Clavicle fractures are a common orthopedic injury, accounting for approximately 2.6%-4% of all adult skeletal fractures. In 2023, the American Academy of Orthopaedic Surgeons (AAOS) developed evidence-based treatment guidelines for clavicle fractures, which include 4 recommended practices and 10 treatment options. This article, based on a thorough review of the guidelines, discusses the clinical treatment of clavicle fractures, aiming to share advancements and the latest diagnostic and therapeutic considerations with orthopedic colleagues to enhance treatment outcomes.
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 M2-like macrophage/microglia-derived mitochondria transplantation in treatment of mouse spinal cord injury (SCI). Methods BV2 cells were classified into M1 (LPS treatment), M2 (IL-4 treatment), and M0 (no treatment) groups. After receiving M1 and M2 polarization, BV2 cells received microscopic observation, immunofluorescence staining [Arginase-1 (Arg-1)] and flow cytometry [inducible nitric oxide synthase (iNOS), Arg-1] to determine the result of polarization. MitoSox Red and 2, 7-dichlorodi-hydrofluorescein diacetate (DCFH-DA) stainings were used to evaluate mitochondrial function difference. Mitochondria was isolated from M2-like BV2 cells through differential velocity centrifugation for following transplantation. Then Western blot was used to measure the expression levels of the relevant complexes (complexes Ⅱ, Ⅲ, Ⅳ, and Ⅴ) in the oxidative phosphorylation (OXPHOS), and compared with M2-like BV2 cells to evaluate whether the mitochondria were obtained. Thirty-six female C57BL/6 mice were randomly divided into 3 groups (n=12). Mice from sham group were only received the T10 laminectomy. After the T10 spinal cord injury (SCI) model was prepared in the SCI group and mitochondria transplantation (MT) group, mitochondrial storage solution and mitochondria (100 μg) derived from M2-like BV2 cells were injected into the injured segment, respectively. After operation, the Basso Mouse Scale (BMS) score was performed to evaluate the motor function recovery. And immunofluorescence staining, lycopersicon esculentum agglutinin (LEA)-FITC staining, and ELISA [vascular endothelial growth factor A (VEGFA)] were also performed. Results After polarization induction, BV2 cells in M1 and M2 groups showed specific morphological changes of M1-like and M2-like macrophages, respectively. Immunofluorescence staining showed that the positive expression of M2-like macrophages marker (Arg-1) was significantly higher in M2 group than in M0 group and M1 group (P<0.05). Flow cytometry showed that the expression of M1-like macrophage marker (iNOS) was significantly higher in M1 group than in M0 group and M2 group (P<0.05), and the expression of Arg-1 was significantly higher in M2 group than in M0 group and M1 group (P<0.05). MitoSox Red and DCFH-DA stainings showed that the fluorescence intensity of the M2 group was significantly lower than that of the M1 group (P<0.05), and there was no significant difference with the M0 group (P>0.05). The M2-like BV2 cells-derived mitochondria was identified through Western blot assay. Animal experiments showed that the BMS scores of MT group at 21 and 28 days after operation were significantly higher than those of SCI group (P<0.05). At 14 days after operation, the number of iNOS-positive cells in MT group was significantly lower than that in SCI group (P<0.05), but still higher than that in sham group (P<0.05); the number of LEA-positive cells and the expression of VEGFA in MT group were significantly more than those in the other two groups (P<0.05). Conclusion M2-like macrophage/microglia-derived mitochondria transplantation can promote angiogenesis and inhibit inflammatory M1-like macrophage/microglia polarization after mouse SCI to improve function recovery.
ObjectiveTo review the advances of the role of mitochondrial dysfunction in the spinal cord injury (SCI) and its relevant treatments. MethodsFocusing on various mechanisms of mitochondrial dysfunction, recent relevant literature at home and abroad was identified to summarize the therapeutic strategies for SCI. ResultsMitochondrial dysfunction is mainly manifested in abnormalities in mitochondrial energy metabolism, mitochondrial oxidative stress, mitochondrial-mediated apoptosis, mitophagy, mitochondrial permeability transition, and mitochondrial biogenesis, playing a vital role in the development of SCI. Drug that enhanced mitochondrial function have been proved beneficial for the treatment of SCI. ConclusionMitochondrial dysfunction can serve as a potential therapeutic target for SCI, providing ideas and basis for the development of SCI therapeutic candidates in the future.
