Musculoskeletal imaging: lunate dislocation: 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: lunate dislocation

Sample item

After a fall on a dorsiflexed wrist, a lateral radiograph shows the lunate tipped volarly out of the lunate fossa like a spilled cup, while the capitate remains in line with the radius. On the PA view the lunate looks triangular. What is the injury?

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

The answer and the reasoning

A. Volar lunate dislocation

In lunate dislocation the lunate rotates volarly out of the radius (spilled teacup sign) while the capitate stays aligned with the radius. In perilunate dislocation the lunate stays in the radius and the capitate and carpus dislocate dorsally around it.

Option by option

  • A. Volar lunate dislocation (correct)

    Correct. The lunate tipped volarly out of the fossa with the capitate still aligned with the radius is a lunate dislocation.

  • B. Perilunate dislocation

    In perilunate dislocation the lunate remains in the radial fossa and the capitate lies dorsal to it.

  • C. Scapholunate dissociation

    Scapholunate dissociation shows a widened scapholunate gap on the PA view without volar lunate displacement.

  • D. Kienbock disease

    Kienbock disease is avascular necrosis of the lunate, with sclerosis and collapse, and no acute dislocation.

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.

More Radiology questions

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is A, Volar lunate dislocation. In lunate dislocation the lunate rotates volarly out of the radius (spilled teacup sign) while the capitate stays aligned with the radius.

Why is "Perilunate dislocation" not the answer?

In perilunate dislocation the lunate remains in the radial fossa and the capitate lies dorsal to it.

Why is "Scapholunate dissociation" not the answer?

Scapholunate dissociation shows a widened scapholunate gap on the PA view without volar lunate displacement.

Why is "Kienbock disease" not the answer?

Kienbock disease is avascular necrosis of the lunate, with sclerosis and collapse, and no acute dislocation.

What concept does this question test?

It tests Musculoskeletal imaging: lunate dislocation in Radiology. In perilunate dislocation the lunate stays in the radius and the capitate and carpus dislocate dorsally around it.

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: lunate dislocation?

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.