No x-ray needed? Ultrasound effective at screening for pediatric elbow fractures

Point-of-care ultrasonography may be useful to rule out elbow fracture in pediatric patients, according to a study published online Nov. 12 in Annals of Emergency Medicine.

The findings support the use of ultrasonography by clinicians in settings without easy access to radiography to screen patients for elbow fracture, according to Joni E. Rabiner, MD, of the Children’s Hospital at Montefiore/Albert Einstein College of Medicine in New York City, and colleagues.

“Elbow injuries are a common occurrence in pediatrics,” wrote the authors. “We have shown that point-of-care sonographic identification of an elevated posterior fat pad and lipohemarthrosis is a feasible, accurate, and reliable marker for elbow fractures.”

The prospective study featured 130 patients with a mean age of 7.5 years who presented to the emergency department (ED) with an elbow injury requiring radiographs. Focused elbow ultrasonography was conducted before obtaining radiographs and a positive for fracture was defined as an elevated posterior fat pad or lipohemarthrosis of the posterior fat pad. Ultrasonography findings were then compared against the radiographs.

“We chose to evaluate posterior fat pad elevation and lipohemarthrosis as indirect signs of fracture because it can be difficult to directly visualize fracture at the curved ends of long bones and areas adjacent to joints, and it has been suggested that posterior fat pad elevation may be a reliable indicator of elbow fracture,” wrote the authors.

Results showed that 43 patients had a fracture on radiograph. Positive elbow ultrasonographic results had a sensitivity of 98 percent, specificity of 70 percent, positive likelihood ratio of 3.3 and a negative likelihood ratio of 0.03 for fracture, according to Rabiner and colleagues.

The authors noted that the use of elbow ultrasonography to rule out fracture would have reduced the use of radiographs in 48 percent of the patients, but would have missed one fracture.

“Ultrasonographic machines are becoming more portable, which makes their use ideal in locations that do not have access to radiography,” wrote Rabiner and colleagues. Acute care centers without on-site radiography and crowded EDs may find the technique useful.

However, the authors indicated that radiography will be necessary to confirm the presence of fracture after a positive ultrasonography result, and also to evaluate the degree of displacement.