The ankle AP and mortise x-rays show a syndesmotic injury.

The tibiofibular clear space, when measured 1cm above the tibial plafond, should be less than 5mm (approximately 6mm in our case).

The tibiofibular overlap, which is another radiological finding used to determine a syndesmotic injury, should be greater than 6mm on the AP view and 1mm on a mortise view (about 5mm on AP and 0.6 mm on the mortise view in our case).

The patient had an MRI scan of the ankle which confirmed a tibiofibular syndesmotic injury, and underwent operative management.

Reference here.