Isolated musculocutaneous nerve palsy

The musculocutaneous nerve innervates the coracohumeral muscle, the brachial biceps and the brachialis muscle, and gives the external part of the forearm its sensitivity.
Isolated paralysis of this nerve is exceptional and mainly found as a result of shoulder surgery.

Signs of paralysis are weak elbow flexion and supination although these movements remain partially possible.

Early signs of recovery can be detected through close monitoring over a period of several months.If no sign of recovery is visible after 5 months from injury, explorative surgery will be required.

Depending on the findings of the intraoperative assessment, a simple release, nerve repair (suture, graft) or neurotisation of the ulnar nerve into the nerve of the biceps and of the median nerve into the nerve of the brachialis can be performed.

For injuries diagnosed late, musculotendinous transfer from the forearm to the arm (Steindler procedure) can be considered.