Musculoskeletal imaging: ossific nucleus in hip dysplasia: 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.

Try it

Radiology · Musculoskeletal imaging: ossific nucleus in hip dysplasia

Sample item

A 6-month-old girl has a breech history and a pelvis radiograph with Hilgenreiner and Perkin lines drawn. In a dysplastic hip, where does the femoral ossific nucleus lie?

AIn the inferomedial quadrantBIn the superolateral quadrantCOn the Hilgenreiner lineDMedial to the Perkin line

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

The answer and the reasoning

B. In the superolateral quadrant

The femoral head ossific nucleus normally lies in the inferomedial quadrant formed by the Hilgenreiner and Perkin lines. In dislocation or severe dysplasia it lies superolaterally, and the Shenton line is broken.

Option by option

A. In the inferomedial quadrant
The inferomedial quadrant is the normal position of the ossific nucleus.
B. In the superolateral quadrant (correct)
Correct. The nucleus of a dislocated or dysplastic hip lies in the superolateral quadrant.
C. On the Hilgenreiner line
The Hilgenreiner line is the horizontal line through the triradiate cartilages and the nucleus does not normally sit on it.
D. Medial to the Perkin line
Medial to the Perkin line is the normal side of the femoral head in a located hip.

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, In the superolateral quadrant. The femoral head ossific nucleus normally lies in the inferomedial quadrant formed by the Hilgenreiner and Perkin lines.

Why is "In the inferomedial quadrant" not the answer?

The inferomedial quadrant is the normal position of the ossific nucleus.

Why is "On the Hilgenreiner line" not the answer?

The Hilgenreiner line is the horizontal line through the triradiate cartilages and the nucleus does not normally sit on it.

Why is "Medial to the Perkin line" not the answer?

Medial to the Perkin line is the normal side of the femoral head in a located hip.

What concept does this question test?

It tests Musculoskeletal imaging: ossific nucleus in hip dysplasia in Radiology. In dislocation or severe dysplasia it lies superolaterally, and the Shenton line is broken.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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: ossific nucleus in hip dysplasia?

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.