1.Real-world efficacy and safety of azvudine in hospitalized older patients with COVID-19 during the omicron wave in China: A retrospective cohort study.
Yuanchao ZHU ; Fei ZHAO ; Yubing ZHU ; Xingang LI ; Deshi DONG ; Bolin ZHU ; Jianchun LI ; Xin HU ; Zinan ZHAO ; Wenfeng XU ; Yang JV ; Dandan WANG ; Yingming ZHENG ; Yiwen DONG ; Lu LI ; Shilei YANG ; Zhiyuan TENG ; Ling LU ; Jingwei ZHU ; Linzhe DU ; Yunxin LIU ; Lechuan JIA ; Qiujv ZHANG ; Hui MA ; Ana ZHAO ; Hongliu JIANG ; Xin XU ; Jinli WANG ; Xuping QIAN ; Wei ZHANG ; Tingting ZHENG ; Chunxia YANG ; Xuguang CHEN ; Kun LIU ; Huanhuan JIANG ; Dongxiang QU ; Jia SONG ; Hua CHENG ; Wenfang SUN ; Hanqiu ZHAN ; Xiao LI ; Yafeng WANG ; Aixia WANG ; Li LIU ; Lihua YANG ; Nan ZHANG ; Shumin CHEN ; Jingjing MA ; Wei LIU ; Xiaoxiang DU ; Meiqin ZHENG ; Liyan WAN ; Guangqing DU ; Hangmei LIU ; Pengfei JIN
Acta Pharmaceutica Sinica B 2025;15(1):123-132
Debates persist regarding the efficacy and safety of azvudine, particularly its real-world outcomes. This study involved patients aged ≥60 years who were admitted to 25 hospitals in mainland China with confirmed SARS-CoV-2 infection between December 1, 2022, and February 28, 2023. Efficacy outcomes were all-cause mortality during hospitalization, the proportion of patients discharged with recovery, time to nucleic acid-negative conversion (T NANC), time to symptom improvement (T SI), and time of hospital stay (T HS). Safety was also assessed. Among the 5884 participants identified, 1999 received azvudine, and 1999 matched controls were included after exclusion and propensity score matching. Azvudine recipients exhibited lower all-cause mortality compared with controls in the overall population (13.3% vs. 17.1%, RR, 0.78; 95% CI, 0.67-0.90; P = 0.001) and in the severe subgroup (25.7% vs. 33.7%; RR, 0.76; 95% CI, 0.66-0.88; P < 0.001). A higher proportion of patients discharged with recovery, and a shorter T NANC were associated with azvudine recipients, especially in the severe subgroup. The incidence of adverse events in azvudine recipients was comparable to that in the control group (2.3% vs. 1.7%, P = 0.170). In conclusion, azvudine showed efficacy and safety in older patients hospitalized with COVID-19 during the SARS-CoV-2 omicron wave in China.
2.A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020
Cai-Yun WANG ; Hong-Mei XU ; Gang LIU ; Jing LIU ; Hui YU ; Bi-Quan CHEN ; Guo ZHENG ; Min SHU ; Li-Jun DU ; Zhi-Wei XU ; Li-Su HUANG ; Hai-Bo LI ; Dong WANG ; Song-Ting BAI ; Qing-Wen SHAN ; Chun-Hui ZHU ; Jian-Mei TIAN ; Jian-Hua HAO ; Ai-Wei LIN ; Dao-Jiong LIN ; Jin-Zhun WU ; Xin-Hua ZHANG ; Qing CAO ; Zhong-Bin TAO ; Yuan CHEN ; Guo-Long ZHU ; Ping XUE ; Zheng-Zhen TANG ; Xue-Wen SU ; Zheng-Hai QU ; Shi-Yong ZHAO ; Lin PANG ; Hui-Ling DENG ; Sai-Nan SHU ; Ying-Hu CHEN
Chinese Journal of Contemporary Pediatrics 2024;26(2):131-138
Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]
3.Effects of tramadol hydrochloride preemptive analgesia in kyphoplasty of thoracolumbar osteoporotic fractures un-der local anesthesia
Guo-Qing LI ; Hua-Guo ZHAO ; Shao-Hua SUN ; Wei-Hu MA ; Hao-Jie LI ; Yang WANG ; Lian-Song LU ; Chao-Yue RUAN
China Journal of Orthopaedics and Traumatology 2024;37(6):560-564
Objective To explore preemptive analgesic effect of preoperative intramural tramadol injection in percutaneous kyphoplasty(PKP)of vertebrae following local anesthesia.Methods From August 2019 to June 2021,118 patients with thora-co lumbar osteoporotic fractures were treated and divided into observation group and control group,with 59 patients in each gruop.In observation group,there were 26 males and 33 females,aged from 57 to 80 years old with an average of(67.69±4.75)years old;14 patients on T11,12 patients on T12,18 patients on L1,15 patients on L2;tramadol with 100 mg was injected intramuscularly half an hour before surgery in observation group.In control group,there were 24 males and 35 females,aged from 55 to 77 years old with an average of(68.00±4.43)years old;19 patients on T11,11 patients on T12,17patients on L1,12 patients on L2;the same amount of normal saline was injected intramuscularly in control group.Observation indicators included operation time,intraoperative bleeding,visual analogue