Nonskeletal cervical spine injuries: epidemiology and diagnostic pitfalls.

BACKGROUND: Cervical spine injuries are the most commonly missed severe injuries with serious implications for the patient and physician. The diagnosis of subluxations or spinal cord injuries in the absence of vertebral fractures, especially in unevaluable patients, poses a major challenge. The objective of this study was to study the incidence and type of cervical spine trauma according to mechanism of injury; identify problems and pitfalls in the diagnosis of nonskeletal cervical spine injuries.
METHODS: Retrospective study of all C-spine injuries caused by traffic accidents or falls admitted over a 5-year period at a large Level I trauma center. Data were obtained from the trauma registry, review of patient charts, and radiology reports.
RESULTS: During the study period, there were 14,755 admissions due to traffic injuries or falls who met trauma center criteria. There were 292 patients with C-spine injuries, for an overall incidence of 2.0% (3.4% in car occupants, 2.8% for pedestrians, 1.9% for motorcycle riders, and 0.9% for falls). The incidence of C-spine injuries in patients with a Glasgow Coma Scale score of 13 to 15 was 1.4%, 9 to 12 was 6.8%, and in < or =8 was 10.2% (p < 0.05). Of C-spine injuries, 85.6% (250 patients) were a vertebral fracture, 10.6% of the injuries (31 patients) were subluxation without fractures, and 3.8% (11 patients) were an isolated spinal cord injury without fracture or subluxation. Of the 31 patients with isolated subluxations, one-third required an early endotracheal intubation before clinical evaluation of the spine, because of associated severe head injury or hypotension. Adequate lateral C-spine films diagnosed or suspected 30 of the 31 subluxations (96.8%). The combination of plain films and computed tomographic (CT) scan diagnosed or suspected all injuries. Of the 11 patients with isolated cord injury, 27.3% required early intubation before clinical evaluation of the spine. The diagnosis of cord injury was made on admission in only five patients (45.5%). In three patients, the neurologic examination on admission was normal and neurologic deficits appeared a few hours later. In the remaining three patients (two intubated, one intoxicated), the diagnosis was missed clinically and radiologically.
CONCLUSIONS: Isolated nonskeletal C-spine injuries are rare but potentially catastrophic because of the high incidence of neurologic deficits and missed diagnosis. In subluxations, the combination of an adequate lateral film and CT scan was reliable in diagnosing or highly suspecting the injury. A large prospective study is needed to confirm these findings, before a recommendation is made to remove the cervical collar if the findings of these investigations are normal. However, in isolated cord injuries, the diagnosis was often missed because of associated severe head trauma and the low sensitivity of the plain films and CT scans.