1.Production of GTKO pigs and kidney xenotransplantation from pigs to rhesus macaques
Yan WANG ; Yue CHANG ; Chang YANG ; Taiyun WEI ; Xiaoying HUO ; Bowei CHEN ; Jiaoxiang WANG ; Heng ZHAO ; Jianxiong GUO ; Hongfang ZHAO ; Xiong ZHANG ; Feiyan ZHU ; Wenmin CHENG ; Hongye ZHAO ; Kaixiang XU ; Ameen Jamal MUHAMMAD ; Zhendi WANG ; Hongjiang WEI
Organ Transplantation 2025;16(4):526-537
Objective To explore the construction of α-1,3-galactosyltransferase (GGTA1) gene-knockout (GTKO) Diannan miniature pigs and the kidney xenotransplantation from pigs to rhesus macaques, and to assess the effectiveness of GTKO pigs. Methods The GTKO Diannan miniature pigs were constructed using the CRISPR/Cas9 gene-editing system and somatic cell cloning technology. The phenotype of GTKO pigs was verified through polymerase chain reaction, Sanger sequencing and immunofluorescence staining. Flow cytometry was used to detect antigen-antibody (IgM) binding and complement-dependent cytotoxicity. Kidney xenotransplantation was performed from GTKO pigs to rhesus macaques. The humoral immunity, cellular immunity, coagulation and physiological indicators of the recipient monkeys were monitored. The function and pathological changes of the transplanted kidneys were analyzed using ultrasonography, hematoxylin-eosin staining, immunohistochemical staining and immunofluorescence staining. Results Single-guide RNA (sgRNA) targeting exon 4 of the GGTA1 gene in Diannan miniature pigs was designed. The pGL3-GGTA1-sgRNA1-GFP vector was transfected into fetal fibroblasts of Diannan miniature pigs. After puromycin selection, two cell clones, C59# and C89#, were identified as GGTA1 gene-knockout clones. These clones were expanded to form cell lines, which were used as donor cells for somatic cell nuclear transfer. The reconstructed embryos were transferred into the oviducts of trihybrid surrogate sows, resulting in 13 fetal pigs. Among them, fetuses F04 and F11 exhibited biallelic mutations in the GGTA1 gene, and F04 had a normal karyotype. Using this GTKO fetal pig for recloning and transferring the reconstructed embryos into the oviducts of trihybrid surrogate sows, seven surviving piglets were obtained, all of which did not express α-Gal epitope. The binding of IgM from the serum of rhesus monkey 20# to GTKO pig PBMC was reduced, and the survival rate of GTKO pig PBMC in the complement-dependent cytotoxicity assay was higher than that of wild-type pig. GTKO pig kidneys were harvested and perfused until completely white. After the left kidney of the recipient monkey was removed, the pig kidney was heterotopically transplanted. Following vascular anastomosis and blood flow restoration, the pig kidney rapidly turned pink without hyperacute rejection (HAR). Urine appeared in the ureter 6 minutes later, indicating successful kidney transplantation. The right kidney of the recipient was then removed. Seven days after transplantation, the transplanted kidney had good blood flow, the recipient monkey's serum creatinine level was stable, and serum potassium and cystatin C levels were effectively controlled, although they increased 10 days after transplantation. Seven days after transplantation, the levels of white blood cells, lymphocytes, monocytes and eosinophils in the recipient monkey increased, while platelet count and fibrinogen levels decreased. The activated partial thromboplastin time, thrombin time and prothrombin time remained relatively stable but later showed an upward trend. The recipient monkey survived for 10 days. At autopsy, the transplanted kidney was found to be congested, swollen and necrotic, with a small amount of IgG deposition in the renal tissue, and a large amount of IgM, complement C3c and C4d deposition, as well as CD68+ macrophage infiltration. Conclusions The kidneys of GTKO Diannan miniature pigs may maintain normal renal function for a certain period in rhesus macaques and effectively overcome HAR, confirming the effectiveness of GTKO pigs for xenotransplantation.
