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.