Is the cervical spine clear? Undetected cervical fractures diagnosed only at autopsy

Development and first application testing of a new protocol for CT-based stability evaluation of the injured upper cervical spine

PURPOSE

For trauma surgeons, the evaluation of the stability of the upper cervical spine may be demanding. The aim of this study was to develop a protocol for decision-making on upper cervical spine stability in trauma patients based on established parameters obtained by CT imaging as well as testing the protocol by having it applied by trauma surgeons.

METHODS

A structured literature search on upper cervical spine stability was performed. The best evaluated instability criteria in CT imaging were determined. Based on these parameters a protocol for stability evaluation of the injured upper cervical spine was developed. A first application testing was performed. In addition to the assessment of instability, the time required for the assessment was analyzed.

RESULTS

A protocol for CT-based stability evaluation of the injured upper cervical spine based on the current literature was developed and displayed in a flow chart. Testing of the protocol found the stability of the cervical spine was correctly assessed in 55 of 56 evaluations (98.2%). In one test run, a stable upper cervical spine was judged to be unstable. Further analysis showed that this case was based on a measurement error. The assessment time of CT-images decreased significantly during repeat application of the protocol (p < 0.0001), from 336 ± 108 s (first case) to 180 ± 30 s (fourth case).

CONCLUSION

The protocol can be applied quickly and safely by non-specialized trauma surgeons. Thus, the protocol can support the decision-making process in CT-based evaluation of the stability of the injured upper cervical spine.

Preventable diagnostic errors in fatal cervical spine injuries: a nationwide register-based study from 1987 to 2010

BACKGROUND

Fall-induced injuries in patients are increasing in number, and they often lead to serious consequences, such as cervical spine injuries (CSI). CSI diagnostics remain a challenge despite improved radiological services.

PURPOSE

Our aim is to define the incidence and risk factors for diagnostic errors among patients who died following a CSI.

STUDY DESIGN/SETTING

A retrospective death certificate-based study of the whole population of Finland was carried out.

PATIENT SAMPLE

We identified 2,041 patients whose death was, according to the death certificate, either directly or indirectly caused by a CSI.

OUTCOME MEASURES

Demographics, injury- and death-related data, and adverse event (AE)-related data were the outcome measures.

METHODS

All death certificates between the years 1987 and 2010 from Statistics Finland that identified a CSI as a cause death were reviewed to identify preventable AEs with the emphasis on diagnostic errors.

RESULTS

Of the 2,041 patients with CSI-related deaths, 36.5% (n=744) survived at least until the next day. Errors in CSI diagnostics were found in 13.8% (n=103) of those who died later than the day of injury. Those with diagnostic errors were significantly older (median age 79.4 years, 95% confidence interval 75.9-80.1 vs. 74.9, 95% confidence interval 70.2-72.9, p<.001) and the mechanism of injury was significantly more often a fall (86.4%, n=89 vs. 69.7%, n=447, p=.002) compared with those who did not have a diagnostic error. The incidence of diagnostic errors increased slightly during the 24-year study period.

CONCLUSIONS

Cervical spine injury diagnostics remain difficult despite improved radiological services. The majority of the patients subjected to diagnostic errors are fragile elderly people with reduced physical capacity. In our analysis, preventable AEs and diagnostic errors were most commonly associated with ground-level falls.

The presence of nonthoracic distracting injuries does not affect the initial clinical examination of the cervical spine in evaluable blunt trauma patients: a prospective observational study

BACKGROUND

A distracting injury mandates cervical spine (c-spine) imaging in the evaluable blunt trauma patient who demonstrates no pain or tenderness over the c-spine. The purpose of this study was to examine which distracting injuries can negatively affect the sensitivity of the standard clinical examination of the c-spine.

METHODS

This is a prospective observational study conducted at a Level I Trauma Center from January 1, 2008, to December 31, 2009. After institutional review board approval, all evaluable (Glasgow Coma Scale score ≥13) blunt trauma patients older than 16 years sustaining a c-spine injury were enrolled. A distracting injury was defined as any immediately evident bony or soft tissue injury or a complaint of non-c-spine pain whether or not an actual injury was subsequently diagnosed. Information regarding the initial clinical examination and the presence of a distracting injury was collected from the senior resident or attending trauma surgeon involved in the initial management.

