Question

Which one of the following is NOT a radiological feature of osteoarthritis?

• A. Widening of the joint space
• B. Osteophyte formation
• C. Subchondral sclerosis
• D. Cyst formation

Hint:

Osteoarthritis narrows the joint space, it does not widen it.

Answer 1

The Correct Option is A

This question tests the classic x-ray picture of osteoarthritis and which listed finding does not belong.

1. Widening of the joint space: Osteoarthritis wears down cartilage, so the joint space narrows, it never widens. This is the false statement.
2. Osteophyte formation: Bony spurs grow at the joint edges as the joint tries to spread load over a larger surface, a true and classic sign.
3. Subchondral sclerosis: The bone just under the damaged cartilage becomes denser from the extra stress, a true sign seen on x-ray.
4. Cyst formation: Fluid filled cystic spaces form in the bone below the joint surface, another true and recognized sign.

Since narrowing, not widening, of the joint space is what actually happens, widening of the joint space is the feature that is not seen in osteoarthritis.

Let's summarize:

• The four classic x-ray signs of osteoarthritis are joint space narrowing, osteophytes, subchondral sclerosis, and subchondral cysts.
• Widening of the joint space is the opposite of what actually happens and is not a true feature.

So the correct answer is widening of the joint space.