[Comparison between the distraction and grafting methods in the treatment of peripheral neural defects: an...

We compared the electrophysiologic and histopathologic results of grafting and distraction methods in the treatment of defective peripheral neural injuries.

Thirty male white rabbits (age 6 months) were divided into three groups and a circular external fixator (CEF) was applied to the right tibias. In group I (primary repair), the right deep peroneal nerve was cut without inducing any defect and a tibial osteotomy was performed. The remaining groups underwent bone and nerve excision of about 1 cm in the middle third of the tibia. In group II, the defect area was closed acutely with the CEF and the continuity of the nerve was restored. In group III, a nerve graft obtained from the left side was placed in the defect area and an epiperineural repair was made. Group II underwent distraction 21 days after surgery for 10 days with a rate of 0.25 mm four times a day. Electrophysiological studies were performed in the 12th and 24th weeks and nerve biopsies were obtained in the 32nd week for histopathologic examination.

Electrophysiological studies in the 12th week did not show any significant differences in nerve conduction between the three groups; however, in the 24th week, amplitude and latency values of the graft group were 50% lower than those of the primary repair and distraction groups (p<0.05). On histological examination, the results were good in group I and II, but poor in group III with respect to nerve fiber density, thickness of the myelin sheath, degenerative changes in the myelin sheath, and average axon number.

Our data demonstrate that treatment of neural defects by the distraction method results in much better results than the grafting method.