Peripheral nerve injuries: musculocutaneous nerve: practice question

A Orthopaedics 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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Orthopaedics · Peripheral nerve injuries: musculocutaneous nerve

Sample item

After an anterior shoulder injury, a man has weak elbow flexion with the forearm supinated, a reduced biceps reflex and numbness over the lateral forearm. Elbow flexion with the forearm in mid-position is partly preserved. Which nerve is involved?

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

The answer and the reasoning

C. Musculocutaneous nerve

The musculocutaneous nerve supplies coracobrachialis, biceps and brachialis and ends as the lateral cutaneous nerve of the forearm. Its injury weakens elbow flexion and supination with loss of sensation on the lateral forearm. Brachioradialis, supplied by the radial nerve, helps flexion in mid-pronation.

Option by option

  • A. Median nerve at the elbow

    A median lesion at the elbow affects pronation and finger flexors, not biceps.

  • B. Axillary nerve

    An axillary lesion affects deltoid and regimental badge sensation.

  • C. Musculocutaneous nerve (correct)

    Correct. Weak flexor muscles and lateral forearm sensory loss localise to the musculocutaneous nerve.

  • D. Radial nerve

    A radial nerve lesion causes wrist drop and loss of dorsal sensation.

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.

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Questions about this Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is C, Musculocutaneous nerve. The musculocutaneous nerve supplies coracobrachialis, biceps and brachialis and ends as the lateral cutaneous nerve of the forearm.

Why is "Median nerve at the elbow" not the answer?

A median lesion at the elbow affects pronation and finger flexors, not biceps.

Why is "Axillary nerve" not the answer?

An axillary lesion affects deltoid and regimental badge sensation.

Why is "Radial nerve" not the answer?

A radial nerve lesion causes wrist drop and loss of dorsal sensation.

What concept does this question test?

It tests Peripheral nerve injuries: musculocutaneous nerve in Orthopaedics. Its injury weakens elbow flexion and supination with loss of sensation on the lateral forearm. Brachioradialis, supplied by the radial nerve, helps flexion in mid-pronation.

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 Peripheral nerve injuries: musculocutaneous nerve?

Pair each fracture with its classic complication and nerve injured. Then use the flashcards and the other Orthopaedics 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.