Ultrasound in the Diagnostics of Metaphyseal Forearm Fractures in Children
Authors: Katzer Christoph , Wasem Jürgen , Eckert Kolja , Ackermann Ole , Buchberger Barbara 
Published: June 2015

Objectives
Metaphyseal forearm fractures are a common occurrence in childhood accounting up to 20% of all pediatric fractures. The standard diagnostic procedure is an x-ray scan. Sonographic examinations could be an alternative that avoids exposition to ionizing radiation and possibly reduces pain, time, and costs. This is a systematic review of clinical studies evaluating ultrasound as a possible alternative to radiographs in diagnosing metaphyseal forearm fractures in children.

Methods
A systematic literature research for diagnostic studies and reviews was conducted in EMBASE, MEDLINE, and the Cochrane Library in May 2013 and updated in May 2014. In addition, reference lists of publications included were scanned. Outcome parameters were diagnostic accuracy, costs, examination time, and the assessment of pain. The study population is defined as children, because forearm fractures are very common in this age group and the impact of radiation on younger patients is greater than that on adults. Methodological quality of the studies has been assessed with Quality Assessment of Diagnostic Accuracy Studies-2. In addition, we carried out a cost center accounting.

Results
Eight diagnostic studies and 2 reviews were included in the analysis. The risk of bias of 4 studies was low; and of the other 4 ones, it was moderate. Critical aspects were missing or inaccurate blinding and insufficient descriptions of the study protocol, especially the order of examinations.
Twenty-six to 115 patients within the age of 0 to 21 years were included in the studies. Sensitivity ranged from 64% to 100% and specificity did between 73% and 100%. Sensitivity was in six studies and specificity was in seven studies higher than 90%.
Chaar-Alvarez et al reported an average time reduction of 25 minutes by using sonography instead of x-ray and a reduction of pain from 1.7 to 1.2 points on a visual analog scale (0-5 points). In 2 other studies, all patients reported pain-free sonographic examinations. The results of the cost center accounting, not being representative, were costs of €20.54 per examination with ultrasound and €26.60 per radiography-based one, which is a potential saving of 22.79% by replacing radiographic examinations by ultrasound.

Conclusions
Sensitivity and specificity of ultrasound examinations are high. Single study results show that sonographic examinations can be faster and less painful. In addition, the calculation model shows a tendency towards less-expensive ultrasound examinations.
Further studies are needed with an adequate sample size calculation for assessing equivalence or non-inferiority of ultrasound and x-ray and to collect data on pain, examination time, and costs. The age of the older participants may be problematic because of the fact that epiphyseal plates close within the age from 15 to 22 years, which may influence the diagnostic accuracy of sonographic examinations. Therefore, future studies should contain age-stratified analyses. In addition, the calculation model for costs should be tested on a wider data base.