Knee X-rays: When to Get One & What It Shows

“I’m only having my knee x-ray in 3 weeks… not great!” It was this sentence uttered by a friend of mine in her thirties, prone to knee pain, that inspired me to write this article.

I take a look at what I think you need to know about this type of imaging for the knee: when is it appropriate to use them, who can prescribe or interpret them for you, and what to do depending on the results.

♻️ Last update: May 5, 2025.
👩‍⚖️ Declaration of financial interests: none directly related to the subject. My complete declaration of financial interests is in the legal notice section.
Written by Nelly Darbois, physiotherapist and scientific editor

When is a knee X-ray appropriate?

Your knee hurts, and you’re wondering if an X-ray can help you see more clearly? It’s only natural. Many people, like my friend, have this reflex: they want an image, “to make sure they’re not missing anything”.

Knee X-rays are particularly useful for looking for a knee fracture following a fall or impact, or for assessing wear and tear and osteoarthritis on the joint.

👉 For example, if you’ve had a major trauma and can’t put your foot down, or your knee has suddenly swollen and you’re having trouble bending or stretching it, this is a good indication.

But if you just have pain with no obvious cause, especially if it’s been going on for a long time, the X-ray often shows nothing abnormal. And that can be frustrating: “My X-ray’s normal, but I’m still in pain!”

It’s important to know: just because you can’t see anything on the radio doesn’t mean you’re crazy, or that the pain is all in your head. Pain is a complex phenomenon, influenced by many factors – mechanical, biological, emotional and environmental.

It’s not always a visible lesion that causes pain, and just because you can’t see it doesn’t mean it doesn’t exist. The good news is that it can diminish, or even disappear, either simply by the passage of time, or by adapting certain things: your movements, your rhythm, your activities.

And what do the experts think?

In France, the Haute Autorité de Santé (HAS) insists on one point: the diagnosis of knee pain is above all clinical. In other words, it’s the health professional’s examination – his or her questions, tests and observations – that should guide the rest.

📌 If an image is required, radiography remains the first-line examination, whether after trauma or in cases of persistent pain with no obvious cause.

📌 MRI is rarely needed initially, as in the majority of cases it does not change management. It is reserved for more complex cases.

This message is all the more important given the excessive increase in the number of MRI scans performed in France, sometimes without justification, which overloads imaging departments and can delay examinations for more serious pathologies, such as cancer.

American recommendations (American College of Radiology – ACR) are along the same lines. Their guide to chronic knee pain is updated annually by a multidisciplinary panel. Their watchword: choose the right imaging at the right time, according to symptoms, and don ‘t skip any steps.

Whether in France, the United States or elsewhere, recommendations are converging:

🎯 We can’t imagine a good diagnosis without listening to the patient. Imaging does not replace clinical examination, and is often dispensable.

Doctors often prescribe an X-ray “to be on the safe side” – and understandably so. They want to avoid missing something serious, and think it will reassure their patient. But this well-intentioned reflex can sometimes have the opposite effect.

Because an X-ray can reveal things… that aren’t necessarily pain-related. And this can cause unnecessary concern, or trigger a longer medical course of action for no real purpose.

That’s one of the paradoxes of knee pain: wanting an image to reassure yourself, when sometimes that’s what creates more doubts than answers.

Who can prescribe a knee x-ray in the United States?

In the United States, several professionals can prescribe a knee x-ray:

• your general practitioner;
• a specialist or surgeon (rheumatologist, orthopedist, etc.);
• an emergency doctor.

Physiotherapists cannot prescribe X-rays, but some do perform ultrasound scans.

The X-ray is then taken by a radiology technician, and analyzed by a radiologist. He or she writes the report.

But beware: results alone are not enough. It’s up to your healthcare professional to link the imaging to your symptoms, so that it makes sense.

What can you see on the radio?

An X-ray can show :

• fracture (broken or cracked bone);
• osteoarthritis (worn cartilage, pinched joints, bone spurs, etc.);
• calcifications, bone foreign bodies, joint malposition…

But it doesn’t allow you to see ligaments, menisci or tendons. So if you have a knee sprain, a cracked meniscus or a tendon problem, the X-ray will often be normal.

How do you interpret your X-ray results?

The minutes are often a little technical.

And sometimes it says:
➡️ “Radio normal”
➡️ “No abnormality detected”.
➡️ Or on the contrary: “Moderate femorotibial osteoarthritis “.

But you don’t really understand what that means for you.

💡 Things to remember:

• a normal X-ray does not rule out a tissue lesion that cannot be seen on the X-ray. But in the vast majority of cases, no specific treatment other than symptomatic will be required, whatever the tissue concerned;
• an X-ray that shows something does not mean that specific surgery or treatment is required;
• it’s not the image that dictates care, but your pain (at rest) and what you feel like doing.

The same knee can be painful on a normal X-ray, or function perfectly well despite osteoarthritis on imaging. It’s not that rare.

Should I have an MRI in addition to or instead of a knee X-ray?

You may be thinking:
➡️ “What if I had an MRI instead?”
➡️ “The X-ray didn’t show anything, maybe the MRI will see what I have?”
➡️ “How do I know if my knee pain is serious?”

MRI may be indicated if ligament, meniscus or inflammatory damage is suspected, and X-rays are not sufficient. But it is not systematically useful.

Sometimes, both MRI and X-ray are normal, even though you’re in pain. This is often the case with chronic knee pain.

It’s not easy to hear, but it’s the reality:
👉 Knee pain that doesn’t show up on tests is common.
👉 And that doesn’t mean there’s nothing we can do!

What often helps the most is toadapt one’s activity, modulate the constraints, and move progressively while respecting one’s pain.

If this applies to you, I invite you to read one of these article:

• patellofemoral syndrome (the main cause of “unexplained” knee pain).

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That’s all I wanted to say on the subject! Any questions or comments? See you in comments!