Anatomy and physiology of peripheral nerve injury and repair.

The management of peripheral nerve injury continues to be a major clinical challenge. Despite advancements in microsurgical technique, results after nerve repair have been unpredictable and dis appointing. The management of these nerve injuries relies on having a thorough understanding of peripheral nerve anatomy. This is the basis of the classification schemes by Seddon and Sunderland, in which the prognosis of nerve injuries varies depending on the degree of injury to their substructures. The most recent advances in the management of peripheral nerve injuries rely on the ability to manipulate the pathophysiologic processes triggered by nerve injuries and regeneration. End-to-end primary repair should be sought whenever a tension-free repair can be attained. If there is a significant nerve gap, use of nerve autograft remains the gold standard. In nerve injuries where a nerve autograft is not possible, the use of nerve allograft, as well as autogenous, biodegradable, and synthetic nerve conduits has shown promising results in experimental studies.