Reappraisal of use of X-rays in childhood ankle and midfoot injuries.

Objectives: To determine whether the Ottawa ankle rules (OAR) can be applied in children and what the potential reduction in the use of X-ray studies might be.

Methods: Prospective, observational study of children attending emergency department with blunt ankle and midfoot injuries. X-ray studies were obtained after recording of the physical assessment. A single investigator who was blinded to the emergency physician's interpretations and to the radiologist's interpretations of the studies then applied the OAR to each patient. Sensitivity, specificity, and positive and negative predictive values of the OAR were calculated with 95% confidence intervals.

Results: The OAR were 100% sensitive (95% CI=81-100%) and 30% specific (95%CI=19-43%). Positive and negative predictive values were 28% (95%CI=17-41%) and 100% (95% CI=82-100%) respectively. The number of X-ray studies ordered would have been reduced by 24% if the OAR had been applied.

Conclusions: The Ottawa ankle rules are very sensitive and can be applied in children, resulting in a reduction in the use of X-rays studies.