The Ottawa ankle rules: when to order imaging.

Ortho Reviews - Image

An estimated $500,000,000 is spent annually on ankle radiography in Canada and the United States. (1)

The management of ankle sprains is a daily routine at emergency departments, and although most patients undergo radiography, fracture of the ankle or mid-foot occurs in less than 15%. This small yield triggered the development of the Ottawa ankle rule (2)

In phase 0, we demonstrated that more than 95% of ankle injury patients seen at three Ottawa hospital emergency departments underwent an ankle or foot radiographic series (or both) but that 85% of these x-ray films showed no abnormalities. (1)

What are the Ottawa ankle rules?
The Ottawa ankle rules are a set of criteria to help physicians identify which patients should receive imaging for an ankle injury. Radiographs should be performed if any of the following are present:

1) inability to bear weight
2) tenderness over the medial or lateral malleoli
3) tenderness over the distal 6 cm of the tibia or fibula
4) point tenderness over the base of the 5th metatarsal or navicular

Ortho Reviews - Image

In phase 2, we prospectively validated and refined the rules in another 1485 patients and found the rules to be 100% sensitive for identifying clinically important fractures of the malleoli and the midfoot. (1)

Finally, the Ottawa ankle rules accurately identified all 93 malleolar and midfoot fractures in the 593 patients. (1)

Evidence supports the Ottawa ankle rules as an accurate instrument for excluding fractures of the ankle and mid-foot. The instrument has a sensitivity of almost 100% and a modest specificity, and its use should reduce the number of unnecessary radiographs by 30-40%. (2)

The Ottawa ankle rules have a high sensitivity for identifying clinically important fractures and can help reduce patient wait times in emergency rooms and improve cost-effectiveness.

Particularly important for physicians to remember is that the Ottawa ankle rules have not been tested in children and are not meant to override clinical judgment. (1)


Full Review and Conversation on Twitter

Ortho Reviews - Ottowa Ankle Rules