Prospective validation of the Ottawa Ankle Rules in a deployed military population

This study prospectively validated the Ottawa Ankle Rules (OAR) in patients presenting with acute ankle trauma to a deployed military clinic at Prince Sultan Air Base in Saudi Arabia. The treating physician determined whether the patient met OAR criteria. The decision to obtain radiographs was left to the discretion of the physician. All radiographs were read by a radiologist blinded to the study. Patients who were not evaluated by radiographs received follow-up in the orthopedic clinic or by telephone. Forty-five consecutive patients were enrolled over a 3-month period. Twenty-nine (64%) patients met the OAR criteria, 32 (71%) received radiographs, and 5 (11%) fractures were identified. All fractures were predicted by the OAR. The sensitivity of the OAR was 1.0 and specificity was 0.40. Negative predictive value was 1.0, positive predictive value was 0.17, likelihood ratio positive value was 1.67, and likelihood ratio negative value was 0.0. The OAR correctly predicted all ankle fractures in the military population studied.