Cervical Spine Injuries Following Trauma

Authors

Como, John J. MD; Diaz, Jose J. MD; Dunham, C Michael MD; Chiu, William C. MD; Duane, Therese M. MD; Capella, Jeannette M. MD; Holevar, Michele R. MD; Khwaja, Kosar A. MD; Mayglothling, Julie A. MD; Shapiro, Michael B. MD; Winston, Eleanor S. MD

Process

Identification of References

A search of the National Library of Medicine and the National Institutes of Health MEDLINE database was performed using (www.pubmed.gov). The search retrieved English language articles regarding the identification of CS injury from 1998 to 2007; review articles, letters to the editor, editorials, other items of general commentary, and case reports were excluded from the search. These articles were then reviewed for relevance by the committee chair, and the final reference list of 78 citations was distributed to the remainder of the study group for review. Of these, 52 were felt to be useful for construction of these guidelines, and an evidentiary table was constructed (Table 1).

Quality of the References

Articles were classified as Class I, II, or III as described in the EAST primer on evidence based medicine as follows:^[3]

Class I: Prospective, randomized clinical trials (no references).

Class II: Clinical studies in which data were collected prospectively or retrospective analyses based on clearly reliable data (20 references).

Class III: Studies based on retrospectively collected data (32 references).

Recommendations were classified as level 1, 2, or 3 according to the following definitions:

Level 1: The recommendation is convincingly justifiable based on the available scientific information alone. This recommendation is usually based on class I data, however, strong class II evidence may form the basis for a level 1 recommendation, especially if the issue does not lend itself to testing in a randomized format. Conversely, low quality or contradictory class I data may not be able to support a level 1 recommendation.

Level 2: The recommendation is reasonably justifiable by available scientific evidence and strongly supported by expert opinion. This recommendation is usually supported by class II data or a preponderance of class III evidence.

Level 3: The recommendation is supported by available data but adequate scientific evidence is lacking. This recommendation is generally supported by class III data. This type of recommendation is useful for educational purposes and in guiding future clinical research.

Recommendations

a. Removal of cervical collars:
I. Cervical collars should be removed as soon as feasible after trauma (level 3).

b. In the patient with penetrating trauma to the brain:
I. Immobilization in a cervical collar is not necessary unless the trajectory suggests direct injury to the CS (level 3).

c. In awake, alert patients with trauma without neurologic deficit or distracting injury who have no neck pain or tenderness with full range of motion of the CS:
I. CS imaging is not necessary and the cervical collar may be removed (level 2).

d. All other patients in whom CS injury is suspected must have radiographic evaluation. This applies to patients with pain or tenderness, patients with neurologic deficit, patients with altered mental status, and patients with distracting injury.
I. The primary screening modality is axial CT from the occiput to T1 with sagittal and coronal reconstructions (level 2).
II. Plain radiographs contribute no additional information and should not be obtained (level 2).
III. If CT of the CS demonstrates injury:
      1. Obtain spine consultation.
IV. If there is neurologic deficit attributable to a CS injury:
      1. Obtain spine consultation.
      2. Obtain MRI.
V. For the neurologically intact awake and alert patient complaining of neck pain with a negative CT:
    1. Options.
         A. Continue cervical collar.
         B. Cervical collar may be removed after negative MRI (level 3).
        C. Cervical collar may be removed after negative and adequate F/E films (level 3).
VI. For the obtunded patient with a negative CT and gross motor function of all four extremities:
      1. F/E radiography should not be performed (level 2).
      2. The risk/benefit ratio of obtaining MRI in addition to CT is not clear, and its use must be individualized in each     
      institution (level 3). Options are as follows:
           A. Continue cervical collar immobilization until a clinical examination can be performed.
           B. Remove the cervical collar on the basis of CT alone.
           C. Obtain MRI.
      3. If MRI disclosed nothing abnormal, the cervical collar may be safely removed (level 2).

Scientific Foundation

Removal of Cervical Collars

Cervical collars should be removed as soon as feasible after trauma. Early removal of cervical collars may be associated with decreased collar-related decubitus ulceration, decreased intracranial pressure (ICP), fewer ventilator days, fewer intensive care unit (ICU) and hospital days, and a decrease in the incidence of delirium and pneumonia.