2.Analysis of the current situation and influencing factors of comorbidity of depressive and anxiety symptoms among middle school students in Chongqing
LI Xia, XIONG Ying, YANG Siwei, ZHANG Jing, PENG Chang, LI Mengfen, WANG Hong
Chinese Journal of School Health 2025;46(10):1443-1448
Objective:
To understand the current situation and influencing factors of comorbidity of depressive and anxiety symptoms among middle school students in Chongqing, so as to provide a scientific basis for formulating a comprehensive strategy for the co prevention of multiple diseases among middle school students.
Methods:
From September to December 2024, 12 327 middle school students were selected from 6 districts and counties in Chongqing by the combination of stratified cluster sampling and convenience sampling method. The current status of depressive and anxiety symptoms was investigated by using the Center for Epidemiological Survey-Depression Scale (CES-D) and the Generalized Anxiety Disorder-7 (GAD-7). The Chi-squared test was used to compare the differences between groups with comorbidity of depressive and anxiety symptoms, multivariate Logistic regression analysis was used to analyze its related factors, and a nomogram prediction model was drawn.
Results:
The detection rates of depressive symptoms, anxiety symptoms and comorbidity among middle school students in Chongqing were 26.34%, 34.55% and 21.16%, respectively. Among them, the detection rates of the three types of symptoms in girls (29.80%, 40.99%, 25.15%) were all higher than those in boys (23.22%, 28.73%, 17.55%) ( χ 2=68.61, 204.23, 106.51, all P <0.01). Statistical significance was observed in the distribution of depressive and anxious symptoms among middle school students across different gender, academic stage, school district, family type, physical activity levels, parental discipline, smoking, alcohol consumption, sleep deprivation, excessive screen time, Internet addiction, and bullying ( χ 2=14.49-991.46, all P <0.01). Multivariate Logistic regression analysis showed that compared with junior high school students, ordinary high school students had a higher risk of comorbidity ( OR=2.71, 95% CI = 2.41-3.05); girls ( OR=2.17, 95%CI =1.95-2.40), non-core family ( OR=1.20, 95%CI =1.08-1.32), and good neighborhood ( OR=1.16, 95%CI =1.02-1.30), campus bullying ( OR=4.88, 95%CI =4.32-5.50), Internet addiction ( OR=4.77, 95%CI = 3.41 -6.68), parental beating and scolding ( OR=3.18, 95%CI =2.72-3.71), alcohol consumption ( OR=2.10, 95%CI =1.86- 2.37 ), and insufficient sleep ( OR=1.73, 95%CI =1.54-1.95) had higher risks with comorbidity of depression and anxiety symptoms (all P <0.05). A nomogram prediction model was constructed based on significant variables shows that C-index=0.75 (AUC= 0.75 , 95% CI=0.74-0.76, P <0.05), and the model had good predictive performance.
Conclusions
The current situation of comorbidity of depressive and anxiety symptoms among middle school students in Chongqing is not optimistic. The nomograms can be used to effectively predict the risk of comorbidity of depressive and anxiety symptoms in middle school students.