scale(VAS)evaluation and recording of preoperative(T0),intraoper-ative puncture(T1),and working cannula placement(T2)between two groups of patients,at the time of balloon dilation(T3),when the bone cement was injected into the vertebral body(T4),2 hours after the operation(T5),and the pain degree at the time of discharge(T6);adverse reactions such as dizziness,nausea and vomiting were observed and recorded;the record the patient's acceptance of repeat PKP surgery.Results All patients were successfully completed PKP via bilateral pedicle ap-proach,and no intravenous sedative and analgesic drugs were used during the operation.There was no significant difference in preoperative general data and VAS(T0)between two groups(P>0.05).There was no significant difference in operation time and intraoperative blood loss between the two groups(P>0.05).VAS of T1,T2,T3,T4 and T5 in observation group were all lower than those in control group(P<0.05),and there was no significant difference in T6 VAS(P>0.05).T6 VAS between two groups were significantly lower than those of T0,and the difference was statistically significant(P<0.05).There was no signifi-cant difference in incidence of total adverse reactions between two groups(P>0.05).There was a statistically significant differ-ence in the acceptance of repeat PKP surgery(P<0.05).Conclusion Half an hour before operation,intramuscular injection of tramadol has a clear preemptive analgesic effect for PKP of single-segment thoracolumbar osteoporotic fracture vertebral body under local anesthesia,which could increase the comfort of patients during operation and 2 hours after operation,and improve patients satisfaction with surgery.
4.Incidence of postoperative complications in Chinese patients with gastric or colorectal cancer based on a national, multicenter, prospective, cohort study
Shuqin ZHANG ; Zhouqiao WU ; Bowen HUO ; Huining XU ; Kang ZHAO ; Changqing JING ; Fenglin LIU ; Jiang YU ; Zhengrong LI ; Jian ZHANG ; Lu ZANG ; Hankun HAO ; Chaohui ZHENG ; Yong LI ; Lin FAN ; Hua HUANG ; Pin LIANG ; Bin WU ; Jiaming ZHU ; Zhaojian NIU ; Linghua ZHU ; Wu SONG ; Jun YOU ; Su YAN ; Ziyu LI
Chinese Journal of Gastrointestinal Surgery 2024;27(3):247-260
Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.
5.Age Estimation by Machine Learning and CT-Multiplanar Reformation of Cra-nial Sutures in Northern Chinese Han Adults
Xuan WEI ; Yu-Shan CHEN ; Jie DING ; Chang-Xing SONG ; Jun-Jing WANG ; Zhao PENG ; Zhen-Hua DENG ; Xu YI ; Fei FAN
Journal of Forensic Medicine 2024;40(2):128-134,142
Objective To establish age estimation models of northern Chinese Han adults using cranial suture images obtained by CT and multiplanar reformation(MPR),and to explore the applicability of cranial suture closure rule in age estimation of northern Chinese Han population.Methods The head CT samples of 132 northern Chinese Han adults aged 29-80 years were retrospectively collected.Volume reconstruction(VR)and MPR were performed on the skull,and 160 cranial suture tomography images were generated for each sample.Then the MPR images of cranial sutures were scored according to the closure grading criteria,and the mean closure grades of sagittal suture,coronal sutures(both left and right)and lambdoid sutures(both left and right)were calculated respectively.Finally taking the above grades as independent variables,the linear regression model and four machine learning models for age estimation(gradient boosting regression,support vector regression,decision tree regression and Bayesian ridge regression)were established for northern Chinese Han adults age estimation.The accu-racy of each model was evaluated.Results Each cranial suture closure grade was positively correlated with age and the correlation of sagittal suture was the highest.All four machine learning models had higher age estimation accuracy than linear regression model.The support vector regression model had the highest accuracy among the machine learning models with a mean absolute error of 9.542 years.Conclusion The combination of skull CT-MPR and machine learning model can be used for age esti-mation in northern Chinese Han adults,but it is still necessary to combine with other adult age estima-tion indicators in forensic practice.
