Pittsburgh Knee Rules (knee-radiograph indication)
Pittsburgh Knee Rules for whether a knee radiograph is indicated after acute injury: given a blunt-trauma/fall mechanism, image if age < 12 or > 50 or unable to bear weight four steps.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Blunt-trauma or fall mechanism
- Yes
- Age > 50 years
- Yes
Result: Knee radiograph indicated — blunt-trauma/fall mechanism plus age > 50 years.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Entry gate
- the rule applies only to a blunt-trauma or fall mechanism. Without that mechanism the rule does not apply and does not classify the injury.
- Indication
- given the gate, a radiograph is indicated if age < 12 or > 50 years, or the patient cannot take 4 weight-bearing steps in the ED. About 99% sensitive, 60% specific (Seaberg 1998).
What you enter
- Blunt-trauma or fall mechanism (entry gate)
- Age < 12 years
- Age > 50 years
- Unable to take 4 weight-bearing steps
How this is calculated
Seaberg DC, Jackson R. Clinical decision rule for knee radiographs. Am J Emerg Med. 1994;12(5):541-543. Validated: Seaberg DC, et al. Ann Emerg Med. 1998;32(1):8-13. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.