3.Analysis factors influencing left ventricular thrombus in patients with non-ischemic heart failure
Zhiyan WANG ; Hao ZHANG ; Wenjie LI ; Chang HUA ; Yangyang TANG ; Xinru LIU ; Yuling XIONG ; Qiang LYU ; Jianzeng DONG ; Xin DU
Chinese Journal of Cardiology 2024;52(10):1155-1161
Objective:To explore the influencing factors of left ventricular thrombus (LVT) in patients with non-ischemic heart failure (NIHF) and to construct a nomogram prediction model for NIHF patients with LVT.Methods:This study was a case-control study. A total of 2 592 patients with NIHF hospitalized in Beijing Anzhen Hospital affiliated to Capital Medical University from January 2018 to July 2022 were selected. Fifty-one patients with LVT identified by echocardiography and cardiac magnetic resonance were classified into LVT group. One hundred and sixty patients were selected as the non-LVT group using a 1∶3 propensity score matching based on age and gender. Multivariate logistic regression analysis was used to explore the influencing factors of LVT in patients with NIHF. A nomogram prediction model was constructed, and the area under (AUC) the receiver operating characteristic (ROC) curve was calculated to evaluate the predictive effect of the model.Results:A total of 211 patients were enrolled, with a median age of 40 years old and 160 males (76%). Compared with non-LVT group, LVT group had lower systolic blood pressure ((112±20) mmHg vs. (120±19) mmHg; 1 mmHg=0.133 kPa), lower left ventricular ejection fraction (LVEF; (27±12)% vs. (39±14)% ), lower proportion of patients with history of hypertension (28% (14/51) vs. 44% (70/160)) and atrial fibrillation (8% (4/51)vs.39% (62/160)), higher proportion of patients with New York Heart Association functional class Ⅲ to Ⅳ (class Ⅲ: 59% (30/51) vs. 41% (66/160); class Ⅳ: 28% (14/51) vs. 19% (31/160)), and larger left ventricular end-systolic diameter (LVESD; (56±14) mm vs. (50±15) mm). The levels of hemoglobin ((152±23) g/L vs. (142±30) g/L), D-dimer (508 (300, 1 105) μg/L vs. 158 (68, 379) μg/L), and N-terminal pro-brain natriuretic peptide (3 429 (2 462, 4 734) ng/L vs. 1 288 (422, 2 544) ng/L) were higher in LVT group than in non-LVT group ( P all<0.05). LVT group had a higher proportion of patients using beta-blockers (92% (47/51) vs. 78% (124/160)), angiotensin-converting enzyme inhibitors or angiotensin receptor blockers or angiotensin receptor neprilysin inhibitors (88% (45/51) vs. 72% (115/160)), and anticoagulant drugs (98% (50/51) vs. 32% (51/160)) than non-LVT group (all P <0.05). Multivariate logistic regression showed that reduced LVEF ( OR=1.08, 95% CI 1.02-1.15, P=0.008), decreased LVESD ( OR=1.07, 95% CI 1.01-1.12, P=0.013), and increased D-dimer levels ( OR=5.40, 95% CI 1.98-14.74, P=0.001) were independent influencing factors for LVT in patients with NIHF. The ROC curve showed that the AUC of the nomogram for predicting LVT in patients with NIHF was 0.793 (95% CI 0.710-0.876, P<0.001). Conclusion:Reduced LVEF, decreased LVESD, and elevated D-dimer are associated with LVT in NIHF patients. The predictive model developed based on the above indicators has certain value in predicting LVT in NIHF patients.
4.Latent profile analysis of academic burnout among primary and middle school students in Wuxi City
XIONG Chang, BAO Yebo, WANG Jihong, LI Zhijuan, QIAN Hongdan
Chinese Journal of School Health 2024;45(11):1589-1593
Objective:
To understand the current situation of academic burnout among primary and middle school students and to explore its associated factors, so as to provide a scientific guidance and preventing and amelioration academic burnout among primary and middle school students.
Methods:
Between September and October 2023, a total of 10 474 primary and middle school students residing in Wuxi City participated in a questionnaire survey and physical examination conducted through stratified cluster random sampling. Latent profile analysis was used to classify academic burnout among primary and middle school students. Furthermore, differences in the types of academic burnout among children and adolescents with varying characteristics were examined using the Chi square test. Additionally, multinomial Logistic regression analysis was utilized to identify the associated factors for academic burnout.
Results:
The academic burnout of primary and middle school students was divided into 4 categories:no/light academic burnout group(43.6%),physical and mental exhaustion group (32.9%), low achievement group(15.0%), high physical and mental exhaustion/high academic burnout group(8.5%). Middle and high school students, boys, not living with parents, smoking, daily screen time ≥2 hours, suffering from campus bullying, sometimes/often subjected to cyber attacks, abused by parents were more likely to have high physical and mental exhaustion/high academic alienation among primary and middle school students ( OR=1.70, 1.42, 1.56, 1.56, 2.31, 1.48, 2.94, 3.03, 5.94, 2.08, P <0.01).
