A
compression fracture is a collapse of a
vertebra. It may be due to trauma or due to a weakening of the vertebra (compare with
burst fracture). This weakening is seen in patients with
osteoporosis or
osteogenesis imperfecta, lytic lesions from metastatic or primary tumors, or infection. In healthy patients it is most often seen in individuals suffering extreme vertical shocks, such as ejecting from an
ejection seat. Seen in lateral views in plain x-ray films, compression fractures of the spine characteristically appear as
wedge deformities, with greater loss of height anteriorly than posteriorly and intact
pedicles in the anteroposterior view.