The ghost sign is a feature that has been described in a clay shoveler fracture as seen on the AP projection of a cervical spine radiograph. It is caused by the appearance of a "double spinous process" on C6 or C7 resulting from caudal displacement of the avulsed spinous process fragment, giving the appearance of two smaller spinous processes, one immediately on the top of the other.
- 1. Baker BK, Sundaram M, Awwad EE. Case report 688. Fractures of the spinous processes of multiple thoracic vertebrae. Skeletal Radiol. 1991;20 (6): 463-4. Pubmed citation