In the alert and cooperative patient standard criteria has been evaluated and verified to provide an appropriate method to clear the C spine and remove the collar without imaging. In 1998 Hoffman et al. proposed a clinical evaluation tool for the awake trauma patient without posterior midline neck pain, neurologic deficit, altered mental status and/or a distracting injury [3]. If the physical examination was negative then the cervical collar (C collar) could be removed without imaging. This same group validated their findings with a much larger sample size in 2000 involving 34,000 patients [4]. In 2001 Stiell et al. published the Canadian C spine rules which again identified a safe strategy for clinical evaluation alone for clearing the cervical spine [5]. Twenty-five clinical variables were incorporated and the final rules require an answer to three main questions; are there any high-risk factors that mandate imaging, any low-risk factors that allow for safe assessment of range of motion and is the patient able to actively rotate their neck. The answers to these questions determine the need for imaging or not. Although many trauma centers today do not have a standard protocol for evaluation and clearance of the cervical spine, most agree that a clinical exam in an appropriate patient will allow removal of the C collar without imaging [6]. The Eastern Association for the Surgery of Trauma (EAST) Practice Management Guidelines (PMG) for cervical spine were updated in 2009 and state that in the awake trauma patient with blunt mechanism the C collar may be removed without imaging if the patient has no neck pain, no neurologic deficit and full range of motion [7].

For all blunt trauma patients not meeting clinical clearance criteria an imaging study is needed to screen for cervical spine injury. Patients needing imaging of the cervical spine include those with neck pain, altered mental status, neurologic deficit, and/or a distracting injury. The diagnosis of a distracting injury is subjective and has been the focus of several research projects attempting to determine its true impact on clinical exam. In 2012 Rose et al. looked at 1000 patients deemed to have distracting injury and documented their neck exams [8]. It was found that even with a “distracting injury” a negative clinical examination had a 99 % negative predictive value. Distracting injury does continue to be an indication for imaging.

The highest quality imaging study would be the one with the least risk to the patient and the greatest ability to identify an injury. Prior to the development of computed tomography (CT) scanning, plain radiographic evaluation of the C spine was standard of care in the blunt trauma patient. As early as 1993 concern for the accuracy of plain radiographs to diagnose cervical spine injury was being questioned [9]. During the early 2000s several researchers compared the use of plain radiographs with CT scan for evaluation of the cervical spine [10, 11]. The consistent result was that plain 3-view or 5-view imaging of the cervical spine missed between 30 and 40 % of cervical spine injuries. The gold standard screening modality in the adult blunt trauma patient is CT scan from the occiput through the first thoracic vertebrae. The EAST PMG guideline in 2009 was revised and states that CT scan is the screening modality of choice in this patient population.

Patients with blunt trauma and positive findings on CT scan of the cervical spine should have spine consultation and a treatment plan as appropriate.

The best way to avoid any unplanned event is to have an organized plan of attack for a particular situation as evidence will allow. The plan for a patient with negative screening C spine CT scan will be determined based on patient condition. However, the use of a standard protocol for any trauma center will maintain consistency and avoid potentially dangerous practice patterns. The various patient populations will now be presented and the potential best practice pattern proposed.

The alert patient with neck pain who requires imaging for possible cervical spine injury must then have an organized treatment plan for the cervical spine when the CT scan is negative. The first major decision is does the collar stay on or not. The practice of a clinical exam after resolution of any mental status change or distracting injury for the determination of continued neck pain is alluded to throughout the literature. Como et al. discuss clearing patient cervical spine and removing the collar once the patient has resolved their mental status concerns and a reliable exam can be completed [12]. Using the clinical examination at a later time in the hospitalization for clearing the C spine and removing the collar after having had a negative CT scan is a safe practice.

The alert patient with continued neck pain and/or neurologic deficit after negative CT scan imaging will remain in the collar and further imaging may be necessary. Flexion and extension films can provide a dynamic evaluation of the cervical spine and assess potential instability of the ligaments. The timing of flexion and extension films impacts the quality of the films toward completing the evaluation and clearing the C spine. In the acute setting there has been concern with use of flexion and extension films because of muscle spasm and an inability to have the patient adequately flex or extend the required 30 degrees. The patient body habitus may also impact the success of the films to imaging the C7–T1 junction. Two recent studies demonstrated great limitations to flexion and extension films in the acute phase of care. McCracken in 2012 did a retrospective review of their team’s standard practice at the time of flexion-extension films in patients with a negative CT scan and continued neck pain. The overall rate of adequate films was 19.8 % and no useful data was gathered by completing flexion-extension films in the acute setting [13]. This team reviewed 1000 flexion and extension films and found 80 % to be inadequate to assess the cervical spine. The authors do not recommend the use of flexion and extension films in the acute phase of care to supply any additional information that would allow for clearance of the C spine and removal of the collar. There is some support for use of flexion and extension films in a later phase of recovery when muscle spasms have resolved to improve the ability to get adequate films. Khan et al. in 2011 reviewed the use of flexion and extension films in the acute setting and had similar conclusions to the above studies but did recommend the continuation of the cervical collar for patients with a negative CT and neck pain. Follow-up in clinic 7–10 days later with clinical exam should be completed and if neck pain persists flexion and extension films in this more chronic stage is warranted [14].

Magnetic resonance imaging (MRI) has also been used in this patient population for clearing the C spine . Although not a dynamic study to evaluate the cervical spine MRI can identify ligamentous injury, soft tissue injury, spinal cord contusion and disc herniation better then CT scan. Several studies have suggested the use of MRI in this patient population will allow for earlier clearance of the cervical spine and collar removal.

The final option in this group of awake patients is continuation of the collar and reevaluation in an outpatient setting for resolution of pain and collar removal versus continued pain and further imaging. The potential for losing patients to follow-up is always a concern.

The patient population that continues to be of the greatest debate is the obtunded or altered patient who has a physical exam that cannot be trusted. Many questions have arisen and some have answers rooted in evidence-based medicine but others continue to remain sources of controversy. A review of the most recent data to support the best evidence-based recommendations for clearing the cervical spine and removing the collar in the obtunded patient is provided. Data supports that with a negative CT scan it is unlikely that any ligamentous injury present is unstable and patients are stable in the cervical collar and may be mobilized as needed.

Four main options exist for managing the cervical spine and cervical collar in the obtunded blunt trauma patient. The use of flexion-extension films, the continuation of the cervical collar and no further imaging acutely, the use of MRI for clearance of the cervical spine or the removal of the C collar after negative CT scan and no evidence of neurologic deficit are all discussed in the literature. Flexion and extension films, although a dynamic study cannot be completed with patient participation and requires a healthcare provider to perform the flexion and extension of the neck. The inability to determine if the patient has pain or that potential harm is being done rules out this option as a viable plan for clearing the C collar in the obtunded patient. The use of dynamic flexion and extension cervical films to clear the neck in the obtunded trauma patient is not recommended.