Conclusions
The phenomenon of academic burnout among primary and middle school students is prominent. And targeted intervention measures shoould be actively taken to prevent and reduce the occurrence of academic burnout among primary and middle school students.
5.TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children
Xi MING ; Liqun WU ; Ziwei WANG ; Bo WANG ; Jialin ZHENG ; Jingwei HUO ; Mei HAN ; Xiaochun FENG ; Baoqing ZHANG ; Xia ZHAO ; Mengqing WANG ; Zheng XUE ; Ke CHANG ; Youpeng WANG ; Yanhong QIN ; Bin YUAN ; Hua CHEN ; Lining WANG ; Xianqing REN ; Hua XU ; Liping SUN ; Zhenqi WU ; Yun ZHAO ; Xinmin LI ; Min LI ; Jian CHEN ; Junhong WANG ; Yonghong JIANG ; Yongbin YAN ; Hengmiao GAO ; Hongmin FU ; Yongkun HUANG ; Jinghui YANG ; Zhu CHEN ; Lei XIONG
Journal of Nanjing University of Traditional Chinese Medicine 2024;40(7):722-732
Following the principles of evidence-based medicine,in accordance with the structure and drafting rules of standardized documents,based on literature research,according to the characteristics of chronic cough in children and issues that need to form a consensus,the TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children was formulated based on the Delphi method,expert discussion meetings,and public solicitation of opinions.The guideline includes scope of application,terms and definitions,eti-ology and diagnosis,auxiliary examination,treatment,prevention and care.The aim is to clarify the optimal treatment plan of Chinese medicine in the diagnosis and treatment of this disease,and to provide guidance for improving the clinical diagnosis and treatment of chronic cough in children with Chinese medicine.
6.Clinical analysis of contrast-enhanced ultrasound combined with serum SMURF1 detection in the diagnosis of thyroid cancer
Jin WANG ; Xin CHANG ; Chun-Rong HAN ; Ke WAN ; Hui CHEN ; Jing ZHAO ; Juan XIONG
Journal of Regional Anatomy and Operative Surgery 2024;33(2):153-157
Objective To investigate the diagnostic value of contrast-enhanced ultrasound(CEUS)combined with serum Smad ubiquitin regulatory factor 1(SMURF1)detection for thyroid cancer.Methods A total of 144 suspected thyroid cancer patients admitted to Lishui branch of Zhongda Hospital Affiliated to Southeast University from February 2019 to February 2020 were selected as the study subjects.Based on the histopathological results,they were divided into the thyroid cancer group(76 cases)and the benign group(68 cases).All patients underwent contrast-enhanced ultrasound examination and serum SMURF1 level detection;the diagnostic value of contrast-enhanced ultrasound parameters,serum SMURF1 detection alone,and the combination of the two methods for thyroid cancer were analyzed.Results Contrast-enhanced ultrasound parameters peak intensity(PI),mean perfusion intensity(SImean)and maximum perfusion intensity(SImax)in the thyroid cancer group were lower than those in the benign group,and the level of SMURF1 mRNA was higher than that in the benign group(P<0.05).The sensitivity of contrast-enhanced ultrasound parameter SImax in the diagnosis of thyroid cancer was 82.89%,the specificity was 72.06%,the accuracy was 77.78%,and the Kappa value was 0.552.The sensitivity of serum SMURF1 in the diagnosis of thyroid cancer was 65.79%,the specificity was 94.12%,the accuracy was 79.17%,and the Kappa value was 0.589.The sensitivity,specificity,accuracy and Kappa value of SImax combined with serum SMURF1 in the diagnosis of thyroid cancer were 97.37%,85.29%,91.67%and 0.832,respectively,which were higher than those of SImax and SMURF1 alone(P<0.05),the AUC of the combination of the two methods was 0.927,which was significantly higher than that of the two methods alone(Zcombined vs.SImax=3.999,P<0.001;Zcombined vs.SMURF1=3.270,P=0.001).Conclusion Contrast-enhanced ultrasound combined with serum SMURF1 detection can improve the diagnostic efficiency of thyroid cancer,which may avoid the over-diagnosis on the premise of ensuring the effective diagnosis of thyroid cancer patients.
