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:
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