Ottawa Ankle Rules
Determines need for ankle and foot X-ray following acute injury
How to use & interpret
The Ottawa ankle (and foot) rules are a highly sensitive decision aid to decide whether an ankle or mid-foot injury needs an X-ray, safely reducing unnecessary imaging.
An ankle X-ray is indicated only if there is bony tenderness at the posterior edge or tip of either malleolus, OR an inability to bear weight (four steps) both immediately and in the department. A foot X-ray is indicated for bony tenderness at the navicular or the base of the fifth metatarsal, or the same weight-bearing inability. Because the rules are very sensitive (few missed fractures) but not very specific, a 'positive' rule means image — it does not mean a fracture is present.
Score interpretation
All criteria absent — fracture effectively excluded
→ No X-ray required. RICE, analgesia, weight-bearing as tolerated.
One or more criteria present — fracture cannot be excluded
→ X-ray ankle (if malleolus or weight-bearing criteria) and/or foot (if 5th met or navicular criteria)
Interpretation bands for the Ottawa Ankle. Apply clinical judgement and local guidance.
Frequently asked questions
Do the Ottawa rules apply to children?
They perform well in children over about 5–6 years, but apply them cautiously in young children and where there is significant swelling, distracting injury, or intoxication.
References
- Stiell IG, et al. Implementation of the Ottawa ankle rules. JAMA. 1994;271(11):827–32.
Related
Curated clinical cross-links plus same-class fallbacks.
- Tranexamic Acid (ICU/Trauma/Surgical) · Antifibrinolytic
- Co-amoxiclav (Open Fracture Antibiotic Prophylaxis) · Beta-lactam / Beta-lactamase Inhibitor Combination
- Piperacillin-Tazobactam (Polymicrobial Open Fracture Infections) · Extended-spectrum Beta-lactam / Beta-lactamase Inhibitor
- Tranexamic Acid (Surgical / Trauma Haemorrhage) · Antifibrinolytic (Haemostatic)
- Difficult Airway Algorithm (DAS) · DAS 2015; Royal College of Anaesthetists
- Major Haemorrhage Protocol · NICE NG24; UK MHP guidelines
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Featured in these MRCEM clinical pathways
The Ottawa Ankle is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.
MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.