Small series show that skin breakdown is associated with days in cervical collar. Ackland et al.^[4] showed that ICU admission, mechanical ventilation, the necessity for MRI CS, and the time to CS clearance were clinically significant predictors of collar-related decubitus ulceration, with time to CS clearance being the strongest indicator. Chendrasekhar et al.^[5]documented a 38% incidence of collar-related decubitus ulceration in patients with head injuries who survived for > 24 hr. Those who developed decubitus ulcers had a significantly longer duration of cervical collar use than those who did not. Powers et al.^[6] found skin breakdown in 6.8% of ICU patients who remained in a cervical collar for >24 hr. In their study, the most significant predictor of breakdown was time in a cervical collar.

Small prospective series have shown a decrease in ICP when cervical collars were removed. Hunt et al.^[7] applied cervical collars to patients with traumatic brain injury and found a significant rise from the baseline ICP when the collars were applied. Mobbs et al.^[8] found that 9 of 10 patients with head injuries had a rise in ICP after application of a cervical collar.

Stelfox et al.^[9] found a decreased duration of CS immobilization in patients who had CS precautions removed based on normal CT findings alone. These patients had fewer days of mechanical ventilation and shorter ICU and hospital stays. They also had significantly fewer pressure ulcers, and a lower incidence of delirium and health care associated pneumonia. In summary, there are several advantages to early cervical collar removal.

Penetrating Trauma to the Brain

Immobilization in a cervical collar after penetrating trauma to the brain is not necessary unless the trajectory suggests direct injury to the CS. A large proportion of these patients will require emergency airway management, and CS immobilization may complicate or delay this.

A number of retrospective studies have shown no injuries in >500 patients. Of 105 patients with a gunshot wound (GSW) limited to the cranium in a study by Kennedy et al.,^[10]none were found to have CS injury. Chong et al.^[11] reviewed the CS x-rays of 53 consecutive patients with a GSW to the cranium and found that all these films disclosed nothing abnormal. Kaups and Davis^[12] reviewed 215 patients with a GSW to the head and found that no patient sustained indirect (blast or fall related) spinal column injury. Finally, Lanoix et al.^[13] reviewed 174 charts of patients with a GSW to the head, excluding those with penetrating face or neck trauma. Although 23 died without evaluation, no patient was found to have CS injury.

Clinical Clearance of the CS

The most recent version of the EAST guidelines for evaluation of the CS after trauma stated that CS radiography is not required in awake and alert patients without distracting injury, neurologic deficit, or neck pain or tenderness on full range of motion of the CS, and that the cervical collar may be removed in these patients. These recommendations were based on multiple series, most small.^[14-24] Since the last update of the EAST guidelines, several authors have addressed the issue of clinical clearance of the CS.

Gonzales et al.^[25] performed a prospective evaluation of 2,176 consecutive patients with trauma, of whom 33 (1.6%) had a CS injury. Of the 33 CS injuries, only three had negative clinical examinations. These three patients were found to have a C2 spinous process fracture (no specific treatment needed) and C6-C7 body fractures (considered stable fracture but treated with a halo), and a C1 lamina fracture along with C6-C7 body fractures (considered stable, but treated with a cervical-thoracic orthosis). This article concluded that clinical examination of the neck could reliably rule out significant CS injury in the awake and alert patient with blunt trauma.

In 2000, the New England Journal of Medicine published the landmark National Emergency X-Radiography Utilization Study (NEXUS). NEXUS was a prospective observational study conducted at more than 21 trauma centers across the United States to validate five criteria for a low probability of CS injury.^[26] This decision instrument required patients to have (1) no midline cervical tenderness, (2) no focal neurologic deficit, (3) normal alertness, (4) no intoxication, and (5) no painful distracting injury. The decision instrument was evaluated in 34,069 patients who underwent CS radiography after blunt trauma. All but eight of the 818 patients who had a radiographically identified CS injury were identified; only two of these eight met predefined criteria for clinically significant injury. One patient had a fracture of the anteroinferior portion of C2; this patient refused treatment and had no symptoms at 6-week follow-up. The second patient had a fracture of the right lamina of C6; this patient underwent laminectomy and fusion. The authors concluded that the sensitivity of their decision instrument approached 100% and helped to avoid radiographic imaging in those who did not require it.

Three years later, the New England Journal of Medicine published a comparison of the NEXUS criteria and the Canadian C-spine Rule (CCR), an additional decision rule for CS radiography.^[27] The CCR was based on three high-risk criteria, five low-risk criteria, and the ability of patients to rotate their necks. Among the eight, 283 patients, 169 (2.0%) had clinically significant CS injuries, and the NEXUS criteria would have missed almost 10% of these injuries. The authors determined that the CCR was more sensitive and specific than the NEXUS criteria, and its use would have resulted in lower radiography rates.

