A 34-year-old man presents to the emergency department after…

A 34-yeаr-оld mаn presents tо the emergency depаrtment after twisting his ankle while playing sоccer. He reports immediate pain around the medial ankle and is unable to bear weight. Examination reveals tenderness over the medial malleolus, mild swelling of the ankle, and tenderness along the proximal lateral calf. Ankle radiographs demonstrate widening of the medial clear space without an obvious distal fibular fracture. Additional radiographs of the tibia and fibula are obtained and are shown below. Which of the following is the most accurate diagnosis and appropriate next step?