Ottawa Knee Rules
Purpose[edit | edit source]
A clinic decision rule to help determine need for x-rays or rule out fractures of the knee after acute injury. "Plain radiographs of the knee are among the most commonly ordered radiographs in U.S. emergency departments; 60% to 80% of patients with knee pain have a knee film at an estimated annual cost of $1 billion."[1]
Criteria[edit | edit source]
If one of the following is present, radiographs are indicated[2]:
1. Age>55 years
2. Islolated patellar tenderness without other bone tenderness
3. Tenderness of the fibular head
4. Inability to flex to 90°
5. Inability to bear weight immediately after injury and in the emergency department (4 steps) regardless of limping.
Research[edit | edit source]
Diagnostic Accuracy[edit | edit source]
Adult Population: Sensitivity: 1.0 Specificity: .49-.56
+LR: 1.9-2.3 -LR: 0
A systematic review by Buchmann et al found a negative result on the Ottawa knee rule test is associated with a fracture
probability of less than 1.5% in an adult population.
Pediatric Population: Sensitivity: 1.0 Specificity: .43
+LR: 1.8 -LR: 0
References[edit | edit source]
(1) Jackson JL, O'Malley PG, Kroenke, K. Evaluation of acute knee pain in primary care. Ann Intern Med. 2003 Oct 7;139(7):575-88. Review.
Stiell IG, Wells GA, Hoag RH, Sivilotti ML, Cacciotti TF, Verbeek PR, Greenway KT, McDowell I, Cwinn AA, Greenberg GH, Nichol G, Michael JA. Implementation of the Ottawa Knee Rule for the use of radiography in acute knee injuries. JAMA. 1997 Dec 17;278(23):2075-9.
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):121-4. Review.
