Lightning Learning: Ottawa Knee Rules
“The Ottawa Knee Rules are a set of criteria, which guide a clinician as to when an x-ray of the knee is required.”
What?
The Ottawa Knee Rules are a set of criteria, which guide a clinician as to when an x-ray of the knee is required.
An x-ray should be performed if any of these criteria are met:
Age >55 years
Isolated patellar tenderness (A)
Tenderness of the fibular head (B)
Inability to flex the knee to 90°
Inability to bear weight immediately after injury and in the Emergency Department
Why?
It was developed to prevent unnecessary imaging. Provides a fast and accurate decision-making tool.
Patients who do not meet criteria of the Ottawa Knee Rules are highly unlikely to have a significant fracture and do not require an x-ray.
When used appropriately, the Ottawa Knee Rules can reduce the number of unnecessary x-rays by 20-30%
Further Reading
- Physiopedia: Ottawa Knee Rules
- MDCalc: Ottawa Knee Rule calculator
- e-LFH: Ottawa Knee Rules: a useful clinical decision tool
