ObjectiveTo evaluate the effects of drinking chlorinated water on the intestinal flora of rats and mice and to explore differences in the intestinal microecological responses of model animals to chlorine stimulation in chlorinated drinking water systems. MethodsSix 8-week-old male SD rats and six 8-week-old male C57BL/6J mice were acclimated for 5 days. Subsequently, the drinking water for both rats and mice was changed from pure water to water containing free chlorine at a concentration of 25.4–32.4 nmol/L. The intervention lasted for 8 weeks, during which all animals were fed the same diet. Fecal samples were collected before the intervention (week 0, as the control group) and on the last day of week 3 and week 8 (as the chlorinated water group), and microbial composition was analyzed by 16S rRNA sequencing, including α diversity (Chao1 and Shannon indices), β diversity [principal component analysis (PCA)], and linear discriminant analysis effect size (LEfSe) analysis. ResultsAfter 3 weeks of intervention, α diversity of the intestinal flora in both rats and mice in the chlorinated water group was significantly lower than that in the control group (P < 0.01). After 8 weeks of intervention, no significant difference in α diversity was observed between rats in the chlorinated water group and those in the control group, whereas α diversity in mice remained significantly lower than that in the control group (P < 0.01). β diversity analysis showed significant alterations in microbial structure in the chlorinated water group. LEfSe analysis indicated that, compared with the control group, the abundances of Bacteroides and Ruminococcus were significantly reduced in the chlorinated water group, and microbial disturbance was more pronounced in mice [linear discriminant analysis (LDA) > 4.0], with a greater decrease in microbial diversity and a larger number of differentially abundant genera. ConclusionConsumption of chlorinated water can alter the diversity and structure of the intestinal flora in both rats and mice, with mice being more sensitive to this exposure. These findings suggest that the potential effects of chlorine on gut microecology should be considered in drinking water management and model selection for animal experiments.

Objective:To investigate the application value of intraoperative sliding rail computed tomography （CT） in complicated and difficult cochlear implantation by analyzing the cases of complicated and difficult cochlear implantation. Methods:The clinical data of patients with complicated and difficult cochlear implantation assisted by sliding rail CT were retrospectively analyzed, the intraoperative complications and the number of electrode adjustments were summarized, and the patients were followed up. Results:A total of 51 subjects were included in this study, including 46 patients with inner ear malformation, 2 patients with cochlear ossification, there were 7 patients underwent secondary scanning to adjust the electrode and achieved satisfactory implantation position. Conclusion:Intraoperative CT scanning is a reliable adjunctive tool for determining the placement of complex cochlear implantation, and it improves the accuracy of difficult cochlear implantation surgeries.
Humans ; Cochlear Implantation/methods* ; Retrospective Studies ; Tomography, X-Ray Computed ; Cochlear Implants ; Male ; Female ; Child, Preschool ; Child ; Cochlea ; Electrodes, Implanted ; Infant

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: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.

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.

Objective:To analyzed the correlation between the sacral slope (SS) and the slip degree of vertebral body, the morphological parameters of intervertebral disc, paraspinal muscle and pedicle in patient with degenerative lumbar spondylolisthesis (DLS).Methods:A retrospective cohort study was conducted. One hundred and forty patients with L 4-5 degenerative spondylolisthesis who visited the Department of Orthopedics, the Affiliated Hospital of Southwest Medical University from July 2018 to October 2022 were included. There were 32 males and 108 females, with an age of (62.6±10.0) years (range: 42 to 87 years) and the body mass index was (23.8±2.8) kg/m 2(range: 14.7 to 28.7 kg/m 2). General information and imaging data (lumbar X-ray, CT three-dimensional reconstruction, MRI images) of the patients were collected. SS and the slip degree (SD) of the L 4 vertebral body were measured on lateral lumbar radiographs. Based on Roussouly classification, 140 patients with DLS were divided into a low SS group (SS<35°), a medium SS group (35°≤SS<45°), and a high SS group (SS≥45°). The morphological parameters of the L 4 pedicle of the patient were measured on the lumbar CT three-dimensional reconstruction images, including pedicle length (PL), pedicle width (PW), pedicle screw trajectory length (PSTL), pedicle camber angle(PCA) and pedicle height (PH). The morphological parameters of the paraspinal muscles (psoas major, multifidus and erector spinae) were measured on MRI images, including total cross-sectional muscle area (TCSA), functional cross-sectional muscle area (FCSA), and the ratio of functional cross-sectional muscle area (FCSA/TCSA) was calculated. The degree of degeneration of the L 4-5 disc was assessed on MRI images. The slip degree, morphological parameters of the pedicle, intervertebral disc, and paraspinal muscles among the groups were compared and their correlation was analyzed. The comparison of quantitative data was conducted using one-way analysis of variance, and the post hoc analysis for pairwise comparisons among groups was performed using the least significant difference method. The comparison of unordered categorical data was carried out using the χ2 test, and the comparison of ordered categorical data was conducted using the Kruskal-Wallis rank sum test. Pearson correlation analysis was used to test the correlation. Results:Among the 140 patients, there were 70 in the low SS group, 48 in the medium SS group, and 22 in the high SS group. The SD and PL of the low SS group were the lowest ((18.6±4.2)%, (14.0±1.0) mm), those of the medium SS group were slightly higher ((21.0±3.6)%, (15.7±0.9) mm), and those of the high SS group were the highest ((23.7±2.8)%, (16.2±0.7) mm), with statistically significant differences among the groups (all P<0.01). The PW, PH and PCA of the low SS group were the highest ((11.0±1.1) mm, (11.0±1.0) mm, 22.9°±1.1°), those of the medium SS group were slightly lower ((10.2±1.1) mm, (10.4±0.9) mm, 21.6°±1.3°), and those of the high SS group were the lowest ((9.6±0.9) mm, (9.4±0.7) mm, 18.7°±1.5°), with statistically significant differences among the groups (all P<0.05). The FSCA/TCSA of the psoas major, erector spinae and multifidus muscles in the low SS group were the highest ((93.1±4.0)% and (77.6±6.4) %), next were those in the medium SS group ((90.9±3.5)% and (74.9±6.1)%), and those in the high SS group were the lowest ((88.6±4.4)% and (71.2±7.4) %), with statistically significant differences among the different groups (all P<0.05). Pearson correlation analysis showed that SS was positively correlated with SD( r=0.557, P<0.01); SS was negatively correlated with the FSCA/TCSA of the paraspinal muscles (psoas major, erector spinae+multifidus) ( r=-0.393,-0.394,both P<0.01); SS was positively correlated with PL and PSTL ( r=0.706, P<0.01; r=0.264, P<0.01), and negatively correlated with PW, PCA and PH ( r=-0.469,-0.669,-0.549, all P<0.01). The Pfirrmann grade of intervertebral disc degeneration in the low SS group was better than that in the medium SS group and the high SS group( H=23.128, P<0.01). Conclusions:In DLS patients, as SS increases, the SD of the L 4 vertebral body gradually increases, the proportion of paraspinal muscle functional area gradually decreases, the degree of intervertebral disc degeneration gradually worsens, the pedicle gradually becomes slender, and the pedicle camber angle gradually decreases. There is a correlation between SS and the degree of vertebral slippage, as well as morphological parameters of pedicle, intervertebral disc, and paraspinal muscles.