RESULTS

During the study period, 101 evaluable patients sustained a c-spine injury. Distracting injuries were present in 88 patients (87.1%). The most common was rib fracture (21.6%), followed by lower extremity fracture (20.5%) and upper extremity fracture (12.5%). Only four (4.0%) patients had no pain or tenderness on the initial examination of the c-spine. All four patients had bruising and tenderness to the upper anterior chest. None of these four patients developed neurologic sequelae or required a surgical stabilization or immobilization.

CONCLUSION

C-spine imaging may not be required in the evaluable blunt trauma patient despite distracting injuries in any body regions that do not involve the upper chest. Further definition of distracting injuries is mandated to avoid unnecessary utilization of resources and to reduce the imaging burden associated with the evaluation of the c-spine.

Evaluation of acute cervical spine imaging based on ACR Appropriateness Criteria®

The objectives of this study were to determine the rate of acute blunt cervical spine injury at an academic urban level 1 trauma center and to evaluate the utilization of cervical spine imaging based on the established American College of Radiology (ACR) Appropriateness Criteria®. We retrospectively reviewed all radiography and CT imaging of the cervical spine performed over a year period in adult patients presenting with acute blunt cervical spine trauma. Exclusion criteria were children ≤17 years, non-acute trauma of ≥72 h, and penetrating trauma. Any fracture, dislocation, or ligamentous instability demonstrated by diagnostic imaging and requiring stabilization or specialized follow-up was defined as clinically significant cervical spine injury. A total of 1,325 cervical spine studies were reviewed in 1,245 patients; 32.7% (433/1,325) were cervical spine radiographs and 67.3% (892/1,325) were CT examinations. Approximately 1.5% (19/1,245) of the patients demonstrated clinically significant acute cervical spine injury. There were 6.4% (80/1,245) patients who received both cervical spine radiographs and CT as imaging evaluation. Based on the ACR Appropriateness Criteria®, all of the cervical spine radiographs performed (433) were determined to be "inappropriate" imaging in the setting of acute cervical spine injury.

Role of cervical spine radiography in the initial evaluation of stable high-energy blunt trauma patients

BACKGROUND

Detecting cervical spine injuries in trauma patients is essential because undetected injuries in the this area may result in severe neurological disability and probably quadriplegia. Thus, radiography of the cervical spine is considered mandatory in the initial evaluation of trauma patients according to Advanced Trauma Life Support. This approach results in many unnecessary normal radiographs. Therefore, we performed this study to determine the role of routine cervical radiography in the initial evaluation of stable high-energy blunt trauma patients.

METHODS

This was a prospective cross-sectional study including all hemodynamically stable high-energy blunt trauma patients with negative cervical physical examinations referred to our trauma center during a 5-month period (May to September 2010). Cervical radiographs, computed tomography (CT) scanning and magnetic resonance imaging were performed and reviewed for abnormalities.

RESULTS

During the study period, 1,679 high-energy blunt trauma patients were referred to our center, of which 400 were hemodynamically stable and had negative cervical physical examinations. Cervical radiographs were found to be normal in all patients.

CONCLUSION

Cross-table cervical spine radiographs can be limited to those high-energy blunt trauma patients who have a positive cervical physical examination or those in whom the physical examination is not revealing. These radiographs also have low value for detecting occult cervical spine fractures, and CT imaging is considered the modality of choice in these cases.

Major trauma & cervical clearance radiation doses & cancer induction

AIM

To compare the radiation dose of cervical spine clearance and body CT in a cohort of unconscious, major trauma patients for three different protocols, comparing spiral to multislice CT. To quantify the radiation exposure effect of the protocols on the lifetime cancer risk.

METHOD

The hospital trauma database was used to find the unconscious (GCS<9), severely injured (Injury Severity Score >15) from 1 January 2001 to 31 December 2003, excluding isolated head injuries. The protocols used for imaging the brain and cervical spine were, including the radiographs performed as a mode: The exposure factors and field of view used were put into the Monte Carlo software, to estimate the CT and radiographic X-ray doses to the body as a whole and the dose to the thyroid associated with each region imaged. The associated nominal additional lifetime cancer risk was assessed.

