OBJECTIVE: To investigate the mechanism, diagnosis, and treatment of common fibular nerve compression syndrome secondary to sciatic nerve injury. METHODS: Based on the clinical manifestation and Tinel’s sign at fibular tunnel, 5 cases of common fibular nerve secondary compression following sciatic nerve injury were identified and treated by decompression and release of fibular tunnel. All 5 cases were followed up for 13-37 months, 25 months in average, and were evaluated in dorsal flexion strength of ankle. RESULTS: The dorsal flexion strength of ankle in 4 cases increased from 0-I degrees to III-V degrees, and did not recover in 1 case. CONCLUSION: Fibular tunnel is commonly liable to fibular nerve compression after sciatic nerve injury. Once the diagnosis is established, either immediate decompression and release of the entrapped nerve should be done or simultaneous release of fibular tunnel is recommended when the sciatic nerve is repaired.
ObjectiveTo construct recombinant adenovirus expressing nerve growth factor (NGF) and myelin associated glycoprotein (MAG) (Ad-NGF-MAG) and to investigate its effect on repair and regeneration of sciatic nerve injury in rats. MethodsNGF and MAG gene sequences were cloned into shuttle plasmid pCA13 of adenovirus type 5. After packed in HEK293 cells, the recombinant Ad-NGF-MAG underwent sequence and identification. Thirty-two male Sprague Dawley rats were randomly divided into 4 groups (n=8): control group (normal control), adenovirus vector group (Ad group), Ad-NGF group, and Ad-NGF-MAG group. The sciatic nerve injury model was established by transection of the right sciatic nerve; then, the empty adenovirus vector, Ad-NGF, and Ad-NGF-MAG were injected into the gastrocnemius muscle of the affected limb at a dose of 1×108 PFU every other day for 3 times in Ad group, AdNGF group, and Ad-NGF-MAG group, respectively. The right sciatic nerve was exposed only, and then the incision was closed in the control group. The sciatic nerve function index (SFI) was measured, and neuro-electrophysiology was observed; mRNA and protein expressions of NGF and MAG were detected by RT-PCR and Western blot; and histological examination was performed at 31 days after operation. ResultsRecombinant adenovirus vectors of Ad-NGF and Ad-NGF-MAG were constructed successfully. All rats survived and incision healed by first intension. The SFI, nerve conduction velocity, evoked potential amplitude, and latent period of Ad-NGF-MAG group were significantly better than those of Ad group and Ad-NGF group (P < 0.05). MAG mRNA and protein expressions of Ad-NGF-MAG group were the highest in all the groups (P < 0.05). The expressions of NGF mRNA and protein increased in Ad-NGF group and AdNGF-MAG group when compared with control group and Ad group (P < 0.05). Histological examination showed that the nerve had good continuity in control group; nerve fibers disarranged in Ad group; neurons connections formed in some nerve fibers of Ad-NGF group, but nerve fibers arrange disorderly; and the growth of the nerve were ordered and wellstructured in Ad-NGF-MAG group. ConclusionAd-NGF-MAG can effectively promote the growth of the nerve and inhibit the form of abnormal branches, facilitating the repair of sciatic nerve injury in rats.
OBJECTIVE: To study the effect of subcutaneous implant of peripheral nerve allograft on sciatic nerve regeneration in rats. METHODS: Out of 30 male Wistar rats, 6 were donors and 24 were divided randomly into 2 groups. In experimental group (group A, n = 12), a 15 mm segment of sciatic nerve harvested from donors was separately inserted into subcutaneous compartment on the right thigh; two weeks later, the segment of sciatic nerve in subcutaneous compartment was removed and transplanted into a 10 mm sciatic nerve defect of left, which was made immediately. In the control group (group B, n = 12), a 10 mm sciatic nerve defect was made and immediately repaired in situ on the left thigh. The regeneration of sciatic nerve was examined histologically (after 2, 4, 8, and 14 weeks) and electrophysiologically (after 14 weeks of operation). RESULTS: After 2 weeks of operation, the inflammatory reaction was a little ber in group A than in group B. After 4 weeks, the intensity of the inflammatory reaction was similar between two groups; some collagen fibers proliferated. After 8 weeks, the inflammatory reaction ended and the collagen fibers proliferated obviously. After 14 weeks of operation, the structure of epineurium was in integrity and there was no obvious difference in perineurium and endonurium between two groups. A large number of myelinated nerve fibers and a small number of unmyelinated nerve fibers regenerated. The structure of myelin sheath was in integrity. The number and size of regenerated axon had no significant difference between two groups(P gt; 0.05). The conduction velocity, the peak value and the latent period of motor nerve were no significant difference between two groups (P gt; 0.05). CONCLUSION: The allograft of sciatic nerve inserted into subcutaneous compartment can promote nerve regeneration.