7.An accurate diagnostic approach for urothelial carcinomas based on novel dual methylated DNA markers in small-volume urine.
Yucai WU ; Di CAI ; Jian FAN ; Chang MENG ; Shiming HE ; Zhihua LI ; Lianghao ZHANG ; Kunlin YANG ; Aixiang WANG ; Xinfei LI ; Yicong DU ; Shengwei XIONG ; Mancheng XIA ; Tingting LI ; Lanlan DONG ; Yanqing GONG ; Liqun ZHOU ; Xuesong LI
Chinese Medical Journal 2024;137(2):232-234
8.Effects of compound Duzhong Jiangu Granules on joint function and gut microbiota in patients with Kashin-Beck disease
Xi WANG ; Yu ZHANG ; Yifan WU ; Shujin LI ; Chaowei WANG ; Xi LYU ; Yuequan YUAN ; Yanli LIU ; Feihong CHEN ; Feiyu ZHANG ; Sijie CHEN ; Zhengjun YANG ; Gangyao XU ; Cheng LI ; Hong CHANG ; Cuiyan WU ; Xiong GUO ; Yujie NING
Chinese Journal of Endemiology 2024;43(9):698-703
Objective:To investigate the effects of compound Duzhong Jiangu Granules on joint function and gut microbiota in patients with Kashin-Beck disease.Methods:A single group pre- and post-experimental design was conducted, the patients with Kashin-Beck disease were selected as the subjects in Xunyi County, Xianyang City, Shaanxi Province; and treated with oral administration of compound Duzhong Jiangu Granules (12 g/bag, 1 bag/time, 3 times/day) for a period of 1 month. The improvement of joint function was evaluated using the joint dysfunction index scoring method before and after treatment. Morning stool samples of patients were collected and the changes in gut microbiota were analyzed before and after treatment using 16S rDNA sequencing technology.Results:A total of 87 patients with Kashin-Beck disease were included, including 44 males and 43 females; the age was (60.38 ± 7.12) years old, and the body mass index was (23.67 ± 3.59) kg/m 2. The comprehensive scores of joint dysfunction index for patients with Kashin-Beck disease before and after treatment were (7.27 ± 2.05) and (5.86 ± 2.01) points, respectively, and the difference was statistically significant ( t = 5.88, P < 0.001). The sequencing results of gut microbiota showed that there were statistically significant differences in the alpha diversity (chao1, observed species index) and beta diversity of gut microbiota in patients with Kashin-Beck disease before and after treatment ( Z = - 5.08, - 5.03, R = 0.09, P < 0.001). In the distribution of gut microbiota, Firmicutes was the dominant phylum, with relative abundances of 50.21% and 52.09% before and after treatment, respectively; the Bifidobacterium was the dominant bacterial genus, with relative abundances of 16.83% and 18.81% before and after treatment, respectively. At the genus level, a total of 17 gut microbiota genera were screened out, among which the relative abundances of Hafnia-Obesumbacterium, Gammaproteobacteria_unclassified, Acinetobacter, Pantoea, Leuconostoc, and Akkermanisia were significantly higher than before treatment ( Z = - 2.40, - 2.24, - 2.06, - 3.59, - 2.24, - 2.11, P < 0.05). The relative abundances of Dubosiella, Selenomonas, Anaeroplasma, Lachnospiraceae_ NK4A136_group, Rikenella, Prevotella, Megasphaera, Lactobacillus, Prevotella-9, Phascolarctobacterium, and Desulfovibrio were significantly lower than before treatment ( Z = - 9.38, - 2.61, - 2.18, - 8.43, - 2.45, - 2.46, - 2.49, - 7.29, - 2.29, - 2.55, - 2.08, P < 0.05). Conclusions:Compound Duzhong Jiangu Granules can effectively improve the joint function of patients with Kashin-Beck disease, and alter the diversity and richness of the gut microbiota community. It may reduce clinical symptoms in patients by regulating the structure of gut microbiota.
