What is the significance of a slight lateral offset of the right lateral mass of C1 (cervical vertebra 1) with respect to C2 (cervical vertebra 2) lateral mass on an odontoid view in an 11-year-old patient with a history of trauma?

From the Guidelines

The 11-year-old patient's X-ray finding of a slight lateral offset of the right C1 lateral mass relative to the C2 lateral mass is likely due to positional rotation rather than true injury, but if there are significant clinical concerns about trauma or symptoms, a cervical spine CT scan should be performed for definitive evaluation. This recommendation is based on the American College of Radiology's (ACR) appropriateness criteria for suspected spine trauma in children, which suggests that radiographs of the cervical spine are usually appropriate for the initial imaging of children with acute cervical spine trauma, but CT cervical spine may be of value as a follow-up examination in patients who had radiographs with abnormal or ambiguous findings 1. The ACR also notes that CT cervical spine has superior visualization of bony detail and can differentiate congenital variants from traumatic injuries, making it a useful tool for evaluating children with suspected cervical spine trauma 1.

Some key points to consider in this case include:

• The patient's age and the potential for subtle cervical spine injuries on plain radiographs
• The importance of clinical symptoms, such as neck pain, limited range of motion, or neurological symptoms, in guiding the decision to perform further imaging
• The role of CT imaging in providing superior visualization of bony structures and detecting fractures or true atlantoaxial subluxation
• The potential risks and benefits of different imaging modalities, including radiation exposure and the need for sedation

Overall, the decision to perform a cervical spine CT scan should be based on a careful evaluation of the patient's clinical symptoms and the results of initial imaging studies, with the goal of providing timely and accurate diagnosis and treatment of any potential cervical spine injuries. The current evidence suggests that CT imaging is a valuable tool in this context, particularly when there are significant clinical concerns about trauma or symptoms 1.

From the Research

Cervical Spine Trauma Evaluation

• The evaluation of cervical spine trauma typically begins with computed tomography (CT) for initial osseous and basic soft tissue evaluation, followed by magnetic resonance imaging (MRI) for complementary evaluation of the neural structures and soft tissues 2.
• CT scans are excellent at detecting bony injuries but not ligamentous injuries, and removing cervical collars based on CT scans alone may be expeditious, but some injuries may be missed without further imaging 3.

Diagnostic Power of Imaging Modalities

• A study evaluating the diagnostic power of CT, MRI, X-Ray, and LODOX in identifying c-spine injuries found that CT had a sensitivity of 88.6% and specificity of 99%, while MRI had a sensitivity of 88.5% and specificity of 96.9% 4.
• The same study highlighted that MRI holds clinical significance in revealing injuries not recognized by CT in symptomatic patients, and recommended extended MRI use when CT scans are negative for patients with neurological symptoms 4.

Clinical Relevance of Imaging Findings

• The clinical relevance of imaging findings is crucial in directing patient care, including diagnosis, next steps in treatment plan, and prognosis 2.
• A study on acute traumatic spinal cord injury emphasized the importance of early stabilization of the patient's airway, breathing, and circulation, as well as cervical and thoracolumbar spinal immobilization, to prevent additional injury and optimize outcomes 5.

Cervical Spine Clearance

• A retrospective study on cervical spine clearance in obtunded patients without high impact trauma found that CT had a sensitivity of 0.875 and a specificity of 1.000 in detecting all cervical spine injuries compared to MRI 6.
• The same study suggested that CT is highly sensitive in detecting unstable injuries in obtunded patients with GCS of 14 or less in the absence of high impact trauma, and that neurosurgeons should be comfortable to discontinue the cervical collar after a negative, high-quality CT in this patient population 6.