Final answer:
Imaging of the ankle is required when a patient exhibits tenderness over the anterior edge of the distal medial malleolus or the posterior edge of the distal lateral malleolus, as these signs suggest possible malleolar fractures.
Step-by-step explanation:
The need for imaging of the ankle in a 17-year-old boy who was injured while playing soccer is indicated by tenderness over certain anatomical landmarks following an injury that suggest the possibility of a fracture. When considering the Ottawa ankle rules for when to perform imaging, the following clinical signs would prompt an X-ray:
- B Tenderness over the anterior edge of the distal medial malleolus
- D Tenderness over the posterior edge of the distal lateral malleolus
Both of these areas are associated with possible malleolar fractures. Specifically, tenderness at the posterior edge of the lateral malleolus could be related to an inversion ankle sprain, which might cause a fracture of the distal fibula due to the talus tilting laterally and can also impact the posterior edge of the tibia in severe cases. Furthermore, tenderness over the anterior edge of the distal medial malleolus might suggest an eversion injury, which may lead to a Pott's fracture, involving the medial malleolus of the tibia and possibly the fibula and the posterior margin of the tibia.