title: Proximal versus Distal Nerve Transfer for Biceps Reinnervation-A Comparative Study in a Rat's Brachial Plexus Injury Model.
abstract: BACKGROUND
  The exact role of proximal and distal nerve transfers in reconstruction strategies of brachial plexus injury remains controversial. We compared proximal with distal nerve reconstruction strategies in a rat model of brachial plexus injury.
  
  
  METHODS
  In rats, the C6 spinal nerve with a nerve graft (proximal nerve transfer model, n = 30, group A) and 50% of ulnar nerve (distal nerve transfer model, n = 30, group B) were used as the donor nerves. The targets were the musculocutaneous nerve and the biceps muscle. Outcomes were recorded at 4, 8, 12, and 16 weeks postoperatively. Outcome parameters included grooming test, biceps muscle weight, compound muscle action potentials, tetanic contraction force, and axonal morphology of the donor and target nerves.
  
  
  RESULTS
  The axonal morphology of the 2 donor nerves revealed no significant difference. Time interval analysis in the proximal nerve transfer group showed peak axon counts at 12 weeks and a trend of improvement in all functional and physiologic parameters across all time points with statistically significant differences for grooming test, biceps compound action potentials, tetanic muscle contraction force, and muscle weight at 16 weeks. In contrast, in the distal nerve transfer group, the only statistically significant difference was observed between the 4 and 8 week time points, followed by a plateau from 8 to 16 weeks.
  
  
  CONCLUSIONS
  Outcomes of proximal nerve transfers are ultimately superior to distal nerve transfers in our experimental model. Possible explanations for the superior results include a reduced need for cortical adaptation and higher proportions of motor units in the proximal nerve transfers.
authors.affiliation: Department of Hand and Plastic Surgery, Norrland's University Hospital, Umeå, Sweden; Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden; and Department of Plastic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taipei-Linkou, Taiwan.
authors.forename: Aleksandra M
authors.initials: AM
authors.lastname: McGrath
authors.affiliation: Department of Hand and Plastic Surgery, Norrland's University Hospital, Umeå, Sweden; Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden; and Department of Plastic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taipei-Linkou, Taiwan.
authors.forename: Johnny Chuieng-Yi
authors.initials: JC
authors.lastname: Lu
authors.affiliation: Department of Hand and Plastic Surgery, Norrland's University Hospital, Umeå, Sweden; Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden; and Department of Plastic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taipei-Linkou, Taiwan.
authors.forename: Tommy Naj-Jen
authors.initials: TN
authors.lastname: Chang
authors.affiliation: Department of Hand and Plastic Surgery, Norrland's University Hospital, Umeå, Sweden; Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden; and Department of Plastic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taipei-Linkou, Taiwan.
authors.forename: Frank
authors.initials: F
authors.lastname: Fang
authors.affiliation: Department of Hand and Plastic Surgery, Norrland's University Hospital, Umeå, Sweden; Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden; and Department of Plastic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taipei-Linkou, Taiwan.
authors.forename: David Chwei-Chin
authors.initials: DC
authors.lastname: Chuang