Critical points to consider when evaluating patients with peripheral nerve injury:
• Time is muscle.
• Open injury versus closed injury versus gunshot wound dictates management path.
Timing and Muscle Function:
• Time is muscle function.
• If the muscle is not re-innervated in a timely fashion, the window of opportunity to restore function is lost forever due to nerve degeneration, muscle atrophy, and associated effects.
Importance of Mechanism of Injury:
• Mechanism of injury dictates the management path.
Open Injuries: Requires exploration as soon as possible, though not emergently unless care is dictated by associated injuries such as devascularizing injuries or active hemorrhage.
Closed Injuries: Requires close observation on a monthly basis. If continued improvement is noted, no surgery may be needed.
Gunshot Wounds: Best managed as a closed injury except that the zone of injury is always larger than expected with a typical closed injury. Time is needed for the damage from the gunshot to settle, for the extent of the injury to ‘declare itself,’ so that nerve repairs may be completed outside the zone of injury.
Blast Injuries: These are challenging to manage and may benefit from exploration, identification, and tagging of the nerve with the initial soft tissue debridement. However, it is important know that long nerve grafts should be avoided until the extent of the injury ‘declares itself,’ as the zone of injury is still manifesting, so that nerve repairs are completed outside of the zone of injury.