RESULTS

Excluding inter hospital transfers, where data was incomplete, 87 patients survived to be admitted and fulfilled the criteria. In 30 cases, the CT films were missing, the exposure factors were not recorded or no imaging was performed. In a further 21 cases, the X-ray packets were missing. Three patients had brain and cervico-dorsal CT imaging only, leaving 33 cases for evaluation. The effective radiation dose for a spiral CT of the brain using the Toshiba Xpress GX CT scanner was 3.8 mSv. The total effective doses for imaging the brain and cervical spine using the three protocols with the same CT scanner were (S.D. as % of mean): (1) 4.4 mSv (5%), (2) 7.1 mSv (10%) and (3) 8.2 mSv (15%). The corresponding mean thyroid doses were: (1) 8.5 mGy (25%), (2) 48.9 mGy (20%) and (3) 66.5 mSv (20%). The resultant nominal lifetime cancer risks were: (1) 1:4500, (2) 1:2800 and (3) 1:2400. For the Siemens Sensation 16 multislice CT scanner, the total effective doses (S.D. as % of mean) were: (1) 2.3 mSv (10%), (2) 4.3 mSv (25%) and (3) 5.4 mSv (35%). The mean doses to the thyroid were: (1) 5.9 mGy (30%), (2) 36.1 mGy (50%) and (3) 52.4 mGy (40%). The lifetime cancer risks were: (1) 1:8700, (2) 1:4600 and (3) 1:3700. Using the Toshiba spiral CT scanner, the total dose and additional lifetime nominal cancer risk associated with CT of the chest, abdomen and pelvis (CAP) as 16 mSv and 1:1250, respectively. Using the Siemens multislice CT scanner, these were 11.8 mSv and 1:1700. The cancer risk for protocol 1 when combined with a CT scan of the chest, abdomen and pelvis was 1:1000 for the spiral CT scanner and 1:1500 for the multislice CT (MCT) scanner. The cancer risk for protocol 2 with CAP CT using the MCT was 1:1200. The cancer risk for protocol 3 when combined with a CT scan of the chest, abdomen and pelvis was 1:1100 for the multislice CT scanner. Prior to the introduction of the BTS guidelines for cervical clearance, 12% of cases had CT of the body, which increased to 16% post-guidelines.

CONCLUSIONS

CT of the trunk (chest, abdomen and pelvis) is associated with the greatest risk of inducing a fatal cancer in the severely injured patient with a GCS less than 9. In our institution the multislice CT protocols expose the patient to less radiation than single slice CT, which is contrary to much of the published work to date. CT scanning the thyroid (or whole cervical spine) still has a marked effect on the cancer risk in cervical clearance. Many centres will relax cervical spinal precautions in unconscious trauma patients if the cervical spine CT with reconstructions is normal. CT of the whole cervical spine may be justified in the unconscious, severely injured patient. In conscious trauma patients, the additional lifetime risk may not justify CT of the whole cervical spine as a routine practice.

Isolated ligamentous cervical spinal injury in the polytrauma patient with a head injury

The evaluation of the cervical spine in the unconscious trauma patient is a difficult and controversial topic in trauma management. Conventional cervical clearance protocols consisting of plain radiology and computed tomography may not adequately detect unstable cervical ligament and disc injuries, even though a high-risk mechanism of injury has occurred. We present two cases where cervical clearance protocols, utilising plain X-rays and multi-slice computed tomography, failed to identify significant ligamentous spinal injuries. A delay in diagnosis or a missed spinal injury can lead to delays in treatment, thereby increasing the risk of neurological deterioration with the potential devastating sequela of quadriplegia. Therefore, in the unconscious trauma patient who, by definition, has sustained a high-risk mechanism injury, we routinely recommend the use of magnetic resonance imaging in addition to plain X-rays and computed tomography, to evaluate further discoligamentous status.

