Upper cervical spine injuries: age-specific clinical features.

BACKGROUND: There are few reports on the age-specific clinical features of upper cervical spine injury. To identify these age-specific changes, we reviewed 103 patients with upper cervical spine injury.
METHODS: We subdivided the patients into four groups according to age: 12 patients were classified as old elderly (> or = 75 years), 18 patients as young elderly (65-74 years), 67 patients as young adults (18-64 years), and 6 patients as adolescents (< or = 17 years). Data were collected on injury etiology, mortality, neurological deficit, distribution and pattern of injury, degenerative changes of each joint in the upper cervical spine and disc in the cervical spine, and osteoporosis of the axis.
RESULTS: The proportion of patients with a simple fall as the etiology of their injury showed a statistically significant trend to increase with aging. Although no specific distribution or pattern of injury was statistically elucidated, we were able to detect some common features. A high proportion of the old elderly group (5/12) had a type II odontoid fracture. Body fracture of the axis tends to be frequent in the young elderly and traumatic spondylolisthesis and hyperextension teardrop fracture to be frequent in the young adults. In adolescents, a traffic accident as an unbelted rear seat passenger was the most frequent etiology. Among the 103 patients, 16 died during the initial hospitalization. The mortality rate for upper cervical spine injury was similar in all groups.
CONCLUSIONS: In the old elderly, stiffness of the lower cervical spine, caused by degenerative changes and osteopenia, might contribute to upper cervical spine injury in response to low-energy trauma. The disproportion of degenerative change in joints of the upper cervical spine might also contribute to the high frequency of type II odontoid fracture. In young adults, high-energy and hyperextension injury was the most frequent cause of upper cervical spine injury.