Ottawa knee rule
Whether a knee X-ray is needed after acute injury.
Inputs
Age 55 or older
Isolated tenderness of the patella
Tenderness at the head of the fibula
Unable to flex to 90 degrees
Unable to bear weight for 4 steps, immediately and in the ED
Worked calculation
Your values are highlighted.
- Criteria present
When to use
- Acute knee injury in adults.
Pearls and pitfalls
- Not validated under age 18 or with altered sensation.
Why use
Reduces unnecessary knee X-rays.
Positive if any criterion is present