Reappraisal of the Use of X-Rays in Acute Ankle and Midfoot Injuries. A Prospective Evaluation of the Ottawa Ankle Rules (OAR) in a Single Tertiary Trauma Centre

Abstract

INTRODUCTION: Acute ankle and foot injuries commonly present to the emergency departments, often resulting in routine radiography referrals, despite the fact that less than 15% of cases exhibit clinically significant fractures. The OAR has been designed to reduce the number of unnecessary radiographs ordered for these patients. We evaluated the OAR for predicting ankle and midfoot fractures in a cohort of patients treated in a single tertiary trauma centre. MATERIALS AND METHOD: A prospective study was conducted in the emergency department and orthopaedic clinics of a tertiary trauma centre. 73 patients aged 18 years and older were recruited during a 12-month study period. Radiographs were performed for all patients after clinical evaluation findings were recorded. The main outcomes measured were sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratios (positive and negative) of the OAR. RESULTS: 41 patients had ankle injuries, 21 around the midfoot, and 11 within both areas. In detecting ankle fractures, OAR had a sensitivity of 100%, a specificity of 73.68%, and a negative predictive value of 100% compared to the detection of midfoot fractures (100%, 84.61%, and 100%, respectively). The OAR had the potential of reducing radiographs by 42.47%. CONCLUSION: OAR is an accurate and highly sensitive tool to detect ankle and midfoot fractures. The implementation would lead to a significant reduction in the request for radiographs without missing any clinically significant fractures, thus, reducing costs, radiation exposures, and waiting times.