Objective:To investigate the anatomical characteristics of the atlantoaxial joint associated with nonuniform settlement of the C 2 lateral mass (C 2LM-NUS) and its correlation with atlantoaxial osteoarthritis. Methods:A retrospective analysis was conducted on clinical and imaging data of 522 hospitalized patients (288 males, 234 females; mean age 60.8±11.2 years; range 18-83 years) who underwent CT scans of the head/neck or cervical spine at the Second Affiliated Hospital of Army Medical University between January 1, 2022 and December 31, 2022. Multiplanar reconstruction of CT data was performed to measure the settlement of the C 2 lateral mass (C 2LMS). Patients with a difference in bilateral C 2LMS (d-C 2LMS) >1.4 mm were classified into the C 2LM-NUS group (137 cases; 71 males, 66 females; mean age 63.3±11.6 years), while the normal group included 385 patients (217 males, 168 females; mean age 59.9±11.0 years). Imaging parameters of the atlantoaxial joint were measured, including the C 1, 2 coronal inclination angle (C 1, 2 CI), atlanto-dental interval (ADI), lateral atlanto-dental interval (LADI), coronal deviation angle of the odontoid (Od-CDA), and C 1, 2 relative rotation angle (C 1, 2 RRA). Osteoarthritis prevalence was recorded. A normal C 0-C 3 finite element (FE) model was constructed using CT data from a 48-year-old female in the normal group. A C 2LM-NUS FE model was developed based on anatomical differences between the C 2LM-NUS and normal groups, and stress distribution on the C 2 lateral mass articular surface was analyzed under flexion-extension, lateral bending, and axial rotation torques. Results:The C 2LM-NUS group exhibited asymmetric atlantoaxial joint morphology, with bilateral differences in C 1, 2CI and LADI of 8.5°(5.8°, 11.3°) and 0.8(0.1, 1.4) mm, respectively, significantly greater than those in the normal group [1.7°(0.8°, 2.7°) and 0.2(0.1, 0.5) mm, P<0.05]. Od-CDA and C 1, 2RRA were 3.9°(2.0°, 5.4°) and 7.2°(5.0°, 10.0°) in the C 2LM-NUS group, exceeding the normal group's values [0°(0°, 1.0°) and 0°(0°, 5.5°), P<0.05]. The prevalence of C 2LM-NUS was 37.8% in the atlantoaxial osteoarthritis group, significantly higher than in the non-osteoarthritis group (22.8%, P<0.05). Significant differences were observed in age (68.3±9.4 vs. 58.6±10.8 years), sex distribution (50/69 vs. 238/165), and C 1, 2RRA [5.6°(0°, 8.2°) vs. 3.8°(0°, 6.2°)] between the osteoarthritis and non-osteoarthritis groups ( P<0.05). After adjusting for age, sex, and C 1, 2RRA, binary logistic regression identified C 2LM-NUS as an independent risk factor for atlantoaxial osteoarthritis [ OR=2.024, 95% CI (1.300, 3.150), P<0.001]. FE analysis demonstrated a reduced C 1, 2 range of motion in the C 2LM-NUS model, with elevated stress concentrations on the settled side lateral mass during simulated flexion-extension, lateral bending, and rotation. Conclusions:The study indicated that C 2LM-NUS is associated with asymmetric anatomical changes in the atlantoaxial joint, increasing the risk of osteoarthritis. Stress concentration on the C 2 lateral mass articular surface, caused by C 2LM-NUS, is a biomechanical contributor to this heightened risk.