Low Risk Ankle Rule For Children Reduces Unnecessary X-Rays

August 5, 2015
Diagnostic Imaging Staff

Ankle radiographs not always needed among some children presenting with acute ankle injury.

Following the Low Risk Ankle Rule results in fewer unnecessary radiographs for children and saves money, according to a study published in the Annals of Emergency Medicine.

The Low Risk Ankle Rule states that an X-ray of the ankle is likely not necessary to rule out high risk injury if a child presents with tenderness and swelling that is isolated to the distal fibula and/or adjacent lateral ligaments distal to the tibial anterior joint line.

Researchers from Canada undertook this study to examine the costs and consequences of implementing the Low Risk Ankle Rule among 2,151 children who presented with ankle injuries.

"Currently, x-rays are ordered for up to 95 percent of children who come to emergency departments with ankle injuries, though only 12 percent of those x-rays show fractures," lead study author Kathy Boutis, MD, MSc, of The Hospital for Sick Children and the University of Toronto in Canada, said in a release. "Widespread implementation of the LRAR could lead to a safe reduction of x-rays in children with ankle injuries, reducing unnecessary radiation exposure and health care costs."

The researchers collected data on children aged 3 to 16 who presented to the emergency department (ED) with an acute ankle injury: health care provider visits, imaging, and treatment at the index ED visit, and days 7 and 28 post–ED discharge. This was done during three consecutive six-month phases at six emergency departments. There were 1,055 at the intervention EDs and 1,096 at the control EDs.

The Low Risk Ankle Rule was introduced after the baseline phase 1, in phases 2 and 3 in three intervention EDs, but not in the three pair-matched control EDs. The researchers compared the effect of the Ankle rule on health care and patient-paid costs, the proportion of radiographs ordered, the proportion of missed clinically important fractures, and the follow-up use of health care resources.

The results showed that health care costs were $36.93 less per patient at intervention compared with control sites and out-of-pocket costs to the patients were $2.09 more per patient at intervention sites. “In intervention versus control sites, the main contributor to cost reduction was the 22.9 percent reduction in ankle radiography,” the authors wrote. “Furthermore, there were no significant differences in the frequency of missed clinically important fractures (0.1 percent versus 0.9 percent) or follow-up use of health care resources.”

"Our findings are good news for the two million American and Canadian children with hurt ankles who visit emergency departments each year: although most currently receive x-rays, many do not actually need them," Boutis said in the release. "There are also potential cost savings. In a publicly funded health care system, using the LRAR to decide if x-rays are necessary in children with ankle injuries modestly reduced health system costs without increasing patient costs. In a privately funded health care system like the one in the United States, the cost savings would likely be realized by the patient or insurer."

Related Content:

News | X-Ray