Evidence-based clinical decision rules for X-ray in ankle, foot, and knee injuries. Sensitivity ~99% for fractures.
📋 Source: Ottawa Ankle Rules: Stiell IG et al. JAMA 1994. Ottawa Knee Rules: Stiell IG et al. BMJ 1995. OHRI — Official Ottawa Rules. Sensitivity >96% for clinically significant fractures. Your doctor or healthcare provider knows your history and circumstances — always follow their personalised advice over general information.
Applicability: Valid for adults ≥18 years presenting within 10 days of injury, with pain and ability to be assessed. Do not apply to: children under 18, pregnant women, patients with diminished sensation (e.g. diabetic neuropathy), multiple trauma, or intoxicated patients who cannot cooperate with assessment.
An ankle or foot X-ray series is indicated if there is pain in the malleolar or midfoot zone AND one or more of the following:
Ankle X-ray criteria
Foot X-ray criteria (midfoot zone)
A knee X-ray is indicated if any one of the following is present:
Clinical decision support only. The Ottawa Rules are a clinical aid — they do not replace clinical judgement. A negative Ottawa screen (X-ray not indicated) still requires appropriate clinical assessment, advice, and follow-up. If there is any clinical concern about a fracture not captured by these rules, imaging should be obtained. The rules have been validated in adults ≥18 years with acute musculoskeletal injury.
Sources & Validation
Stiell IG, Greenberg GH, McKnight RD, et al. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Annals of Emergency Medicine. 1992;21(4):384–390. doi:10.1016/s0196-0644(05)82656-3
Stiell IG, Wells GA, Hoag RH, et al. Implementation of the Ottawa Knee Rule for the use of radiography in acute knee injuries. JAMA. 1997;278(23):2075–2079. doi:10.1001/jama.1997.03550230051036
Bachmann LM, Kolb E, Koller MT, et al. Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review. BMJ. 2003;326:417. doi:10.1136/bmj.326.7386.417
Australasian College for Emergency Medicine (ACEM). Clinical practice guidelines. acem.org.au