Creation of a ‘tension free repair' may require utilizing a segment of sensory nerve, vein or a synthetic nerve tube to bridge a gap. Nerves regenerate at a rate of approximately one inch per month (1mm/day). Therefore, the distance the nerve must grow from the site of injury to the down stream muscle or sensory receptor will determine the time of recovery.
To regain muscle function, it is important that the nerve and muscle become reconnected within one year. Muscles denervated for periods greater than one year develop internal scar and lose their ability to receive nerve signals. This time restriction does not hold true for sensation that can be regained many years after injury.
Blunt injuries are not explored immediately because the zone of damage is difficult to determine. Electrical testing is performed approximately six weeks after the injury. These tests provide predictive information regarding the severity of injury, the prospects for spontaneous recovery and the need for surgery.
Mild pressure or stretching of the nerve can produce a temporary impairment of local circulation that interrupts normal nerve conduction. This is referred to as neuropraxia and usually resolves within days to weeks with return of good function. |
