A knee X-ray is a scan that shows the bones and alignment of your knee joint.
Your doctor may request it if you have knee pain, swelling, injury, stiffness, or trouble walking. It is often used to check for fractures, arthritis, and changes in joint space.
About this scan
Common Indications for Knee X-Ray
- Knee pain after a fall or twisting injury
- Swelling, stiffness, or reduced movement
- Difficulty standing or walking
- Suspected fracture or dislocation
- Arthritis or long-term knee pain
- Follow-up after surgery or a previous injury
What exactly does a knee X-ray show?
It shows the lower thigh bone, upper leg bones, kneecap, and the spaces in the knee joint. It can show fractures, arthritis, dislocation, bone spurs, and some alignment problems.
Do I need to stop taking medication?
No. Keep taking your regular medication unless your referring doctor gives different instructions.
What happens when I arrive for my scan?
The radiographer will confirm which knee is being scanned and ask where the pain is. If you use a brace or crutch, keep it with you.
Is there any discomfort?
No. The X-ray itself is painless. If your knee is injured, bending it or standing for the image may hurt briefly.
Are there risks?
A knee X-ray uses a small amount of radiation. No radiation stays in your body after the scan. The benefit of checking a painful or injured knee usually outweighs the small risk.
What if the scan finds something?
Your referring doctor will explain the result and the next step. This may be rest, pain treatment, a brace, physiotherapy, orthopaedic review, or another scan.
What can this X-ray miss?
Plain X-rays show bone and alignment well but may miss a small, non-displaced, stress, or early fracture. They also provide limited information about cartilage, tendons, ligaments, nerves, and other soft tissues. Persistent focal pain, inability to use the limb, or worsening symptoms after a normal X-ray needs clinical reassessment; repeat X-rays, CT, MRI, or ultrasound may be appropriate.
Seek urgent care rather than waiting for a routine report if there is an open wound over a suspected fracture, severe deformity, rapidly increasing swelling, loss of feeling or movement, or a limb that becomes pale, blue, or cold.
Before your appointment
How should I prepare for a knee X-ray?
You do not need to fast. Wear clothing that can move easily above the knee. You may need to remove braces, zips, buttons, or metal objects around the knee.
During the scan
How is the procedure performed?
You may stand, sit, or lie down depending on the views needed. The radiographer will position your knee and may take images from the front, side, and an angle. Some arthritis checks are done while standing.
How long does a knee X-ray take?
The scan usually takes about 10 to 15 minutes. It may take longer if standing views or extra images are needed.
After your scan and results
When will I get my results?
A radiologist will review the images and send a report to your referring doctor. Urgent injury results may be handled faster.
Safety and special situations
Can children have this scan?
Yes. Children can have a knee X-ray when needed, such as after injury or for bone growth concerns. The radiographer adjusts the technique for age and size.
Can I have this scan if I am pregnant?
Sources and summary
Sources and further reading
Conclusion
A knee X-ray is a fast first test for knee pain, swelling, injury, and arthritis. To make it smoother, tell the radiographer if standing or bending the knee is difficult.