Principles
Successful peripheral nerve reconstruction depends on:
- Correct diagnosis and localisation
- Viable proximal and distal nerve ends
- Tension-free coaptation
- Accurate fascicular alignment where possible
- Minimal scar and tissue trauma
- Timely reinnervation of the target muscle
Injury severity
Neurapraxia
Conduction block without axonal disruption. Recovery is expected without repair.
Axonotmesis
Axons are disrupted but some connective-tissue architecture remains. Regeneration may occur spontaneously depending on severity.
Neurotmesis
Complete disruption of the nerve requires surgical reconstruction if meaningful spontaneous recovery is not possible.
Primary repair
Indicated when cleanly divided nerve ends can be approximated without tension.
Common methods:
- Epineurial repair
- Grouped fascicular repair in selected nerves
Fine sutures are placed with minimal handling of the nerve.
Nerve grafting
When a gap prevents tension-free primary repair, an autologous nerve graft is commonly used. Sural nerve is a frequently used donor.
The graft should bridge healthy nerve ends without tension.
Nerve transfer
A functioning expendable donor nerve or fascicle is coapted to a distal denervated nerve to shorten regeneration distance. This is useful in selected proximal injuries and brachial plexus reconstruction.
Timing
Motor end plates progressively lose the capacity for successful reinnervation after prolonged denervation. This makes timely reconstruction especially important in proximal motor injuries.
Assessment of recovery
- Serial clinical examination
- Tinel progression
- EMG and nerve-conduction studies
- Recovery of motor units and strength
References
- Orthobullets. Peripheral Nerve Injury & Repair.