【Abstract】 Objective To establ ish an artificial physiological reflex arc with reconstruction of the sensory and themotorial functions of atonic bladder simultaneously after the conus medullary injury in rats. Methods Twenty 3-month-oldmale SD rats, with the weight of 250 to 300 g, were included. The right side was the experimental side, while the left side served as a control. Intradural microanastomosis of the right L5 ventral root to S2 ventral root and L5 dorsal root to S2 dorsal root wasperformed to reconstruct the sensory and the motorial functions of atonic bladder. After axonal regeneration, the new motor-tomotor and sensory-to-sensory artificial bladder reflex pathway was establ ished. At 5 months postoperatively, the early function of the reflex arc was observed by electrophysiological examinations, and the bladder pressure was tested. Results Eighteen rats survived for 5 months after the operation. Single stimul i (3 mA, 0.3 ms) of the S2 dorsal root of the experimental side resulted in evoked potentials recorded from the right vesical plexus before and after the spinal cord was destroyed horizontally between L6 and S4 segmental levels. The ampl itudes of the evoked potentials were (0.10 ± 0.02) mV and (0.11 ± 0.03) mV, respectively, before and after paraplegia, and there was no statistically significant difference (P gt; 0.05). The figures of the evoked potentials were similar to those of the control side. Bladder contraction was initiated by trains of stimul i (3 mA, 20 Hz, 5 s) of the S2 dorsal root of the experimental side. The bladder pressures were (6.55 ± 1.33) cmH2O and (6.11 ± 2.01) cmH2O, respectively, and the ampl itudes of bladder smooth muscle complex action potential were (0.11 ± 0.02) mV and (0.11 ± 0.03) mV, respectively, beforeand after paraplegia. There was no significant difference (P gt; 0.05). These figures were similar to those of the control side before paraplegia. Before paraplegia, when the S2 dorsal root of the control side was stimulated, the ampl itude of the evoked potential was (0.14 ± 0.02) mV, the bladder pressures was (10.77 ± 1.78) cmH2O and the ampl itude of bladder smooth muscle complex action potential was (0.17 ± 0.02) mV. There was statistically significant difference bewteen the experimental side and the control side (P lt; 0.01). All the results of electrophysiological examinations and bladder pressure were negative when the left S2 dorsal root was stimulated after paraplegia. Conclusion Suprasacral nerve motor-to-motor and sensory-to-sensory transfers after the spinal cord injury to reconstruct the bladder autonomic reflex arc by intradural microanastomosis of ventral root and the dorsal root between L5 and S2 simultaneously is practical in a rat model and may have potential in cl inical appl ication.
Objective To investigate the biocompatibil ity of sil ica gel embedded permanent magnets of themicturition alert device dedicated to neurogenic bladder. Methods According to the national standards of biologicalevaluation of medical equipment (GB/T 16886), Shanghai Biomaterial Research and Test Center was confided to evaluate the biocompatibil ity of sil ica gel embedded permanent magnets both in vitro and in vivo, including cytotoxicity test, sensitization test, primary skin irritant test and acute general toxicity test. The cytotoxicity test was performed according to the agar diffusion method. The L929 cell discoloration index and cell lysis index were counted at 24 hours after the action of the specimen. The sensitization test was performed according to the maximal dose method. The skin response was evaluated in 30 male albino guinea-pigs at 24 and 48 hours after the routine induction and provocation of leaching l iquors of the specimen. The primary skin irritant test was evaluated in 2 male healthy New Zealand rabbits according to the local tissue response at 24, 48 and 72 hours after intradermal injection of leaching l iquors of the specimen. The acute general toxicity test was evaluated in 10 male Kumming mice musculus albus according to animal condition at 4, 24, 48 and 72 hours after injection of leaching l iquors of the specimen through the caudal vein. Both the general reaction of canines and the pathology of the local bladder walls were observed at 2, 4 and 8 weeks after a permanent magnet was fixed on the anterior wall of urinary bladder in three canines. Results No sensitization, no stimulation and no acute general toxicity were observed except sl ight cytotoxicity to sil ica gel embeddedpermanent magnets. After implantation of a permanent magnet, the canines showed excellent tolerace, which manifested as no abnormal ity in spirit, appetite, urine and stool, healed wounds and no infection. Adhesions occurred between the epiploon and the bladder wall around the permanent magnet in two canines at 2 and 4 weeks, and between the lower abdominal wall and the bladder wall around the permanent magnet in the other canine at 8 weeks. The local bladder wall below permanent magnet was thickened, the fibrous capsule around the permanent magnet was thin, but the bladder mucosa was normal. Inflammatory reaction such as congestion, edema and inflammatory cells lessened from the serosa layer to the mucosa layer microscopically. Conclusion Sil ica gel embedded permanent magnets used in the micturition alert device dedicated to neurogenic bladde has excellent biocompatibil ity and meet the criteria for cl inical appl ication．
