C7 Nervetransfer in the Reconstruction of Brachial Plexus

Lesion of the brachial plexus resulting in root avulsion is one of the most disastrous injuries and is predominantly seen in young males (McAllister et al. 1996; Noble et al. 1998). These patients suffer lifelong function impairment, chronic pain and cold-temperature intolerance of the affected extremity, impacting severely on the patient`s life. Though functional integrity of the affected upper extremity can be restored through spinal-cord implantation, nerve transfer, pedicle-muscle transfer, and functioning free-muscle transplantation (Chuang 2006), the techniques of nerve-transfer used when no proximal nerve source is available for peripheral nerve reconstruction still needs to be investigated (Frey et al. 1990; Samardzic et al. 1992; Thomeer et al. 1993; Mackinnon et al. 1999; Chuang 2005; Wood et al. 2007). Functional deficit caused by injuries of brachial plexus C5 and C6 roots, can be partially restored with ipsilateral C7 root transfer, first described by Xu in 1999 (Xu et al. 1999). It is said to be an optimal surgical procedure. C7 nerve transfer has been widely used in many centers since its introduction by Gu et al. in 1992 (Gu et al. 1992) and is reported to achieve up to 60% recovery of motor function (M3) and up to 83% sensory function (S3) (Waikakul et al. 1999; Gu 2007). Since root C7 is often concomitantly injured at C5 and C6 plexus lesion and evaluation of C7 root cannot be clearly clinically made before it is used as a donor nerve, this experimental study will determine if partially damaged C7 transferred to musculocutaneous nerve, can be used to restore function in elbow flexion. Hence, the purposes of this study are to describe the outcome of the crushed injured C7 root in various degrees, after an ipsilateral C7 root transfer to the musculocutaneous nerve. To the best of our knowledge, this is the first research of its kind to be reported.