This feels wrong. Like I’m about to do some shady insider trading with you , or something. Every industry has its secrets. Medicine is no different. But, that’s what this blog is about: sharing medicine’s little secrets so you know when you need us.
Ready? (speaking under my breath): Not every twisted ankle needs an x-ray. There. I said it. Glance over my shoulder, no medical information police around… I think we’re good.
Sprained ankles hurt. They swell. They bruise. They resist bearing the weight of our bodies. Most people who have participated in sports know the prescription for a sprained joint is R.I.C.E therapy, right? Rest. Ice. Compression. Elevation. But, doc, don’t I need an x-ray to make certain it’s not broken? As usual, the answer is not necessarily. I’ll explain.
Let me clarify one thing first. Broke and fractured are the same thing. One isn’t better than the other. To medical providers, the two have the same exact meaning.
Let’s start with a little anatomy lesson first. The long bones from the knee to the ankle are the tibia and fibula. The tibia is closer to the middle of the body, the fibula along the outside of the lower leg. The tibia is bigger and bears weight for us. These two bones bulge out around the ankle and form the medial (toward the inside of the body) malleolus, and the lateral (toward the outside of the body) malleolus. Lots of ligaments are around the ankle to hold it all together like duct tape.
How do I know from examining you whether you need an x-ray? Studies. There are these clinical decision tools called the Ottawa Ankle Rules. They were developed by our northern neighbors in Ottawa, Canada. The researchers originally looked at over 1000 patients with ankle injuries. Then they validated their findings with tens of thousands of patients. These rules don’t predict that there is absolutely no fracture. It’s looking for fractures that need to be treated differently than a sprain. This is good research. Trust me. I’m a doctor.
So, the Ottawa Ankle Rules help me see a patient with an injury and determine if he needs an x-ray. Just because the rules say you need an x-ray, doesn’t mean there is going to be a fracture. It just means I can’t rule out a fracture by examining you. I need some pics.
Who needs an x-ray?
Unable to bear weight. So, if you’re unable to bear weight (4 steps) BOTH at the time of the injury AND in the emergency department, you need an x-ray. It doesn’t say it won’t hurt to walk, it just asks if you’re able to. If you could walk initially, but later can’t, or vice versa, that doesn’t meet the criteria.
Tender over the back or bottom tip of the medial malleolus (inside of the ankle). So, feel that bump on the inside (medial malleolus). If you’re looking at your ankle standing up, go to the back part (we call that posterior). If the bottom 6 cm (2.5 inches) of the back part or the bottom tip is tender, you need an x-ray. Basically, if only the front (anterior) part is tender, no big deal. That’s a sprain.
Tender over the back or bottom tip of the lateral malleolus (outside of ankle). Same as above, only check out the outside bone. Still, we’re paying attention to the back (posterior) part, not the front.
You’ll notice there isn’t anything in here about swelling. Ankle sprains and fractures swell. Now, the doctor still has to use good judgment. If the patient is intoxicated, or there are other severe injuries (we call these distracting injuries), x-rays may be needed.
How do I use these when I see a patient? I usually explain why I don’t think an x-ray is necessary. If she still wants it, I usually oblige. Peace of mind is sometimes worthwhile. But, getting out of the ED an hour or two faster without an x-ray is also valuable.
I tend to get more x-rays in children, open growth plates and all, but there is data that says these rules can be applied to reduce the number of x-rays for kids as well.
Next time you twist your ankle, you may still need to see the doctor for pain control or a good splint, or just to make certain you are applying these rules properly (we’re the trained professionals). But, maybe this helps your openness to the idea that you may not need that x-ray you would have otherwise expected was necessary.
What ankle injuries have you suffered that, looking back, may not have needed an x-ray?