Clinical Question

How accurate is ultrasonography for diagnosing upper extremity fractures in children?

Bottom Line

Diagnostic ultrasonography is highly accurate for diagnosing most upper extremity fractures but slightly less accurate for fractures involving the elbow. Clinicians should not use ultrasonography alone to rule in elbow fractures in children. (Level of Evidence = 1a−)

Synopsis

The authors searched PubMed, EMBASE, and the Web of Science to find studies that compared diagnostic ultrasonography with an external reference standard to diagnose upper extremity fractures in children. The included studies used various reference standards: plain radiography, magnetic resonance imaging, bone scan, and clinical diagnosis. Two of the authors independently evaluated articles for inclusion and assessed the methodologic quality of the included studies. They resolved discrepancies through consensus and third-party adjudication if consensus could not be reached. They wound up with 32 studies with 2,994 children; 27 were prospective studies. Seven studies used radiology-based ultrasonography, and 17 used point-of-care ultrasonography. Nineteen studies took place in the emergency department. The studies were of mixed quality. Several studies did not describe the setting, the training of those performing the ultrasonography, or even the ages of the participants. Ultrasonography was 98% accurate based on the area under receiver operating characteristic curve. The sensitivity and specificity were high (95% for each); the positive likelihood ratio (LR+) was 21.1 (95% CI, 10.8 to 41.5), and the negative likelihood ratio (LR–) was 0.05 (95% CI, 0.03 to 0.07). Ultrasonography was very good at ruling in and ruling out fractures. When the authors looked at elbow fractures, ultrasonography was 96% accurate with high sensitivity (0.95) but slightly lower specificity (0.87). For fractures involving the elbow, ultrasonography was less accurate at ruling in fractures (LR+ = 7.3; 95% CI, 3.7 to 14.4) but was still accurate at ruling them out (LR− = 0.06; 95% CI, 0.02 to 0.16). The authors report high levels of heterogeneity in the data.

Study design: Meta-analysis (other)

Funding source: Self-funded or unfunded

Setting: Various (meta-analysis)

Reference: Tsou P-Y, Ma Y-K, Wang Y-H, et al. Diagnostic accuracy of ultrasound for upper extremity fractures in children: a systematic review and meta-analysis. Am J Emerg Med. 2021;44:383–394.