Physical Exam

Ottawa Knee Rule

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Video coming September 2026

How to Perform

In a patient with an acute knee injury, assess the five criteria: age 55 years or older; isolated tenderness of the patella; tenderness at the head of the fibula; inability to flex the knee to 90°; and inability to bear weight (take four steps) both immediately after the injury and at the time of evaluation. The rule is positive if any one of these criteria is present.

How to Interpret

Acute Knee Fracture

Ottawa knee rule positive (any of: age ≥55 years; isolated patellar tenderness; tenderness of the fibular head; inability to flex knee to 90°; inability to bear weight both immediately and in the emergency department for 4 steps)

Rule in

Minimally helpful

Rule out

Very helpful

Evidence:Strong

References

Bachmann LM, Haberzeth S, Steurer J, ter Riet G. The accuracy of the Ottawa knee rule to rule out knee fractures: a systematic review. Ann Intern Med. 2004 Jan 20;140(2):121-124. doi:10.7326/0003-4819-140-5-200403020-00013. PMID: 14734335. Systematic review with random-effects meta-analysis; 11 studies identified, 6 pooled for adults (n=4249); radiography or follow-up reference standard; MEDLINE/PREMEDLINE 1966-2003, EMBASE 1980-2003, CINAHL 1982-2003, BIOSIS 1990-2003, Cochrane Library 2002 Issue 3 + Science Citation Index search.
Stiell IG, Greenberg GH, Wells GA, et al. Derivation of a decision rule for the use of radiography in acute knee injuries. Ann Emerg Med. 1995;26(4):405-413.