1.Machine Learning-Based Computed Tomography-Derived Fractional Flow Reserve Predicts Need for Coronary Revascularisation Prior to Transcatheter Aortic Valve Implantation
Kai Dick David LEUNG ; Pan Pan NG ; Boris Chun Kei CHOW ; Keith Wan Hang CHIU ; Neeraj Ramesh MAHBOOBANI ; Yuet-Wong CHENG ; Eric Chi Yuen WONG ; Alan Ka Chun CHAN ; Augus Shing Fung CHUI ; Michael Kang-Yin LEE ; Jonan Chun Yin LEE
Cardiovascular Imaging Asia 2025;9(1):2-8
Objective:
Patients with severe symptomatic aortic stenosis are assessed for coronary artery disease (CAD) prior to transcatheter aortic valve implantation (TAVI) with treatment implications. Invasive coronary angiography (ICA) is the recommended modality but is associated with peri-procedural complications. Integrating machine learning (ML)-based computed tomography-derived fractional flow reserve (CT-FFR) into existing TAVI-planning CT protocol may aid exclusion of significant CAD and thus avoiding ICA in selected patients.
Materials and Methods:
A single-center, retrospective study was conducted, 41 TAVI candidates with both TAVI-planning CT and ICA performed were analyzed. CT datasets were evaluated by a ML-based CT-FFR software. Beta-blocker and nitroglycerin were not administered in these patients. The primary outcome was to identify significant CAD. The diagnostic performance of CT-FFR was compared against ICA.
Results:
On per-patient level, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were 89%, 94%, 80%, 97% and 93%, respectively. On per-vessel level, the sensitivity, specificity, PPV, NPV and diagnostic accuracy were 75%, 94%, 67%, 96% and 92%, respectively. The area under the receiver operative characteristics curve per individual coronary vessels yielded overall 0.90 (95% confidence interval 85%–95%). ICA may be avoided in up to 80% of patients if CT-FFR results were negative.
Conclusion
ML-based CT-FFR can provide accurate screening capabilities for significant CAD thus avoiding ICA. Its integration to existing TAVI-planning CT is feasible with the potential of improving the safety and efficiency of pre-TAVI CAD assessment.
2.Singapore consensus statements on the management of obstructive sleep apnoea.
Leong Chai LEOW ; Chuen Peng LEE ; Sridhar VENKATESWARAN ; Michael Teik Chung LIM ; Oon Hoe TEOH ; Ruth CHANG ; Yam Cheng CHEE ; Khai Beng CHONG ; Ai Ping CHUA ; Joshua GOOLEY ; Hong Juan HAN ; Nur Izzianie KAMARUDDIN ; See Meng KHOO ; Lynn Huiting KOH ; Shaun Ray Han LOH ; Kok Weng LYE ; Mark IGNATIUS ; Yingjuan MOK ; Jing Hao NG ; Thun How ONG ; Chu Qin PHUA ; Rui Ya SOH ; Pei Rong SONG ; Adeline TAN ; Alvin TAN ; Terry TAN ; Jenny TANG ; David TAY ; Jade TAY ; Song Tar TOH ; Serene WONG ; Chiang Yin WONG ; Mimi YOW
Annals of the Academy of Medicine, Singapore 2025;54(10):627-643
INTRODUCTION:
Obstructive sleep apnoea (OSA) is common in Singapore, with moderate to severe OSA affecting around 30% of residents. These consensus statements aim to provide scientifically grounded recommendations for the management of OSA, standar-dise the management of OSA in Singapore and promote multidisciplinary collaboration.
METHOD:
An expert panel, which was convened in 2024, identified several areas of OSA management that require guidance. The expert panel reviewed the current literature and developed consensus statements, which were later independently voted on using a 3-point Likert scale (agree, neutral or disagree). Consensus (total ratings of agree and neutral) was set a priori at ≥80% agreement. Any statement not reaching consensus was excluded.
RESULTS:
The final consensus included 49 statements that provide guidance on the screening, diagnosis and management of adults with OSA. Additionally, 23 statements on the screening, diagnosis and management of paediatric OSA achieved consensus. These 72 consensus statements considered not only the latest clinical evidence but also the benefits and harms, resource implications, feasibility, acceptability and equity impact of the recommendations.
CONCLUSION
The statements presented in this paper aim to guide clinicians based on the most updated evidence and collective expert opinion from sleep specialists in Singapore. These recommendations should augment clinical judgement rather than replace it. Management decisions should be individualised, taking into account the patient's clinical characteristics, as well as patient and caregiver concerns and preferences.
