Clinical decision rule
Ottawa Ankle Rules
The Ottawa Ankle Rules determine whether an acute ankle or midfoot injury requires radiographs, based on bone tenderness at four specific sites and the ability to bear weight for four steps; they are approximately 98% sensitive for clinically significant fractures.
What the Ottawa Ankle Rules mean
Ottawa Ankle Rules scores run from 0 to 1, where a lower score is better. The bands below are conventional reporting categories, not diagnostic cut-offs.
- Imaging not indicated0–0
- Imaging indicated1–1
Published criteria and reliability
The published cut-offs that define this instrument, and the measured agreement between observers using it. Each is reported with the population it was derived in.
| Type | Value | Subscale | Population | Follow-up | Source |
|---|---|---|---|---|---|
| Criterion | Sensitivity ~98%, specificity ~30–40% | — | Adults with acute ankle injury | — | Bachmann LM 2003 |
| Criterion | Reduces radiography use by 30–40% | — | Emergency department | — | Stiell IG 1994 |
Criterion is a published cut-off, definition or performance figure belonging to a classification or decision rule — it is not a change score and should not be read as one.
How the score is calculated
Stated in full so the calculation can be independently checked, and reproduced by hand if needed.
An ankle series is indicated when there is pain in the malleolar zone together with bone tenderness at the posterior edge or tip of either malleolus, or an inability to bear weight both immediately and at assessment. A foot series is indicated when there is pain in the midfoot zone together with bone tenderness at the base of the fifth metatarsal or the navicular, or the same inability to bear weight. The two rules are applied independently and either, both, or neither series may be indicated.
Instrument profile
- Developer
- Ian Stiell and colleagues
- Institution
- University of Ottawa, Canada
- First published
- 1992
- Items
- 7
- Response format
- Yes/No criteria
- Score range
- 0 to 1
- Direction
- Lower score = better
- Completion time
- About 1 minutes
- Age range
- Adults 18 and over; a validated paediatric application exists from roughly age 5
- Regions
- Foot & Ankle
- Conditions
- Acute ankle injury, Ankle sprain, Midfoot injury, Malleolar fracture
- Validity
- Pooled sensitivity around 98% for clinically significant malleolar and midfoot fractures across more than 60 studies.
- Reliability
- Specificity is deliberately low — the rule is designed to rule out, not to rule in.
When to use the Ottawa Ankle Rules
Well suited to
- Acute ankle or midfoot injury within 10 days in a cooperative adult patient.
- Any setting where reducing unnecessary radiography is a goal.
Limitations and poor fits
- Intoxicated or uncooperative patients, or those with distracting painful injuries.
- Diminished sensation in the leg, or gross swelling that prevents accurate palpation of bony landmarks.
- Injuries more than 10 days old, and referred patients who already have radiographs.
Ottawa Ankle Rules compared with other instruments
Instruments measuring a related construct, with the practical difference between them.
| Instrument | Items | Range | What it adds |
|---|---|---|---|
| Ottawa Knee Rule | 5 | 0–1 | The Ottawa Knee Rule determines whether an acute knee injury requires radiographs using five criteria — age 55 or over, isolated patellar tenderness, fibular head tenderness, inability to flex to 90 degrees, and inability to bear weight for four steps — and is close to 99% sensitive for clinically significant fractures. |
| Canadian C-Spine Rule | 3 | 0–1 | The Canadian C-Spine Rule decides whether an alert, stable blunt trauma patient needs cervical spine radiography through three sequential steps — high-risk factors, low-risk factors, and the ability to actively rotate the neck 45 degrees each way — with a reported sensitivity of about 99% for clinically significant injury. |
Copyright and permitted use
Published openly because it is the question every clinician and researcher asks before using an instrument, and almost nobody answers it.
The Ottawa Ankle Rules are a published clinical decision rule. The criteria are freely reproducible and no licence is required.
References
- Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Annals of Emergency Medicine. 1992.PMID 1554175
- Stiell IG, McKnight RD, Greenberg GH, et al.. Implementation of the Ottawa Ankle Rules. JAMA. 1994.PMID 8114236
- Bachmann LM, Kolb E, Koller MT, Steurer J, ter Riet G. Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review. BMJ. 2003.doi:10.1136/bmj.326.7386.417PMID 12595378
Editorial status
This page has not yet been signed off by a named clinical reviewer. The scoring logic is stated in full above so it can be independently verified, and every threshold is traceable to its source. See our editorial methodology.