More recently, Duane et al.^[28] prospectively evaluated 534 patients with blunt trauma, comparing clinical examination with CT CS. To our knowledge, this is the only such study to date. History and physical examination identified only 40 of the 52 patients with a CS fracture. In awake and alert patients with a GCS of 15 who were not intoxicated and did not have distracting injuries, 17 patients had CS fractures, seven of which had a negative clinical examination. Three of these patients had transverse process fractures that required no further intervention; one had a hangman's fracture; another had a C1 lateral mass fracture; a sixth patient had an occipital condyle fracture; and the last had a fracture through the C3 transverse foramen requiring evaluation of the vertebral artery. The latter four patients were treated with a cervical collar.

Although the Gonzales and NEXUS studies support the most recent EAST guidelines, the Duane and CCR studies suggest that clinical examination may miss significant injuries. This will require further study and duplication of the aforementioned studies before a change in the EAST guidelines is warranted. At present we recommend no change in the guidelines for clinical clearance of the CS.

Radiographic Evaluation of the CS

All patients with a suspected CS injury who cannot be clinically cleared must have radiographic evaluation. This applies to patients with pain, tenderness, a neurologic deficit, altered mental status, a distracting injury, and obtunded patients. In the past, the initial radiographic screening test was a three-view (lateral, anteroposterior, and odontoid views) CS series supplemented by swimmer's views and CT CS for poorly visualized areas. Recently, a number of manuscripts have addressed the most appropriate initial radiographic screening test for CS evaluation after trauma.

In 1999, Berne et al.^[29] published a prospective study of 58 patients with blunt trauma who required an ICU admission, CS imaging and a CT of another body region. These patients received both plain radiography and CT CS. In this group, 20 patients (34.4%) had CS injuries. Plain radiography missed eight injuries, including three unstable ones, whereas CT CS missed only two injuries, both of which were stable. The sensitivity for plain CS films was 60%, but reached 90% for CT CS.

Griffen et al.^[30] reported a cohort of 1,199 patients with blunt trauma with posterior neck tenderness, altered mental status, or neurologic deficit that underwent both plain films, and CT CS for CS evaluation. A CS injury was found in 116 patients. The injury was identified on both plain films and CT CS in 75 of these patients. In the remaining 41 patients, the injury was detected by CT CS but missed by plain radiography. CT CS missed no injuries. The authors concluded that there was no apparent role for screening with plain CS radiography in this patient group.

Diaz et al.^[31] performed a prospective study of 1,006 hemodynamically stable patients with either altered mental status or distracting injury who underwent five-view plain films and CT CS. Plain films of the CS missed 90 of 172 (52.3%) injuries. Plain radiography also missed 5 of 29 (17.2%) of patients with unstable injuries. CT CS missed three injuries, none of which were unstable. They concluded that CT CS outperformed plain films in this group of patients.

Brohi et al.^[32] studied 437 unconscious, intubated patients with blunt trauma who underwent CT CS. They found that an adequate lateral CS film detected injuries with a sensitivity of 53.3%. In addition, 14 of 31 (45%) unstable injuries were missed using plain lateral CS films. No unstable injury was missed using CT CS.

In a study by Mathen et al.^[33] a population of injured patients who received both plain radiography and CT CS was prospectively studied. In a sample of 667 patients, 60 (9%) had acute CS injuries. Plain films had a sensitivity of 45% and a specificity of 97.4%. CT CS had a sensitivity of 100% and a specificity of 99.5%. All clinically significant injuries were detected by CT CS. Plain radiography added no clinically relevant information.

Finally in 2005, Holmes and Akkinepalli^[34] published a meta-analysis comparing plain films to CT CS. The pooled sensitivity for plain radiography was 52%, whereas for CT CS it was 98%. Other authors have also reported similar findings.^[35-40] In two studies, Daffner^[41][42] found that CT CS was more time-efficient than plain films of the CS. Furthermore, Blackmore et al.,^[43] reported that CT was more cost-effective in moderate- and high-risk patients.

As a result of this data, CT CS has supplanted plain radiography as the primary modality for screening suspected CS injury after trauma. Specifically, a CT CS must include axial images from the occiput to T1 with sagittal and coronal reconstructions. Not only CT CS is more accurate than plain radiography but also is time effective, cost effective, and does not require additional plain films. If a CT CS demonstrates an injury or there is a neurologic deficit referable to a CS injury, a spine consultation should be obtained.

