Validation of the Ottawa ankle rules in children

Objective-To assess whether the Ottawa ankle rules can be used to accurately predict which children with ankle and midfoot injuries need radiography. Methods-Prospective study with historical control group of all children aged 1-15 years presenting to Sheffield Children's Hospital accident and emergency department with blunt ankle and/or midfoot injuries during two five month periods before and after implementation of the Ottawa ankle rules. Results-In the study group 432 out of 761 (56.76%) patients received radiography compared with 500 out of 782 (63.93%) in the control group. This was a statistically significant reduction in radiography rate of 7.2% (95% confidence interval 2.3% to 12.1%, p < 0.01). The sensitivity of the Ottawa ankle rules was 98.3% and the specificity 46.9%. There was no increase in the number of missed fractures (one in each group). Conclusion-The Ottawa ankle rules can be applied in children to determine the need for radiography in ankle and midfoot injuries. Their implementation leads to a reduction in the radiography rate without leading to an increase in the number of missed fractures.