A 36-year-old Man with Right Dorsal Ankle Pain

SECTION 1 – QUIZ CASE A 36-year-old man experienced pain in the dorsal area of his right foot after being struck by a stone 2 weeks ago. Initially, there had been visible bruising, which was absent by the time he visited the ultrasound examination room. However, the swelling was still present on the dorsal side of his right foot. There was not any instability of the ankle. The ultrasound (US) transducer was placed on the dorsal side of his right foot [Figure 1a] and gradually moved to the plantar surface [Figure 1b]. US image of the unaffected/asymptomatic side is given in Figure 2. Based on these findings, what is your suggestive diagnosis?Figure 1: Ultrasound imaging of the right anterolateral (a) and inferolateral (b) ankle. Black arrowheads, the lateral root of the inferior extensor retinaculum; black arrow, the intermediate root of the inferior extensor retinaculum; white arrowheads, the medial root of the inferior extensor retinaculum. T: Talus, C: Calcaneus, EDL: Extensor digitorum longus tendonFigure 2: Ultrasound imaging of the left inferolateral ankle. Black arrowheads, the lateral root of the inferior extensor retinaculum; white arrowheads, the medial root of the inferior extensor retinaculum. T: Talus, EDL: Extensor digitorum longus tendonDeclaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published, and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed. Financial support and sponsorship This work was funded by the National Taiwan University Hospital, Bei-Hu Branch; Ministry of Science and Technology (MOST 106-2314-B-002-180-MY3 and 109-2314-B-002-114-MY3); and the Taiwan Society of Ultrasound in Medicine. Conflicts of interest Dr. Ke-Vin Chang, an editorial board member at the Journal of Medical Ultrasound, had no role in the peer-review process or decision to publish this article. The other authors declared no conflicts of interest in writing this article.