Sensitivity of plain radiography for pediatric cervical spine injury

Triage tools for detecting cervical spine injury in paediatric trauma patients

BACKGROUND

Paediatric cervical spine injury (CSI) after blunt trauma is rare but can have severe consequences. Clinical decision rules (CDRs) have been developed to guide clinical decision-making, minimise unnecessary tests and associated risks, whilst detecting all significant CSIs. Several validated CDRs are used to guide imaging decision-making in adults following blunt trauma and clinical criteria have been proposed as possible paediatric-specific CDRs. Little information is known about their accuracy.

OBJECTIVES

To assess and compare the diagnostic accuracy of CDRs or sets of clinical criteria, alone or in comparison with each other, for the evaluation of CSI following blunt trauma in children.

SEARCH METHODS

For this update, we searched CENTRAL, MEDLINE, Embase, and six other databases from 1 January 2015 to 13 December 2022. As we expanded the index test eligibility for this review update, we searched the excluded studies from the previous version of the review for eligibility. We contacted field experts to identify ongoing studies and studies potentially missed by the search. There were no language restrictions.

SELECTION CRITERIA

We included cross-sectional or cohort designs (retrospective and prospective) and randomised controlled trials that compared the diagnostic accuracy of any CDR or clinical criteria compared with a reference standard for the evaluation of paediatric CSI following blunt trauma. We included studies evaluating one CDR or comparing two or more CDRs (directly and indirectly). We considered X-ray, computed tomography (CT) or magnetic resonance imaging (MRI) of the cervical spine, and clinical clearance/follow-up as adequate reference standards.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance, and carried out eligibility, data extraction and quality assessment. A third review author arbitrated. We extracted data on study design, participant characteristics, inclusion/exclusion criteria, index test, target condition, reference standard and data (diagnostic two-by-two tables) and calculated and plotted sensitivity and specificity on forest plots for visual examination of variation in test accuracy. We assessed methodological quality using the Quality Assessment of Diagnostic Accuracy Studies Version 2 tool. We graded the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included five studies with 21,379 enrolled participants, published between 2001 and 2021. Prevalence of CSI ranged from 0.5% to 1.85%. Seven CDRs were evaluated. Three studies reported on direct comparisons of CDRs. One study (973 participants) directly compared the accuracy of three index tests with the sensitivities of NEXUS, Canadian C-Spine Rule and the PECARN retrospective criteria being 1.00 (95% confidence interval (CI) 0.48 to 1.00), 1.00 (95% CI 0.48 to 1.00) and 1.00 (95% CI 0.48 to 1.00), respectively. The specificities were 0.56 (95% CI 0.53 to 0.59), 0.52 (95% CI 0.49 to 0.55) and 0.32 (95% CI 0.29 to 0.35), respectively (moderate-certainty evidence). One study (4091 participants) compared the accuracy of the PECARN retrospective criteria with the Leonard de novo model; the sensitivities were 0.91 (95% CI 0.81 to 0.96) and 0.92 (95% CI 0.83 to 0.97), respectively. The specificities were 0.46 (95% CI 0.44 to 0.47) and 0.50 (95% CI 0.49 to 0.52) (moderate- and low-certainty evidence, respectively). One study (270 participants) compared the accuracy of two NICE (National Institute for Health and Care Excellence) head injury guidelines; the sensitivity of the CG56 guideline was 1.00 (95% CI 0.48 to 1.00) compared to 1.00 (95% CI 0.48 to 1.00) with the CG176 guideline. The specificities were 0.46 (95% CI 0.40 to 0.52) and 0.07 (95% CI 0.04 to 0.11), respectively (very low-certainty evidence). Two additional studies were indirect comparison studies. One study (3065 participants) tested the accuracy of the NEXUS criteria; the sensitivity was 1.00 (95% CI 0.88 to 1.00) and specificity was 0.20 (95% CI 0.18 to 0.21) (low-certainty evidence). One retrospective study (12,537 participants) evaluated the PEDSPINE criteria and found a sensitivity of 0.93 (95% CI 0.78 to 0.99) and specificity of 0.70 (95% CI 0.69 to 0.72) (very low-certainty evidence). We did not pool data within the broader CDR categories or investigate heterogeneity due to the small quantity of data and the clinical heterogeneity of studies. Two studies were at high risk of bias. We identified two studies that are awaiting classification pending further information and two ongoing studies.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the diagnostic test accuracy of CDRs to detect CSIs in children following blunt trauma, particularly for children under eight years of age. Although most studies had a high sensitivity, this was often achieved at the expense of low specificity and should be interpreted with caution due to a small number of CSIs and wide CIs. Well-designed, large studies are required to evaluate the accuracy of CDRs for the cervical spine clearance in children following blunt trauma, ideally in direct comparison with each other.

Relationship of cervical soft tissue injury and surgical predication following pediatric cervical spinal trauma and its sequelae on long-term neurologic outcome

Within the sample of 181 patients with cervical CT, CT identified unstable injury with a sensitivity of 100% and specificity of 95%. CT identified operable injury at the CCJ with 86% sensitivity and 91% specificity. CT was considered the gold standard for identification of fractures. Together, the presence of CT imaging suggestive of unstable injury or persistent neurologic complaint had a 100% sensitivity and 81% specificity. Finally, across all patients MRI had 100% sensitivity and 89% specificity for detection of unstable injury requiring surgery.