Humans
;
Sleep Apnea, Obstructive/diagnosis*
;
Singapore
;
Consensus
;
Adult
3.Association between ABO Blood Types and the Risk of Gestational Diabetes Mellitus: A Prospective Cohort Study.
Shuang Hua XIE ; Shuang Ying LI ; Shao Fei SU ; En Jie ZHANG ; Shen GAO ; Yue ZHANG ; Jian Hui LIU ; Min Hui HU ; Rui Xia LIU ; Wen Tao YUE ; Cheng Hong YIN
Biomedical and Environmental Sciences 2025;38(6):678-692
OBJECTIVE:
To investigate the association between ABO blood types and gestational diabetes mellitus (GDM) risk.
METHODS:
A prospective birth cohort study was conducted. ABO blood types were determined using the slide method. GDM diagnosis was based on a 75-g, 2-h oral glucose tolerance test (OGTT) according to the criteria of the International Association of Diabetes and Pregnancy Study Groups. Logistic regression was applied to calculate the odds ratios ( ORs) and 95% confidence intervals ( CIs) between ABO blood types and GDM risk.
RESULTS:
A total of 30,740 pregnant women with a mean age of 31.81 years were enrolled in this study. The ABO blood types distribution was: type O (30.99%), type A (26.58%), type B (32.20%), and type AB (10.23%). GDM was identified in 14.44% of participants. Using blood type O as a reference, GDM risk was not significantly higher for types A ( OR = 1.05) or B ( OR = 1.04). However, women with type AB had a 19% increased risk of GDM ( OR = 1.19, 95% CI = 1.05-1.34; P < 0.05), even after adjusting for various factors. This increased risk for type AB was consistent across subgroup and sensitivity analyses.
CONCLUSION
The ABO blood types may influence GDM risk, with type AB associated with a higher risk. Incorporating it-either as a single risk factor or in combination with other known factors-could help identify individuals at risk for GDM before or during early pregnancy.
Humans
;
Female
;
Pregnancy
;
Diabetes, Gestational/etiology*
;
ABO Blood-Group System
;
Adult
;
Prospective Studies
;
Risk Factors
;
Young Adult
4.A multicenter study of neonatal stroke in Shenzhen,China
Li-Xiu SHI ; Jin-Xing FENG ; Yan-Fang WEI ; Xin-Ru LU ; Yu-Xi ZHANG ; Lin-Ying YANG ; Sheng-Nan HE ; Pei-Juan CHEN ; Jing HAN ; Cheng CHEN ; Hui-Ying TU ; Zhang-Bin YU ; Jin-Jie HUANG ; Shu-Juan ZENG ; Wan-Ling CHEN ; Ying LIU ; Yan-Ping GUO ; Jiao-Yu MAO ; Xiao-Dong LI ; Qian-Shen ZHANG ; Zhi-Li XIE ; Mei-Ying HUANG ; Kun-Shan YAN ; Er-Ya YING ; Jun CHEN ; Yan-Rong WANG ; Ya-Ping LIU ; Bo SONG ; Hua-Yan LIU ; Xiao-Dong XIAO ; Hong TANG ; Yu-Na WANG ; Yin-Sha CAI ; Qi LONG ; Han-Qiang XU ; Hui-Zhan WANG ; Qian SUN ; Fang HAN ; Rui-Biao ZHANG ; Chuan-Zhong YANG ; Lei DOU ; Hui-Ju SHI ; Rui WANG ; Ping JIANG ; Shenzhen Neonatal Data Network
Chinese Journal of Contemporary Pediatrics 2024;26(5):450-455
Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75%(27/36);boys accounted for 64%(23/36).Among the 36 neonates,31(86%)had disease onset within 3 days after birth,and 19(53%)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61%)had left cerebral infarction and 13(36%)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75%)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72%)and seizures in 10 neonates(34%).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33%,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44%(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.
