Peripheral Nerve and Plexus Surgery
What the candidate must own
Know the microanatomy of peripheral nerve - epineurium, perineurium, endoneurium - and the Seddon and Sunderland classification of nerve injury (neuropraxia, axonotmesis, neurotmesis). Be fluent in the brachial plexus: roots, trunks, divisions, cords, and terminal branches, and the clinical patterns of upper (Erb) and lower (Klumpke) plexus injuries, plus the distinction between preganglionic and postganglionic lesions (root avulsion versus distal injury). Know the common entrapment neuropathies - carpal tunnel, cubital tunnel, and tarsal tunnel - with their electrodiagnostic findings and surgical indications. Understand nerve repair options: primary repair, nerve graft, nerve transfer, and tendon transfer, and the timing of each.
Traps that appear in questions
- Assuming a nerve injury that shows no recovery at 3 months is permanent - axonotmesis can recover over months.
- Confusing preganglionic (root avulsion) with postganglionic injury; preganglionic lesions do not recover and require nerve transfer.
- Missing the indication for urgent decompression in acute compartment syndrome or in a nerve compressed by a haematoma.
- Forgetting that electrodiagnostics may be normal in the first weeks after injury.
Rule of thumb
For any peripheral nerve lesion, ask where is the lesion, what is the mechanism, and is it pre- or postganglionic? Worked example: a motorcyclist with a flail arm, absent biceps and triceps, and Horner syndrome suggests a preganglionic C8-T1 avulsion, which will not recover spontaneously and requires nerve transfer reconstruction rather than primary repair.