9.Artificial intelligence predicts direct-acting antivirals failure among hepatitis C virus patients: A nationwide hepatitis C virus registry program
Ming-Ying LU ; Chung-Feng HUANG ; Chao-Hung HUNG ; Chi‐Ming TAI ; Lein-Ray MO ; Hsing-Tao KUO ; Kuo-Chih TSENG ; Ching-Chu LO ; Ming-Jong BAIR ; Szu-Jen WANG ; Jee-Fu HUANG ; Ming-Lun YEH ; Chun-Ting CHEN ; Ming-Chang TSAI ; Chien-Wei HUANG ; Pei-Lun LEE ; Tzeng-Hue YANG ; Yi-Hsiang HUANG ; Lee-Won CHONG ; Chien-Lin CHEN ; Chi-Chieh YANG ; Sheng‐Shun YANG ; Pin-Nan CHENG ; Tsai-Yuan HSIEH ; Jui-Ting HU ; Wen-Chih WU ; Chien-Yu CHENG ; Guei-Ying CHEN ; Guo-Xiong ZHOU ; Wei-Lun TSAI ; Chien-Neng KAO ; Chih-Lang LIN ; Chia-Chi WANG ; Ta-Ya LIN ; Chih‐Lin LIN ; Wei-Wen SU ; Tzong-Hsi LEE ; Te-Sheng CHANG ; Chun-Jen LIU ; Chia-Yen DAI ; Jia-Horng KAO ; Han-Chieh LIN ; Wan-Long CHUANG ; Cheng-Yuan PENG ; Chun-Wei- TSAI ; Chi-Yi CHEN ; Ming-Lung YU ;
Clinical and Molecular Hepatology 2024;30(1):64-79
Background/Aims:
Despite the high efficacy of direct-acting antivirals (DAAs), approximately 1–3% of hepatitis C virus (HCV) patients fail to achieve a sustained virological response. We conducted a nationwide study to investigate risk factors associated with DAA treatment failure. Machine-learning algorithms have been applied to discriminate subjects who may fail to respond to DAA therapy.
Methods:
We analyzed the Taiwan HCV Registry Program database to explore predictors of DAA failure in HCV patients. Fifty-five host and virological features were assessed using multivariate logistic regression, decision tree, random forest, eXtreme Gradient Boosting (XGBoost), and artificial neural network. The primary outcome was undetectable HCV RNA at 12 weeks after the end of treatment.
Results:
The training (n=23,955) and validation (n=10,346) datasets had similar baseline demographics, with an overall DAA failure rate of 1.6% (n=538). Multivariate logistic regression analysis revealed that liver cirrhosis, hepatocellular carcinoma, poor DAA adherence, and higher hemoglobin A1c were significantly associated with virological failure. XGBoost outperformed the other algorithms and logistic regression models, with an area under the receiver operating characteristic curve of 1.000 in the training dataset and 0.803 in the validation dataset. The top five predictors of treatment failure were HCV RNA, body mass index, α-fetoprotein, platelets, and FIB-4 index. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the XGBoost model (cutoff value=0.5) were 99.5%, 69.7%, 99.9%, 97.4%, and 99.5%, respectively, for the entire dataset.
Conclusions
Machine learning algorithms effectively provide risk stratification for DAA failure and additional information on the factors associated with DAA failure.
10.Biomechanical study of load-bearing stability of Pilon fracture fixed with external fixator.
Yong-Zhong CHENG ; Xiao-Dong YIN ; Yang CHEN ; Chao-Lu WANG ; Guang-Wei LIU ; Chang-Long SHI ; Xiao-Yu HUANG ; Yi-Li CHEN ; Hong-Ying CHEN ; Xiong-Wei WANG ; Ji-Yang ZHAO
China Journal of Orthopaedics and Traumatology 2024;37(12):1196-1201
OBJECTIVE:
To explore weight-bearing stability of Pilon fracture fixed by external fixator.