LITIGATION OF MISSED CERVICAL SPINE INJURIES IN PATIENTS PRESENTING WITH BLUNT TRAUMATIC INJURY

BACKGROUND

Approximately 800,000 cervical spines are cleared in emergency departments each year. Errors in diagnosis of cervical spine injury are a potentially huge medicolegal liability, but no established protocol for clearance of the cervical spine is known to reduce errors or delays in diagnosis.

METHODS

The Lexis-Nexis, Westlaw, and Medline databases were queried for cases of missed cervical injury. Errors were categorized according to a novel system of classification. Type I errors occurred when inadequate or improper tests were ordered. Type II errors occurred when adequate tests were ordered, but were either misread or not read. Type III errors occurred when adequate tests were ordered and read accurately, but the ordered test was not sensitive enough to detect the injury.

RESULTS

Twenty cases of missed or delayed diagnosis of cervical spine injury were found in 10 jurisdictions. Awards averaged $2.9 million (inflation adjusted to 2002 dollars). Eight cases resulted in verdicts in favor of the defendant, but none of these cases involved an alleged Type II error.

CONCLUSION

Fear of lawsuits encourages defensive medicine and complicates the process of clearing a patient's cervical spine. This analysis adds medicolegal support for the judicious use of imaging studies in current cervical spine clearance protocols. However, exposure to significant liability suggests that a low threshold for computed tomography is a reasonable alternative.

What Defines a Distracting Injury in Cervical Spine Assessment?

BACKGROUND

The National Emergency X-Radiography Utilization Study defined five criteria for obtaining cervical spine radiographic investigations in blunt trauma patients. Distracting injury was given as the indication for more than 30% of all x-ray studies ordered. The hypothesis of this study was that upper and lower torso injuries would have different effects on clinical cervical spine assessment.

METHODS

This is a single-center, prospective, observational study of admitted, alert, adult blunt-trauma patients. All patients underwent cervical spine plain-film radiography. Data were collected on all injuries, physical examination findings, narcotic administration, and radiograph results. Patients with upper and lower torso injuries were compared in their ability complain of pain or midline tenderness relative to a cervical spine fracture.

RESULTS

In all, 406 patients participated. All patients received narcotic analgesics before examination. Forty patients (9.9%) had cervical spine fractures, of whom seven had a nontender neck examination. All seven patients with a nontender cervical spine and a neck fracture had at least one upper torso injury. None of the 99 patients with injuries isolated to the lower torso and a nontender neck had a cervical spine fracture (p < 0.05). The frequency of cervical spine fracture among patients with cervical spine tenderness was 19.8% (n = 33).

CONCLUSIONS

The National Emergency X-Radiography Utilization Study definition of a distracting injury may be narrowed. Upper torso injuries may be sufficiently painful to distract from a reliable cervical spine examination. Patients may detect spine tenderness in the presence of isolated painful lower torso injuries. Patients with spine tenderness warrant imaging.

Cervical spine clearance: a review

Ethical concerns have hindered any randomised control blinded studies on the imaging required to assess the cervical spine in an unconscious trauma patient. The issue has been contentious for many years and has resulted in burgeoning but inconclusive guidance. MRI and multislice CT technology have made rapid advances, but the literature is slower to catch up. Never the less there appears to be an emerging consensus for the multiply injured patient. The rapid primary clinical survey should be followed by lateral cervical spine, chest and pelvic radiographs. If a patient is unconscious then CT of the brain and at least down to C3 (and in the USA down to D1) has now become routine. The cranio-cervical scans should be a maximum of 2 mm thickness, and probably less, as undisplaced type II peg fractures, can be invisible even on 1 mm slices with reconstructions. If the lateral cervical radiograph and the CT scan are negative, then MRI is the investigation of choice to exclude instability. Patients with focal neurological signs, evidence of cord or disc injury, and patients whose surgery require pre-operative cord assessment should be imaged by MRI. It is also the investigation of choice for evaluating the complications and late sequela of trauma. If the patient is to have an MRI scan, the MR unit must be able to at least do a sagittal STIR sequence of the entire vertebral column to exclude non-contiguous injuries, which, since the advent of MRI, are now known to be relatively common. Any areas of oedema or collapse then require detailed CT evaluation. It is important that cases are handled by a suitably skilled multidisciplinary team, and avoid repeat imaging due to technical inadequacies. The aim of this review is to re-examine the role of cervical spine imaging in the context of new guidelines and technical advances in imaging techniques.

