J Manipulative Physiol Ther 2002 (May); 25 (4): 263–269 ~ FULL TEXT
Steven W. King, DC, Bryan K. Hosler, DC, Mark A. King, DC, Eric W. Eiselt, DC
This study was funded by Life Chiropractic College West,
Hayward, California, the Gonstead Clinical Studies Society,
Santa Cruz, California, and the
International Chiropractic Pediatric Association,
Steven W. King, DC,
3197 Linwood Ave,
Cincinnati, OH 45208, USA
OBJECTIVE: To review the case of a patient who suffered a cervical spine fracture-dislocation missed at a hospital emergency department.
CLINICAL FEATURES: A 77-year-old man involved in a motor vehicle accident was transported to a local emergency hospital where cervical spine x-ray films taken were reported as demonstrating no evidence of acute injury. The patient visited a chiropractic clinic 6 days later, where x-ray films were again obtained, finding that the patient sustained fractures of C5 and C6, as well as a bilateral facet dislocation at C5/C6. Computed tomography confirmed the fractures, and magnetic resonance imaging findings demonstrated cervical spinal cord compression and posterior spinal cord displacement.
INTERVENTION AND OUTCOME: The patient was referred for preoperative medical evaluation. He underwent C5-6 closed reduction and anterior/posterior fusion surgery and was released without complication. Patient follow-up indicated full recovery with minimal neurologic symptoms.
CONCLUSION: Cervical spine fracture-dislocations are often missed during standard radiographic examinations in emergency department settings. Chiropractors are encouraged to perform a comprehensive evaluation of patients presenting with cervical trauma even if they have had prior x-ray films reported as normal. Standard x-ray films taken at emergency department facilities are not entirely reliable for detecting or revealing cervical spine fracture-dislocations. This case stresses the importance of careful clinical assessment and imaging procedures on patients who have encountered cervical spine trauma.
From the Full-Text Article:
Cervical spine fractures, unilateral facet dislocations, and fracture-dislocations, although not uncommon, can easily be missed. [1-6] Cervical spine fracture-dislocation injuries can be extremely severe and life-threatening. In a study by Hadley et al,  68 patients with acute traumatic cervical facet fracture-dislocation injuries were studied. Thirty-one had unilateral facet injuries and 37 had bilateral facet injuries. Neurologic morbidity was 90% and most severe with bilateral facet injury patients.  Although treatment for cervical spine fracture-dislocations is controversial, operative intervention appears superior to nonoperative treatment.  Chiropractic manipulation would certainly be contraindicated and chiropractors should be extremely cautious when initiating manipulative therapy in those patients having sustained previous cervical spine trauma even if they have had prior x-ray films reported as normal. [5, 6]
It is generally accepted that early radiographs should be obtained on all patients with pain or neurologic deficit referable to the cervical spine after acute trauma.  Cervical spine fractures should be assumed in any patients with multiple trauma. The absence of neurologic deficit or pain does not rule out injury to the cervical spine, and one should consider the presence of such a finding until ruled out by adequate roentgenographic examination. Common emergency department practice mandates cervical spine x-ray films on all patients with trauma with potential injuries, but the number of views ordered is left up to the discretion of the attending emergency physician and is based on clinical assessment and mechanism of injury.
A trauma series of x-ray films, which is often routinely ordered on cervical-spine-injury patients, includes a cross table lateral, a supine anteroposterior, and an open-mouth odontoid view. Several studies have suggested that the trauma series may not be enough as a reliable method to rule out cervical spine fracture-dislocation. [7-9] In a study done by Woodring and Lee, 216 consecutive patients with cervical injuries were reviewed. The trauma series falsely identified 23% of the patients as having normal cervical spines, half of whom had unstable cervical injuries. 
The addition of special x-ray views, such as flexion/extension or supine obliques, to the standard trauma series, does not necessarily eliminate the risk for missing cervical spine fracture-dislocations. [10-12] Wang et al  designed a study to determine the effectiveness of obtaining cervical spine flexion/extension radiographs in the emergency department on acutely injured patients. Their study showed that the additional views were inadequate because one third of the patients could not move enough to assess cervical stability. The addition of supine oblique views to the standard trauma series did not improve detection of cervical spine fractures, partial dislocations, etc. according to a study done by Freemyer et al.  A review of the literature does suggest that the addition of CT along with a standard trauma series for assessment of suspected cervical spine injuries could eliminate the risk of missing a cervical spine fracture-dislocation. [13-15] Use of CT, as well as radiography, on all patients with cervical spine trauma would be cost-prohibitive considering that a cervical spine CT is approximately $500.
A review of this case highlights the necessity for a complete radiologic and clinical assessment to ensure that cervical spine fracture-dislocations are not missed. Although the fractures were not detectable on examination of the radiographs taken of the patient at the hospital emergency facility immediately after the accident, there were radiographic findings that did justify further imaging. For example, there was a break in George's line at C5/C6, which is a radiograph sign for a possible dislocation/fracture, yet flexion/extension radiography and CT were not performed. [16, 17] There were also clinical examination findings that were not fully addressed that justified additional imaging. For example, evaluation of hospital records on the day of the accident showed that the patient complained of right-sided neck, upper shoulder and arm pain, right and left arm numbness and tingling, and numbness of the fingers in his left hand. The records revealed that the primary diagnosis was a cervical strain/sprain. Although the patient certainly sustained a cervical strain/sprain, there was no explanation or diagnosis for the arm pain/numbness/tingling. The arm symptoms alone would justify further imaging of the cervical spine, such as cervical oblique plain-film radiography, CT, or MRI, considering that a cervical strain/sprain does not typically cause bilateral arm pain/numbness and tingling.
Current emergency department/urgent care facility procedures mandate performing radiography on patients sustaining cervical spine trauma, but the number of x-ray films or the need for additional imaging, such as CT, is left up to the attending emergency physician. This case shows that cervical spine fracture-dislocations can be missed, and chiropractors are cautioned to perform a comprehensive evaluation of patients suffering from cervical trauma even if they have prior x-ray films reported as normal. Although CT is extremely reliable for detection of cervical spine fracture-dislocation, mandatory use of CT for all patients with cervical spine trauma is most likely cost-prohibitive. This case clearly demonstrates the importance of careful clinical assessment and imaging procedures on patients after cervical trauma. The x-ray films taken at the emergency facility did appear negative for fracture, but there were radiographic signs and clinical findings that were not ruled out. A comprehensive assessment addressing all significant radiographic and physical examination findings would have justified further imaging, such as CT or MRI and revealed the fracture-dislocation that was not detectable on plain film.