The accuracy of ultrasound evaluation in foot and ankle trauma

Abstract

Objectives: Foot and ankle injuries that result in sprains or fractures are commonly encountered at the emergency department. The purpose of the present study is to find out the accuracy of ultrasound (US) scanning in injuries in the aforementioned areas.

Methods: Ottawa Ankle Rules-positive patients older than 16 years who presented to the emergency department with foot or ankle injuries were eligible. For all patients, US evaluation of the whole foot and ankle was performed by an emergency physician before radiographic imaging. All radiographic images were evaluated by an orthopedic specialist and compared with the interpretations of the US.

Results: One hundred thirty-one patients were included in the study. Radiographic evaluation enabled the determination of fractures in 20 patients, and all of these were identified with US imaging. Moreover, US evaluation radiographically detected a silent ankle fracture in 1 patient. The sensitivity of US scanning in detecting fractures was 100% (95% confidence interval [CI], 83.8-100), the specificity was 99.1% (95% CI, 95-99.8), the positive predictive value was 95.2% (95% CI, 89.6-98), and the negative predictive value was 100% (95% CI, 96.4-100), respectively. The most common fractures were detected at the lateral malleolus and at the basis of the fifth metatarsal.

Conclusions: Ultrasound imaging permits the evaluation of foot and ankle fractures. Because it is a highly sensitive technique, US can be performed in the emergency department with confidence.