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 inj uries. The OAR state that ankle roentgenograms are needed only if ther e 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 te nderness 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 patien ts with acute ankle injuries. Setting: Pediatric emergency department of an urban university hospital. Participants: Seventy-one children wi th acute ankle injuries were enrolled from July 22, 1993, to December 1, 1993. interventions: Twenty-four standardized clinical variables we re assessed and recorded by physicians in the pediatric emergency depa rtment. The OAR were applied to each patient by the investigator to de termine which ones would qualify for roentgenography. Main Outcome Mea sures: Sensitivity and specificity of the OAR were calculated, as was percent reduction in roentgenograms ordered. Results: Seventy-one of 7 3 eligible patients were enrolled. The two missed patients had open fr actures of the tibia. Sixty-eight of 71 patients had ankle roentgenogr aphy during the visit. Fourteen patients (21%) (mean age, 11.8+/-4.0 y ears) 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% wit hout missing any fractures. Sensitivity of OAR was 100% (95% confidenc e interval, 77% to 100%), specificity was 32% (95% confidence interval , 21% to 43%), negative predictive value was 100% (95% confidence inte rval, 80% to 100%), and positive predictive value was 28% (95% confide nce interval, 17% to 39%). Conclusions: Initial testing suggests that the OAR may help determine which children with acute ankle injuries co uld safely forgo roentgenograms without risk of missing fractures.