Validation of the Ottawa Ankle Rules for Acute Foot and Ankle Injuries

The original and modified Ottawa Ankle Rules (OARs) were developed as clinical decision rules for use in emergency departments. However, the OARs have not been evaluated as an acute clinical evaluation tool. Objective: To evaluate the measures of diagnostic accuracy of the OARs in the acute setting. Methods: The OARs were applied to all appropriate ankle injuries at 2 colleges (athletics and club sports) and 21 high schools. The outcomes of OARs, diagnosis, and decision for referral were collected by the athletic trainers (ATs) at each of the locations. Contingency tables were created for evaluations completed within 1 h for which radiographs were obtained. From these data the sensitivity, specificity, positive and negative likelihood ratios, and positive and negative predictive values were calculated. Results: The OARs met the criteria for radiographs in 100 of the 124 cases, of which 38 were actually referred for imaging. Based on radiographic findings in an acute setting, the OARs (n = 38) had a high sensitivity (.88) and are good predictors to rule out the presence of a fracture. Low specificity (0.00) results led to a high number of false positives and low positive predictive values (.18). Conclusion: When applied during the first hour after injury the OARs significantly overestimate the need for radiographs. However, a negative finding rules out the need to obtain radiographs. It appears the AT's decision making based on the totality of the examination findings is the best filter in determining referral for radiographs.