Objective To investigate the effect of the sciatic nerve elongation on pain in rats. Methods Thirty-six adult male Wistar rats of SPF grade, weighing 250-300 g. Eighteen of them were randomly divided into 3 groups, 6 rats in each group. They were sciatic nerve elongation group (group A), nerve no-elongation group (group B), and nerve ligation group (group C). The model of 10-mm sciatic nerve defect was established in all 3 groups. The sciatic nerve was extended at a speed of 1 mm/d for 14 days in group A. The group B was only installed with external fixation. The nerve stumps were ligated in the group C. At 3, 7, 10, and 14 days after operation, the foot injury was evaluated by the autotomy scoring scale. At 14 days after operation, the dorsal root ganglia (DRG) of L4-S1 spinal cord of rats in each group was observed by tumor necrosis factor α (TNF-α) immunohistochemical staining, and the primary antibodies were replaced by pure serum as negative control group. Another 18 rats were randomly divided into 3 groups, 6 rats in each group. They were sciatic nerve elongation group (group A1), nerve no-elongation group (group B1), positive control group (group C1). In groups A1 and B1, the 10-mm long sciatic nerve defect model was established by the same method as groups A and B, and then fixed with external fixation. Nerve elongation was done or not done without anesthesia at 3 days after operation. In group C1, no modeling was done and 20 μL 2.5% formaldehyde was injected into the toes. After 90 minutes, the dorsal horn of spinal cord of L4-S1 segment of rats was cutting for c-Fos immunohistochemical staining and the number of positive cells was counted. Primary antibodies were replaced with pure serum as negative control group. Results The autotomy scores of rats in groups B and C gradually increased postoperatively, and group A remained stable at 0.25±0.50. The scores of group C were significantly higher than those of group A and group B at each time point postoperatively (P<0.05). The scores of group A were significantly lower than those of group B at 10 and 14 days postoperatively (P<0.05). TNF-α immunohistochemical staining showed that the TNF-α expression in group A was weak, slightly positive (+/-); in group B was positive (+); in group C was strongly positive (++); and the negative control group had no TNF-α expression (-). c-Fos immunohistochemical staining showed that the c-Fos expressions in groups A1 and B1 were weak positive, in group C1 was strong positive, and negative control group had no c-Fos positive expression. The number of c-Fos positive cells in groups A1, B1, C1, and negative control group were (21.5±6.6), (19.3±8.1), (95.6±7.4), and 0 cells/field, respectively, and group C1 was significantly higher than groups A1 and B1 (P<0.05), there was no significant difference between group A1 and group B1 (P>0.05). Conclusion Nerve elongation does not cause obvious pain neither during the operation of elongation nor throughout the whole elongation.
ObjectiveTo investigate clinical application of the free peroneal artery perforator flap in soft tissue defect of foot and ankle.MethodsThe clinical data of 18 patients with soft tissue defects of foot and ankle who were repaired with free peroneal artery perforator flaps between March 2019 and March 2020 were retrospectively analyzed. Among them, there were 11 males and 7 females; the age ranged from 21 to 58 years, with an average age of 45 years. The defect was located in the ankle in 2 cases, in the hindfoot in 4 cases, in the midfoot in 5 cases, and in the forefoot in 7 cases. The causes of injury included 11 cases of traffic accident, 4 cases of machine injuries, 3 cases of infection and necrosis after internal fixation. The time from injury to flap repair was 12-48 days, with an average of 24 days. The range of wound was 3 cm×3 cm to 15 cm×8 cm, and the range of skin flap was 4 cm×3 cm to 16 cm×9 cm. The flap harvesting time, operation time, intraoperative blood loss, and complications were recorded; the flap survival and patient satisfaction were observed during follow-up; and the American Orthopaedic Foot and Ankle Society (AOFAS) foot function score was used to evaluate the foot function.ResultsThe flap harvesting time was 15-33 minutes (mean, 22 minutes); the operation time was 120-160 minutes (mean, 150 minutes); the intraoperative blood loss was 90-180 mL (mean, 120 mL). There were 3 cases of vascular crisis after operation, including 2 cases of arterial crisis, which survived after vascular exploration and vein graft repair; 1 case of venous crisis, partial necrosis of the skin flap, and skin grafting to cover the wound after repeated debridement. The remaining 15 skin flaps survived completely. All patients were followed up 6 months. The skin flaps were in good shape without obvious bloat. According to the AOFAS foot function score, 5 cases were excellent, 10 cases were good, and 3 cases were fair. The excellent and good rate was 83.3%.ConclusionThe free peroneal artery perforator flap is easy to harvest, the shape and size of the flap are easy to design, and it does not damage the main blood vessels of the limb. The appearance and function of the limbs are satisfactory after operation. It can be widely used in the repair of soft tissue defects of the foot and ankle.