Which of the following pairs are classic radiographic features of osteoarthritis?

• A. Joint space narrowing and subchondral sclerosis
• B. Joint space narrowing and osteophyte formation
• C. Osteophyte formation and subchondral sclerosis
• D. Erosions and periarticular osteopenia

Answer: (B)

Osteoarthritis on radiographs shows changes from cartilage loss and the bone’s response to that loss. The most telling pattern is joint space narrowing, which directly reflects thinning and loss of articular cartilage. Alongside this, osteophyte formation—the growth of bone spurs at joint margins—is a hallmark adaptive response to altered joint mechanics as cartilage disappears. Seeing both joint space narrowing and osteophyte formation together provides a classic radiographic signature of OA, because it combines the direct cartilage loss with the typical bone remodeling that accompanies it.

Subchondral sclerosis can occur in OA, but it’s not as specific a pairing as narrowing plus osteophytes. Erosions and periarticular osteopenia point more toward inflammatory arthritis, such as rheumatoid disease, rather than the degenerative pattern seen in OA.