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BACKGROUND: Exercise is an effective method for preventing and treating osteoporosis, but it is unclear whether its effect on postmenopausal osteoporosis is related to changes in bone autophagy levels. OBJECTIVE: To observe the effects of exercise via cellular autophagy on the morphology and mechanical properties of bone tissue in ovariectomized rats, and to explore the mechanism of exercise on bone mass in ovariectomized rats from the perspective of autophagy. METHODS: A rat model of postmenopausal osteoporosis was established, and a 24-week moderate-intensity exercise was used for intervention. After the experiment, serum estradiol levels were measured by ELISA, and bone mineral density and bone microstructure of the cortical and trabecular bone were detected by micro-CT. The biomechanical indicators of the tibia were tested by a three-point bending test. Autophagosomes were observed by transmission electron microscopy. The expression of LC3 and ATG7 proteins was analyzed by western blot. RESULTS AND CONCLUSION: The serum estradiol level in the ovariectomized group was significantly lower than that of the sham-operation group and ovariectomized+exercise group (P < 0.01). The body mass of rats in each group increased, and the order was the ovariectomized group > the ovariectomized+exercise group > the sham-operation group > the sham-operation+exercise group. The bone mineral density and bone mass of rats in all groups significantly increased (P < 0.01), but the increase in the ovariectomized group was significantly lower than that of the other groups, and the increase in the ovariectomized+exercise group was significantly higher than that of the ovariectomized group. Compared with the sham-operation group, the bone mineral density of the tibial cancellous bone in the sham-operation+exercise group was significantly increased (P < 0.01), while the bone mineral density in the ovariectomized and ovariectomized+exercise groups was significantly decreased (P < 0.01). Compared with the ovariectomized+exercise group, the ovariectomized group showed significantly lower bone volume fraction, number of trabeculae, and bone mineral density of cancellous bone (P < 0.05), extremely significantly lower trabecular thickness (P < 0.01), and significantly higher mean trabecular pattern factor, trabecular separation, and structural model index (P < 0.01). Compared with the ovariectomized group, the LC3-II/LC3-I ratio and the relative expression of ATG7 protein significantly increased in the ovariectomized+exercise group (P < 0.05). Compared with the sham-operation and ovariectomized groups, the number of autophagosomes increased in the sham-operation+exercise and ovariectomized+exercise groups, respectively. To conclude, moderate-intensity treadmill exercise can improve the bone microstructure and biomechanical properties of the tibial cancellous bone and increase bone mass in ovariectomized rats by increasing serum estradiol levels and bone autophagy levels. [ABSTRACT FROM AUTHOR]

BACKGROUND: Decreased expression of neurotrophic factors and increased expression of regenerating inhibitors are the main mechanisms of nerve injury. It has been proven that mitochondrial fission inhibitor-1 can decrease clinical score and relieve pathological injury in a mouse model of multiple sclerosis. However, its neuroprotective effects still need to be further explored. OBJECTIVE: To observe the state of neurons and axons in a mouse model of experimental autoimmune encephalomyelitis and to evaluate the neuroprotective effect of mitochondrial fission inhibitor-1. METHODS: A mouse model of experimental autoimmune encephalomyelitis was prepared in C57BL/6 mice by immunizing with myelin oligodendrocyte glycoprotein peptide fragment 35-55. Animal models were randomly divided into two groups (n=15 per group): model group and mitochondrial fission inhibitor-1 group. Mice were euthanized and lumbar spinal cord consecutive sections were harvested at day 28 post immunization. Immunofluorescence staining was used to analyze the state of neuronal cell body and synapse, the phosphorylation level of dynamin-related protein 1, and the expression of neurotrophic factor, regeneration inhibitor and its signaling pathway molecules in spinal cord tissue. RESULTS AND CONCLUSION: Compared with the model group, treatment with mitochondrial fission inhibitor-1 increased the number of neurons marked by neuron-specific nuclear protein in the spinal cord tissue, improved neuronal body morphology, increased the length of synaptophysin-positive synapse, decreased the loss of Neurofilament M, and inhibited the phosphorylation of dynamin-related protein 1. Mitochondrial fission inhibitor-1 treatment could significantly promote the expression of glial cell-derived neurotrophic factor, ciliary neurotrophic factor, and brain-derived neurotrophic factor. Mitochondrial fission inhibitor-1 intervention could markedly reduce the expression of myelin-associated glycoprotein, axon growth inhibitory factor A, axon growth inhibitory factor protein receptor, p75 neurotrophin protein receptor, and Rho-related protein kinase II in the mouse model. To conclude, mitochondrial fission inhibitor-1 can inhibit the phosphorylation level of dynamin-related protein 1, increase the expression of neurotrophic factor protein, and reduce the expression of regeneration inhibitor and related signaling pathway molecular proteins, thus alleviating damage to spinal cord neuron cell bodies, axons, and cysts. [ABSTRACT FROM AUTHOR]

