A 32 yo M presents with ankle pain and swelling after forcefully externally rotating it while playing soccer. He is unable to ambulate.  Ankle x ray is shown below.

What other joint should you image?

Answer: The knee.  This patient is at risk for a concurrent proximal spiral fibular fracture.  The above xray shows widening of the medial distal tibio-fibular syndesmosis/mortis suggesting a tear in the deltoid ligament, the resulting fracture is called a Maisonneuve.  This combination is usually an unstable injury requiring operative repair.

Proximal fibular fracture: