Ottawa Ankle Rules

Ottawa ankle rules explained

This model can be applied to screen patients aged from 3 to 55, who don’t require x-ray imagining. It accounts for pain and tenderness in key areas of the lower limbs.

The first criteria which is that of exclusion considers pain present in the malleolar zone.

The ankle area x-ray rule consists of the following answer choices:

■ Bone tenderness at the posterior edge or tip of lateral malleolus;

■ Bone tenderness at the posterior edge or top of medial malleolus;

■ Inability to bear weight both immediately after injury and in ED.

The foot area x-ray consists of the following answer choices:

■ Bone tenderness at the base of 5th metatarsal;

■ Bone tenderness at navicular;

■ Inability to bear weight both immediately after injury and in ED.

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

The Ottawa rules are known to be a highly sensitive model that produces very few false negatives.

The interpretation is that once any of the rules is met, x-ray testing is required. However, it is important that clinical judgment should prevail.

This type of ruling doesn’t specify whether the injury classifies as sprain or fracture but its usage in the emergency rooms has decreased costs and patient radiation exposure during unnecessary radiographies (reduced by 28%).

Similarly, the Ottawa rules for knee, an equivalent for knee related injury, has reduced radiographies by 12%.

Recommendations

The following four actions represent the most common recommendations that are given first hand to help monitor and ameliorate symptoms of the most common ankle and foot injuries:

■ 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.

About the original study

The name of the model comes from the emergency department of the Ottawa Civic Hospital in Canada where it was first implemented in 1993.

The original study conducted by Stiell et al. is based on a cohort of 12,777 adult patients with acute ankle injuries, from the Emergency departments of eight teaching and community hospitals in Canada. The rate of referral to x-ray imaging after the application of the Ottawa rules was recorded.

The study found the rules to be feasible for application in a large variety of hospital and clinical settings. Its usage has led to a decrease in radiography, associated costs, waiting and hospitalization times.

A subsequent validation study involved two stages, one of validation and refinement of the original rules and one of validation of the refined rules.

In total, a cohort of 1,485 patients participated in the study. Refinement and validation have shown that the Ottawa ankle rules are 100% sensitive for fractures and provide a reliable mean to reduce unnecessary radiographies.

Original source

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

Validations

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

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