ABSTRACT
In nerve injuries, if it is not possible to reinnervate muscle by using neurorrhaphy
and nerve grafting technique, reinnervation should be provided by the use of neuroization-directly
implanting motor nerve into muscle. A comparative study of three techniques of neurotization
is presented in rabbits.
In this experimental study, a total of 40 white New Zealand rabbits were used and
divided into four groups, each including 10 rabbits. In the first group (control-Group
1), only surgical exposure of the gastrocnemius muscle, main muscle nerve (tibial
nerve), and peroneal nerve was done, without any injury to the nerves. In the second
group (direct neurotization group-Group 2), the tibial nerve was transected, and the
peroneal nerve, which had already been divided into fascicles, was implanted into
the lateral head of the gastrocnemius muscle aneural zone. In the third group (dual
neurotization group-Group 3), the tibial nerve which had been transected and re-anastomosed,
and the peroneal nerve were implanted into the lateral head of the gastrocnemius muscle.
In the last experimental group (hyperneurotization group-Group 4), fascicles of the
peroneal nerve were implanted into the lateral head of the gastrocnemius, preserving
the tibial nerve. Six months later, changes in the histologic pattern and the functional
recovery of the gastrocnemius muscle were investigated. It was found that functional
recovery was achieved in all neurotization groups.
Groups with the tibial nerve transected had less muscular weights than those of groups
with the tibial nerve intact. EMG recordings showed that polyphasic and late potentials
were frequently seen in groups with the tibial nerve transected. Degeneration and
regeneration of myofibrils was observed in such groups as well. New motor end-plates,
including vesicles, were formed in a scattered manner in all neurotization groups.
As a result, the authors conclude that direct and dual neurotization techniques are
useful in peripheral nerve injuries, if it is not possible to reinnervate muscle by
using neurorraphy and nerve grafting, and that there is no suggested superiority among
these techniques.
KEYWORD
Neurotization - denervation and reinnervation - gastronuemius muscle - experimental
