Ottawa ankle and foot rules

Trauma & imaging rules

Acute ankle injury in adults. Decides separately whether an ankle series and a foot series are needed.

What you enter

Pain in the malleolar zone
Bone tenderness: posterior edge or tip of the lateral malleolus (distal 6 cm)
Bone tenderness: posterior edge or tip of the medial malleolus (distal 6 cm)
Pain in the midfoot zone
Bone tenderness: base of the fifth metatarsal
Bone tenderness: navicular
Unable to bear weight both immediately and in the emergency department (4 steps)

FORMULAAnkle series if malleolar-zone pain AND (lateral or medial malleolus tenderness, posterior edge or tip, distal 6 cm, OR unable to bear weight). Foot series if midfoot-zone pain AND (5th metatarsal base or navicular tenderness OR unable to bear weight).

SourceStiell IG et al. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA 1993;269:1127-32NoteFirst derived in Stiell IG et al. Ann Emerg Med 1992;21:384-90. The refined rules tested in the 1993 paper are the ones in use and the ones coded here.ReviewedFormula and thresholds checked against the source on 2026-09-28. If the source updates, this line will say so.