5. Research progress of antineoplastic drugs targeting platelets
Yue-Ke ZHOU ; Cheng QIAN ; Yu TANG ; Zhong-Hong WEI ; Yin LU ; Ai-Yun WANG ; Yin LU ; Ai-Yun WANG
Chinese Pharmacological Bulletin 2024;40(1):20-25
Platelets have long been recognized as key players in hemostasis and thrombosis; however, there is growing evidence that they are also involved in cancer. Preclinical and clinical studies have shown that platelets can promote tumorigenesis and metastasis through various crosstalks between platelets and cancer cells. Platelets play an active role in all stages of tumorigenesis, including tumor growth, tumor cell extravasation, and metastasis. In addition, thrombocytosis in cancer patients is associated with poor patient survival. Platelets are also well-placed to coordinate local and distant tumor-host interactions due to the a- bundance of microparticles and exosomes. Therefore, antitumor drugs targeting platelets have great development and application prospects. The following will review the research progress of anti-tumor drugs targeting platelets.
6.Analysis of Clinical Efficacy and Central Response Mechanism of Transcutaneous Auricular Vagus Nerve Stimulation for the Treatment of Overweight/Obesity Patients Based on Regional Homogeneity
Wen-Fei FAN ; Cheng-Feng ZHANG ; Shun-Ying ZHAO ; Li-Hong YIN ; Si-Ning YAN ; Meng-Ying LIAO ; Jun CHEN ; Yu CHEN ; Chang-Cai XIE
Journal of Guangzhou University of Traditional Chinese Medicine 2024;41(11):2954-2960
Objective To investigate the therapeutic effect of transcutaneous auricular vagus nerve stimulation(taVNS)on overweight/obesity patients,and to explore its central mechanism.Methods Twenty-six overweight/obesity patients were randomly divided into two groups,12 cases in the taVNS test group(shortened as the taVNS group)and 14 cases in the lifestyle intervention control group(shortened as the control group).The patients in the control group were treated with online lifestyle intervention of calorie-restricted diet(CRD),and the patients in the taVNS group were treated with taVNS on the basis of the intervention for the control group.The taVNS was performed on unilateral acupoints of spleen and endocrine,twice(in the morning and at evening)per day,for five days a week.The treatment for the two groups covered four weeks.The obesity indicators such as body weight,body mass index(BMI)and waist circumference of the patients in the two groups were observed before and after treatment.Moreover,the resting-state cerebral functional magnetic resonance imaging(fMRI)data of the patients were collected after treatment,and then the regulatory effect of taVNS on the regional homogeneity(ReHo)of local cerebral area of the patients was observed.Results(1)During the trial,one case in each group dropped off,and a total of 24 patients(including 13 cases in the control group and 11 cases in the taVNS group)were finally included in the statistical analysis of the observation indicators.(2)After treatment,the body weight,BMI and waist circumference of patients in the taVNS group were decreased compared with those before treatment(P<0.05),while the obesity indicators in the control group only showed a downward trend compared with those before treatment,the differences being not statistically significant(P>0.05).The improvement of the obesity indicators of body weight,BMI,and waist circumference in the taVNS group was significantly superior to that in the control group,and there were statistically significant differences in the post-treatment indicators and in the pre-and post-treatment difference values of the indicators between the two groups(P<0.05 or P<0.01).(3)After treatment,the taVNS group had greater ReHo values in the left prefrontal lobe and medial frontal gyrus than the control group,and the control group had greater ReHo value in the right parietal lobe than the taVNS group,which indicated that compared with the control group,the ReHo of the left prefrontal lobe and medial frontal gyrus in the taVNS group was increased and the ReHo of the right parietal lobe was decreased(Pvoxel<0.001,Pcluster<0.05,corrected by FWE level).Conclusion As a non-invasive treatment method,taVNS exerts certain efficacy for the treatment of overweight/obesity patients.The central response mechanism for treatment of obesity is probably related with the modulation of taVNS on the functional areas of left prefrontal lobe,medial frontal gyrus,and right parietal lobe of the patients.
7.Research status of bevacizumab associated hypertension
Huan WANG ; Song-Tao MA ; Hong-Tao XIAO ; Yan CHEN ; Jun YIN ; Ke XU ; Kai CHENG
The Chinese Journal of Clinical Pharmacology 2024;40(5):763-767
Objective Bevacizumab has been clinically used in colorectal cancer,ovarian cancer,cervical cancer,non-small cell lung cancer and other tumor diseases.Common adverse reactions during bevacizumab treatment include albuminuria,thrombosis,bleeding,gastrointestinal perforation and hypertension,among which the incidence of hypertension is as high as 19%-47%.The occurrence of hypertension affects the quality of life of patients,hinds the normal development of tumor treatment,and even induces serious cardiovascular diseases and increases the risk of death,which requires clinical attention.In this paper,the mechanism,influencing factors,prognosis and related treatment of bevacizumab associated hypertension were reviewed,so as to provide reference for clinical rational drug use.
