The ankle x-ray shows a lateral talar dome fracture. There is also significant soft tissue swelling over the medial malleolus.
This is a missable fracture.
Fractures of the lateral talar dome usually occur due to trauma, whereas medial talar dome fractures are caused by repetitive stress and may be chronic.
Treatment involves a below knee cast, non-weight bearing crutches, and a referral to an orthopaedician. Displaced talar dome fractures will need operative management.