Neck Pain With Negative CT CS

For patients who complain of neck pain but are awake, alert, have no neurologic deficit and a negative CT CS, there are several treatment options, but limited data. First, the cervical collar may be continued. Second, the collar may be removed after a negative MRI CS, ideally before 72 hr from injury.^[44] Finally, the collar may be removed after negative and adequate F/E films.

Few studies have addressed the use of MRI in the patient with persistent CS pain after trauma. Schuster et al.,^[44] evaluated 93 patients who had a normal admission motor examination result, a CT result negative for trauma, and persistent CS pain. These patients were examined with MRI. All examination results were negative for clinically significant injury. Clinical follow-up revealed no complications.

Most articles addressing F/E films of the CS also concern the obtunded patient. Few studies assess the utility of the F/E study in patients with neck pain after blunt trauma. Those that address this patient population are generally anecdotal case reports.^[45-46]

Lewis et al.^[47] performed a retrospective review of 141 patients who had F/E after plain films of the CS were obtained. CS instability was found in 11 of the 141 patients (8%), four of whom had normal plain radiography. Three of these four patients required surgical stabilization. No neurologic sequelae resulted from performing F/E. There was one false negative F/E study.

Brady et al.^[48] performed a retrospective review of 451 patients who had plain films of the CS and F/E. Plain films were negative in 372 patients, five of which had abnormal F/E; of these five patients, none required surgical stabilization. No complications of F/E were noted.

Insko et al.^[49] performed a review of 106 consecutive cases of awake patients with blunt trauma who were evaluated with F/E of the CS after negative plain radiography of the CS with swimmer's views and CT added for poorly visualized areas. The adequate range of flexion and extension of the CS was established at >30 degrees from the neutral position. Seventy-four patients (70%) had a range of flexion and extension motion interpreted as adequate for diagnostic purposes. Five of these patients (6.75%) had CS injuries (five disk herniations, one cord contusion, and one ligamentous injury). Thirty-two of the F/E films were interpreted as inadequate due to limited motion. When adequate motion was present on F/E films, the false negative rate was zero.

The final study addressing the use of F/E films to be discussed was a secondary analysis of the NEXUS cohort.^[50] Of 818 patients ultimately found to have CS injury, 86 (10.5%) underwent F/E testing. Two patients sustained stable bony injuries detected only on F/E views, whereas four others had a subluxation detected only on F/E views. The injuries seen on F/E but not on plain films were four spinous process fractures, one small C3 avulsion fracture, and a laminar fracture at C2. None of these injuries were unstable. All others had injuries apparent on routine CS imaging (plain films supplemented as appropriate by other adjunctive studies including CT and MRI). The conclusion of this study was that F/E imaging adds little to the acute evaluation of patients with blunt trauma.

Although the yield of F/E imaging is low, an adequate and negative study seems to rule out CS instability in the patient with CS pain after acute trauma. Further study on this topic is required.

Obtunded Patient

There are a number of options for the obtunded patient with a negative CT CS. Recent studies have addressed F/E radiography, and the overwhelming majority recommend that it should no longer be an option for CS clearance in the unconscious trauma patient.^[51-57] In particular, Bolinger et al.^[52] found that bedside fluoroscopic F/E films in comatose patients with trauma were considered to be adequate in only 4% of patients. Davis et al.^[53] found that the incidence of ligamentous injury identified by dynamic fluoroscopy in patients with altered mental status was 0.7%. Padayachee et al.^[56] performed dynamic F/E fluoroscopy in 276 unconscious patients with trauma and found no instances of true positive results. In summary, it seems that F/E radiography in obtunded patients adds no useful information, is almost always inadequate, is not cost-effective, and may be dangerous.

For the obtunded patient with a negative CT and gross motor function of extremities, the risk/benefit ratio of obtaining MRI in addition to CT is not clear at present, and its use should be individualized in each institution. The incidence of ligamentous injury in the setting of negative CT is very low (<5%), and the incidence of clinically significant injury is unknown, but is much <1%. MRI is very expensive, and obtaining MRI may put the obtunded ICU patient at significant risk. Options are to leave the cervical collar in place until a clinical examination can be performed, to remove the collar on the basis of CT alone, or to obtain MRI. If MRI CS is negative, the cervical collar may be safely removed.

A number of studies have investigated the issue of the obtunded patient with a negative CT CS. Ghanta et al.^[58] retrospectively reviewed 51 obtunded patients who had received both CT CS and MRI CS; it was found that 10 of 46 patients (22%) with a normal CT CS had an abnormal MRI CS. Of these, four disk herniations, two ligamentous injuries, and a meningeal tear were felt to be potentially unstable. Even so, it is unclear how significant these injuries are. The authors of this article concluded that the 2000 EAST guidelines might not be sensitive enough in the obtunded patient.

