For healthcare professionals
Ottawa Ankle Rules
The Ottawa ankle and foot rules help decide which ankle and midfoot injuries need an X-ray. They use bone tenderness at 4 sites and whether the patient can walk four steps. Stiell and colleagues published them in 1992 and 1993. This tool is written for clinicians and is not a diagnosis.
Patient findings
Tick each finding that applies. Nothing you enter leaves this page.
What you will see
Whether the rules call for an ankle or foot X-ray, and which findings triggered it.
Educational only, not medical advice. Not a diagnosis. Imaging decisions belong to the treating team.
Source
Stiell IG and colleagues, Annals of Emergency Medicine 1992 and JAMA 1993. The criteria are taken from the open-access (CC BY) methods of Wallace and colleagues, Cureus 2025, and match the wording in Carvalho and colleagues, Revista Brasileira de Ortopedia 2025 (CC BY). The tests check each tenderness site, the weight-bearing item and that each finding only counts with pain in the matching zone.
Validated in
Patients with an acute ankle or foot injury. The rules were developed and validated in adults (Stiell 1992 and 1993). Carvalho and colleagues applied them to 144 children and adolescents aged 16 or younger in Brazil.
Limits
The rules are built to rule out fractures, not to find them: a positive result means an X-ray is indicated, not that a fracture is present. In the pediatric study, sensitivity was 100% and specificity 63.9% (Carvalho 2025). A systematic review quotes a sensitivity of 99.4% for the ankle rules (Kharel 2023).
The rules
Ankle X-ray series
An ankle X-ray is indicated if there is pain in the malleolar zone and any one of the following (Wallace 2025):
- Bone tenderness along the distal 6 cm of the posterior edge of the fibula or tip of the lateral malleolus
- Bone tenderness along the distal 6 cm of the posterior edge of the tibia or tip of the medial malleolus
- Inability to bear weight (walk four steps) both immediately after the injury and when examined
Foot X-ray series
A foot X-ray is indicated if there is pain in the midfoot zone and any one of the following (Wallace 2025):
- Bone tenderness at the base of the fifth metatarsal
- Bone tenderness at the navicular bone
- Inability to bear weight (walk four steps) both immediately after the injury and when examined
The same criteria are described by Carvalho and colleagues (Carvalho 2025). The rules were first developed by Stiell and colleagues (Stiell 1992) and then refined and validated (Stiell 1993).
Worked example: a patient who twisted an ankle, has pain over the outer ankle and tenderness at the tip of the lateral malleolus, but can walk four steps, meets one ankle finding, so the rules call for an ankle X-ray series.
What the studies found
In 144 children and adolescents aged 16 or younger with an ankle sprain, the rules had a sensitivity of 100% and a specificity of 63.9% for fracture. Inability to walk four steps was the single most sensitive item. Using the rules could have avoided 43.8% of the X-rays (Carvalho 2025).
In a London emergency department, documentation in line with the Ottawa foot rules rose from 48% to 78% after teaching and a handout (Wallace 2025). A systematic review found that awareness and use of the rules varies widely among clinicians, and quotes a sensitivity of 99.4% for the ankle rules (Kharel 2023).
Related calculators
For knee injuries, see the Ottawa Knee Rule. For head injury, see the Canadian CT Head Rule and the Glasgow Coma Scale calculator. Other bedside scores are listed under For healthcare professionals.
Sources
- Wallace W, Limaye N, Rao C, et al. Assessing Compliance With Ottawa Foot and Ankle Rules in the Emergency Department: A Closed-Loop Quality Improvement Project. Cureus. 2025;17(5):e84908. doi:10.7759/cureus.84908. PMID 40575204. Open access (CC BY 4.0). Methods: the Ottawa ankle and foot rule criteria; Results: foot documentation compliance 48% to 78%. pmc.ncbi.nlm.nih.gov/articles/PMC12200823/
- Carvalho MO, Marcolino HM, Daleffe MR. Ottawa Ankle Rules: A Reliable Clinical Instrument to Detect Fractures in Children and Adolescents. Rev Bras Ortop (Sao Paulo). 2025;60(1). doi:10.1055/s-0044-1800938. PMID 40041750. Open access (CC BY). 144 patients aged 16 or younger; sensitivity 100%, specificity 63.9%; 43.8% fewer radiographs. pmc.ncbi.nlm.nih.gov/articles/PMC11879485/
- Kharel P, Zadro JR, Chen Z, et al. Awareness and use of five imaging decision rules for musculoskeletal injuries: a systematic review. Int J Emerg Med. 2023;16:85. doi:10.1186/s12245-023-00555-4. Open access (CC BY 4.0). Quotes a sensitivity of 99.4% for the Ottawa Ankle Rules (citing Beckenkamp 2017). pmc.ncbi.nlm.nih.gov/articles/PMC10644430/
- Stiell IG, Greenberg GH, McKnight RD, et al. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med. 1992;21(4):384-390. doi:10.1016/s0196-0644(05)82656-3. PMID 1554175. Original paper (cited; the criteria used here are taken from Wallace 2025, CC BY). doi.org/10.1016/s0196-0644(05)82656-3
- Stiell IG, Greenberg GH, McKnight RD, et al. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA. 1993;269(9):1127-1132. PMID 8433468. Original paper (cited; the criteria used here are taken from Wallace 2025, CC BY). pubmed.ncbi.nlm.nih.gov/8433468/
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