High ankle sprain: sonographic demonstration of a posterior inferior tibiofibular ligament avulsion.

Syndesmotic injuries, also referred as high ankle sprains, may cause significant ankle instability and chronic pain. Ultrasound (US) is a well-proven imaging modality to evaluate the ligaments of the ankle, due to its high spatial resolution and the possibility to perform dynamic examinations. However, considering the syndesmosis complex, the sonographic appearance of the posterior inferior tibiofibular ligament (PITFL) is not well described in the pertinent literature and, to the best of our knowledge, we found no report of PITFL avulsion demonstrated at US, as in the case presented.