A 6-year-old child presents after a fall from a bicycle, complaining of right ankle pain and inability to bear weight. On examination, there is swelling and tenderness over the distal fibula. The FNP performs the Ottawa ankle rules to determine the need for radiography. Which of the following findings would necessitate an ankle X-ray?
- AIsolated tenderness over the distal fibula.
- BInability to bear weight immediately and in the emergency department for four steps.
- CTenderness over the base of the fifth metatarsal.
- DTenderness over the medial malleolus.
Show answer & explanationAnswer & explanation
Correct answer: B. Inability to bear weight immediately and in the emergency department for four steps.
The Ottawa Ankle Rules are a clinical decision tool used to reduce unnecessary ankle and foot X-rays. One of the key criteria for an ankle X-ray is the inability to bear weight both immediately after the injury and in the emergency department for four steps. Options B and C are criteria for a foot X-ray, not an ankle X-ray, and option D, isolated tenderness over the distal fibula without other criteria, might not necessitate an X-ray if the patient can bear weight.
Why the other options are wrong
- A. Isolated tenderness over the distal fibula is a criterion for an ankle X-ray only if accompanied by inability to bear weight or tenderness at the posterior edge/tip of the lateral malleolus.
- C. Tenderness over the base of the fifth metatarsal is a criterion for a foot X-ray, not an ankle X-ray.
- D. Tenderness over the medial malleolus is an ankle X-ray criterion, but the question asks about the distal fibula and the inability to bear weight is a more comprehensive and direct indication for the ankle X-ray.
Ottawa Ankle Rules
A set of clinical decision rules to determine if radiography is needed for ankle or midfoot injuries, reducing unnecessary X-rays.
- Reduces healthcare costs and radiation exposure.
- Highly sensitive for detecting fractures.
- Criteria include bone tenderness and inability to bear weight.
Memory trick: Ottawa: Walk 4 Steps, Feel the Bones