In order to understand the change of free radicals in the course of injury and regeneration of nerve, the sciatic nerve of Wistar rat was crushed to, prepare the model of nerve injury and measured the content of Malondialdehyde (MDA) and superoxide dismutase (SOD) of the nerve. Thirty rats were used in this study. The sciatic nerve on one side was crushed, the contralateral sciatic nerve was served as control. According to the time of assessment (2,4,6,11,21 days after crushing), the rats were divided into 5 groups. The MDA concentration of the controlwas 19.65±0.27 and that of the crushing groups at different time were 21.25±0.36, 21.98±0.35, 22.77±0.38, 23.73±0.13, 23.92±0.44, respectively (nmol/100mg pro, x±s), while the SOD concentration of the control was 119.18±0.58 and that of the crushing groups at different time were 144.85±1.70, 136.14±1.71, 130.58±0.57, 126.41±0.98, 122.36±0.79, respectively (ug/mg pro, x±s), In the experimental groups, all the MDA concentrations were markedly higher than that of the control Plt;0.01, t-test) and tended to increase with the time passing by. The SOD concentrations in the experimental groups were also higher than that of the control Plt;0.01, t-test) and tended to decrease with the time passing on. The study suggested that after crushing or ligation of the nerve, the free radicals would increase.
OBJECTIVE To investigate the effects of basic fibroblast growth factor(bFGF) on repairing transected sciatic nerves in rats. METHODS The animal models of the transected sciatic nerve of 40 SD rats were established, which divided into 4 groups: normal saline (NS) group, nerve growth factor (NGF) group, bFGF group and normal control group. The epineurium of the transected sciatic nerve was sutured under microscope, then bFGF or NGF was dropped into local sites and injected intramuscularly once a day for 30 days after operation. Functional repair for the transected sciatic nerves was studied by nerve conductive velocity (NCV) and sciatic nerve function index (SFI). RESULTS As a criterion, the level of the normal control group was regarded as zero, SFI of NS group, NGF group and bFGF group were -114.30 +/- 10.34, -70.50 +/- 11.01, -50.45 +/- 7.82 respectively at 1 month after operation, and they were -54.96 +/- 16.46, -35.21 +/- 10.80, -27.53 +/- 11.23 respectively in 3 months after operation. NCV of bFGF group was significantly faster than NS group and NGF group. CONCLUSION bFGF can significantly promote the functional repair of injured peripheral nerve, and its effects are better than NGF.
Objective To make a histological evaluation of poly(dextrogyr-levogyr)lactide acide-triiodothy-ronine (PDLLA-T3) in sciatic nerve defect of rat. Methods Ninety SD rats were evenly divided into 3 groups (autograft group A, PDLLA-T3 group B and PDLLA group C). Group D was control group. The left sciatic nerves were cut off by operation and 1 cm-nerve-defect was set up. The specimens were collected 2 weeks,1 month and 2 months after the operation respectively, simultaneously the right sciatic nerves were collected as normal control group D. HE stainning, electron microscope, S100 immunohistochemistry, and Bielschowsky staining were done in all the specimens, the quantity and quality of the regenerated nerves were observed, and all the results were processed by image analyzer.Results Two weeks after the operation,histological observation indicated that the materials in groups B and C were not completely degraded. Transmission electron microscopic observationshowed that the myelin sheath was not thick and it was about 0.5 μm in thickness. There was no significant difference among the 3 groups. One month after theoperation, histological observation indicated that in group A the regenerated nerves passed through the scaffold and in the new nerves there were regenerated blood vessels. The materials in groups B and C were not completely degraded. S-100 immunohistochemical observation and Bielschowsky staining showed that in groupB PDLLA-T3 repaired the defect successfully and the regenerated nerve myelinsheath was 1.81±0.19 μm in thickness. The effect in group B was better thanthat of groups A and C (P＞0.05). Two months after the operation, the materials in groups B and C were completely degraded. The quantity of the regeneratednerves in group B confirmed by S-100 immunohistochemical observation and Bielschowslcy staining was more than that in group C(P＜0.05) and close to that in group A. The regenerated nerve myelin sheath in group B was 2.15±0.27 μm in the thickness and was thicker than that in group C (P＜0.05)， but thinner than that in groups A and D (P＜0.05). Conclusion PDLLA-T3 can repair the defect of rat sciatic nerve with satisfactory quantity andquality of regenerated nerves.
