A 22-year-old motorcyclist sustains a high-velocity road traffic accident. On examination, he has a flail arm with absent sensation from C5 to T1 dermatomes. Horner's syndrome is present. CT myelogram shows pseudomeningoceles at C7 and C8 levels. The type of brachial plexus injury is:

• A Postganglionic rupture — amenable to nerve grafting
• B Preganglionic (root avulsion) injury — not repairable by direct nerve repair ✓
• C Neuropraxia — expect full spontaneous recovery
• D Axonotmesis — Wallerian degeneration with intact endoneurial tubes

Explanation

Pseudomeningoceles on CT myelogram, Horner's syndrome (stellate ganglion involvement), and complete flail arm are diagnostic of preganglionic root avulsion injury. Because the dorsal root ganglion remains intact within the foramen, sensory nerve conduction studies may paradoxically be normal despite complete sensory loss (negative Tinel's sign proximal to clavicle). Avulsed roots cannot be repaired directly; neurotisation (nerve transfer) using donor nerves (intercostal, phrenic, contralateral C7, accessory nerve) is the only surgical option.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

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Written and medically reviewed by the StethoPrep medical team.