8.Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients (version 2024)
Yao LU ; Yang LI ; Leiying ZHANG ; Hao TANG ; Huidan JING ; Yaoli WANG ; Xiangzhi JIA ; Li BA ; Maohong BIAN ; Dan CAI ; Hui CAI ; Xiaohong CAI ; Zhanshan ZHA ; Bingyu CHEN ; Daqing CHEN ; Feng CHEN ; Guoan CHEN ; Haiming CHEN ; Jing CHEN ; Min CHEN ; Qing CHEN ; Shu CHEN ; Xi CHEN ; Jinfeng CHENG ; Xiaoling CHU ; Hongwang CUI ; Xin CUI ; Zhen DA ; Ying DAI ; Surong DENG ; Weiqun DONG ; Weimin FAN ; Ke FENG ; Danhui FU ; Yongshui FU ; Qi FU ; Xuemei FU ; Jia GAN ; Xinyu GAN ; Wei GAO ; Huaizheng GONG ; Rong GUI ; Geng GUO ; Ning HAN ; Yiwen HAO ; Wubing HE ; Qiang HONG ; Ruiqin HOU ; Wei HOU ; Jie HU ; Peiyang HU ; Xi HU ; Xiaoyu HU ; Guangbin HUANG ; Jie HUANG ; Xiangyan HUANG ; Yuanshuai HUANG ; Shouyong HUN ; Xuebing JIANG ; Ping JIN ; Dong LAI ; Aiping LE ; Hongmei LI ; Bijuan LI ; Cuiying LI ; Daihong LI ; Haihong LI ; He LI ; Hui LI ; Jianping LI ; Ning LI ; Xiying LI ; Xiangmin LI ; Xiaofei LI ; Xiaojuan LI ; Zhiqiang LI ; Zhongjun LI ; Zunyan LI ; Huaqin LIANG ; Xiaohua LIANG ; Dongfa LIAO ; Qun LIAO ; Yan LIAO ; Jiajin LIN ; Chunxia LIU ; Fenghua LIU ; Peixian LIU ; Tiemei LIU ; Xiaoxin LIU ; Zhiwei LIU ; Zhongdi LIU ; Hua LU ; Jianfeng LUAN ; Jianjun LUO ; Qun LUO ; Dingfeng LYU ; Qi LYU ; Xianping LYU ; Aijun MA ; Liqiang MA ; Shuxuan MA ; Xainjun MA ; Xiaogang MA ; Xiaoli MA ; Guoqing MAO ; Shijie MU ; Shaolin NIE ; Shujuan OUYANG ; Xilin OUYANG ; Chunqiu PAN ; Jian PAN ; Xiaohua PAN ; Lei PENG ; Tao PENG ; Baohua QIAN ; Shu QIAO ; Li QIN ; Ying REN ; Zhaoqi REN ; Ruiming RONG ; Changshan SU ; Mingwei SUN ; Wenwu SUN ; Zhenwei SUN ; Haiping TANG ; Xiaofeng TANG ; Changjiu TANG ; Cuihua TAO ; Zhibin TIAN ; Juan WANG ; Baoyan WANG ; Chunyan WANG ; Gefei WANG ; Haiyan WANG ; Hongjie WANG ; Peng WANG ; Pengli WANG ; Qiushi WANG ; Xiaoning WANG ; Xinhua WANG ; Xuefeng WANG ; Yong WANG ; Yongjun WANG ; Yuanjie WANG ; Zhihua WANG ; Shaojun WEI ; Yaming WEI ; Jianbo WEN ; Jun WEN ; Jiang WU ; Jufeng WU ; Aijun XIA ; Fei XIA ; Rong XIA ; Jue XIE ; Yanchao XING ; Yan XIONG ; Feng XU ; Yongzhu XU ; Yongan XU ; Yonghe YAN ; Beizhan YAN ; Jiang YANG ; Jiangcun YANG ; Jun YANG ; Xinwen YANG ; Yongyi YANG ; Chunyan YAO ; Mingliang YE ; Changlin YIN ; Ming YIN ; Wen YIN ; Lianling YU ; Shuhong YU ; Zebo YU ; Yigang YU ; Anyong YU ; Hong YUAN ; Yi YUAN ; Chan ZHANG ; Jinjun ZHANG ; Jun ZHANG ; Kai ZHANG ; Leibing ZHANG ; Quan ZHANG ; Rongjiang ZHANG ; Sanming ZHANG ; Shengji ZHANG ; Shuo ZHANG ; Wei ZHANG ; Weidong ZHANG ; Xi ZHANG ; Xingwen ZHANG ; Guixi ZHANG ; Xiaojun ZHANG ; Guoqing ZHAO ; Jianpeng ZHAO ; Shuming ZHAO ; Beibei ZHENG ; Shangen ZHENG ; Huayou ZHOU ; Jicheng ZHOU ; Lihong ZHOU ; Mou ZHOU ; Xiaoyu ZHOU ; Xuelian ZHOU ; Yuan ZHOU ; Zheng ZHOU ; Zuhuang ZHOU ; Haiyan ZHU ; Peiyuan ZHU ; Changju ZHU ; Lili ZHU ; Zhengguo WANG ; Jianxin JIANG ; Deqing WANG ; Jiongcai LAN ; Quanli WANG ; Yang YU ; Lianyang ZHANG ; Aiqing WEN
Chinese Journal of Trauma 2024;40(10):865-881
Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.
