57-Year-Old with Left Foot Pain

A 57-year-old man presents to the urgent care with a 3-day history of left foot pain and swelling after walking barefoot on a wooden deck under construction. He recalls feeling a sharp pain in the affected foot at the time but could not see any foreign object. On examination, he has mild erythema, tenderness, and induration over the plantar surface of the midfoot. There is no visible puncture wound or foreign body present. Plain radiographs (XR) of the foot reveal no radiopaque foreign body or bony abnormalities. A point-of-care ultrasound (POCUS) of the foot is performed in 2 planes.

View the POCUS image above and consider the likely diagnosis and next steps. The resolution of the case is described on the following page.