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    Ottawa Ankle Rule

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