BACKGROUND: Gutta-percha has low yield strength and shows hard and tough mechanical properties. On this basis, a sports protective gear that can be freely shaped according to the body shape has been developed, and it has been preliminarily confirmed that this performance can reduce the damage to athletes caused by external impact forces. OBJECTIVE: To evaluate the effect of gutta-percha splint on fracture fixation. METHODS: Thirty-five adult male New Zealand rabbits were used to establish closed fracture models of the left tibia by the modified three-point stress method. Totally 30 successful models were randomly divided into two groups (n=15) and fixed with gutta-percha splint and gypsum, respectively. The effects of the two external fixation methods were compared by X-ray imaging and fracture healing was observed at 2 hours, 4 and 6 weeks after fixation. After 6 weeks of fixation, the tibia specimens were observed for gross and histological morphology. RESULTS AND CONCLUSION: (1) X-ray films: Clear fracture line was seen 2 hours after fixation, without obvious periosteal reaction. After 4 weeks, the fracture line became blurred, and a large area of spindle low-density callus shadow was seen at the broken end. After 6 weeks, the fracture line nearly disappeared; the callus connected together to form a cortical bone bridge, and the bone marrow cavity was partially canalized, and partially close to recanalization. After 6 weeks, gray value at the fracture site was higher in the gutta-percha splint group than that in the gypsum group (P < 0.05). (2) General observation: In the gutta-percha splint group, except for three rabbits with malunion, the fracture line of the rest of the rabbits basically disappeared; part of the outer callus was absorbed, and the cortical bone density was close to the normal level. In the gypsum group, except for four rabbits with malunion, the fracture line of the rest of the rabbits disappeared, a small part of the outer callus was absorbed, and the cortical bone density was close to the normal level. (3) Histological morphology: In the gutta-percha splint group, new bone trabeculae were thick; the trabecular space was reduced and fused to form lamellar bone, and the medullary cavity had been partially recanalized. In the gypsum group, new bone trabeculae were reticular, forming a woven bone, and a large number of transected small arteries, veins and capillaries could be seen in the medullary cavity. (4) Complications: Within 6 weeks of fixation, the extremity swelling, purple darkening, displacement and malunion, and the number of local pressure ulcers in the gutta-percha splint group tended to be less than those in the gypsum group, but there was no significant difference in statistical analysis (P > 0.05). (5) The results showed that gutta-percha splint could play a similar fixation effect to plaster on the rabbit model of closed tibial fracture. [ABSTRACT FROM AUTHOR]

BACKGROUND: Endplate chondrocytes are regulated by many factors in the microenvironment of the intervertebral disc and the influence of microenvironmental changes inside the intervertebral disc caused by abnormal stress on endplate chondrocytes still needs to be explored. OBJECTIVE: To observe the exosome secretion of nucleus pulposus cells under cyclic mechanical tension conditions and the effect of exosomes on endplate chondrocytes under this condition. METHODS: Nucleus pulposus cells were isolated and cultured from the nucleus pulposus of patients undergoing lumbar surgery in vitro. The cells were loaded with cyclic mechanical tension by FX-5000T system. Exosomes secreted from nucleus pulposus cells under stress and non-stress conditions were extracted by magnetic bead method. Purity and concentration of nucleus pulposus cells-derived exosomes were identified by flow cytometry. The exosomes were labeled with PKH67 fluorescent dye and incubated with endplate chondrocytes for 24 hours. Endplate chondrocytes cultured alone were used as control. The uptake of exosomes by endplate chondrocytes was observed under inverted fluorescence microscope. Then the apoptosis and activity of endplate chondrocytes were observed. Type II collagen, depolymerized protein like metalloproteinase 5, matrix metalloproteinase 3, bone morphogenetic protein 2, and β-catenin mRNA expression were detected. RESULTS AND CONCLUSION: Under certain cyclic mechanical tension conditions, nucleus pulposus cells could be promoted to