ObjectiveTo investigate the regularity of myelin degeneration and regeneration and the difference of axonal density between tibial nerve and common peroneal nerve after sciatic nerve injury repair in rhesue monkey. MethodsNine adult rhesue monkeys (male or female, weighing 3.5-4.5 kg) were selected to establish the model of rat sciatic nerve transaction injury. The tibial nerve and common peroneal nerve of 5 mm in length were harvested at 5 mm from injury site as controls in 3 monkeys; the distal tibial nerve and common peroneal nerve were repaired with 9-0 suture immediately in the other 6 monkeys. And the gross observation and neural electrophysiological examination were performed at 3 and 8 weeks after repair respectively. Then, distal tibial nerve and common peroneal nerve at anastomotic site were harvested to observe the myelin sheath changes, and to calculate the number of axon counts and axonal density by staining with Luxol Fast Blue. ResultsAtrophy of the lower limb muscle and various degrees of plantar ulcer were observed. Gross observation showed nerve enlargement at anastomosis site, the peripheral connective tissue hyperplasia, and obvious adhesion. The compound muscle action potential (CMAP) of tibial nerve and common peroneal nerve could not be detected at 3 weeks; the CMAP amplitude of common peroneal nerve was less than that of the tibial nerve at 8 weeks. Different degrees of axonal degeneration was shown in the tibial nerve and common peroneal nerve, especially in the common peroneal nerve. The average axonal density of common peroneal nerve was lower than that of tibial nerve at 3 weeks (13.2% vs. 44.5%) and at 8 weeks (10.3% vs. 35.3%) after repair. ConclusionThe regeneration of tibial nerve is better and faster than that of common peroneal nerve, and gastrocnemius muscle CMAP recovers quicker, and amplitude is higher, which is the reason of better recovery of tibial nerve.
Objective To investigate the effect of exogenous erythropoietin (EPO) on the denervated muscle atrophy. Methods Twenty-four SD male rats, weighting 200-220 g were made the models of denervated gastrocnemius muscle after sciatic nerves were transected under the piriform muscle at the right lower leg, and were randomly divided into two groups (n=12). rhEPO (2 500 U/kg) was injected daily into the denervated gastrocnemius muscle in EPO group, and normal sal ine was injected into the denervated gastrocnemius muscle in control group. To observe the general state of health of the experimental animal, the muscle wet weight, the muscle cell diameter, the cross section area, the protein amount, thepercentage of the apoptotic muscle cells, and the Na+-K+-ATPase and Ca2+-ATPase activities were measured 2 and 4 weeks after operation. Results All experimental animals were survived during experiment without cut infection, and all animals could walk with pull ing the right knee. At 4 weeks after operation, 7 cases showed ulcer in the right heel, inculding 5 in the control group and 2 in the EPO group. At 2 and 4 weeks after operation, the muscle wet weight in EPO group was (885.59 ± 112.35) and (697.62 ± 94.74) g, respectively; in control group, it was (760.63 ± 109.05) and (458.71 ± 58.76) g, respectively; indicating significant differences between two groups (P lt; 0.01). The protein amount in EPO group was (77.37 ± 5.24) and (66.37 ± 4.87) mg/mL, respectivly；in control group, it was (65.39 ± 4.97) and (54.62 ± 6.32) mg/mL；indicating significant differences between two groups (P lt; 0.01). At 2 and 4 weeks after operation, the myofibrillar shapes were nearly normal in EPO group while there were muscle fiber atrophy, some collapse and obviously hyperblastosis between muscle bundle. There were significant differences in the muscle cell diameter and the cross section between two groups (P lt; 0.01). However, the percentage of the apoptotic muscle cells was 11.80% ± 1.74% and 28.47% ± 1.81% in control group, respectively, which was significantly smaller than that in EPO group (21.48% ± 2.21% and 55.89% ± 2.88%, P lt; 0.01). At 2 and 4 weeks after operation, Na+-K+-ATPaseand Ca2+-ATPase activities in EPO group were higher than those in control group (P lt; 0.01). Conclusion EPO can delay the denervated muscle atrophy.
