Musculoskeletal imaging: reactive arthritis: practice question

A Radiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Radiology · Musculoskeletal imaging: reactive arthritis

Sample item

A 24-year-old man develops asymmetric lower limb arthritis, urethritis and conjunctivitis after an episode of dysentery. Which pattern is typical on imaging of the spine and sacroiliac joints?

ASymmetric sacroiliitis with marginal syndesmophytesBAsymmetric sacroiliitis with non-marginal syndesmophytesCMarginal erosions of the metacarpophalangeal joints with periarticular osteopeniaDJoint space narrowing with osteophytes and subchondral sclerosis

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Asymmetric sacroiliitis with non-marginal syndesmophytes

Reactive and psoriatic arthritis produce asymmetric or unilateral sacroiliitis and bulky non-marginal syndesmophytes, often with fluffy periostitis at entheses. Ankylosing spondylitis gives symmetric sacroiliitis and thin marginal syndesmophytes, rheumatoid arthritis gives marginal erosions, and osteoarthritis gives osteophytes.

Option by option

A. Symmetric sacroiliitis with marginal syndesmophytes
Symmetric sacroiliitis with marginal syndesmophytes is ankylosing spondylitis.
B. Asymmetric sacroiliitis with non-marginal syndesmophytes (correct)
Correct. Asymmetric sacroiliitis with non-marginal syndesmophytes fits reactive arthritis.
C. Marginal erosions of the metacarpophalangeal joints with periarticular osteopenia
Marginal erosions with periarticular osteopenia are typical of rheumatoid arthritis.
D. Joint space narrowing with osteophytes and subchondral sclerosis
Osteophytes and subchondral sclerosis are degenerative changes.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is B, Asymmetric sacroiliitis with non-marginal syndesmophytes. Reactive and psoriatic arthritis produce asymmetric or unilateral sacroiliitis and bulky non-marginal syndesmophytes, often with fluffy periostitis at entheses.

Why is "Symmetric sacroiliitis with marginal syndesmophytes" not the answer?

Symmetric sacroiliitis with marginal syndesmophytes is ankylosing spondylitis.

Why is "Marginal erosions of the metacarpophalangeal joints with periarticula…" not the answer?

Marginal erosions with periarticular osteopenia are typical of rheumatoid arthritis.

Why is "Joint space narrowing with osteophytes and subchondral sclerosis" not the answer?

Osteophytes and subchondral sclerosis are degenerative changes.

What concept does this question test?

It tests Musculoskeletal imaging: reactive arthritis in Radiology. Ankylosing spondylitis gives symmetric sacroiliitis and thin marginal syndesmophytes, rheumatoid arthritis gives marginal erosions, and osteoarthritis gives osteophytes.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Musculoskeletal imaging: reactive arthritis?

Learn signs with the image, and the disease they point to. Then use the flashcards and the other Radiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.