The Ottawa Ankle Rules were developed in adults with acute blunt ankle injuries presenting to two university emergency departments in Canada, to identify which patients need ankle or foot radiographs for clinically important fractures in the malleolar and midfoot zones.

Source	Population	Key findings
Stiell et al. 1992 derivation	905 adults with acute blunt ankle injuries in two Canadian university emergency departments.	The malleolar rule was 100% sensitive and 40% specific for 70 clinically important malleolar fractures, with an estimated 36% reduction in ankle radiographs; all 32 midfoot fractures occurred in patients with midfoot pain and midfoot bone tenderness.
Stiell et al. 1993 validation	1,485 adults with acute ankle injuries across two emergency departments.	Refined ankle and foot rules were 100% sensitive for 50 malleolar and 19 midfoot fractures, with estimated reductions of about 34% in ankle radiography and 30% in foot radiography; the probability of fracture after a negative rule was below 1%.
Bachmann et al. 2003 review	27 studies of adults and children with acute ankle and midfoot injuries.	Pooled sensitivity was close to 98% with median specificity around 31%; the pooled negative likelihood ratio was approximately 0.08, giving a post-test fracture probability of around 1–2% after a negative rule when baseline fracture prevalence was about 15%, and suggesting a 30–40% reduction in radiography use.
Plint et al. 1999 paediatric validation	670 children aged 2–16 years in two paediatric emergency departments.	The rules were 100% sensitive for clinically significant ankle and midfoot fractures, with specificities of about 24–36% and modelled reductions of 16% in ankle and 29% in foot radiographs if the rules were followed.
Gomes et al. 2022 meta-analysis	15 adult studies including 8,560 patients from 13 countries.	Pooled sensitivity was 0.91 and specificity 0.25, confirming high sensitivity but modest specificity, with many positive rules in patients without fracture, and supporting use of the rules to safely reduce radiographs when combined with clinical reasoning.

Across derivation, validation and implementation work, the Ottawa Ankle Rules consistently show very high sensitivity for clinically important fractures and modest specificity. They are best used to rule out fracture and avoid unnecessary imaging, recognising that a positive rule has a lower positive predictive value and many patients who meet criteria will still have soft tissue injuries only.

The rules have also been validated in children aged 2 years and older, with sensitivities close to 100% for clinically important ankle and midfoot fractures but similar low specificity, supporting reduced imaging when examinations are reliable. They are less well studied in non-ambulant children, in high-energy multi-trauma, or when the examination is unreliable (for example, due to intoxication, head injury, major distracting injuries, communication barriers or severe pain), and local guidance often recommends caution or alternative imaging pathways in these groups.

Use the Ottawa Ankle Rules to support, rather than replace, overall clinical assessment, particularly when there is concern for injuries outside the malleolar or midfoot zones (for example, hindfoot, forefoot or syndesmotic injury) or evolving neurovascular compromise.

Ottawa Ankle Rules for Ankle and Foot Radiography