9.Effect of Plasma Epstein-Barr Virus Nucleic Acid Loads on the Clinical Features and Prognosis in Adult Secondary Hemopha-gocytic Lymphohistiocytosis
Li-Min DUAN ; Guang-Li YIN ; Tian TIAN ; Ju-Juan WANG ; Xin GAO ; Wan-Ying CHENG ; Zi-Wei FANG ; Hong-Xia QIU ; Ji XU
Journal of Experimental Hematology 2024;32(4):1238-1247
Objective:To investigate the effect of pre-treatment plasma Epstein-Barr virus(EBV)DNA copy number on the clinical features and prognosis of patients with adult secondary hemophagocytic lymphohistiocytosis(sHLH).Methods:The clinical characteristics,survival rate,and prognostic factors of 171 patients with adult sHLH treated at Jiangsu Province Hospital from June 2017 to January 2022 were retrospectively analyzed in this study.Patients were divided into three groups,including the EBV DNA-negative group(<5.0 × 102 copies/ml),lower EBV-DNA loads group(5.0 × 102-8.51 × 104 copies/ml),and higher EBV-DNA loads group(>8.51 × 104 copies/ml),according to pre-treatment plasma EBV-DNA copy number.Cox regression model was established for screening prognostic factors.Adult sHLH survival prediction model was constructed and realized through the nomogram based on EBV-DNA load after adjusted the factors affecting survival of etiology and treatment strategy.Concordance index(C-index)and calibration curves were calculated to verify model predictive and discriminatory capacity.Results:Among 171 adult sHLH patients,84 patients were not infected with EBV(EBV DNA-negative group),and 87 with EBV(EBV DNA-positive group,48 lower EBV-DNA loads group and 39 higher EBV-DNA loads group).Consistent elevations in the levels of liver enzymes(ALT and AST),LDH,TG,β2-microglobulin and ferritin across the increasing of EBV-DNA load(all P<0.05),while the levels of fibrinogen decrease(P<0.001).The median follow-up time was 52 days(range 20-230 days),and 123 patients died.The overall survival(OS)rate of patients in EBV DNA-positive group was lower than that in EBV DNA-negative group(median OS:40 days vs 118 days,P<0.001).Higher EBV-DNA loads had worse OS(median OS:24 days vs 45 days vs 118 days,P<0.0001 for trend)compared to lower EBV-DNA loads and EBV DNA-negative group.Multivariate Cox analysis revealed that higher EBV-DNA loads(P=0.005),fibrinogen≤ 1.5 g/L(P=0.012),ferritin(P=0.041),associated lymphoma(P=0.002),and anti-tumor based strategy(P=0.001)were independent prognostic factors for OS.The C-indexes of 30 day,90 days,365 days survival rate were all greater than 0.8 of the nomogram model and calibration curves provided credibility to their predictive capability.Subgroup analysis showed that patients with higher EBV-DNA loads had a significantly worse prognosis in adult sHLH who were women,ferritin>5 000 μg/L,β2-microglobulin>7.4 mmol/L and regardless of age,etiologies,HScore points.Conclusion:The EBV-DNA load is a strong and independent predictor for survival in patients with sHLH.The prognostic nomogram based on EBV-DNA loads was dependable and provides a visual tool for evaluating the survival of adult sHLH.
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

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