Objective To evaluate an effect of the vascularendothelial growth factor (VEGF) geneactivated matrix (GAM) on repair of the sciatic nerve defect in rats. Methods The peripheral nerve extracellular matrix（ECM） was harvested by the chemical extraction from 30 SD rats. The VEGF-GAM comprised of ECM and the plasmids encoding VEGF. Thirty adult Wistar rats were made as a model of the asciatic nerve defect and were randomly divided into the following 3 groups(n=10): Group A (VEGF-GAM conduits), Group B (ECM conduits),and Group C (autografts). At 12 weeks, the rats from each groupwere subjected to an inspection for the walking tract analysis and electrophysiological and histomorphological studies.Results The VEGF DNA could be retained in GAM, promoting the transgene expressing in the sciatic nerve, and more importantly, in the axotomized neurons in the spinal cord for 12 weeks. The motor neuron recovery rate in Group A (79.13％±2.53％) was similar to that in Group C (75.26％±4.48％, Pgt;0.05), but significantly better than that in Group B (56.09％±1.89％, Plt;0.01). The number of the regenerationaxons in the distal sciatic nerve in Group A (13 463±794/mm2) was significantly lower than that in Group C (16 809±680/mm2, Plt; 0.01), but significantly higher than that in Group B (10 260±1 117/mm2,Plt;0.01). The motor nerve conduction velocity in Group A (16.44±1.65 m/s) was significantly lowerthan that in Group C (23.79±2.75 m/s, Plt;0.01), but significantly higherthan that in Group B (12.8 ±1.42 m/s, Plt;0.01). The recovery rate of thegastrocnemius muscle wet weight in Group A (71.40％±3.05%) was significantlylower than that in Group C (87.00％±1.87％,Plt;0.01), but significantly higher than that in Group B (50.00％±4.90％, Plt;0.01). The sciatic nerve function index in Group A （39.37%±4.81%） was significantly lower 〖KG6〗than that in Group C (26.27%±2.71%, Plt;0.01), but significantly higher than that in Group B (4693％±296％, Plt;0.01). Conclusion The results indicate that VEGF-GAM as a bridge can promote the functional recovery of the defected sciatic nerve in rats, but the effect is not so good as that by autografts.
ObjectiveTo fabricate salidroside/collagen/polycaprolactone (PCL) nerve conduit composite and to investigate the effect of composite nerve conduits for repairing sciatic nerve defect. MethodsThe salidroside microspheres were prepared by W/O/W method, and the sustained release rate of microspheres was detected. The microspheres containing 10, 20, and 40 μg salidroside were mixed with collagen to prepare the nerve conduit core layer by freeze-drying method. The shell layer of collagen/PCL scaffold material was fabricated by electrospinning technology. The genipin cross-linked salidroside/collagen/PCL nerve conduit composite was prepared. The structure of nerve conduit was observed before and after cross-linked by scanning electron microscope. Thirty-eight Wistar rats were used to make the right sciatic nerve defect model of 15 mm in length, and randomly divided into groups A, B, C, D (n=9), and group E (n=2), then defect was repaired with the collagen/PCL conduit in group A, autologous nerve in group E, the 10, 20, and 40 μg/mL salidroside/collagen/PCL conduit in groups B, C, and D, respectively. The survival of rats was observed. The sciatic functional index (SFI) was evaluated at 1, 3, and 6 months after operation. At 6 months, the tissue of defect area was harvested for the general, electrophysiology, histological, and immunohistochemical[S-100 and peripheral myelin protein 0(P0)] staining observations. ResultsSalidroside microspheres showed burst release at 3 days, and then it tended to be stable at 13 days and lasted for 16 days, with a cumulative release rate of 76.59%. SEM showed that the disordered fiber of nerve conduit shell layer after crosslinking became conglutination, shrinkage, and density, and had void. The channels of core layer were clearly visible before and after crosslinking. The rats had no infection or death after operation. The SFI of group E was significantly higher than that of groups A, B, C, and D at 1, 3, and 6 months (P<0.05); it was significantly higher in groups B, C, and D than group A (P<0.05), but no significant difference was found among groups B, C, and D at 1 month (P>0.05); there was no significant difference in SFI among groups A, B, C, and D at 3 months (P>0.05); SFI was significantly higher in group C than groups A, B, and D and in groups A and B than group D (P<0.05), but no significant difference between groups A and B (P>0.05) at 6 months. In addition, no significant difference was shown among different time points in the other groups (P>0.05) except groups C and E at 1, 3, and 6 months (P<0.05). The general observation showed that good connection with the thick nerve in groups B and C, and connection with the fine nerves in groups A and D. The conduit materials obviously degraded. Nerve electrophysiological examination showed that the latency/conduction velocity of groups C and E were significantly lower than those of groups A, B, and D (P<0.05), but difference was not significant between groups C and E, and among groups A, B, and D (P>0.05). The histological observation showed that the nerve fiber tissue of groups B, C, and E was obviously more than that of groups A and D, and group C was similar to group E in the nerve fiber arrangement, and the core layer material of each group was completely degraded. Immunohistochemical staining showed that S-100 and P0 proteins expressed in all groups; and the expression level of groups B, C, and E was significantly higher than that of groups A and D, and gradually increased (P<0.05); difference in S-100 expression level was not significant between groups A and D (P>0.05), and P0 expression level of group A was significantly lower than that of group D (P<0.05). ConclusionSalidroside/collagen/PCL nerve conduit can promote sciatic nerve defect repair.