Which feature is NOT associated with rheumatoid arthritis (RA) on an X-ray?

In rheumatoid arthritis (RA), X-ray findings typically reflect the underlying pathophysiology of chronic inflammation. Among the features associated with RA, periarticular osteoporosis, juxta-articular bony erosions, and narrowing of joint space are all critical indicators of the disease's progression.

Periarticular osteoporosis occurs due to increased bone resorption in the areas surrounding inflamed joints. This finding helps in assessing the impact of the disease on bone health and provides insight into the inflammatory activity at the joint level.

Juxta-articular bony erosions are characteristic of RA and result from the inflammatory process that attacks the synovial tissue and leads to localized bone destruction. The presence of these erosions can help differentiate RA from other forms of arthritis.

Narrowing of joint space is another common feature observed in RA due to the progressive damage to cartilage over time, reflecting the joint's deteriorating condition.

On the other hand, osteophytes are bony projections that develop in response to joint degeneration and are more commonly associated with osteoarthritis rather than rheumatoid arthritis. The absence of osteophytes in RA is significant because their presence in a joint would suggest a degenerative process contrary to the inflammatory nature of RA. This distinction is crucial in differenti