secrete exosomes, and the particle concentration of nucleus pulposus cells-derived exosomes was higher than that under non-stress conditions. Under the inverted fluorescence microscope, both stress and non-stress nucleus pulposus cells-derived exosomes could be ingested by endplate chondrocytes. Compared with the control group, the viability of endplate chondrocytes decreased significantly (P < 0.05) and the apoptosis rate increased in the stress group (P < 0.05). Compared with the control group, the mRNA expression of matrix metalloproteinase 3 and bone morphogenetic protein 2 in endplate chondrocytes decreased significantly in the non-stress group (P < 0.05). Compared with the control group, the mRNA expression of type I collagen decreased significantly in the stress group (P < 0.05), while the mRNA expression of depolymerized protein like metalloproteinase 5, matrix metalloproteinase 3 and β-catenin increased significantly in the stress group (P < 0.05). Compared with the non-stress group, the mRNA expression of type II collagen decreased significantly in the stress group, while the mRNA expression of depolymerized protein like metalloproteinase 5, matrix metalloproteinase 3 and bone morphogenetic protein 2 increased significantly in the stress group (P < 0.05). Therefore, abnormal stress could promote the exosome secretion of nucleus pulposus cells, and the exosomes under this condition could inhibit the viability of endplate chondrocytes and cause the disorder of cell matrix synthesis and catabolism. [ABSTRACT FROM AUTHOR]

BACKGROUND: Relevant studies have shown that anterior cruciate ligament rupture may be related to the anatomical morphology of the distal femur and proximal tibia. OBJECTIVE: To investigate the correlation between anterior cruciate ligament rupture and the match between the tibial intercondylar eminence and the femoral intercondylar fossa. METHODS: A total of 74 male soldier patients who were admitted at the 904 Hospital of the Joint Logistics Support Force from January 2016 to March 2021 and suffered unilateral knee injuries or discomfort due to non-contact mechanism were selected. According to X-ray and magnetic resonance imaging findings, they were divided into two groups (n=37 per group): an anterior cruciate ligament rupture group and an intact anterior cruciate ligament group. Width index of the intercondylar fossa was detected using coronal magnetic resonance imaging, and the morphology of the intercondylar fossa was observed using axial magnetic resonance imaging. In X-ray, posteroanterior films were used to detect the width, lateral and medial height of the tibial intercondylar eminence. Ratio of the width of the tibial intercondylar eminence to the width of the intercondylar fossa was used to describe the match between the tibial intercondylar eminence and the femoral intercondylar fossa. RESULTS AND CONCLUSION: There was no significant difference between the two groups in the width of femoral bicondyle, the lateral and medial heights of the tibial intercondylar eminence (P > 0.05). The width of the intercondylar fossa, the width index of the intercondylar fossa, the width of the tibial intercondylar eminence, and the ratio of the width of the tibial intercondylar eminence to the width of the intercondylar fossa in the anterior cruciate ligament rupture group was lower than that in the intact anterior cruciate ligament group (P < 0.05). The A-shaped intercondylar fossa was more common in the anterior cruciate ligament rupture group, and the U-shaped intercondylar fossa was more common in the intact anterior cruciate ligament group. Univariate Logistic regression analysis showed that the width of the intercondylar fossa, the width index of the intercondylar fossa, the morphology of the intercondylar fossa, the parameters of the tibial intercondylar eminence, and the ratio of the width of the tibial intercondylar eminence to the width of the intercondylar fossa were all the influencing factors for anterior cruciate ligament rupture (P < 0.05). Multivariate Logistic regression analysis showed that the ratio of the width of the tibial intercondylar eminence to the width of the intercondylar fossa was an independent risk factor for anterior cruciate ligament rupture (P < 0.05). Receiver operating characteristic curve showed that the ratio of the width of the tibial intercondylar eminence to the width of the intercondylar fossa had a certain predictive value for anterior cruciate ligament rupture. To conclude, the ratio of the width of the tibial intercondylar eminence to the width of the intercondylar fossa is an independent risk factor for anterior cruciate ligament rupture. It has a certain predictive value for anterior cruciate ligament rupture. The worse the match between the tibial intercondylar eminence and the femoral intercondylar fossa is, the higher the risk of anterior cruciate ligament rupture is. [ABSTRACT FROM AUTHOR]

