Ottawa Ankle Rules
Medical context
Decide whether ankle or foot radiographs are indicated after acute blunt injury using Ottawa rules.
Emergency clinicians use this at triage, resuscitation, and disposition to standardize risk communication across shifts.
This page explains the Ottawa Ankle formula, how to interpret the output, known limitations, and peer-reviewed references so you can verify results against primary sources and local protocols.
It is grouped under Emergency Medicine because trauma, triage, and acute risk scores used in the ed.
How to use this calculator
- Enter the values requested by the Ottawa Ankle calculator using the units shown beside each field.
- Review the calculated result and read the interpretation section before acting on the output.
- Check limitations and references if the result will change management, dosing, or disposition.
- Use the related calculators section when you need supporting values (for example electrolytes, weight, or complementary risk scores).
Calculator
Ankle assessment
Foot assessment
Result
No X-ray
X-ray not indicated if rules applied correctly
- Ankle series: No
- Foot series: No
Educational use only. Confirm results with clinical judgment, primary sources, and local protocols. Not a substitute for professional medical advice. Full disclaimer.
Formula
Ankle or midfoot pain plus specified bone tenderness or inability to bear weight triggers imaging.
Interpretation
Highly sensitive for clinically significant fractures when applied correctly in adults.
Limitations
Caution in intoxication, multiple injuries, diminished sensation, and pediatric use varies.
Frequently asked questions
- Do the rules include the foot?
- Yes — separate midfoot criteria guide foot series imaging.
- Is the Ottawa Ankle result enough to make a treatment decision?
- No. Calculators support medical decision-making but do not replace examination, shared decision-making, institutional protocols, or consultant input when stakes are high.
- Does Calcmedical store the values I type in?
- Inputs are processed in your browser for this session. We do not ask for patient names or medical record numbers. See our privacy policy for hosting and analytics details.
References
- Stiell IG et al. Ottawa ankle rules