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Ottawa Ankle Rules

Ankle X-ray is indicated if there is malleolar-zone pain plus bone tenderness at the posterior edge or tip of either malleolus, or inability to bear weight (4 steps) both immediately and in the ED. Foot X-ray is indicated if there is midfoot-zone pain plus tenderness at the base of the 5th metatarsal or navicular, or inability to bear weight.

  • Pain in the malleolar zone (yes/no, +1)
  • Bone tenderness: posterior edge or tip of lateral malleolus (distal 6 cm) (yes/no, +1)
  • Bone tenderness: posterior edge or tip of medial malleolus (distal 6 cm) (yes/no, +1)
  • Pain in the midfoot zone (yes/no, +1)
  • Bone tenderness: base of 5th metatarsal (yes/no, +1)
  • Bone tenderness: navicular (yes/no, +1)
  • Unable to bear weight (4 steps) both immediately and in ED (yes/no, +1)
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Interpretation

ResultMeaning
Malleolar pain + (malleolar tenderness or unable to bear weight)Ankle X-ray
Midfoot pain + (5th MT base or navicular tenderness or unable to bear weight)Foot X-ray
NeitherNo X-ray

Formula

Ankle series if malleolar-zone pain AND any: posterior edge/tip lateral malleolus tenderness · posterior edge/tip medial malleolus tenderness · unable to bear weight immediately and in ED. Foot series if midfoot-zone pain AND any: base of 5th MT tenderness · navicular tenderness · unable to bear weight.

Clinical pearls

  • Derived and validated in adults (≥18 y) with acute blunt ankle injury seen in the ED; excluded pregnancy, isolated skin injuries, injury >10 days old, and patients returning for reassessment. Later studies support use in children ≥5 y.
  • Not reliable in intoxicated patients, those with diminished sensation (e.g. neuropathy), head injury or distracting injuries.
  • "Unable to bear weight" means unable to take 4 steps (two transfers onto each foot), even limping.

Examples

ottawa ankle: lateral malleolar pain, tender tip of lateral malleolus, can weight bearinversion injury, midfoot pain, tender base of 5th metatarsal, walked 4 steps

FAQ

Do the Ottawa Ankle Rules apply to children?

They were derived in adults, but meta-analyses support their use in children aged 5 and older.

How sensitive are the Ottawa Ankle Rules?

Close to 100% for clinically significant fractures in validation studies, reducing radiography by about a quarter to a third.

Evidence

  1. Stiell IG et al. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med 1992;21:384–90.
  2. Stiell IG et al. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA 1993;269:1127–32.

Emergency & Trauma · Reviewed 2026-10-14 · Methodology