To establ ish the animal model of the artificial physiological reflex arc with the reconstruction of the sensory and the motorial functions of atonic bladder simultaneously in the rats, and to provide the foundation to furtherinvestigate the repairing effectiveness of this technique. Methods There were 20 adult male SD rats (weighing 280-300 g)which were randomly divided into 2 groups (n=10): group A and group B. Group A was anastomosis of the ventral roots(VR) and the dorsal roots (DR) between L6 and S2 simultaneously to establ ish the model of the artificial physiological reflex arc. Group B was anastomosis of the main trunk between L6 and S2 to establ ish the model. The contents of the observation included: ① To measure the external diameter of the VR, DR and the main trunk of L6 and S2 with the sl iding cal iper; and to measure not only the distance between L6 and S2 but also the separable length of L6 with the ruler. ② Fast Blue dyeing of the VR, DR and the main trunk of L6 and S2 was performed to count their nerve fibers assisted by the Leica FW4000 system 2 weeks after opertation. ③ The observation of the urination of the rat and BBB scoring to evaluate the motorial function of the lower l imbs was performed postoperatively. Results ① L6 located in the lateral side of the S1-4 in the vertebral body of L6. The external diameters of the VR, DR and the main trunk of L6 were (0.68 ± 0.13), (0.88 ± 0.10) and (1.54 ± 0.33) mm, respectively, while those of S2 were (0.62 ± 0.08), (0.79 ± 0.14) and (1.39 ± 0.42) mm, respectively. The distance between L6 and S2 was (14.21 ± 1.95) mm, and the separable length of L6 was (10.76 ± 2.11) mm. Furthermore, the microdissection indicated the VR and the DR between L6 and S2 could be anastomosed respectively with no-tension at the level of the vertebral body of L6; and the main trunk of L6 and S2 could be anastomosed with no-tension at the level of the confluens of L5, 6. ② With Fast Blue dyeing, there were 892 ± 32, 354 ± 26 and 532 ± 17 nerve fibers of the VR, DR and the main trunk of L6, respectively. And there were 788 ± 29, 325 ± 19, and 478 ± 22 nerve fibers of the VR, DR and the main trunk of S2, respectively. There were no volar ulcer,trichomadesis and self-eating of the affected l imbs in the both groups postoperatively. The urinations of the rats after operationwere not different from those before operation. The mean BBB scores of pre- and postoperation in group A were 20.20 ± 0.35 and 19.80 ± 0.23, respectively; the mean BBB scores of pre- and postoperation in group B were 20.20 ± 0.35 and 19.20 ± 0.31, respectively. There was no significant difference of the above indexes between group A and group B (P gt; 0.05). Conclusion Anastomosis of the VR and the DR between L6 and S2 simultaneously in rats is an ideal animal model to establ ish the artificial physiological reflex arc owing to its simple and reproducible procedures.
To introduce a micturition alert device dedicated to neurogenic bladders. Methods The design and mechanism of the micturition alert device were explained, the effectiveness was tested in a cranine experiment. Results The micturition alert device consisted of a permanent magnet sutured on the anterior bladder wall and a warning unit sutured on theinferior abdominal wall. The warning unit was assembled with a compass-l ike switch, a power supply, a buzzer and a power switch. Bladder volume determined the position of the magnet which determined the magnetic field at the point of the warning unit. The change of magnetic field was read by the warning unit. With increasing bladder volume from initial state to 200 mL in 8 dogs, the magnet moved cranially 32.8 mm averagely (from 31.3 mm to 34.1 mm) and the hand of warning unit turned 52° (from 47° to 57°). The value of the warning unit was correlated positively to the bladder volume (r =1.0, P lt; 0.01）. If the desired bladder volume was determined as 150 mL to activate the warning unit to alarm in advance, the fullness of bladder was 147.6 mL averagely from135 mL to 160 mL, with an error less than 15 mL (10%). Conclusion The micturition alert device including a warning unit and permanent magnet could monitor bladder volume continuously and alarm in time for the patients with loss of micturition desire. It is simple, easily-made, cheap and conveniently used. It is worth of further study.
Objective To study major influential factors of the micturition alert device dedicated to neurogenic bladders for the product design and cl inical appl ication of the device. Methods One ferrite permanent magnet with thickness and diameter of 3 mm and 10 mm, respectively, and three NdFeB permanent magnets with the thickness of 3 mm and diameter of 10, 15 and 20 mm, respectively, were used. The effects of thickness of the abdominal wall as well as the position and type of permanent magnets on the micturition alert device dedicated to neurogenic bladders were measured in vitro simulated test, when the abdominal wall was set to 2, 3, 4, 5, 6, 7, 8 and 9 cm, respectively, and the position of permanent magnets was 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 cm, respectively. The effect of the geomagnetic field on the device was measured under the condition that the thickness of the simulated abdominal wall was set to 2, 3, 4 and 5 cm, respectively,and the position of permanent magnets was 2, 3, 4, 5, 6, 7, 8, 9 and 10 cm, respectively. Results The value showed inthe warning unit was positively correlated with the position of the ferrite permanent magnet only when the thickness ofthe simulated abdominal wall was 2 cm (r=0.632, P lt; 0.05). The correlation between the value of the warning unit andthe position of NdFeB permanent magnets was significant (r gt; 0.622, P lt; 0.05), which was intensified with the increasingdiameter of NdFeB permanent magnets, but weakened with the increasing thickness of the simulated abdominal wall. The effect of the geomagnetic field was correlated with the exposition of the body, the position of the permanent magnet and the thickness of the abdominal wall. Conclusion The major influential factors of the micturition alert device dedicated to neurogenic bladder include the magnetism and location of the permanent magnet, the thickness of the abdominal wall and the geomagnetic field. These factors are correlated with and affect each other. Reasonable allocation of these factors may optimize the device.
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.