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Ottawa Knee Rule

Determines which acute knee injury patients need X-rays — any single positive criterion triggers a knee series.

No knee X-ray required
No Ottawa Knee Rule criteria met · 98.5–100% sensitivity for clinically significant fractures
Treat as soft-tissue injury — still assess ligament/meniscus separately
0pts
Age ≥55 years
Isolated patellar tenderness (no other bony knee tenderness)
Tenderness at fibular head
Inability to flex knee to 90°
Inability to bear weight (4 steps) immediately after injury AND in the ED
Stiell IG, et al. 1995 · Sensitivity 98.5–100% for clinically significant fractures · Adults and children ≥2 years with acute knee injury. Detects fractures only — a negative rule does not exclude ligamentous or meniscal injury.