This Ottawa ankle rules calculator predicts the need for foot x-ray or ankle imaging in common injuries based on the accurate Ottawa foot rules. Below the form you can read more about the rules and their interpretation.

Pain present in the malleolar zone?

Ankle area x-ray

Foot area x-ray

How does this Ottawa ankle rules calculator work?

This health tool is able to rule out the necessity of x ray imaging in cases of common ankle and foot injuries based on certain rules that concern pain and tenderness in key areas of the limbs.

The Ottawa ankle rules calculator was designed to ease the process of remembering and then selecting the applicable rules and can automatically tell whether there is still need for further diagnosis through x-rays.

The accurate Ottawa rules start with criteria that can function as an exclusion to begin with if it is not met, this being about pain present in the malleolar zone due to related trauma or not. The rest of the criteria focus on either ankle or foot area x-ray necessities as follows:

Ankle area x-ray

- Bone tenderness along distal 6 cm of posterior edge of tibia/top of medial malleolus.

- Bone tenderness along distal 6 cm of posterior edge of fibula or top of lateral malleolus.

- Inability to bear weight both immediately after injury and in the emergency room.

Foot area x-ray

- Bone tenderness at the base of 5th metatarsal.

- Bone tenderness at the navicular.

- Inability to bear weight both immediately after injury and in the emergency room.

Ottawa Ankle Rules

Picture source: The malleolar and midfoot zones from CDR Ankle Poster.

Being a highly sensitive model, not very specific however but applicable from children aged 3 to adults up to the age of 55, the Ottawa score is considered to have very few false negatives and to rule out cases where x-rays are not needed.

Fulfilling one or more of the Ottawa ankle criteria implies the necessity of x-ray testing as well. Of course, clinical judgment should still be used, regardless of the criteria ruling.

Although not having the specification to discern as a diagnostic between sprains and significant fractures, the rules are efficiently used in emergency rooms to prevent unnecessary radiographies.

The Ottawa ankle rules

This is a set of guidelines to facilitate diagnosis management for clinicians in the cases of patients with possible bone fractures. Not only it allows a rapid discerning between cases but also cuts costs of money, time and radiation exposure adverse effects, that before the introduction of the rules (in 1992), were incurred due to every suspicion of bone fracture being x-rayed. Plus they reduce the number of investigations the patient receives and the hospital stay. The name comes from the emergency department of the Ottawa Civic Hospital in Canada where it was first implemented.

It was found that with the usage of the Ottawa score in the emergency setting, both for ankle and foot but also the newer guideline Ottawa rules for knee, radiographies have been reduced by 28%, respectively 12%.


In case of the most common ankle and foot injuries, there are certain recommendations that are made first hand to monitor and ameliorate the symptoms:

■ X-ray imaging performed, immediate recommendations for x-ray occur in the following situations of tenderness over the navicular,calcaneum, base of 5th metatarsal or proximal fibula;

■ RICE plan (Rest, Ice, Compression, Elevation);

■ Splinting/crutches;

■ Pain medication schedule.

Other proposals in applying the rules state that the entire distal 6 cm should be palpated in the tibia and fibula and also that the clinician should pay attention to any medial malleolar tenderness.


1) Stiell IG, Wells G, Laupacis A, Brison R, Verbeek R, Vandemheen K, Naylor CD. (1995) Multicentre trial to introduce the Ottawa ankle rules for use of radiography in acute ankle injuries. Multicentre Ankle Rule Study Group. BMJ; 311(7005):594-7.

2) Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Reardon M, Stewart JP, Maloney J. (1993) Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA; 269(9):1127-32.

3) Bachmann LM, Kolb E, Koller MT, Steurer J, ter Riet G. (2003) Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review. BMJ; 326(7386):417.

4) Plint AC, Bulloch B, Osmond MH, Stiell I, Dunlap H, Reed M, Tenenbein M, Klassen TP. (1999) Validation of the Ottawa Ankle Rules in children with ankle injuries. Acad Emerg Med; 6(10):1005-9.

11 Sep, 2015