True regarding nerve injury is:
Ans. a. In all cases of open wound with clinical signs of nerve injury, nerve exploration should always be done (Ref: Schwartz 9/e p1532; Bailey 25/e p355; Apley's 9/e p274)Indications of Exploration in Nerve Injuries: (Apley's 9/e p274)Nerve was seen to be divided and needs to be repaired, i.e., open injuryIf the ty pe of injury (example a knife wound or high energy injury) suggest that the nerve has been divided or severely damaged.If recovery is inappropriately delayed and diagnosis is in doubt.Positive Tinel's sign tells about the regeneration of the nerve (does not indicates the accurate location of lesion)Traction nerve injury are usually neuropraxia (managed conservatively, should not be repaired immediately)Nerve InjuryNeuropraxiaAxonotemesisNeurotemesis* Reversible physiological nerve conduction blockQ* Seen in crutch patsy, tourniquet palsy, and Saturday night palsyQ* Loss of conduction due to axonal interruptionQ but the nerve is in continuity and the neural tubes are intact* Seen in closed fractures and dislocations* There is complete division of nerveQ (epineurium, perineurium, endoneurium and axon all lost their continuity)* Seen in open woundsNerve RepairA clean cut nerve is best repaired as soon as this can be done safelyQ.The higher (proximal) the lesion, the worse the prognosisQ.Pure motor or pure sensory nerves recover better than mixed, because there is less chances of axonal confusion.Tinel's sign indicate regeneration of nerveQ.Rate of regeneration of nerve is 1 mm/dayQ.Prognosis after Nerve SuturingRadial nerve (best)Q >Median nerve >Ulnar nerve >Peroneal nerve >Sciatic and femoral nerve (worst prognosis)Q
In all cases of open wound with clinical signs of nerve injury, nerve exploration should always be done.
Nerve conduction velocity is best predictor within 48 hours of injury
Positive Tinel's sign indicates the accurate location of lesion
Traction nerve injury should be repaired immediately
Anatomy and General Principles