Chalkstick fracture

Chalkstick fracture
Other names	Carrot stick fractures
Chalkstick fracture due to bone metastasis of breast cancer. The left image shows the metastasis, on the right a pathological fracture a few days later.
Specialty	Orthopedics
Risk factors	Paget's disease of bone, ankylosing spondylitis, and osteopetrosis.

Chalkstick fractures are fractures, typically of long bones, in which the fracture is transverse to the long axis of the bone, like a broken stick of chalk.^[1] A healthy long bone typically breaks like a hard woody stick as the collagen in the matrix adds remarkable flexibility to the mineral and the energy can run up and down the growth rings of bone. The bones of children will even follow a greenstick fracture pattern.

Chalkstick fractures are particularly common in Paget's disease of bone, and osteopetrosis.^[2] It is also seen in cases of fused spine as in a patient with ankylosing spondylitis.^[3]