Finding the right tests…
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Finding the right tests…
X-Ray
This X-ray gets ordered for two fairly different reasons: a recent injury where a fracture needs ruling out, and ongoing knee pain where osteoarthritis, wear-related joint damage, is the more likely question. The AP view, taken with you standing and bearing weight where possible, is the standard angle for checking joint space width between the thigh bone and shinbone, while the lateral view adds a side-on look at the kneecap and how the joint lines up front to back. For osteoarthritis specifically, X-ray remains the usual first imaging test, since it's widely available and shows the bone changes, like narrowed joint space and bone spurs, that the condition typically produces.
The AP view checks joint space width, alignment, and any fracture line across the knee, while the lateral view adds a look at the kneecap position and joint effusion. For suspected osteoarthritis, radiologists grade the joint space narrowing, bone spurs, and any bone hardening using a standard five-point scale.
A recent fall, twist, or direct blow to the knee usually prompts this X-ray to rule out a fracture or dislocation before anything else is considered. Ongoing knee pain without a specific injury, especially in someone older, more often points toward checking for osteoarthritis instead, where the X-ray looks for a different set of changes entirely.
Radiographic osteoarthritis shows up mainly as narrowed joint space between the thigh bone and shinbone, small bony growths called osteophytes at the joint edges, and sometimes hardened bone just beneath the joint surface. These findings are graded on a standard scale from normal to severe, which your doctor uses alongside how your knee actually feels.
Plain X-ray is good at showing bone but is much less sensitive to early cartilage damage. One study found it caught only about a quarter of the cartilage loss that MRI could detect. So a knee that still hurts despite a normal-looking X-ray hasn't necessarily been fully explained.
No, X-rays show bone, not the soft cartilage of the meniscus, so a suspected tear needs an MRI to confirm. Your doctor may still order this X-ray first to rule out a fracture.
It looks for narrowed joint space, bony growths called osteophytes, and bone hardening near the joint, all graded on a standard scale from normal to severe. These changes, alongside your symptoms, help confirm the diagnosis.
A weight-bearing view shows the joint space as it actually behaves under load, which gives a more accurate picture of narrowing than an X-ray taken lying down. Your doctor or the technologist will tell you which position is needed.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
Not entirely. Plain X-ray is less sensitive to early cartilage damage than MRI, so mild or early joint wear can still be present with a normal-looking film.
The X-ray itself is the same, but what the radiologist looks for differs, recent trauma is checked for a fracture line, while arthritis assessment focuses on joint space and bone spurs.
You may be positioned standing with your knee straight for one view and turned to the side for the other. The technologist will guide your positioning.
That's your doctor's call based on your symptoms and exam. Significant swelling, inability to bear weight, or visible deformity are the kinds of signs that usually prompt imaging sooner rather than later.