Radiographic assessment of the cervical spine in symptomatic trauma patients

STANDARDS

A three-view cervical spine series (anteroposterior, lateral, and odontoid views) is recommended for radiographic evaluation of the cervical spine in patients who are symptomatic after traumatic injury. This should be supplemented with computed tomography (CT) to further define areas that are suspicious or not well visualized on the plain cervical x-rays.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

It is recommended that cervical spine immobilization in awake patients with neck pain or tenderness and normal cervical spine x-rays (including supplemental CT as necessary) be discontinued after either a) normal and adequate dynamic flexion/extension radiographs, or b) a normal magnetic resonance imaging study is obtained within 48 hours of injury. Cervical spine immobilization in obtunded patients with normal cervical spine x-rays (including supplemental CT as necessary) may be discontinued a) after dynamic flexion/extension studies performed under fluoroscopic guidance, or b) after a normal magnetic resonance imaging study is obtained within 48 hours of injury, or c) at the discretion of the treating physician.

Test performance of the individual NEXUS low-risk clinical screening criteria for cervical spine injury

BACKGROUND

The National Emergency X-Radiography Utilization Study (NEXUS) recently validated the ability of a decision instrument to define a population with an extremely low risk of cervical spine injury (CSI) after blunt trauma. It is unclear whether each of the 5 individual criteria is necessary for the decision instrument to maintain its high sensitivity.

METHODS

NEXUS was a prospective observational study at 21 emergency departments, which enrolled all patients with blunt trauma for whom cervical spine radiographs were ordered. In this substudy, we examined the NEXUS database to determine the contribution of each of the 5 individual low-risk clinical criteria to the overall sensitivity of the decision instrument.

RESULTS

All but 8 of 818 patients with CSI, and all but 2 of 578 patients with significant CSI, were identified by using the decision instrument. A substantial number of patients with CSI (236/818 [29%]) and patients with significant CSI (175/578 [30%]) met only 1 of the 5 non--low-risk criteria, and each of the 5 criteria was the only indicator of non--low-risk status in at least 8 patients with CSI and at least 5 patients with significant CSI.

CONCLUSION

Because each of the 5 low-risk criteria was the only marker of non--low-risk status in at least a few patients with significant CSI, modification of the overall NEXUS decision instrument by eliminating any one of the criteria would markedly reduce sensitivity and make the instrument unacceptable for clinical use.

Distracting painful injuries associated with cervical spinal injuries in blunt trauma

Distracting painful injuries (DPIs) may mask symptoms of spinal injury in blunt trauma victims and form an important element in a decision instrument used to identify individuals who require cervical spine radiography.

OBJECTIVE

To identify the types and frequencies of injuries that actually act as DPIs among blunt trauma patients undergoing cervical spinal radiography.

METHODS

This was a prospective observational study of consecutive blunt trauma victims presenting to an urban Level 1 regional trauma center between April 1, 1998, and September 30, 1998. Prior to cervical spinal radiography, treating physicians evaluated each patient to determine whether a DPI was present or absent and, if present, what type of injury was sustained. Injuries were categorized as fractures, soft-tissue injuries and lacerations, burns, visceral injuries, crush injuries, or other injuries.

RESULTS

Data were collected for 778 patients, between 1 month and 98 years old, of whom 264 (34%) were considered to have DPIs. Physicians were unable to determine the DPI status in 47 (6%) additional cases. Fractures accounted for a majority of DPIs (154, or 58%), 42 (16%) were soft-tissue injuries or lacerations, and 86 (34%) were due to a variety of other entities, including visceral, crush, burn, or other miscellaneous injuries. Among the 37 (5%) patients with an acute cervical spinal injury, 20 (54%) had a DPI, including three (8%) who had DPI as the only indication for cervical radiography.

CONCLUSIONS

A significant number of blunt trauma patients are believed by clinicians to have DPIs that can possibly mask the presence of cervical spinal injury. Fractures and trauma to soft tissues are the most common types of DPI.

Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. National Emergency X-Radiography Utilization Study Group

BACKGROUND

Because clinicians fear missing occult cervical-spine injuries, they obtain cervical radiographs for nearly all patients who present with blunt trauma. Previous research suggests that a set of clinical criteria (decision instrument) can identify patients who have an extremely low probability of injury and who consequently have no need for imaging studies.

METHODS

We conducted a prospective, observational study of such a decision instrument at 21 centers across the United States. The decision instrument required patients to meet five criteria in order to be classified as having a low probability of injury: no midline cervical tenderness, no focal neurologic deficit, normal alertness, no intoxication, and no painful, distracting injury. We examined the performance of the decision rule in 34,069 patients who underwent radiography of the cervical spine after blunt trauma.

RESULTS

The decision instrument identified all but 8 of the 818 patients who had cervical-spine injury (sensitivity, 99.0 percent [95 percent confidence interval, 98.0 to 99.6 percent]). The negative predictive value was 99.8 percent (95 percent confidence interval, 99.6 to 100 percent), the specificity was 12.9 percent, and the positive predictive value was 2.7 percent. Only two of the patients classified as unlikely to have an injury according to the decision instrument met the preset definition of a clinically significant injury (sensitivity, 99.6 percent [95 percent confidence interval, 98.6 to 100 percent]; negative predictive value, 99.9 percent [95 percent confidence interval, 99.8 to 100 percent]; specificity, 12.9 percent; positive predictive value, 1.9 percent), and only one of these two patients received surgical treatment. According to the results of assessment with the decision instrument, radiographic imaging could have been avoided in the cases of 4309 (12.6 percent) of the 34,069 evaluated patients.

CONCLUSIONS

A simple decision instrument based on clinical criteria can help physicians to identify reliably the patients who need radiography of the cervical spine after blunt trauma. Application of this instrument could reduce the use of imaging in such patients.

Evaluation of unstable cervical spine injury: a 6-year experience

BACKGROUND

The diagnosis of the unstable cervical spine, and its subsequent management can be difficult and a missed cervical spine injury can obviously have devastating consequences.

METHODS

This study describes a 6-year experience with these injuries and presents an algorithm for their evaluation. The case records of 100 consecutive patients who underwent an operative procedure for an unstable cervical spine injury were reviewed.

RESULTS

The population and injury characteristics were similar to that of previous studies. The process of evaluation of the spine was robust but failed to identify two unstable ligamentous injuries not detected on initial radiologic examination. Ten patients whose injuries were missed at other hospitals were identified by using this system.

CONCLUSION

A systematic, well-structured approach to the potentially injured cervical spine allows safe and effective diagnosis and management of these patients. Failure to adhere to basic principles will result in missed unstable cervical spine injuries.

Selective cervical spine radiography in blunt trauma: methodology of the National Emergency X-Radiography Utilization Study (NEXUS)

Fear of failure to identify cervical spine injury has led to extremely liberal use of radiography in patients with blunt trauma and remotely possible neck injury. A number of previous retrospective and small prospective studies have tried to address the question of whether any clinical criteria can identify patients, from among this group, at sufficiently low risk that cervical spine radiography is unnecessary. The National Emergency X-Radiography Utilization Study (NEXUS) is a very large, federally supported, multicenter, prospective study designed to define the sensitivity, for detecting significant cervical spine injury, of criteria previously shown to have high negative predictive value. Done at 23 different emergency departments across the United States and projected to enroll more than 20 times as many patients with cervical spine injury than any previous study, NEXUS should be able to answer definitively questions about the validity and reliability of clinical criteria used as a preliminary screen for cervical spine injury.

Evaluation of cervical spine abnormalities on cephalometric radiographs

Cephalometric radiographs, a key element of orthodontic diagnosis, contain useful information related to the cervical spine often neglected by orthodontists and medical specialists. This article reviews cervical spine anatomy in a manner that will enable the clinician to trace the cervical spine accurately and detect cervical spine abnormalities. Examples of syndromic, nonsyndromic, and idiopathic anomalies of the cervical spine are presented and their significance discussed. Cephalometric radiographs can be used by clinicians as a potential resource for screening for pathologic abnormalities of the cervical spine and potentially averting some pathologic complications.