The response to injury in the peripheral nervous system.

©2005 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.87B10. 16700 $2.00 J Bone Joint Surg [Br] 2005;87-B:1309-19. Peripheral nerve injuries, particularly in the upper limb, may have devastating consequences. The outcome of injury is determined by the amount of cellular damage, and by variables which include the site of the lesion, the degree of disruption of the connective-tissue sheaths that surround the nerve, the extent of associated injuries, particularly vascular injuries (Fig. 1), and the age and health of the patient. Meticulous surgical repair cannot guarantee full functional recovery because the surgeon does not control the ‘biological battlefield’ which rages inside a damaged nerve. 1 Therapeutic manipulation of the response to injury at the molecular level has the potential to keep more neurones alive, encourage their axons to cross longer interstump gaps, to maximise the accuracy of target re-innervation and to manage neuropathic pain. For now, these objectives remain aspirational – they are predicated on a more detailed understanding of the way in which the peripheral nervous system responds to injury than is presently available. This brief update on the peripheral arm of the response to injury in the peripheral nervous system highlights areas where translational research may prove to be beneficial, for information on axotomy-related central phenomena, the reader is referred to earlier reviews. 2-4