6.Incidence of postoperative complications in Chinese patients with gastric or colorectal cancer based on a national, multicenter, prospective, cohort study
Shuqin ZHANG ; Zhouqiao WU ; Bowen HUO ; Huining XU ; Kang ZHAO ; Changqing JING ; Fenglin LIU ; Jiang YU ; Zhengrong LI ; Jian ZHANG ; Lu ZANG ; Hankun HAO ; Chaohui ZHENG ; Yong LI ; Lin FAN ; Hua HUANG ; Pin LIANG ; Bin WU ; Jiaming ZHU ; Zhaojian NIU ; Linghua ZHU ; Wu SONG ; Jun YOU ; Su YAN ; Ziyu LI
Chinese Journal of Gastrointestinal Surgery 2024;27(3):247-260
Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.
7.Severity of loneliness and factors associated with social and emotional loneliness among the elderly in three districts in Shanghai
Yu-Wen ZHANG ; Ying WANG ; Zhao-Hua XIN ; Jia-Lie FANG ; Rui SONG ; Hao-Cen LI ; Jia-Wen KUANG ; Yu-Ting YANG ; Jing-Yi WANG
Fudan University Journal of Medical Sciences 2024;51(1):1-11
Objective To explore the severity of loneliness among the elderly in communities in Shanghai,and to identify factors associated with social and emotional loneliness respectively.Methods A cross-sectional study was conducted in older adults aged 65 years or above in Pudong New Area,Jing'an District and Huangpu District in Shanghai from Mar to Jun 2021.In Pudong New Area,multi-stage stratified random sampling was conducted based on the age and gender distribution of Shanghai,while in Huangpu District and Jing'an District convenience sampling was conducted.A total of 635 samples were included in the study.Loneliness was assessed using the De Jong Gierveld Loneliness Scale with social and emotional loneliness subscales.Logistic regression analyses were conducted to identify factors associated with social and emotional loneliness.Results Among the 635 participants,only 53 older adults(8.4%)were not lonely.Female(OR=0.46,95%CI:0.31-0.70),higher self-efficacy(OR=0.97,95%CI:0.94-1.00),more objective social support(OR=0.96,95%CI:0.93-0.99)were associated with less severe social loneliness.Meanwhile,higher level of education(secondary education,OR=0.56,95%CI:0.34-0.95;college or above,OR=0.30,95%CI:0.11-0.83)and higher self-efficacy(OR=0.96,95%CI:0.93-0.99)were associated with less severe emotional loneliness,while depression(OR=3.41,95%CI:1.76-6.60)and worse social capital(OR=2.02,95%CI:1.29-3.16)were associated with more severe emotional loneliness.Conclusion Up to 91.6%of the elderly in our study sample were moderately lonely or above.The factors associated with social loneliness include self-efficacy,gender and social support.The factors associated with emotional loneliness are self-efficacy,education level,depression,and social capital.
8.Current status of cognition and skin care behavior in adolescent patients with acne: A survey in China.
Jing TIAN ; Hong SHU ; Qiufang QIAN ; Zhong SHEN ; Chunyu ZHAO ; Li SONG ; Ping LI ; Xiuping HAN ; Hua QIAN ; Jinping CHEN ; Hua WANG ; Lin MA ; Yuan LIANG
Chinese Medical Journal 2024;137(4):476-477
9.Finite element analysis of three different minimally invasive fixation methods for distal tibial fractures with soft tissue injury
Mingming WANG ; Zhong ZHANG ; Jianhua SUN ; Gang ZHAO ; Hua SONG ; Huadong YAN ; Bin LYU
Chinese Journal of Tissue Engineering Research 2024;28(6):879-885
BACKGROUND:The treatment of distal tibial fractures with soft tissue injury has always been challenging,and the new retrograde tibial nailing is a new choice.Up to now,there were few reports on the biomechanical properties between the new retrograde tibial nailing,anterograde intramedullary nailing and supercutaneous locking plate. OBJECTIVE:To explore the biomechanical stability of new retrograde tibial nailing,antegrade intramedullary nailing and supercutaneous locking plate in the treatment of distal tibial fractures with soft tissue injury using finite element analysis so as to offer a scientific foundation for clinical application. METHODS:The finite element model of transverse distal tibia fracture was established by relevant software utilizing the CT data of the tibia from a 42-year-old healthy male.Retrograde tibial nailing,antegrade intramedullary nailing and supercutaneous locking plate finite element models were assembled under the principle of fracture fixation.Finally,meshing,applying loads,and data processing were accomplished with the ANSYS 2019 software.Moreover,the stress distribution and displacement of the tibia and internal fixation of each model were compared. RESULTS AND CONCLUSION:(1)The displacement of fracture end in the three groups increased with the increase of load.In all mode loads,the average displacement of the fracture end was the least in the retrograde tibial nailing group,followed by the supercutaneous locking plate group,and the highest in the antegrade intramedullary nailing group.At 800 N vertical load,the displacement difference of the fracture end was statistically significant(P<0.05).There was no statistical significance in other load modes.(2)Under different loads,the tibial stress in the three groups was the highest in the middle of the tibia,and gradually decreased to the proximal and distal ends.The stress distribution of the tibial shaft was the highest in the retrograde tibial nailing group,followed by the supercutaneous locking plate group,and the least in the antegrade intramedullary nailing group.(3)Under different loads,the stress of the tibial stress raiser in the three groups was significantly higher in the supercutaneous locking plate group than in the other two groups,with statistical significance(P<0.05).(4)Under different loads,the stress of the fixators in the three groups was the largest in the supercutaneous locking plate group,followed by the retrograde tibial nailing group,and the minimum in the antegrade intramedullary nailing group.There were significant differences in the stress of fixator stress raiser among the three groups under different loading modes(P<0.05).(5)It is indicated that all three fixation methods have the good anti-rotation ability and axial stability.Retrograde tibial nail shows better biomechanical stability.