Increased and unjustified CT usage in paediatric C-spine clearance in a level 2 trauma centre

PURPOSE

Cervical spine injury after blunt trauma in children is rare but can have severe consequences. Clear protocols for diagnostic workup are, therefore, needed, but currently not available. As a step in developing such a protocol, we determined the incidence of cervical spine injury and the degree of protocol adherence at our level 2 trauma centre.

METHODS

We analysed data from all patients aged < 16 years suspected of cervical spine injury after blunt trauma who had presented to our hospital during two periods: January 2010 to June 2012, and January 2017 to June 2019. In the intervening period, the imaging protocol for diagnostic workup was updated. Outcomes were the incidence of cervical spine injury and protocol adherence in terms of the indication for imaging and the type of imaging.

RESULTS

We included 170 children in the first study period and 83 in the second. One patient was diagnosed with cervical spine injury. Protocol adherence regarding the indication for imaging was > 80% in both periods. Adherence regarding the imaging type decreased over time, with 45.8% of the patients receiving a primary CT scan in the second study period versus 2.9% in the first.

CONCLUSION

Radiographic imaging is frequently performed when clearing the paediatric cervical spine, although cervical spine injury is rare. Particularly CT scan usage has wrongly been emerging over time. Stricter adherence to current protocols could limit overuse of radiographic imaging, but ultimately there is a need for an accurate rule predicting which children really are at risk of injury.

Have changes in computerised tomography guidance positively impacted detection of cervical spine injury in children? A review of the Trauma Audit and Research Network data

Background

Clinically significant damage to the cervical spine in children is uncommon, but missing this can be life-changing for patients. The balance between rarity and severity leads to inconsistent scanning, with both resource and radiation implications. In 2014, the United Kingdom’s National Institute for Health and Care Excellence updated their computerised tomography neck imaging guidance in children. The aim of this study was to assess if the change in guidance had resulted in a change in diagnosis or imaging rates.

Methods

A retrospective review of the national Trauma Audit and Research Network’s data for computerised tomography spine imaging in children in 2012–2013 was compared to the same data sample collected in 2015–2016.

Results

The percentage of children presenting with neck trauma who were imaged reduced from 15.5 to 14.1% with an increase in confirmed cervical spine injury from 1.6 to 2.3% between the two time periods. The specificity of computerised tomography scanning increased from 10 to 16.4%. There was variation in scan rates, with major trauma centres scanning a greater percentage of children of all ages and with all injury scores, than trauma units.

Discussion

This study suggests national guidance can impact clinical care in a relatively short timeframe. Variation in how guidance is applied, with major trauma centres scanning proportionately more children with a lower yield, could be because scanning is more readily available, or because trauma protocols encourage more scans. Twenty per cent of injuries were not found on the initial computerised tomography, in keeping with previously reported data, because the injuries were ligamentous or cord contusion. This suggests a role for early magnetic resonance imaging in children with suspected spinal injury.

Cervical spine evaluation in pediatric trauma: A cost-effectiveness analysis

OBJECTIVE

The emergent evaluation of children with suspected traumatic cervical spine injuries (CSI) remains a challenge. Pediatric clinical pathways have been developed to stratify the risk of CSI and guide computed tomography (CT) utilization. The cost-effectiveness of their application has not been evaluated. Our objective was to examine the cost-effectiveness of three common strategies for the evaluation of children with suspected CSI after blunt injury.

METHODS

We developed a decision analytic model comparing these strategies to estimate clinical outcomes and costs for a hypothetical population of 0-17 year old patients with blunt neck trauma. Strategies included: 1) clinical pathway to stratify risk using NEXUS criteria and determine need for diagnostic testing; 2) screening radiographs as a first diagnostic; and 3) immediate CT scanning for all patients. We measured effectiveness with quality-adjusted life years (QALYs), and costs with 2018 U.S. dollars. Costs and effectiveness were discounted at 3% per year.

RESULTS

The use of the clinical pathway results in a gain of 0.04 QALYs and a cost saving of $2800 compared with immediate CT scanning of all patients. Use of the clinical pathway was less costly and more effective than immediate CT scan as long as the sensitivity of the clinical prediction rule was greater than 87% and when the sensitivity of x-ray was greater than 84%.

CONCLUSION

A strategy using a clinical pathway to first stratify risk before further diagnostic testing was less costly and more effective than either performing CT scanning or screening cervical radiographs on all patients.

Imaging Gently

Advances in medical imaging are invaluable in the care of pediatric patients in the emergent setting. The diagnostic accuracy offered by studies using ionizing radiation, such as plain radiography, computed tomography, and fluoroscopy, are not without inherent risks. This article reviews the evidence supporting the risk of ionizing radiation from medical imaging as well as discusses clinical scenarios in which clinicians play an important role in supporting the judicious use of imaging studies.