Repair Method Of Peripheral Nerve Defect In Traumatic Orthopedics

Objective: To compare the effects of three different repair methods on the treatment of peripheral nerve injury in traumatic orthopedics. Methods: Twenty-four rats with similar body mass were randomly divided into four groups (A, B, C, and D). To establish a model of nerve injury, their right thighs were excised, and sciatic nerves were discontinued 15 mm. In group A (control group), autologous nerve transplantation was performed and the excised nerve was turned 180 degrees and implanted into the defect part. Group B, C, and D served as the experimental group. Group B received allogeneic nerve graft and sciatic nerve segments excised from group C were suture-implanted to the two broken ends of group B. In group C, a nerve lengthening device was used to lengthen the broken ends of the sciatic nerve, and neural end-to-end suture was carried out. In group D, tissue engineering technology was used to implant polylactic-co-glycolic acid nerve conduit stent at the broken ends. Four weeks after surgery, the control group and the experimental group were respectively subjected to nerve electrophysiological tests such as somatosensory evoked potential (SEP), muscle action potential (MAP) and motor nerve conduction velocity (NCV). Also, the general morphology of the experimental animals was observed. Eight weeks after operation, histological detection was performed for all the subjects and the number and area of myelinated nerve fibers was detected and observed, also, the triceps surae wet weight recovery rate was measured and calculated. Results: After 4 weeks, all the rats showed limb deformity, and had varying degrees of toe swelling. Twelve weeks after the operation, there was no adhesion in the nerve graft junction of group A and group B, and the peripheral neural vascular net of the nerve defect junction in group C and group D was clear. Compared with group A, the latency of SEP and MAP in group C and group D were significantly shortened with higher amplitude, and the NCV increased with statistically significant difference (P<0.05). However, compared with group A, the latency of SEP, MAP in group B was increased with lower amplitude, and NCV decreased with significant difference (P<0.05). Eight weeks after the operation, the number of myelinated nerves at the repair site of nerve injury broken ends in group C and D was more than that in group A; there was less in group B, with the order of D>C>A>B, and the difference was statistically significant (F=14.37, P<0.05). The area of myelinated nerve arranged in order: D>C>A>B, with significant difference (F=31.52, P<0.05). In addition, the rat triceps surae wet weight recovery rate was higher in group C and D than that in group A, and it was lower in group B than in group A and the difference was statistically significant (P<0.05). Conclusion: In the repair methods of peripheral nerve in traumatic orthopedics, the new methods, nerve lengthening and tissue engineering technology, are expected to replace nerve graft.