Stassen et al.,^[59] reported a series of 52 obtunded patients with blunt trauma who received both CT CS and MRI CS. Forty-four of these patients had a negative CT CS, defined as a study with no bony injury. Thirteen of these patients (30%) had an MRI CS positive for bony injury. Of these 13 patients, none required surgery. The stability of these injuries is not addressed.

Sarani^[60] reported 46 obtunded patients with a normal CT CS. All had MRI CS. Of these, an injury was detected by MRI CS in five patients (11%). Four of these injuries were ligamentous, and one was a herniated disk. None of these injuries required surgery. All ligamentous injuries were stabilized in a cervical collar for 6 weeks. This group recommends MRI CS after a negative CT CS in the obtunded patient.

A number of small series have shown no significant findings on MRI CS in obtunded patients with negative CT CS,^[44][61] but the largest study to date on the use of MRI CS in obtunded patients was published by Hogan et al.^[62] in 2005. Complete MRI CS studies were obtained in 366 patients with a CT CS negative for injury. Of these studies, 354 (96.7%) were negative for injury; 7 (1.9%) showed cervical cord contusion; 4 (1.1%) were positive for ligamentous injury; 3 (0.8%) showed intervertebral disk edema; and one patient (0.3%) had a cord contusion, a ligamentous injury, and an intervertebral disk injury. CT CS had negative predictive values of 98.9% (362 of 366 patients) for ligamentous injury and 100% (366 of 366 patients) for unstable CS injury.

Como et al.^[63] reported a prospective series of 115 obtunded patients with blunt trauma with a negative CT CS. All patients then received MRI CS. Six injuries were identified; none of which required CS immobilization. The conclusion of the study was that if CT CS is negative for injury in the obtunded patient with blunt trauma, MRI CS is not necessary.

Stelfox et al.^[9] performed a prospective evaluation of consecutive intubated multiply injured patients with blunt trauma with a negative CT CS admitted to a level 1 trauma center.^[9] In the first 2 years of the study, a negative CT CS along with either a negative clinical examination or a normal MRI CS were required to discontinue CS immobilization. In the final year, the policy was changed so that only a normal CT CS was required to discontinue CS immobilization. It was found that the latter protocol decreased the duration of CS immobilization in obtunded patients with blunt trauma and that this was associated with fewer complications, fewer days of mechanical ventilation and shorter stays in the ICU and the hospital.

MRI CS is more sensitive for the identification of soft tissue injuries than CT CS and is considered the reference standard in identifying injuries to the spinal cord and CS soft tissue injuries.^{[59][62][64-67]} It is not clear, however, if all injuries that are identified by MRI CS are clinically significant. It is clear that MRI CS is not reliable for identifying osseous injury. In one study it missed 45% of fractures.^[66] MRI CS should only be used to clear the CS in the obtunded patient after a CT CS has cleared the CS of any bony abnormality. If possible the MRI CS should be obtained within 72 hr of injury as the ability to detect soft-tissue injury may diminish after this time,^[65] but in practice this is rarely possible. A number of studies have suggested that cervical collar immobilization may be discontinued if a negative MRI CS follows a negative CT CS in the obtunded patient with blunt trauma.^{[44][59-60][64-65][67]}

At present, we cannot make a definitive recommendation on the need for MRI CS after a negative CT CS in the obtunded patient with blunt trauma. The risk to benefit ratio is unclear and the incidence of significant CS injury with a negative CT CS is small and approaches zero. There are significant, nontrivial risks in bringing a severely injured, mechanically ventilated patient to the MRI suite, which is often far from the ICU. However, prolonged CS immobilization has significant risks as previously noted. These issues must be weighed against the devastating possibility of a missed CS injury. Thus, current practice guidelines with regard to this issue are at the discretion of each institution.

Future Investigations

There are a number of issues that remain for future investigation. It is not clear if CT CS is necessary in asymptomatic patients with a significant mechanism of injury. The role of mechanism itself in an asymptomatic patient deserves further study. It is not clear if there is any role for plain films in the clearance of the CS. Likewise, the role of F/E radiography in clearance of the CS needs to be elucidated.

As noted in this manuscript, the optimal method of CS clearance in obtunded patients with blunt trauma with a negative CT CS remains unclear. It remains to be seen if CT CS alone will be sufficient, especially given advances in CT technology. The role of MRI CS in this patient population needs to be clarified.

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