General anatomy: fascial compartments: practice question

A Anatomy 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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Anatomy · General anatomy: fascial compartments

Sample item

A 24-year-old man with a tibial shaft fracture has severe leg pain worsened by passive toe flexion, a tense swollen anterolateral leg, weak ankle dorsiflexion and numbness of the first web space. Which nerve and compartment are first affected?

ATibial nerve in the deep posterior compartmentBSural nerve in the superficial posterior compartmentCDeep fibular nerve in the anterior compartmentDSuperficial fibular nerve in the lateral compartment

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

The answer and the reasoning

C. Deep fibular nerve in the anterior compartment

The anterior compartment is the one most often involved in leg compartment syndrome. It contains the dorsiflexors and the deep fibular nerve, which supplies the skin of the first web space. The tight deep fascia and interosseous membrane cannot expand, so pressure compromises perfusion, and treatment is urgent fasciotomy.

Option by option

A. Tibial nerve in the deep posterior compartment
The tibial nerve in the deep posterior compartment would give weak plantar flexion and sole numbness.
B. Sural nerve in the superficial posterior compartment
The sural nerve is a cutaneous nerve that does not lie within a muscle compartment.
C. Deep fibular nerve in the anterior compartment (correct)
Correct. The deep fibular nerve supplies the dorsiflexors and the first web space and lies in the tight anterior compartment.
D. Superficial fibular nerve in the lateral compartment
The superficial fibular nerve supplies the peroneal muscles and the dorsum of the foot, which would give weak eversion.

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 Anatomy question

What is the answer to this Anatomy question?

The best answer is C, Deep fibular nerve in the anterior compartment. The anterior compartment is the one most often involved in leg compartment syndrome.

Why is "Tibial nerve in the deep posterior compartment" not the answer?

The tibial nerve in the deep posterior compartment would give weak plantar flexion and sole numbness.

Why is "Sural nerve in the superficial posterior compartment" not the answer?

The sural nerve is a cutaneous nerve that does not lie within a muscle compartment.

Why is "Superficial fibular nerve in the lateral compartment" not the answer?

The superficial fibular nerve supplies the peroneal muscles and the dorsum of the foot, which would give weak eversion.

What concept does this question test?

It tests General anatomy: fascial compartments in Anatomy. It contains the dorsiflexors and the deep fibular nerve, which supplies the skin of the first web space. The tight deep fascia and interosseous membrane cannot expand, so pressure compromises perfusion, and treatment is urgent fasciotomy.

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 General anatomy: fascial compartments?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy 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.