[Experimental study on regeneration of sciatic nerve injury with physical therapy]

Peripheral nerve injury is a common clinical disease, to study the effects of the physical therapy on the regeneration of the injured sciatic nerve, and provide a reference for clinical treatment.

Sixty-four female adult Wistar rats (weighing 252-365 g) were chosen and randomly divided into 4 groups (n = 16): group A, group B, group C, and group D. The experimental model of sciatic nerve defect was established by crushing the right sciatic nerve in groups B, C, and D; group A served as the control group without crushing. At 2 days after injury, no treatment was given in group B, electrical stimulation in group C, and combined physical therapies (decimeter and infrared ray) in group D. At 0, 7, 14, and 30 days after treatment, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MNCV) were measured, and morphological and transmission electron microscopy (TEM) examinations were done; at 30 days after treatment, the morphological evaluation analysis of axons was performed.

At 0 and 7 days after treatment, the SFI values of groups B, C, and D were significantly higher than that of group A (P < 0.05); at 14 and 30 days after treatment, the SFI value of group D decreased significantly, no significant difference was observed between group D and group A (P > 0.05) at 30 days; whereas the SFI values of groups B and C decreased, showing significant difference when compared with the value of group A (P < 0.05). At 0, 7, and 14 days after treatment, the MNCV values of groups B, C, and D were significantly lower than that of group A (P < 0.05), and there were significantly differences between group B and groups C, D (P < 0.05); at 14 days, the MNCV value of group D was significantly higher than that of group C (P < 0.05); and at 30 days, the MNCV values of groups B and C were significantly lower than that of group A (P < 0.05), but there was no significant difference between group D and group A (P > 0.05). At 0 and 7 days, only collagen and lipid were observed by TEM; at 14 and 30 days, many Schwann cells and perineurial cells in regeneration axon were observed in groups B, C, and D, especially in group D. Automated image analysis of axons showed that there was no significant difference in the number of myelinated nerve fibers, axon diameter, and myelin sheath thickness between group D and group A (P > 0.05), and the number of myelinated nerve fibers and axon diameter of group D were significantly higher than those of groups B and C (P < 0.05).

Physical therapy can improve the regeneration of the injured sciatic nerve of rats.