MDCalc

Ottawa Knee Rule

Describes criteria for knee trauma patients so low risk as not to warrant knee imaging.

Age ≥55
Isolated tenderness of the patella (no other bony tenderness)
Tenderness at the fibular head
Unable to flex knee to 90°

Unable to bear weight both immediately and in ED (4 steps, limping is okay)

Result:

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Advice

Patients who do not have any of the Ottawa Knee Rules present do not need an x-ray. If one or more of the conditions are met, then x-ray is recommended.

Management

For significant non-bony injuries, often crutches and a knee immobilizer can be helpful to assist with ambulation.

Critical Actions

Patients who do not have any of the Ottawa Knee Rules present do not need an x-ray. If one or more of the conditions are met, then x-ray is recommended.

Many experts would consider this score “one directional.” Because the rule is sensitive and not specific, it provides a clear guide of which patients not to x-ray if all criteria are met. However if a patient fails the criteria, need for x-ray can be left to clinical judgement.