Chalk stick fracture
Chalk stick or carrot stick fractures are fractures of a fused spine, classically seen in ankylosing spondylitis.
Some authors define the chalk stick fracture as a fracture through a Pagetoid long bone (see Paget disease).
They usually occur through the disco-vertebral junction in the lower cervical or upper thoracic spine.
When several contiguous segments of the spine are fused, the fused column acts as a lever arm. This places greater than normal stresses on the spine. These fractures often occur following minimal trauma due to the altered biomechanics of the spine.
Chalk stick fractures may also been seen in:
- surgical spinal fusion
History and etymology
Not surprisingly, it is named because of the resemblance of the fracture to breaking a chalk stick or a carrot.