Decision rules for roentgenography of children with acute ankle injuries.

OBJECTIVE

The Ottawa Ankle Rules (OAR) assist emergency physicians in the appropriate use of roentgenography in adults with acute ankle injuries. The OAR state that ankle roentgenograms are needed only if there is pain near the malleoli and one or more of the following exists: (1) age 55 years or older; (2) inability to bear weight; or (3) bone tenderness at the posterior edge or tip of either malleolus. This study assessed the utility of the OAR on pediatric patients with acute ankle injuries.

DESIGN

Prospective, consecutive survey of pediatric patients with acute ankle injuries.

SETTING

Pediatric emergency department of an urban university hospital.

PARTICIPANTS

Seventy-one children with acute ankle injuries were enrolled from July 22, 1993, to December 1, 1993.

INTERVENTIONS: Twenty-four standardized clinical variables were assessed and recorded by physicians in the pediatric emergency department. The OAR were applied to each patient by the investigator to determine which ones would qualify for roentgenography.

MAIN OUTCOME MEASURES: Sensitivity and specificity of the OAR were calculated, as was percent reduction in roentgenograms ordered.

RESULTS

Seventy-one of 73 eligible patients were enrolled. The two missed patients had open fractures of the tibia. Sixty-eight of 71 patients had ankle roentgenography during the visit. Fourteen patients (21%) (mean age, 11.8 +/- 4.0 years) had fractures noted on the roentgenograms. Fifty-four patients (79%) (mean age, 12.0 +/- 3.6 years) had no fracture. Application of the OAR would have reduced the number of roentgenograms ordered by 25% without missing any fractures. Sensitivity of OAR was 100% (95% confidence interval, 77% to 100%), specificity was 32% (95% confidence interval, 21% to 43%), negative predictive value was 100% (95% confidence interval, 80% to 100%), and positive predictive value was 28% (95% confidence interval, 17% to 39%).

CONCLUSIONS

Initial testing suggests that the OAR may help determine which children with acute ankle injuries could safely forgo roentgenograms without risk of missing fractures.