Rewiring the upper limb: Motor nerve transfer surgery in the reconstruction of paralysis

Surgery to rewire a paralysed limb is now possible using motor nerve transfer surgery. The technique has been adapted from brachial plexus surgery and applied to other causes of paralysis with remarkable results, providing function to patients left paralysed from spinal cord injury, inflammatory neuropathy, tumour surgery and degenerative spinal disease. Adapting the techniques to peripheral nerve injury offers improved outcomes compared to anatomical reconstruction of an injured nerve. Nerve transfer surgery involves harvest of an expendable motor branch or redundant motor fascicle from a peripheral nerve and direct, tension-free coaptation to the distal motor branch of a paralysed muscle close to the motor point. Rapid re-innervation of the denervated muscle results in reliable motor recovery. Originally popularised for the reconstruction of nerve root avulsion, the technique has been adapted for use in other peripheral nerve injuries resulting in motor outcomes that are superior to those achieved through grafting of mixed motor-sensory nerve gaps. Nerve transfer surgery may be used to salvage late presenting cases, failed proximal reconstructions or as an adjunct for key motor functions in proximal nerve repairs where the time-distance phenomenon of peripheral nerve regeneration results in poor distal motor recovery, even following acute direct repair. The extension of the technique to other paralysing conditions demonstrates promise.