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    Ottawa Ankle Rule

    Shows areas of tenderness to be evaluated in ankle trauma patients to determine need for imaging.
    When to Use
    Why Use

    The Ottawa ankle rule should be applied to all patients aged 2 and older with ankle or midfoot pain/tenderness in the setting of trauma.

    The Ottawa ankle rules were derived to aid in the efficient use of radiography in acute ankle and midfoot injuries.

    • Rules have been prospectively validated on multiple occasions in different populations and in both children and adults.
    • Sensitivities for the Ottawa ankle rule range from the high 90%-100% range for “clinically significant” ankle and midfoot fractures. This is defined as a fracture or an avulsion greater than 3 mm.
    • Specificities for the Ottawa ankle rules are approximately 41% for the ankle and 79% for the foot, though the rule is not designed/intended for specific diagnosis.
    • The Ottawa ankle rules are useful in ruling out fracture (high sensitivity), but poor for ruling in fractures (many false positives).

    Tips from the creators at University of Ottawa:

    • Palpate the entire distal 6cm of the fibula and tibia;
    • Do not neglect the importance of medial malleolar tenderness;
    • “Bearing weight” counts even if the patient limps;
    • Be caution in patients under age 18.

    Precautions from the creators at University of Ottawa:

    • Clinical judgment should prevail if examination is unreliable:
      • Intoxication
      • Uncooperative patient
      • Distracting painful injuries
      • Diminished sensation in legs
      • Gross swelling which prevents palpation of malleolar tenderness
    • Always provide written instructions
    • Encourage follow-up in 5-7 days if pain and ability to walk is not better

    Patients without criteria for imaging by the Ottawa ankle rules are highly unlikely to have a clinically significant fracture and do not need plain radiographs.

    Application of the Ottawa ankle rules can reduce the number of unnecessary radiographs by as much as 25-30%, improving patient flow in the ED.

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