Emergency Ultrasound in the Detection of Pediatric Long-Bone Fractures

Abstract

Long-bone fractures represent one of the most commonly sustained injuries following trauma and account for nearly 4% of emergency department visits in the United States each year. These fractures are associated with a significant risk of bleeding and neurovascular compromise. Delays in their identification and treatment can lead to loss of limb and even death. Although emergency physicians currently rely predominantly on radiography for the examination of long-bone injuries, emergency ultrasound has several advantages over radiography and may be useful in the identification of long-bone fractures. Ultrasound is rapid, noninvasive, and cost-effective. Unlike radiography, ultrasound does not expose children to ionizing radiation, which has been linked to cancer. The goal of this study was to assess the agreement between emergency physicians' and radiologists' final assessments of suspected long-bone fractures using emergency ultrasound and radiography, respectively, in the pediatric population. This is a prospective study involving a convenience sample of pediatric patients (<18 years of age) who presented to the emergency department of a university-affiliated, level I trauma center between March 2008 and January 2009 with at least 1 suspected long-bone fracture. Suspected fractures were characterized by swelling, erythema, and localized pain. Patients who had a history of fracture, extremity deformity, orthopedic hardware in the traumatized area, or an open fracture were excluded from this study. Each investigator received limited, focused training in the use of ultrasonography for fracture identification and localization. This training consisted of a brief didactic session and video review of normal and fractured long-bones. A total of 53 subjects (mean age, 10.2 [SD, 3.8] years; 56.6% were male) were enrolled, which corresponded to 98 ultrasound examinations. Sixty-nine scans (70.4%) involved bones of the upper extremity, and 29 (29.6%) the lower extremity. Radiography identified a total of 43 fractures. The sensitivity and specificity of ultrasound in the detection of long-bone fractures were 95.3% (95% confidence interval [CI], 82.9%-99.2%) and 85.5% (95% CI, 72.8%-93.1%), respectively, and the positive and negative predictive values were 83.7% (95% CI, 68.8%-92.2%) and 96% (95% CI, 84.9%-99.3%), respectively. Overall, ultrasound detected 100.0% of diaphyseal fractures and 27 (93.1%) of 29 end-of-bone or near-joint fractures.Radiography revealed 6 displacements that met the published criteria for reduction, all of which were also revealed by ultrasound. The overall sensitivity and specificity for ultrasound identifying the need for reduction were 100.0% (95% CI, 51.7%-100.0%) and 97.3% (95% CI, 84.2%-99.9%), respectively, and positive and negative predictive values were 85.7% (95% CI, 42.0%-99.2%) and 100.0% (95% CI, 88.0%-100.0%), respectively. Emergency department physician-performed focused ultrasound was more accurate in detecting diaphyseal fractures than in detecting fractures in the metaphysis and/or epiphysis. The high sensitivity and specificity of ultrasound in the detection of long-bone fractures and the need for reduction support the use of ultrasound in the evaluation of suspected long-bone fractures in children.