Do I need an X-ray after an Ankle Sprain?

Ankle sprains are one of the most common musculoskeletal injuries sustained by people of all ages and activity levels. In fact, the most commonly torn ligament in the body is located in the ankle! For most of us, ankle sprains are not a major concern, and we tend to “walk it off” or use the “wait-and-see” approach before seeking medical help. For others, ankle sprains can be quite painful and affect your ability to walk, resulting in a visit to the doctor or emergency department.

The vast majority of ankle sprains result in damage to the ligaments and other soft tissues of the ankle. Sometimes, the same injury can also result in a fracture. Because management differs depending on the diagnosis, it is important to be able to quickly distinguish the two, and commence appropriate care as soon as possible.  

As far as imaging goes, plain X-rays are usually all that is required to confirm an ankle fracture. When attending the emergency department or GP’s office following an ankle sprain, most people are immediately referred for an X-ray due to the ease of access and the fact they are bulk-billed (resulting in no cost to the patient). However, this indiscriminate use of X-rays has resulted in high healthcare costs, increased waiting times in emergency departments, and also exposes the patient to unnecessary radiation (1).

The over-utilization of X-rays following ankle sprains and the associated disadvantages was identified, and clinical rules were designed to assist health care providers in properly determining whether X-rays are really needed. These rules are called the “Ottawa Ankle Rules”, and involve palpation of various spots around the foot and ankle to determine whether they are tender (2). The Rules have been found to be highly sensitive. So, if the Ottawa Rules are negative, then there is a very, very low chance that you have a fracture (3). A recent study also found that the Rules are accurate regardless of whether it is your doctor, physio or sports trainer using them!(3)

You can read about the Ottawa Ankle Rules here http://www.theottawarules.ca/ankle_rules

So the next time you have an ankle sprain, ensure that you consult a healthcare professional familiar with the Ottawa Ankle Rules, such as a physiotherapist or sports physician, to ensure that a full physical examination of the ankle is performed and you are not being sent for unnecessary X-rays!

(1) Berrington de Gonzalez A, Darby S. Risk of cancer from diagnostic x-rays: estimates for the UK and 14 other countries. Lancet 2004;363:345–51.

(2) Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med. 1992; 21:384–90.

(3) Beckenkamp, P., Lin, C., Macaskill, P., Michaleff, Z., Maher, C., & Moseley, A. (2017). Diagnostic accuracy of the Ottawa Ankle and Midfoot Rules: A systematic review with meta-analysis. British Journal of Sports Medicine, 51(6), 504-510.