Prevention of denervation atrophy by nerve implantation

Prevention of denervation atrophy in skeletal muscle by nerve implantation to a muscle belly was studied in a rat model. In the animals' legs, the tibial nerve branch innervating the lateral head of the gastrocnemius muscle was transected, and subsequently repaired by either simple nerve suture(n = 20) or interpositional nerve grafting (n = 20). The tibial nerve branch innervating the medial head was dissected out. The peroneal nerve was transected and implanted directly to the lateral head of the gastrocnemius muscle on one side and, as a control, the nerve on the other side was cut. After 6 months, isometric tension of the gastrocnemius muscle was greater on the implantation side than on the control side in the nerve-suture group ( p < 0.05), but no tension difference between the two sides was observed in the nerve-graft group. The effects of neurotization by an implanted nerve may compete with those by a repaired nerve, when neurotization of the latter is delayed. Only when the time interval between neurotization by an implanted nerve and reinnervation by a repaired original nerve is short, does nerve implantation attenuate denervation atrophy.