Consider ankle x-rays
Ankle x-ray needed if:
Pain near the maleoli AND
Inability to bear weight immediately and in the ED (4 steps) OR
Tenderness at posterior edge or tip of lateral malleolus OR
Tenderness at posterior edge or tip of medial malleolus
Foot x-ray series needed if:
Pain in the midfoot AND
Inability to bear weight both immediately and in the ED (4 steps) OR
Tenderness at the navicular OR
Tenderness at the base of the 5th metatarsal
Radiograph-negative ankle injury 
Ankle fracture
Ankle pain
Salter-Harris fracture
Flank pain
Ligimentous injury
Distal radioulnar joint disruption
Contusion of bone or soft tissue