Glossary
Standing (weight-bearing) X-ray
Quick answer
A standing, or weight-bearing, X-ray is taken while you stand on both legs, so the bones press together as they do when you walk. It shows the true joint space and how much cartilage has worn away, which a lying-down X-ray can hide, explains Doha knee surgeon Dr. Pablo Gelber at Aman Hospital.
What to expect
You stand with your weight spread evenly on both feet, usually facing the X-ray plate. Some views are taken with the knees straight and one with the knees bent about 45 degrees, often called the Rosenberg or schuss view. You may be asked to hold a support for balance. It takes a few minutes and is painless, though standing may be uncomfortable if your knee is sore.
Why standing matters
Cartilage does not show on X-ray, so surgeons judge it from the gap between the bones. Lying down, that gap can look normal because nothing is squeezing it. Standing loads the joint and reveals narrowing that would otherwise be missed.
The bent-knee view is especially good at showing wear at the back of the joint, which is where cartilage often thins first. Standing films are therefore the standard for grading arthritis, deciding between treatments such as injections, osteotomy and partial or total knee replacement, and comparing changes over time.
Who needs one
Standing X-rays are usually requested for anyone over about 40 with knee pain, anyone with suspected arthritis, and before most knee surgery. A fresh injury that stops you standing may first need a lying X-ray to rule out a fracture.
Frequently asked questions
Why was my X-ray repeated standing up?
If an earlier X-ray was taken lying down, it may underestimate cartilage loss. A standing film gives your surgeon a more accurate picture of arthritis.
Is a standing X-ray better than an MRI for arthritis?
For grading established arthritis and planning treatment, standing X-rays are often more useful. MRI is better for early cartilage damage, the meniscus and ligaments.
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