to the editor: I enjoyed Drs. Graber and Kathol's recent article1 on the significance of radiographs of the cervical spine in trauma victims, which I thought was a thorough review. However, I would like to address one important point: the fear of failure to identify cervical spine injuries has led doctors to an extremely liberal policy for ordering neck radiographs in trauma patients.
In childhood, adults repeatedly admonished us that if we were not careful we would either “put our eye out” or “break our neck.” Everyone knows what happens when a person hangs from the neck or when a secret agent in a movie grabs someone from behind and gives the victim's neck a twist. The fear of neck injury leads a steady stream of trauma patients into physicians' offices and emergency departments.
The authors of the review note that “low-risk criteria have been defined that can be used to exclude cervical spine fractures, based on the patient's history and physical examination.” However, these criteria have never been prospectively validated, and five of the six references that the authors cite are small, uncontrolled retrospective studies without explicit criteria that evaluated patients with traumatic cervical spine injuries. One referenced study2 was prospective and well researched, but the study group was too small to have the power to validate the low-risk criteria.
In the setting of a litigious society and numerous reports of cervical spine injuries and the common desire of patients to have neck radiographs taken, many physicians order neck radiographs for most patients, regardless of the mechanism of injury or the patient's signs and symptoms. Despite the low-risk criteria described in the review article, Neifeld and colleagues3 have shown that, based on the best estimates of the incidence of occult cervical spine injury in order for the low-risk criteria to be validated, a prospective study of over 30,000 asymptomatic or minimally symptomatic trauma patients would be needed to demonstrate with 99 percent confidence that no significant fracture or dislocation would be missed by failing to obtain a radiograph of the neck in such patients.
The solution to this problem may be at hand. The National Emergency X-Radiography Utilization Study (NEXUS)4 is a very large, federally funded, multicenter, prospective study designed to define the sensitivity for detecting significant cervical spine injury using the described low-risk criteria that was previously shown to have a high negative predictive value. The NEXUS study is being conducted at 23 hospital emergency departments in the United States, and 20,000 to 30,000 trauma patients who are at risk for cervical spine injury are expected to be enrolled.
When the results of NEXUS4 are reported, we should know definitively about the validity and reliability of clinical criteria used as preliminary screening for cervical spine injury. Hopefully, the estimated 800,000 patients who undergo cervical spine radiography annually in the United States will be reduced to a lower number, saving on costs that are currently in excess of $180 million.4 Still, the reported clinical experience to date supports the recommendation that radiographs of the cervical spine be obtained for patients in whom spinal injury is suspected based on clinical assessment.5
in reply: We agree wholeheartedly with the comments of Major Fieg. We, too, await results of the NEXUS trial,1 which will be the largest prospective trial of neck injuries to date. We also agree with his conclusion that “the reported clinical experience to date supports the recommendation that radiographs of the cervical spine be obtained for patients in whom spinal injury is suspected based on clinical assessment.” This is what we suggest in our article.
In patients with low-risk criteria and normal findings on physical examination, current experience suggests and the accepted standard of care indicates that cervical radiographs are unnecessary. As noted in our article, not all of the so-called missed fractures actually met low-risk criteria. We hope that the NEXUS trial will provide additional evidence to support the current best practice.