https://radiopaedia.org/articles/ottawa-ankle-rules-1?lang=gb
Radiology is indicated if there is;
1. inability to weight bear (four steps) immediately after the injury and in emergency department
-or-
2. point tenderness at;
- posterior edge (of distal 6 cm) or tip lateral malleolus
- posterior edge (of distal 6 cm) or tip medial malleolus
- the base of the fifth metatarsal
- the navicular
https://www.healthcare.uiowa.edu/familymedicine/fpinfo/rules.2.jpg