MSK imaging: scapholunate dissociation: 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 · MSK imaging: scapholunate dissociation

Sample item

After a fall on an outstretched hand, a PA wrist film shows a widened gap of more than 3 mm between the scaphoid and lunate. What is this sign called and what does it indicate?

AGilula arc, indicating a normal carpusBDinner fork deformity, indicating a Colles fractureCTerry Thomas sign, indicating scapholunate ligament disruptionDFat pad sign, indicating a radial head fracture

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

The answer and the reasoning

C. Terry Thomas sign, indicating scapholunate ligament disruption

A widened scapholunate interval resembling the gap between the front teeth of the comedian is the Terry Thomas sign of scapholunate ligament rupture. It may lead to carpal instability and arthritis if untreated. Lateral films show a dorsal intercalated segment instability pattern.

Option by option

A. Gilula arc, indicating a normal carpus
The Gilula arcs are smooth lines that are disrupted in carpal injury.
B. Dinner fork deformity, indicating a Colles fracture
Dinner fork deformity is a clinical appearance of Colles fracture.
C. Terry Thomas sign, indicating scapholunate ligament disruption (correct)
Correct. A widened scapholunate gap is the Terry Thomas sign.
D. Fat pad sign, indicating a radial head fracture
The fat pad sign refers to the elbow.

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 C, Terry Thomas sign, indicating scapholunate ligament disruption. A widened scapholunate interval resembling the gap between the front teeth of the comedian is the Terry Thomas sign of scapholunate ligament rupture.

Why is "Gilula arc, indicating a normal carpus" not the answer?

The Gilula arcs are smooth lines that are disrupted in carpal injury.

Why is "Dinner fork deformity, indicating a Colles fracture" not the answer?

Dinner fork deformity is a clinical appearance of Colles fracture.

Why is "Fat pad sign, indicating a radial head fracture" not the answer?

The fat pad sign refers to the elbow.

What concept does this question test?

It tests MSK imaging: scapholunate dissociation in Radiology. It may lead to carpal instability and arthritis if untreated. Lateral films show a dorsal intercalated segment instability pattern.

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 MSK imaging: scapholunate dissociation?

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.