ObjectiveTo explore the potential therapeutic effects of endothelial progenitor cells derived small extracellular vesicles (EPCs-sEVs) on spinal cord injury in mice.MethodsEPCs were separated from femur and tibia bone marrow of 20 C57BL/6 male mice, and identified by double fluorescence staining and flow cytometry. Then the EPCs were passaged and the cell supernatants from P2-P4 generations EPCs were collected; the EPCs-sEVs were extracted by ultracentrifugation and identified by transmission electron microscopy, nanoflow cytometry, and Western blot. Forty C57BL/6 female mice were randomly divided into 4 groups (n=10). The mice were only removed T10 lamina in sham group, and prepared T10 spinal cord injury models in the model group and the low and high concentration intervention groups. After 30 minutes, 3 days, and 7 days of operation, the mice in low and high concentration intervention groups were injected with EPCs-sEVs at concentrations of 1×109 and 1×1010cells/mL through the tail vein, respectively. The behavioral examinations [Basso Mouse Scale (BMS) score, inclined plate test, Von Frey test] , and the gross, HE staining, and immunohistochemical staining were performed to observe the structural changes of the spinal cord at 4 weeks after operation. Another 3 C57BL/6 female mice were taken to prepare T10 spinal cord injury models, and DiR-labeled EPCs- sEVs were injected through the tail vein. After 30 minutes, in vivo imaging was used to observe whether the EPCs-sEVs reached the spinal cord injury site.ResultsAfter identification, EPCs and EPCs-sEVs derived from mouse bone marrow were successfully obtained. In vivo imaging of the spinal cord showed that EPCs-sEVs were recruited to the spinal cord injury site within 30 minutes after injection. There was no significant difference in BMS scores and the maximum angle of the inclined plate test between two intervention groups and the model group within 2 weeks after operation (P>0.05), while both were significantly better than the model group (P<0.05) after 2 weeks. The Von Frey test showed that the mechanical pain threshold of the two intervention groups were significantly higher than that of model group and lower than that of sham group (P<0.05); there was no significant difference between two intervention groups (P>0.05). Compared with the model group, the injured segment of the two intervention groups had smaller spinal cord tissue defects, less mononuclear cells infiltration, more obvious tissue structure recovery, and more angiogenesis, and these differences were significant (P<0.05); there was no significant difference between the two intervention groups.ConclusionEPCs-sEVs can promote the repair of spinal cord injury in mice and provide a new plan for the biological treatment of spinal cord injury.
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.
ObjectiveTo evaluate the effectiveness of Curved Diffusion Needle in unilateral percutaneous vertebroplasty (PVP) by compared with bilateral PVP. MethodsA clinical data of 93 patients with osteoporotic vertebral compression fracture (OVCF) treated with PVP between January 2020 and January 2021 was retrospectively analyzed, including 47 patients underwent unilateral PVP assisted with Curved Diffusion Needle (unilateral group) and 46 patients underwent bilateral PVP (bilateral group). There was no significant difference in gender, age, cause of injury, time from injury to operation, T value of bone mineral density, AO classification, distribution of injured vertebrae, and preoperative visual analogue scale (VAS) score, Oswestry disability index (ODI), relative height of injured vertebrae, and Cobb angle between the two groups (P>0.05). The operation time, the amount of bone cement injection, the incidence of bone cement leakage, the bone cement diffusion distribution, VAS score, ODI, the relative height of injured vertebrae, and Cobb angle were recorded and compared between the two groups. Results All operations successfully completed. The operation time was significantly shorter in unilateral group than in bilateral group (t=−13.936, P=0.000), and the amount of bone cement injection was significantly less in unilateral group than in bilateral group (t=−13.237, P=0.000). The incidence of bone cement leakage in unilateral group was 19.14%, which was significantly lower than that in bilateral group (39.13%) (χ2=4.505, P=0.034). The score of bone cement distribution in unilateral group was 7.0±1.3, of which 41 cases were excellent and 6 cases were well. The score of bilateral group was 7.4±0.8, of which 43 cases were excellent and 3 cases were well. There was no significant difference in score and grading of bone cement distribution between the two groups (t=−1.630, P=0.107; Z=−1.013, P=0.311). All patients were followed up and the follow-up time was 3-10 months (mean, 6.5 months) in unilateral group and 3-10 months (mean, 6.1 months) in bilateral group. The VAS score, ODI, the relative height of injured vertebrae, and Cobb angle at 24 hours after operation and last follow-up were significantly better than those before operation in the two groups (P<0.05). There were significant differences in all indicators between 24 hours after operation and last follow-up (P<0.05). There was no significant difference in all indexes between the two groups (P>0.05) at the same time point after operation. During follow-up, there was no complication such as contralateral vertebral collapse, refracture, adjacent vertebral fracture, or local kyphosis in the two groups. ConclusionUnilateral PVP assisted with Curved Diffusion Needle for OVCF is beneficial to the distribution of bone cement, which can not only achieve similar effectiveness to bilateral PVP, but also achieve shorter operation time, less bone cement injection, and lower risk of bone cement leakage.
Objective To investigate the influence of axis pedicle and intra-axial vertebral artery (IAVA) alignment on C2 pedicle screw placement by measuring the data of head and neck CT angiography. MethodsThe axis pedicle diameter (D), isthmus height (H), isthmus thickness (T), and IAVA alignment types were measured in 116 patients (232 sides) who underwent head and neck CT angiography examinations between January 2020 and June 2020. Defined the IAVA offset direction by referencing the vertical line through the center of C3 transverse foramen on the coronal scan, it was divided into lateral (L), neutral (N), and medial (M). Defined the IAVA high-riding degree by referencing the horizontal line through the outlet of the C2 transverse foramen, it was divided into below (B), within (W), and above (A). The rate of pedicle stenosis, high-riding vertebral artery, and different IAVA types were calculated, and their relationships were analysed. Simulative C2 pedicle screws were implanted by Mimics 19.0 software, and the interrelation among the rates of pedicle stenosis, high-riding vertebral artery, IAVA types, and vertebral artery injury were analyzed. ResultsThe rate of C2 pedicle stenosis was 33.6% (78/232), and the rate of high-riding vertebral artery was 35.3% (82/232). According to the offset direction and the degree of riding, IAVA was divided into 9 types, among which the N-W type (29.3%) was the most, followed by the L-W type (19.0%) and the L-B type (12.9%), accounting for 60.9%. The vertebral artery injury rate of simulative implanted C2 pedicle screws was 35.3% (82/232). The vertebral artery injury rate in patients with pedicle stenosis and high-riding vertebral artery was significantly higher than that who were not (P<0.001). The rate of pedicle stenosis, high-riding vertebral artery, and vertebral artery injury were significantly different among IAVA types (P<0.001), and M-A type was the most common. ConclusionVertebral artery injury is more common in pedicle stenosis and/or high-riding vertebral artery and/or IAVA M-A type. Preoperative head and neck CT angiography examination has clinical guiding significance.