[Accurate use of imaging in ankle sprain]

Imaging ankle trauma has two goals: to evaluate bone lesions and to appreciate the capsulo-ligamentous tears. Concerning bone lesions, Ottawa's criteria specify the clinical characteristics to perform radiography in the emergency conditions. These recommendations negate the need for nearly 30% of unnecessary radiographs initially performed. Four views of the tarsis have been selected: anteroposterior, lateral, internal rotation, external oblique. Immediate screening of the ligament is very accurately performed with ultrasound, which depicts the number of bundle concerned and the extent of the lesions. This requires an experienced operator and a high quality sonograph. Stress radiography should not be performed anymore as sensitivity is around 50%. Arthrography and CT arthrography are very accurate when performed immediately but are more expensive. This report highlights the complementary role of radiography and ultrasound to evaluate ankle sprain.