Ultrasound Can Diagnose Many Arm Fractures in Kids

By Lisa Rappaport

May 22, 2020

(Reuters Health) - While ultrasound can accurately diagnose many upper extremity fractures in children, a new study suggests it may not always catch elbow fractures.

Researchers conducted a systematic review and meta-analysis, examining data from 32 studies with 2,994 pediatric patients who had a total of 3,415 scans for symptoms consistent with upper extremity fracture. As a reference point to compare the accuracy of ultrasounds, 30 studies used plain radiographs; one study used radiographs, MRI or bone scan; and one study used MRI.

Overall, the pooled sensitivity and specificity of ultrasonography for upper extremity fractures in children was 0.95 and 0.96, respectively. The pooled positive and negative likelihood ratios were 21.10 and 0.05, respectively.

"These results are important as they indicate that ultrasound can be used for the diagnosis of some of the most common arm fractures we see in children, namely fractures of the distal forearm or wrist," said senior study author Dr. J. Kate Deanehan, director of emergency ultrasound at Johns Hopkins Children's Center in Baltimore.

"However, for elbow fractures, ultrasound may miss some fractures and therefore X-rays are still recommended for diagnosis," Dr. Deanehan said by email.

In twelve studies evaluating elbow fractures, ultrasound results had a sensitivity of 0.95 and a specificity of 0.87. Elbow diagnostic ultrasounds also had positive and negative likelihood ratios of 7.10 and 0.06, respectively.

By comparison, twenty studies of non-elbow fractures found that ultrasounds had sensitivity of 0.96 and specificity of 0.97, as well as positive and negative likelihood ratios of 32.40 and 0.05, respectively.

In 17 studies evaluating point-of-care diagnostic ultrasounds for upper extremity fractures, researchers found a sensitivity of 0.95 and specificity of 0.96, as well as positive and negative likelihood ratios of 22.70 and 0.06, respectively.

Seven studies that examined radiology-performed diagnostic ultrasounds for upper extremity fractures found a sensitivity of 0.93 and specificity of 0.98, as well as positive and negative likelihood ratios of 48.00 and 0.07, respectively.

One limitation of the analysis is that ultrasound accuracy varies by operator, making it difficult to generalize results, the study team notes in the American Journal of Emergency Medicine. The analysis also had limited statistical power to assess differences in outcomes between ultrasounds done at point-of-care and ultrasounds done by radiologists.

"This study is a great first step in the understanding the role of point-of-care ultrasound in this population," said Dr. David Teng, director of pediatric emergency ultrasound at Cohen Children's Medical Center in New York City.

"However, further anatomical assessment studies may be needed if not required in order to fully obtain the information needed to care for these children," Dr. Teng, who wasn't involved in the study, said by email. "Future studies are also needed to fully investigate the implications of using ultrasound as the sole diagnostic modality for upper extremity injuries in kids."

Even so, the results do suggest that ultrasound is a feasible diagnostic tool to use instead of x-rays in some instances, said Dr. Joni Rabiner, an associate professor of pediatrics in emergency medicine at Columbia University Medical Center and New York-Presbyterian Morgan Stanley Children's Hospital in New York City. Ultrasound may also help limit children's exposure to radiation, said Dr. Rabiner, who wasn't involved in the study.

"For physicians trained in pediatric musculoskeletal ultrasound, ultrasound may be used to help screen for, diagnose, and treat fractures," Dr. Rabiner said by email. "Ultrasound evaluation for arm fractures may be useful in any setting, but it is especially important in austere environments or other sites where x-rays may not be readily available."

SOURCE: https://bit.ly/2LMoUS5 American Journal of Emergency Medicine, online April 27, 2020.