ABSTRACT
Injuries to the upper extremity and hand are a common problem, and two-thirds of these patients, mainly men, are below the age of 30 years (Angermann and Lohmann 1993, Beaton et al 1994). Many of the injuries involve the peripheral nerve trunks in the upper extremity and they may even include the brachial plexus. A far lower number of nerve injuries affect the nerve trunks in the lower extremity and they may require nerve grafting (Trumble and Vanderhooft 1994, Trumble et al 1995, Kline et al 1998, Allan 2000). The peripheral nerve lesion leads to severe and in many cases permanent impairment of the function of the limb. This is particularly evident in the hand, which performs fine manipulative tasks. Understanding of the pathophysiology of nerve injuries has increased during the last 20-30 years (Lundborg 2000a), but the methods available to repair such nerve injuries are still limited. Even though microsurgical techniques to approximate the two nerve ends of a transected nerve trunk have been introduced, the results are still far from ideal (Birch and Raji 1991). At present clinicians can only adapt the epineurial and perineurial sheaths of the transected nerve trunks, but they cannot, for example, influence the orientation of the outgrowing axons.