BACKGROUND: Robot assisted orthopedic surgery has been gradually popularized in clinical practice, and its application fields include spine, joint, trauma and sports medicine, which are precise and minimally invasive. However, there are few reports on the application of robot assisted puncture biopsy in the diagnosis and treatment of spinal lesions. OBJECTIVE: To explore the clinical value of percutaneous biopsy assisted by orthopedic surgical robot in the diagnosis of spinal lesions. METHODS: The clinical data of 38 patients with spinal lesions treated in Sichuan Provincial People’s Hospital from November 2018 to January 2020 were analyzed retrospectively. All patients underwent percutaneous biopsy assisted by TINAVI orthopedic surgery robot. The biopsies were sent to the pathology department for histopathological examination. RESULTS AND CONCLUSION: (1) The successful rate of biopsy was 100% in 38 samples. Of them, 21 cases affected metastases; 4 cases had primary malignant tumors; 5 cases suffered from borderline tumors; 5 cases had benign tumors; and 3 cases experienced non-specific inflammatory reaction. (2) The average operation time was (37.11±5.65) minutes, and no complications occurred in all patients. (3) Robot assisted percutaneous biopsy is a safe, rapid, minimally invasive and accurate method for the diagnosis of spinal lesions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bionic porous scaffolds used in bone tissue engineering requires extracellular matrix-like nanofibrous and connected macroporous structure to effectively support cell implantation, adhesion, proliferation and other behaviors, and promote tissue regeneration. OBJECTIVE: To summarize the research progress in nanorfibrous macroporous scaffold preparation technology for tissue engineering based on the latest relevant research trends. METHODS: The first author searched Web of Science, CNKI and Baidu academic databases to retrieve papers published from 2000 to 2019 with the search terms "bone tissue engineering, nanofibrous, macroporous, scaffolds" in English and Chinese, respectively. Finally, 58 articles were included in result analysis. RESULTS AND CONCLUSION: The scaffolds with nanofibrous structures are fabricated using three strategies, including electrospinning, thermally induced phase separation, and self-assembly process. However, bone scaffold fabricated by a single strategy failed to provide interconnected macropores to simulate the microenvironment in the body, which was necessary for cell migration, growth, differentiation, proliferation, and tissue and organ regeneration. Therefore, it is now of great practical and scientific significance to develop macroporous nanofibrous scaffold using a combination of several strategies. Three-dimensional printing technique can provide precise structure and enables the customization of the internal structure and external shape of the scaffold, which promotes the development of bone tissue engineering technique. [ABSTRACT FROM AUTHOR]

BACKGROUND: The near-infrared fluorescent dyes that directly bind to tumor cells have been developed, and IR-780 stands out. OBJECTIVE: To evaluate the specific imaging effect of near-infrared fluorescent dye IR-780 in clear cell renal cell carcinoma (ccRCC). METHODS: Human ccRCC cells 786-O, ACHN and normal human embryonic kidney 293T cells in logarithmic growth phase were incubated with 20 μmol/L IR-780 for 30 minutes. The localization of the dye in ccRCC was observed by laser confocal microscopy. Human ccRCC cells 786-O in logarithmic phase was incubated with 20 μmol/L IR-780 for 30 minutes. The localization of the dye in mitochondria and lysosomes was observed under confocal laser scanning microscope. 10, 100, 1 000 and 10 000 DAPI-stained human ccRCC cells 786-O were respectively added to human blood samples. The mononuclear cells in each group were isolated and cultured with 20 μmol/L IR-780 for 30 minutes. DAPI and IR-780 double positive cells were observed under confocal laser scanning microscope. RESULTS AND CONCLUSION: IR-780 possessed the ability to visualize a variety of ccRCC cells, but not for normal renal epithelial cells. IR-780 had obvious overlapping staining in lysosomes or mitochondria, indicating its selective accumulation in mitochondria and lysosomes in the organelles. IR-780 could detect a small amount of ccRCC in the blood. These results suggest that the near-infrared fluorescent dye IR-780 can specifically accumulate in ccRCC cells, which can be used for specific diagnosis of ccRCC. [ABSTRACT FROM AUTHOR]

BACKGROUND: Achilles tendon adhesion after Achilles tendon injury can lead to decreased biomechanical properties, weakened healing ability, and ultrastructural changes of Achilles tendon, which further affects patients’ daily life and work ability. Therefore, how to effectively deal with and prevent Achilles tendon adhesion has become a hot and difficult problem in clinical treatment. OBJECTIVE: To analyze the effects of biological amniotic membranes on postoperative Achilles tendon adhesion, biomechanics, and ultrastructural changes in rats with Achilles tendon rupture. METHODS: Sixty 6-week-old SD rats were selected to establish bilateral Achilles tendon rupture models and divided into two groups (n=30 per group) by the random number table method. In the model group, the severed end of the tendon was sutured directly. In the amniotic membrane group, the biological amniotic membrane was wrapped around the broken anastomosis and fixed by a suture. The adhesion, biomechanics, morphology, and structure of the Achilles tendon and the expression of p38 and ERK1/2 protein were evaluated 1, 2, and 4 weeks after surgery. RESULTS AND CONCLUSION: (1) 1 week after operation, the Achilles tendon and peritendinous tissues of the two groups were mildly edema, and the adhesion of the Achilles tendon tissues in the model group was more obvious. 2 weeks after the intervention, the Achilles tendon and peritendinous tissues of the model group still had edema, and the adhesion degree between the Achilles tendon and the surrounding tissues was heavier than that of the amniotic membrane group. 4 weeks after operation, there was no edema around the Achilles tendon in both groups, and the healing was well. The adhesion degree of the Achilles tendon in the amniotic membrane group was less than that in the model group. The maximum tension of Achilles tendons in the amniotic membrane group was higher than that in the model group at 2 and 4 weeks after operation (P < 0.001). (2) Hematoxylin-eosin staining and transmission electron microscopy revealed that 1 week after operation, the tendon structure of rats of the two groups was disordered and the collagen fibers were sparsely arranged, in which the model group demonstrated obvious inflammatory reaction and adhesion to the Achilles tendon. Two weeks after operation, the model group still demonstrated obvious inflammatory response, adhesion of Achilles tendon, and irregular ordering of collagen fibers. The amniotic membrane group exhibited an orderly arrangement of collagen fibers and expansion of the endoplasmic reticulum of fibroblasts. At 4 weeks after operation, the collagen fibers of the Achilles tendon in the model group were thickened and disordered, and the rough endoplasmic reticulum was less in the fibroblasts, while the collagen fibers in the amniotic membrane group were ordered and thin, and the fibroblasts contained a large number of rough endoplasmic reticulum. (3) Four weeks after operation, western blot assay exhibited that the expressions of p38 and ERK1/2 protein in the Achilles tendon tissue of rats in the amniotic membrane group were lower than those in the model group (P < 0.05). (4) The results confirm that the biologic amniotic membrane can promote the healing and inhibit the adhesion of Achilles tendon after the operation of the ruptured Achilles tendon, which may be associated with the regulation of the MAPK/ERK signaling pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: At present, open reduction and internal fixation is an effective method for the treatment of Mason type II radial head fracture. The selection of internal fixation includes screws, micro plates, Kirschner wires, absorbable rods or nails. The clinical efficacy reported is inconsistent. OBJECTIVE: To compare the clinical efficacy of titanium alloy screws or absorbable rod for the internal fixation of Mason type II radial head fractures. METHODS: Totally 25 patients with radial head fractures were collected from January 2016 to February 2017 in Sichuan Provincial People’s Hospital, including 16 males and 9 females, at the age of 38-61 years. All patients received open reduction and internal fixation. Of them, 13 cases received titanium alloy screws, and 12 cases received absorbable rod. X-ray images were obtained during follow-up to identify fracture healing time. During the final follow-up, visual analogue score, elbow motion range, Mayo elbow joint function score and Broberg-Morrey scores were compared between the two groups. The study was approved by the Ethics Committee of Sichuan Provincial People’s Hospital·Sichuan Academy of Medical Sciences. RESULTS AND CONCLUSION: (1) There was no significant difference in fracture healing time between the absorbable rod group (2.35±0.92 months) and titanium alloy screw group (2.10±0.47 months) (P > 0.05). (2) In the final follow-up, there was no significant difference in Mayo elbow joint function score and Broberg-Morrey scores between the two groups (P > 0.05). (3) In the final follow-up, there was no significant difference in elbow flexion, extension, supination, and pronation angle between the two groups (P > 0.05). (4) In the final follow-up, there was no significant difference in visual analogue score between the two groups (P > 0.05). (5) These results indicate that the absorbable rod and titanium alloy screws can obtain satisfactory treatment outcomes for Mason type II radial head fractures. However, the absorbable rod can avoid the secondary operation for removing internal fixators, and the adverse impact of stress shielding. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, there were lots of researches on the treatment of diseases by gene modified mesenchymal stem cells, including the treatment of autoimmune diseases. Various miRNAs have been found to be abnormally expressed in autoimmune diseases, among which miR-1 is low-expressed in polymyositis, and miR-1-3p is one of the miRNAs related to systemic lupus eythematosus susceptibility genes. OBJECTIVE: To investigate the immunoregulatory effect of miR-1-5p modified umbilical cord-mesenchymal stem cells on T lymphocyte subsets in systemic lupus erythematosus. METHODS: The expression level of miR-1-5p in the two groups was detected by real-time fluorescence quantitative PCR in eight patients aged 30-60 years with active systemic lupus erythematosus and eight healthy subjects. Umbilical cord-mesenchymal stem cells were isolated and cultured from umbilical cord of newborns delivered at term or cesarean section under aseptic conditions. Using the liposome method, the umbilical cord-mesenchymal stem cells were transfected with Red Fluorescent Control with a concentration gradient of 5, 7, 10, and 15 nmol/L for 24, 48, and 72 hours. Transfection efficiency of miR-1-5p was determined by flow cytometry at different concentration gradients and time gradients. Peripheral blood mononuclear cells in systemic lupus erythematosus patients were isolated by density gradient centrifugation and co-cultured with umbilical cord-mesenchymal stem cells which were transfected with miR-1- 5p, and divided into four groups: umbilical cord-mesenchymal stem cells transfected with miR-1 and co-cultured with peripheral blood mononuclear cells of systemic lupus erythematosus patients, umbilical cord-mesenchymal stem cells transfected with miRNA negative control and co-cultured with peripheral blood mononuclear cells of systemic lupus erythematosus patients, umbilical cord-mesenchymal stem cells co-cultured with peripheral blood mononuclear cells of systemic lupus erythematosus patients, and peripheral blood mononuclear cells of systemic lupus erythematosus patients without treatment group. The coculture was conducted for 48 hours. The relative expression levels of IL-17A, Foxp3, IFN-γ and IL-4 genes in each group were detected by real-time fluorescence quantitative PCR. Flow cytometry was used to detect the differentiation of Th17, Treg, Th1 and Th2 cells in peripheral blood mononuclear cells of each group. RESULTS AND CONCLUSION: (1) miR-1-5p was significantly down-regulated in peripheral blood mononuclear cells of systemic lupus erythematosus patients compared with healthy controls (P < 0.05). (2) The transfection efficiency was highest when the concentration of miR-1-5p was 10 nmol/L and the transfection time was 48 hours. (3) Compared with the peripheral blood mononuclear cells of systemic lupus erythematosus patients without treatment group, the expression of Foxp3 in umbilical cord-mesenchymal stem cells transfected with miR-1-5p and co-cultured with peripheral blood mononuclear cells of systemic lupus erythematosus patients group was increased; the proportion of Treg cells was significantly increased; and the differences were statistically significant (P < 0.05). Compared with the peripheral blood mononuclear cells of systemic lupus erythematosus patients without treatment group, Th17/Treg ratio decreased in the other three co-culture groups, and the difference was statistically significant (P < 0.01). Th17/Treg cell ratio detected by flow cytometry in each group was not significantly different (P > 0.05). Compared with the peripheral blood mononuclear cells of systemic lupus erythematosus patients without treatment group, the Th1/Th2 ratio in the umbilical cord-mesenchymal stem cells transfected with miR-1-5p and co-cultured with PBMC of systemic lupus erythematosus patients group decreased, and the difference was statistically significant (P < 0.05). However, the Th1/Th2 cell ratio of each group detected by flow cytometry was not significantly different (P > 0.05). (4) The results showed that the umbilical cord-mesenchymal stem cells modified by miR-1-5p had an immunoregulatory effect on Treg cells of systemic lupus erythematosus, and overexpression of miR-1-5p could promote the differentiation and proliferation of Treg cells of systemic lupus erythematosus patients. miR-1-5p regulates the immune imbalance of Th17/Treg and Th1/Th2 by up-regulating the expression of Treg cells. [ABSTRACT FROM AUTHOR]

BACKGROUND: The main reason for the failure after total hip arthroplasty is aseptic loosening of the prosthesis. The traditional acetabular cup fixation method is still controversial in maintaining the initial stability of the acetabular cup. It is a new method that can be considered to further improve the fixation method of the acetabular cup to increase its stability. OBJECTIVE: To analyze the feasibility and superiority of locking screw assisted acetabular cup fixation. METHODS: The digital model of acetabular cup and screws were reconstructed and assembled by software Solidworks. The Von-Mises and shear stress of the acetabular cup and screw by three methods, including acetabular cup, acetabular cup with ordinary cancellous bone screw, and acetabular cup with locked cancellous bone screw, were compared. RESULTS AND CONCLUSION: (1) The finite element model of the established acetabular cup and screw had excellent geometric similarity and could be used for finite element analysis. (2) The acetabular cups with locking screws received less Von-Mises and shear stress than other methods. (3) The locking screws could bear higher stress than ordinary screws and effectively dispersed the shear stress of acetabular cups. (4) It is concluded that the combination of locking screws to fix the acetabular cup can effectively prevent the instability of the acetabular cup and the loosening of the prosthesis; it can better provide stability for the acetabular cup and the mechanical environment that the bone tissue grow in the later stage. The acetabular cups with locking screws have obvious advantages than other ordinary screw, which has the limited bearing capacity and low anti-acetabular cup shear force. [ABSTRACT FROM AUTHOR]

BACKGROUND: Percutaneous kyphoplasty for multi-segmental spinal metastases has some problems, such as long operation time, high fluoroscopic dose, and easy leakage of bone cement. Robot-guided percutaneous kyphoplasty can optimize surgery and reduce the incidence of complications. OBJECTIVE: To evaluate the safety and advantage of robot-guided percutaneous kyphoplasty in treatment of multi-segmental spinal metastases. METHODS: The clinical data of 43 cases with multi-segmental spinal metastases with no signs of nerve injury from January 2018 to April 2019 were analyzed retrospectively. According to the different operation methods, the patients were divided into robot-guided group (22 cases) and traditional fluoroscopy group (21 cases). There was no significant difference in gender, age, number of diseased vertebrae, source of primary tumor and preoperative visual analogue scale score between the two groups (P > 0.05), with comparability. The data of operation time, fluoroscopy frequency, fluoroscopy dose, the incidence rate of pedicle wall breaking, angle of penetration, and leakage of bone cement were collected in both groups. Visual analogue scale score, the midline vertebral height and Cobb angle were compared preoperatively, 2 days postoperatively, and during the final follow-up between the two groups. RESULTS AND CONCLUSION: (1) The number of diseased vertebrae in the robot-guided group and traditional fluoroscopy group was 79 and 70, respectively. (2) The average operation time, fluoroscopy frequency and fluoroscopy dose in the robot-guided group were significantly lower than those in the traditional fluoroscopy group, and the difference was statistically significant (P < 0.001). (3) The incidence rate of pedicle wall breaking was 6% in the robot-guided group and 21% in the traditional fluoroscopy group, and the difference was statistically significant (χ2 =6.040, P=0.014). (4) The angle of penetration in the robot-guided group was larger than those in the traditional fluoroscopy group (P < 0.001). (5) The leakage rate of bone cement in the robot-guided group was lower than in the traditional fluoroscopy group (8%, 23%,χ2 =6.869, P=0.009). (6) There was no significant difference in visual analogue scale score, the midline vertebral heights and Cobb angle between the two groups before and 2 days after operation and during the final follow-up (P > 0.05). (7) It is indicated that robot-guided percutaneous kyphoplasty in treatment of multi-segmental spinal metastases can reduce operation time, reduce fluoroscopy frequency, reduce fluoroscopy dose, have good accuracy of penetration and low leakage rate of bone cement. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the development of surgical instruments and techniques, the unicompartmental knee arthroplasty has been accepted. However, there is still a lack of report on unicompartmental knee arthroplasty for treating medial compartmental knee osteoarthritis in young patients in China. OBJECTIVE: To evaluate the clinical curative effect of unicompartmental knee arthroplasty for medial compartmental knee osteoarthritis in young patients. METHODS: Sixteen patients less than 55 years of age with medial compartmental knee osteoarthritis were treated by unicompartmental knee arthroplasty with Oxford III system from June 2013 to June 2017 at Third Department of Orthopedics,Gansu Provincial Hospital. Curative effects were evaluated by Visual Analogue Scale, Hospital for Special Surgery score, range of motion and angle of femorotibial angle and hip-knee-ankle angle before and after surgery. RESULTS AND CONCLUSION: (1) Primary healing of incision was obtained in all patients, and no infection, fat embolism or fracture around the prosthesis occurred except one case of lower limb deep venous thrombosis. (2) All the patients were followed up for 6-36 months. (3) At the postoperative last follow-up, Visual Analogue Scale, Hospital for Special Surgery score, and range of motion of the knee joint were significantly improved compared with the baseline (P < 0.05). (4) The postoperative femorotibial angle and hip-knee-ankle angle were significantly improved compared with the baseline (P < 0.05). (5) These findings suggest that the unicompartmental knee arthroplasty for treating medial compartmental knee osteoarthritis in young patients has a good short-term effect. The moderate- and long-term efficacy needs long follow-up. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the development of surgical instruments and techniques, the unicompartmental knee arthroplasty has been accepted. However, there is still a lack of report on unicompartmental knee arthroplasty for treating medial compartmental knee osteoarthritis in young patients in China. OBJECTIVE: To evaluate the clinical curative effect of unicompartmental knee arthroplasty for medial compartmental knee osteoarthritis in young patients. METHODS: Sixteen patients less than 55 years of age with medial compartmental knee osteoarthritis were treated by unicompartmental knee arthroplasty with Oxford III system from June 2013 to June 2017 at Third Department of Orthopedics,Gansu Provincial Hospital. Curative effects were evaluated by Visual Analogue Scale, Hospital for Special Surgery score, range of motion and angle of femorotibial angle and hip-knee-ankle angle before and after surgery. RESULTS AND CONCLUSION: (1) Primary healing of incision was obtained in all patients, and no infection, fat embolism or fracture around the prosthesis occurred except one case of lower limb deep venous thrombosis. (2) All the patients were followed up for 6-36 months. (3) At the postoperative last follow-up, Visual Analogue Scale, Hospital for Special Surgery score, and range of motion of the knee joint were significantly improved compared with the baseline (P < 0.05). (4) The postoperative femorotibial angle and hip-knee-ankle angle were significantly improved compared with the baseline (P < 0.05). (5) These findings suggest that the unicompartmental knee arthroplasty for treating medial compartmental knee osteoarthritis in young patients has a good short-term effect. The moderate- and long-term efficacy needs long follow-up. [ABSTRACT FROM AUTHOR]

BACKGROUND: As the rate of re-fracture of the rotator is very high, the rotator cuff patch is designed to enhance the healing of the injured rotator cuff. Therefore, the preparation of temporary rotator cuff patch with good biocompatibility, biodegradability and biomechanical properties has become a committed step. OBJECTIVE: To prepare a temporary rotator cuff patch with different ratio of silk fibroin (SF)/polycaprolactone (PCL) using electrospinning technique, and to evaluate its physiochemical properties and biocompatibility. METHODS: Temporary rotator cuff patches with SF/PCL at different mass ratios of 4:0, 3:1, 1:1, 1:3, 0:4 were prepared using the electrospinning technique. Microstructure, contact angle, degradation properties and composition of the patches were characterized. Temporary rotator cuff patches with the mass ratios of 3:1, 1:1, 1:3, and 0:4 were implanted subcutaneously into the back of Sprague-Dawely rats. After 2 and 4 weeks of implantation, the patch material was taken for hematoxylin-eosin staining. RESULTS AND CONCLUSION: (1) The temporary rotator cuff patches prepared from the mixed material improved the diameter, aperture number, and pore diameter of the pure PCL patch as well as the surface droplets caused by the high brittleness of the pure SF patch. (2) The temporary rotator cuff patches prepared by mixed materials improved hydrophilicity as compared with the SF patch and improved hydrophobicity as compared with the simple PCL patch. (3) In the temporary rotator cuff patch prepared by mixed materials, no chemical reaction occurred between the two materials. (4) With the exception of the temporary rotator cuff patch with a mass ratio of 0:4, the rest patches showed an increase in quality after immersed in PBS for 4 weeks. (5) Two weeks after subcutaneous implantation, a large number of cells were attached to the rotator cuff patch in each group, and capillaries formed in the neonatal tissues. The outer middle layer of the rotator cuff patch had a microstructure similar to the normal tendon tissue, while the middle layer of the pure PCL patch was the worst in microstructure. (6) Four weeks after subcutaneous implantation, the number of cells in the neonatal tissue of the patch significantly decreased, and the thickness of the outer neonatal tissue similar to the normal tendon tissue increased, while the pure PCL patch showed the worst function in the middle layer of the new tissue. To conclude, the results show that SF improves the potential of PCL patch to induce the cell differentiation into tendon cells. [ABSTRACT FROM AUTHOR]