Interpretation
| Result | Meaning |
|---|---|
| Any criterion | Knee X-ray |
| None | No X-ray |
Formula
X-ray if ANY: age ≥55 · isolated patellar tenderness · fibular head tenderness · inability to flex to 90° · inability to bear weight 4 steps immediately and in ED.
Clinical pearls
- Derivation population: adults ≥18 y with acute knee injury (≤7 days). Excluded: age <18, pregnancy, isolated skin injury, injury >7 days old, altered consciousness, paraplegia, multiple injuries, returning for reassessment, or referred with outside films.
- Implementation reduced knee radiography by about a quarter without missed fractures (Stiell 1997).
Examples
ottawa knee 30 yo twisted knee, can flex to 90, walked 4 steps, no bony tendernessknee injury 60 year old woman, does she need an x-ray
FAQ
Does the Ottawa Knee Rule work in children?
It was derived in adults; some studies support use in children over 5, but the derivation population was ≥18.
What does isolated patellar tenderness mean?
Tenderness of the patella with no other bony tenderness of the knee.