Diagnostic Accuracy of the Sonographic Ottawa Foot and Ankle Rules for Ankle and Foot Fractures in Emergency Department

Abstract

Aim:This study was carried out to determine whether the addition of a bedside ultrasound (US) to the Ottawa Foot and Ankle Rules (OAR) could decrease the need for radiographic imaging in the patients presenting to emergency department (ED) with foot and/or ankle trauma.Materials and Methods:In this prospective observational study, adult patients with acute foot and/or ankle injuries were included. Patients were first examined and OAR results were recorded. Then, US exam was performed by emergency physicians who were blinded to the OAR results. After that, the patients received radiography regardless of OAR exam and US findings. The US and OAR results were then compared to the formal radiography interpretation.Results:A total of 240 patients with a mean age of 36±12 years were included in the study of which 86 (35.8%) were female. The sensitivity of OAR in detecting foot and/or ankle fractures was 97.5% [95% confidence interval (CI): 86.8 to 99.9%] and the specificity of OAR increased from 48.5 % (95% CI: 41.4 to 55.7%) to 99.5% (95% CI: 97.2 to 100) with the addition of US. The OAR can reduce radiography by 40%, and if ultrasonography was used before radiography, there would be an approximately 72% reduction in X-ray requests.Conclusion:When used in conjunction with OAR, US can be used by trained physicians in ED to more accurately identify patients who would benefit from having an X-ray performed. US examination can further reduce the ordering of X-rays when compared to using OAR alone.

Keywords

• ultrasonography
• foot
• ankle
• emergency department
• injury