METHODS:
Six ankle bone models (right side) and 4 pairs (8 ankle cadaver specimens) were selected. Pilon fracture model was prepared by using the preset osteotomy line based on Ruedi Allgower Pilon fracture type. Pilon fracture model was built by using a minimally invasive osteotomy. After ankle bone model and cadaver specimen model were fixed with external fixator, axial load was carried out on mechanical loading machine. After ankle bone model and cadaver specimen model were fixed with external fixator, axial load was carried out on mechanical loading machine. Axial loads of 150, 300 and 450 N were applied to ankle bone model, and displacements of fibula fracture blocks, lateral tibia fracture blocks and medial tibia fracture blocks in three-dimensional space (X, Y and Z axes) were recorded by dynamic capture instrument. Axial loads of 300, 600 and 900 N were applied to ankle cadaver model fixed by external fixator. X-ray films of Pilon fracture cadaver model fixed by external fixator under different loading conditions were taken. The anterior tibial angle, tibial malleolar point angle, talus shift value, talus tilt angle, lateral malleolar shift value, lateral malleolar shift value, medial malleolar separation shift value and articular surface step displacement value were measured under different loads by digimizer software.
RESULTS:
After 150, 300 and 450 N axial loads were applied to Pilon fracture models fixed by external fixator, no loosening or fracture of external fixator was observed, and no loosening, fracture or irreversible plastic deformation of Kirschner needle were observed. The displacement values of fibular fracture pieces on X-axis(around) were 0.032 (-0.022, 0.269), 0.061 (-0.002, 0.427), 0.212(-0.016, 1.223) mm, and the displacement values on Y-axis(above and below) were 0.002(-0.031, 0.103), 0.051(-1.133, 0.376), 0.128 (-1.394, 0.516) mm, and displacement values on Z-axis (front and rear) were -0.003 (-0.130, 0.171), 0.137 (-0.076, 0.433), 0.030(-0.487, 0.478) mm;the displacement values of lateral tibial fractures on X-axis were 0.000(-0.108, 0.027), 0.083(-0.364, 0.050), -0.121(-0.289, 0.165) mm, and displacement values on Y-axis were -0.009(-0.200, 0.025), -0.179(-0.710, 0.084), -0.257(-0.799, 0.027) mm, and displacement values on Z-axis were 0.112(-0.024, 0.256), 0.157(-0.068, 0.293), -0.210(-0.035, 0.430) mm;the displacement values of medial tibial fracture block on X-axis were -0.010(-0.060, 0.013), -0.165(-0.289, 0.056), -0.181(-0.395, 0.013) mm, and the displacement values on Y-axis were -0.036(-0.156, 0.007), -0.104(-0.269, 0.178), -0.245(-0.380, -0.011) mm, and displacement values on Z-axis were -0.005(-0.372, 0.189), -0.012 (-1.774, 0.380), 0.200 (-1.963, -0.540) mm. After 300, 600 and 900 N axial loads were applied to Pilon fracture cadaverous models fixed with external fixators, there were no significant difference in anterior tibial angles, angles of malleolar points of tibia, oblique angles of talus, fracture steps, shift values of talus, lateral shift values of lateral malleolus, lateral shift values of medial malleolus, lateral shift values of medial malleolus between under different loading conditions and those without loading (P>0.05). No loosening or fracture of external fixator as a whole, loosening, fracture or irreversible deformation of Kirschner needle at the local fixed fracture end occurred.
CONCLUSION
The early weight-bearing external fixator could maintain stability of fracture end and ankle joint, and the maximum weight is not more than 300 N. In clinical practical application, material characteristics of the implant and type of fracture should be selected.
Humans
;
Weight-Bearing
;
Biomechanical Phenomena
;
External Fixators
;
Tibial Fractures/physiopathology*
;
Fracture Fixation/instrumentation*
;
Male


Result Analysis
Print
Save
E-mail