What are the Ottawa ankle rules?
The Ottawa rules are simple bedside checks after an injury. They show who needs an X-ray to rule out a fracture.
They were developed in Ottawa, Canada, in the 1990s. Their sensitivity for significant fractures is close to 100%. Used well, they cut unnecessary X-rays by about a third.
Ottawa ankle rules
An ankle X-ray is needed if there is pain in the malleolar zone and any of:
- Bone tenderness along the distal 6 cm of the posterior edge, or tip, of the lateral malleolus
- Bone tenderness along the distal 6 cm of the posterior edge, or tip, of the medial malleolus
- Inability to bear weight for 4 steps, both immediately and when examined
Ottawa foot rules
A foot X-ray is needed if there is pain in the midfoot zone and any of:
- Bone tenderness at the base of the fifth metatarsal
- Bone tenderness at the navicular
- Inability to bear weight for 4 steps, both immediately and when examined
Ottawa knee rules
A knee X-ray is needed after injury if any of these apply:
- Age 55 or over
- Isolated tenderness of the patella
- Tenderness at the head of the fibula
- Unable to flex the knee to 90°
- Unable to bear weight for 4 steps, both immediately and when examined
When to be cautious
- Intoxication, head injury or distracting injuries
- Reduced sensation, such as diabetic neuropathy
- Children, especially under 5
- Re-presentation with ongoing pain