10.Biomechanical difference of different fixation methods in bone healing of distal tibial comminuted fractures analyzed by finite element method
Huadong YAN ; Zhong ZHANG ; Gang ZHAO ; Jie LI ; Hua SONG ; Jianhua SUN ; Zhi LIU ; Mingming WANG
Chinese Journal of Tissue Engineering Research 2024;28(24):3814-3821
BACKGROUND:The treatment of distal tibial comminuted fractures with soft tissue injury has always been challenging.The new retrograde tibial nailing and supercutaneous locking plate are important treatment methods,but their strain and stress shielding at the fracture end during different periods of fracture healing and different load conditions have not been reported. OBJECTIVE:To explore the biomechanical stability of retrograde tibial nailing and supercutaneous locking plate in different periods of fracture healing by finite element analysis to offer a scientific foundation for clinical application and rehabilitation exercise. METHODS:The finite element model of distal tibial comminuted fracture was established by utilizing the CT data of the tibia from a 40-year-old healthy male.Retrograde tibial nailing,supercutaneous locking plate,and callus models were assembled in accordance with the principle of fracture fixation.The finite element analysis was performed using ANSYS software to compare the displacement of the fracture end,the stress shielding of the tibia,the stress of the callus,and the stress distribution of the tibia and the fixation device during different periods of fracture healing. RESULTS AND CONCLUSION:(1)The relative displacement of the tibial fracture decreased gradually with the healing of the fracture,and the displacement decreased significantly after 3 months.At 0 and 1 months after operation,the vertical displacement and total displacement of the supercutaneous locking plate group were higher than those in the retrograde intramedullary nail group.The Z-axis displacement(horizontal medial and lateral displacement)of the two fixation methods was more obvious than the X-axis and Y-axis,and the Z-axis displacement of supercutaneous locking plate group was the most obvious.The maximum Z-axis displacement of the two fixation methods was located on the outside of the tibia,and the minimum displacement was located on the inside of the tibia.(2)The stress shielding rate at different periods of fracture healing gradually decreased with time.The stress shielding rate of the retrograde intramedullary nail was higher than that of the supercutaneous locking plate at different stages of fracture healing.After 3 months,the stress shielding rate of the supercutaneous locking plate was reduced to about 4%,and the stress shielding rate of the retrograde intramedullary nail was reduced to about 40%.(3)The stress of the stress concentration site of the callus in the two fixation methods increased with the increase of the load,and the stress of the callus in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The maximum stress distribution of the callus was approximately equally distributed among the two modes of fixation,both in the lateral portion of the tibia.(4)As the fracture healed,the maximum stress of the tibia in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The average stress of the maximum stress area of the tibia in the supercutaneous locking plate group under 1 500 N load was 285 MPa,while that in the retrograde intramedullary nail group was 26 MPa.(5)As the fracture healed,the stress of the fixation device in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was significantly higher than that in the retrograde intramedullary nail group.After 3 months,the stress of the two fixation devices decreased significantly.(6)It is indicated that in the early stage of fracture healing,the strain on the fracture end in the retrograde intramedullary nail group is small,and the maximum stress of the tibia is moderate,allowing early loaded.The fractured ends in the supercutaneous locking plate group had too large strain and too large maximum stress of the tibia,which needed to be partially loaded under protection and could not be fully loaded.In the middle and late stages of fracture healing,the tibial retrograde intramedullary nail and the supercutaneous locking plate could be completely loaded,and the stress shielding rate of the supercutaneous locking plate was significantly lower than the tibial retrograde intramedullary nail.

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