From the Guidelines
Clearing the cervical spine in a patient with potential cervical spine injury involves a thorough evaluation and stabilization protocol to minimize the risk of further injury. The cervical spine can be cleared in patients who are likely to cooperate with a valid clinical evaluation at 48-72 hours, using a three-view plain film series complementing the clinical evaluation at that time 1. However, for patients who are unlikely to be evaluable within this time period, such as those with severe head injuries or multiple injuries, the cervical spine may be cleared without clinical evaluation following adequate and complete imaging studies, including cervical plain films and high-resolution entire cervical spine CT with sagittal reconstructions 1.
- The use of CT scans with 1-2 mm collimation and pitch, and sagittal reconstructions, can detect more than 99.5% of cervical spine injuries 1.
- The decision to use CT alone or combined CT and MRI for screening depends on the institution's previous performance, the patient's individual characteristics, and the potential risks and benefits of each approach 1.
- CT alone may result in faster liberation from spinal precautions and associated complications, but may have a lower sensitivity for injuries, including ligamentous injuries 1.
- Combined CT and MRI may have the best sensitivity for injuries, but may result in an increased rate of false positive tests and prolonged application of spinal precautions 1.
- It is essential for institutions to audit their data to determine the likely screening performance of their chosen modality 1.
From the Research
Cervical Spine Clearance Methods
- The use of flexion and extension computed tomography with reconstruction (FECTR) has been shown to be a safe and effective method for clearing the cervical spine in trauma patients 2.
- A comprehensive diagnostic C-spine protocol, including plain radiographs, cervical CT scan, and functional flexion/extension views, can help avoid unnecessary delays in diagnosis 3.
- Clinical decision rules, such as the NEXUS and Canadian C-Spine Rules, can be used to guide cervical spine clearance in low-risk patients, while high-risk patients require imaging in the form of CT scan of the cervical spine 4.
- A CT-based protocol for cervical spine clearance has been shown to have excellent sensitivity and specificity in detecting cervical spine injuries, allowing for early removal of spinal precautions 5.
Imaging Modalities
- CT scans are highly sensitive in detecting unstable cervical spine injuries, especially in obtunded patients without high impact trauma 6.
- MRI can be used to diagnose intrinsic spinal cord injuries, which may not be unstable, but can help explain focal neurological deficits unexplained by associated intracranial injury 6.
- Functional flexion/extension views and MRI can be necessary to detect significant ligamentous injuries, which may not be visible on plain radiographs or CT scans 3.
Patient Evaluation
- Patients with altered level of alertness (i.e., obtunded patients) require careful evaluation, and CT scans can be used to clear the cervical spine in these patients, unless there is soft tissue injury or non-bony abnormalities detected 4.
- Patients with high-risk trauma require imaging, in the form of CT scan of the cervical spine, to clear the cervical spine 4.
- Patients with low-risk trauma can be evaluated using clinical decision rules, such as the NEXUS and Canadian C-Spine Rules, to determine the need for imaging 4.