Joint Space Narrowing

When looking at a knee X-ray a doctor will often comment on joint space narrowing.

This is a sign of arthritis. Our joints are in contact with each other but every joint is covered by a smooth layer of articular cartilage. This cartilage covering does not show up on an x-ray. It appears as a gap. A healthy knee has an easily identifiable gap between the bones (that appear whites ni on x ray).

When the knee has osteoarthritis, the cartilage cover is worn and the gap is decreased or disappears altogether. An arthritic knee like this is not only a source of pain but also disability.

For the average person a knee x ray is hard to understand. It becomes even more difficult when there are signs of osteoarthritis. 

Understanding the signs of arthritis is a more difficult proposition.

If you are concerned,consult your doctor.