedicles.