BACKGROUND:Osteoporotic vertebral fractures are the most common complication in patients with osteoporosis.As a new imaging technique,spine magnetic resonance imaging(MRI)is much more sensitive than X-ray film in the diagnosis of osteoporotic vertebral fractures.However,total spine MRI is costly and takes a long time to scan.Therefore,there is no consensus on whether all patients with osteoporotic vertebral fractures need to undergo total spine MRI scan and which patients need to undergo total spine MRI. OBJECTIVE:To analyze the distribution characteristics of vertebral fractures and explore their clinical significance by observing the whole spine MRI data of osteoporotic vertebral fractures patients. METHODS:Data of cases and MRI images of all patients diagnosed with fresh osteoporotic vertebral fractures who visited the Department of Orthopedics,Affiliated Hospital of Southwest Medical University from August 2018 to September 2022 were retrospectively analyzed.903 patients were included in the study based on inclusion and exclusion criteria.General information(age,gender,and body mass index),medical history characteristics(duration of illness,history of trauma surgery,percussion pain area,and pain score)were collected.The characteristics of vertebral fractures were analyzed through whole spine magnetic resonance imaging.Firstly,based on the number of vertebral fractures in patients,they were divided into the single vertebral fracture group(484 cases)and the multi-vertebral fracture group(419 cases),and the differences were analyzed between the two groups.Then,based on whether the farthest interval between the fractured vertebrae was greater than or equal to 5,the multi vertebral fracture group was further divided into two subgroups.Among them,Group A(the farthest interval between the fractured vertebrae was less than 5)contained 306 cases;Group B(with the farthest interval between fractured vertebral bodies greater than 5)included 113 cases.The differences were analyzed between two subgroups. RESULTS AND CONCLUSION:(1)Among 903 patients,419 patients(46.4%)had more than two fractured vertebrae.There were 654 patients(72.4%)with thoracolumbar fractures,and 54 patients(6%)with fractures in the thoracic plus lumbar region and the entire thoracic to lumbar region.In group B,96.5%of patients had multiregional percussion pain.(2)Compared with the patients in the single vertebral fracture group and the multi-vertebral fracture group,there were significant differences in bone mineral density,whether the medical history was greater than or equal to 1 month,the history of low energy injury,and the distribution and number of axial percussion pain areas in the spine during physical examination between the two groups(P<0.05).Age,gender,body mass index,whether there was underlying disease,pain visual analog scale score,whether there was a history of elderly thoracolumbar fracture,and whether there was a history of thoracolumbar surgery,and the number of fractured vertebrae had no statistical significance(P>0.05).(3)There were statistically significant differences between the Groups A and B in bone mineral density,the distribution and quantity of percussion pain area,and the history of low energy injury(P<0.05).There were no significant differences in age,gender,history of old fractures,visual analog scale score,body mass index,whether the medical history was longer than or equal to 1 month,history of underlying diseases,and history of thoracolumbar surgery between the two groups(P>0.05).(4)Patients with multiple low-energy trauma history,history of more than 1 month,multiple percussion pain,and the lower bone mineral density should be alert to the occurrence of multiple vertebral fracture and jump fracture.We recommend the whole spinal MRI for these patients.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.

BACKGROUND:NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome is closely related to neuroinflammation after spinal cord injury,in which microglial polarization and pyroptosis play a key role.Targeted regulation of NLRP3 can induce microglial polarization from M1 proinflammatory phenotype to M2 anti-inflammatory phenotype and regulate microglial pyroptosis,which is a promising therapeutic strategy.OBJECTIVE:To summarize the molecular mechanism and therapeutic strategies of NLRP3 inflammasome in microglia after spinal cord injury.METHODS:Databases of PubMed,Web of Science,and CNKI were searched for the articles with search terms "spinal cord injury,NLRP3,microglia,polarization,pyroptosis" in English and "spinal cord injury,NLRP3,microglia,polarization,pyroptosis,inflammation" in Chinese.Finally,a total of 79 articles were included according to the inclusion and exclusion criteria.RESULTS AND CONCLUSION:(1) Currently,there is no consensus on the complex pathogenesis of spinal cord injury.A large number of studies have shown that spinal cord injury is closely related to inflammatory factors and signaling pathways.The NLRP3 inflammasome is a hot topic in current research as a mechanism of disease and a breakthrough in treatment.(2) The NLRP3 inflammasome plays a key role in the inflammatory response,oxidative stress,and neuronal recovery after spinal cord injury.(3) Microglia are immune cells in the brain and spinal cord and are the most important regulatory factors in secondary spinal cord injury.After spinal cord injury,microglia adjust the internal environment,mainly manifested as polarization and necrosis,produce a large number of inflammatory factors,hinder the nerve regeneration and functional recovery of spinal cord injury,and regulating the phenotype change of microglia is another key factor in the treatment of spinal cord injury.(4) The NLRP3 inflammasome is closely related to microglia.After spinal cord injury,NLRP3 is mainly expressed in microglia,which promotes the polarization of microglia to M1 and accelerates the production of cleavage proteins,further disrupting the microenvironment and aggravating the progression of spinal cord injury.(5) Many molecules participate in the regulation of NLRP3 inflammasomes in microglia,involving signaling pathways.Among them,nuclear factor-κB and MAPK signaling pathways promote NLRP3 inflammasome,while the rest inhibit this inflammasome.(6) At present,a large number of exogenous molecules and drugs regulate NLRP3 inflammasomes,with a wide range of clinical application prospects.Relevant drugs are in the clinical trial stage and obtain good effects,such as the NLRP3-specific inhibitor MCC950.However,key issues such as how to precisely control targeted delivery and the impact on other tissues and organs urgently need to be resolved.With the deepening of research,it is expected to make new breakthroughs in delaying the treatment of spinal cord injury in the future.

AIM:This study aims to investigate the mechanisms underlying skeletal muscle mitochondrial damage associated with decline in exercise function during high-altitude de-adaptation,using a mouse model.METHODS:Twen-ty-four healthy male C57BL/6J mice were randomly assigned to two groups:a high-altitude de-adaptation group and a plain control group.The model group was exposed to a low-pressure,low-oxygen chamber simulating an altitude of 7 000 meters for two weeks,followed by eight days of rearing in a plain environment.The control group was maintained in a plain envi-ronment for the same duration.Grip strength and pole-climbing tests were conducted on the 1st,3rd,and 5th days post-re-turn to assess muscle strength and motor coordination.Treadmill exercises were performed on the 4th and 8th days to eval-uate exercise endurance.After the treadmill exercise on the 8th day,serum,liver,and skeletal muscle tissues were col-lected.Levels of lactic acid(LA),glucose(GLU),creatine kinase(CK),lactate dehydrogenase(LDH),alanine trans-aminase(ALT),and aspartate aminotransferase(AST)in serum,as well as glycogen levels in the liver and muscle,were analyzed.Additionally,the expression of proteins related to mitochondrial biogenesis,fission,fusion,and oxidative phos-phorylation in muscle tissues was assessed using Western blot.RESULTS:(1)The model group exhibited significant re-ductions in grip strength,increased pole-climbing T-turn and total times,and decreased total time and distance in the ex-haustion running test.(2)Serum levels of LA,CK,LDH,ALT,and AST were elevated,while GLU levels decreased,and glycogen levels in both the liver and muscle were reduced in the model group following the treadmill exercise.(3)Ab-normal indicators in the model group did not return to normal by the end of the de-adaptation period.(4)Western blot analysis revealed decreased expression of mitochondrial oxidative phosphorylation proteins(ATP6V1A and Mt-CO2)and mitochondrial biogenesis proteins(PGC-1α and FGF21),increased levels of mitochondrial fusion proteins(OPA1 and MFN1),and no significant changes in fission protein expression(FIS1 and DRP1)in muscle tissue from the model group.CONCLUSION:Exercise capacity in mice during the high-altitude de-adaptation period significantly declined,particu-larly in terms of muscle strength,motor coordination,and endurance.This decline is closely associated with abnormal pro-tein expression related to skeletal muscle mitochondrial energy metabolism and production.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.

AIM:This study aims to investigate the mechanisms underlying skeletal muscle mitochondrial damage associated with decline in exercise function during high-altitude de-adaptation,using a mouse model.METHODS:Twen-ty-four healthy male C57BL/6J mice were randomly assigned to two groups:a high-altitude de-adaptation group and a plain control group.The model group was exposed to a low-pressure,low-oxygen chamber simulating an altitude of 7 000 meters for two weeks,followed by eight days of rearing in a plain environment.The control group was maintained in a plain envi-ronment for the same duration.Grip strength and pole-climbing tests were conducted on the 1st,3rd,and 5th days post-re-turn to assess muscle strength and motor coordination.Treadmill exercises were performed on the 4th and 8th days to eval-uate exercise endurance.After the treadmill exercise on the 8th day,serum,liver,and skeletal muscle tissues were col-lected.Levels of lactic acid(LA),glucose(GLU),creatine kinase(CK),lactate dehydrogenase(LDH),alanine trans-aminase(ALT),and aspartate aminotransferase(AST)in serum,as well as glycogen levels in the liver and muscle,were analyzed.Additionally,the expression of proteins related to mitochondrial biogenesis,fission,fusion,and oxidative phos-phorylation in muscle tissues was assessed using Western blot.RESULTS:(1)The model group exhibited significant re-ductions in grip strength,increased pole-climbing T-turn and total times,and decreased total time and distance in the ex-haustion running test.(2)Serum levels of LA,CK,LDH,ALT,and AST were elevated,while GLU levels decreased,and glycogen levels in both the liver and muscle were reduced in the model group following the treadmill exercise.(3)Ab-normal indicators in the model group did not return to normal by the end of the de-adaptation period.(4)Western blot analysis revealed decreased expression of mitochondrial oxidative phosphorylation proteins(ATP6V1A and Mt-CO2)and mitochondrial biogenesis proteins(PGC-1α and FGF21),increased levels of mitochondrial fusion proteins(OPA1 and MFN1),and no significant changes in fission protein expression(FIS1 and DRP1)in muscle tissue from the model group.CONCLUSION:Exercise capacity in mice during the high-altitude de-adaptation period significantly declined,particu-larly in terms of muscle strength,motor coordination,and endurance.This decline is closely associated with abnormal pro-tein expression related to skeletal muscle mitochondrial energy metabolism and production.

BACKGROUND:NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome is closely related to neuroinflammation after spinal cord injury,in which microglial polarization and pyroptosis play a key role.Targeted regulation of NLRP3 can induce microglial polarization from M1 proinflammatory phenotype to M2 anti-inflammatory phenotype and regulate microglial pyroptosis,which is a promising therapeutic strategy.OBJECTIVE:To summarize the molecular mechanism and therapeutic strategies of NLRP3 inflammasome in microglia after spinal cord injury.METHODS:Databases of PubMed,Web of Science,and CNKI were searched for the articles with search terms "spinal cord injury,NLRP3,microglia,polarization,pyroptosis" in English and "spinal cord injury,NLRP3,microglia,polarization,pyroptosis,inflammation" in Chinese.Finally,a total of 79 articles were included according to the inclusion and exclusion criteria.RESULTS AND CONCLUSION:(1) Currently,there is no consensus on the complex pathogenesis of spinal cord injury.A large number of studies have shown that spinal cord injury is closely related to inflammatory factors and signaling pathways.The NLRP3 inflammasome is a hot topic in current research as a mechanism of disease and a breakthrough in treatment.(2) The NLRP3 inflammasome plays a key role in the inflammatory response,oxidative stress,and neuronal recovery after spinal cord injury.(3) Microglia are immune cells in the brain and spinal cord and are the most important regulatory factors in secondary spinal cord injury.After spinal cord injury,microglia adjust the internal environment,mainly manifested as polarization and necrosis,produce a large number of inflammatory factors,hinder the nerve regeneration and functional recovery of spinal cord injury,and regulating the phenotype change of microglia is another key factor in the treatment of spinal cord injury.(4) The NLRP3 inflammasome is closely related to microglia.After spinal cord injury,NLRP3 is mainly expressed in microglia,which promotes the polarization of microglia to M1 and accelerates the production of cleavage proteins,further disrupting the microenvironment and aggravating the progression of spinal cord injury.(5) Many molecules participate in the regulation of NLRP3 inflammasomes in microglia,involving signaling pathways.Among them,nuclear factor-κB and MAPK signaling pathways promote NLRP3 inflammasome,while the rest inhibit this inflammasome.(6) At present,a large number of exogenous molecules and drugs regulate NLRP3 inflammasomes,with a wide range of clinical application prospects.Relevant drugs are in the clinical trial stage and obtain good effects,such as the NLRP3-specific inhibitor MCC950.However,key issues such as how to precisely control targeted delivery and the impact on other tissues and organs urgently need to be resolved.With the deepening of research,it is expected to make new breakthroughs in delaying the treatment of spinal cord injury in the future.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.

Objective: Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed. Methods: This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed. Results: Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA. Conclusion This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.