You stepped off a curb wrong, tripped over your child’s toy, or landed funny while eying that ball. Ouch! Your ankle is now swollen and you’re suffering from ankle pain, but you’re not sure if it’s a simple ankle injury, like a sprain, or if it’s a more serious fracture or break. Does this sound familiar?
Ankle sprains, strains, and fractures are among the most common orthopedic injuries that arise from everyday life, especially for those involved in sports. After an ankle injury, one of the first questions asked is if an X-ray is necessary. An X-ray is a useful way to collect information on a bone injury (such as a break or fracture) but provides little information on soft tissue injuries (such as a sprained ligament or strained muscle/tendon). Since X-rays can be time-consuming and costly (not to mention the high levels of radiation involved), knowing an easy, noninvasive method of characterizing ankle injuries is useful, so you can get back to living your best life ASAP. Allow us to introduce:
The Ottawa Ankle Rules!
Collectively, The Ottawa ankle rules form a clinical decision tool used to aid in ruling out ankle and foot fractures, so as to prevent unnecessary X-rays of ankle sprains. This test has high sensitivity and low specificity, meaning it is a great screening tool for ruling out the possibility of an ankle fracture but not for positively diagnosing a fracture. In other words, if you answer yes to any of the questions it does not necessarily mean you have a fracture, it just means you should seek an X-ray series as you could potentially have one. This screening tool is not only useful for clinicians – it can be helpful to the layperson in order to guide their course of action if they ever find themselves injured without easy access to medical personnel (though, if there is any uncertainty, it is always better to consult a medical professional than risk exacerbating an injury).
The Ottawa ankle rules state that an ankle or foot X-Ray series is only required if you answer yes to any of the following questions. [“Clinician-speak” is provided in brackets].
- Is the bone tender on the lower 6cm (~3in) of your leg (along the sides, above the ankle)? [Is bony tenderness present along the distal 6cm of the medial and/or lateral malleolus?]
Feel for the bone protrusion present approximately halfway between your heel and pinky toe on the outside edge of the foot.
- Is the bone tender? [Is bony tenderness present around the base of the 5th metatarsal?]
- Feel for the bone protrusion present approximately halfway between your heel and big toe on the inside edge of the foot. Is the bone tender? [Is bony tenderness present at the navicular?]
- Are you unable to bear weight on the injured ankle and take four steps?* (Limping is okay!) [Is the ankle unable to bear weight for four steps both immediately following injury and in the ER?]
(*) Keep in mind, these assessments are typically administered by a physical therapist or medical professional sometime after injury. This fourth rule is testing whether pain in the affected ankle is lessened with time. A sprained ankle may not support weight immediately following an injury but may be more tolerant 30 minutes later.
How to self-assess:
These rules have been used in clinical practice for almost thirty years, and have been tried and tested. A systematic review published in the British Medical Journal in 2003 analyzed the efficacy of the Ottawa ankle rules and conducted a meta-analysis on 27 studies comprising over 15,000 patients, concluding that their implementation may reduce the number of unnecessary scans by 30-40% (Bachmann et al., 2003). For more information on the derivation, validation, or implementation of the rules, a selection of peer-reviewed medical publications can be found here. If you have any other questions about ankle sprains or any other kind of musculoskeletal injury, don’t hesitate to reach out to us by phone or fill out the form below.
Bachman, L., et al., 2003. “Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review”. BMJ. 2003;326:417