1.Compact Fundus Imaging System Using Shack-Hartmann Wavefront Sensing for High-speed Auto-focus
Zhe-Kai LIN ; Long CHEN ; Geng-Yong ZHENG ; Jin-Tian HUANG ; Jia-Xin DONG ; Shang-Pan YANG ; Wen-Zheng DING ; Ding-An HAN ; Xue-Hua WANG ; Ya-Guang ZENG
Progress in Biochemistry and Biophysics 2026;53(4):1076-1086
ObjectiveThe widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF) technologies. Image-based methods relying on sharpness evaluation require iterative searches, resulting in slow convergence, while projection-based techniques are susceptible to optical artifacts and calibration errors. To address these challenges, this study introduces a novel AF system based on direct wavefront sensing, designed to deliver simultaneous high speed, high precision, and operational robustness within the compact form factor essential for portable ophthalmic devices. MethodsOur approach fundamentally reimagines the AF process by directly measuring the ocular wavefront aberration. We developed a custom portable fundus camera integrating a miniaturized Shack-Hartmann wavefront sensor (SHWS) into the optical path. An 850 nm laser diode projects a point source onto the retina via oblique illumination to minimize corneal reflections. Light scattered from this spot carries the eye’s refractive error through the imaging optics and is directed to the SHWS, positioned at a plane optically conjugate to the primary color CMOS imaging sensor. A microlens array within the SHWS samples the incident wavefront, generating a pattern of focal spots on a CCD. Real-time centroid analysis of these spots provides a map of local wavefront slopes. These measurements are processed through a singular value decomposition (SVD) algorithm to fit a Zernike polynomial basis set, enabling real-time reconstruction of the wavefront phase. The defocus component (S) is extracted from the second-order Zernike coefficients, providing a direct, quantitative measure of the refractive error in diopters. This value serves as a precise error signal in a closed-loop control system, which commands a voice-coil actuated focusing lens to its null position in a single, deterministic step, eliminating the need for iterative search algorithms. ResultsComprehensive evaluation demonstrated the system’s high performance. Testing on a calibrated model eye (OEMI-7) established a highly linear relationship between the computed defocus S and the focusing lens position across a ±20 Diopter (D) compensation range, achievable within a 5 mm mechanical travel. The system achieved a focusing precision of 0.08 D, corresponding to an 18-fold improvement over a conventional projection spot-size method tested under identical conditions. The total focus acquisition time, encompassing wavefront measurement, computation, and lens actuation, averaged under 0.5 s. Clinical validation with 25 human volunteers (50 eyes, refractive range -15 D to +10 D) confirmed practical efficacy. The wavefront-sensing AF succeeded in 92% of attempts with a mean time of 0.5 s, substantially outperforming a projection-based benchmark which achieved only a 32% success rate with an average time of 4.25 s. The system provided instantaneous directional guidance and maintained stability during minor ocular movements. Objective assessment of image quality, via amplitude contrast of retinal vasculature, showed consistent and significant enhancement following AF correction across the entire tested diopter range. ConclusionThis work successfully implements and validates a direct wavefront-sensing autofocus paradigm for portable fundus cameras. By directly quantifying and compensating for the optical defocus aberration, this method bypasses the fundamental limitations of image-processing and projection-based techniques, enabling rapid, precise, and deterministic diopter compensation. The developed system delivers an exceptional combination of a wide operational range (±20 D), high accuracy (0.08 D), fast convergence (0.5 s), and a compact physical footprint. This technology provides a practical and high-performance focusing solution capable of enhancing the reliability, throughput, and diagnostic utility of portable retinal imaging in large-scale screening applications. Future efforts will be directed towards system cost optimization and performance adaptation for diverse ocular conditions.
2.Guideline for Adult Weight Management in China
Weiqing WANG ; Qin WAN ; Jianhua MA ; Guang WANG ; Yufan WANG ; Guixia WANG ; Yongquan SHI ; Tingjun YE ; Xiaoguang SHI ; Jian KUANG ; Bo FENG ; Xiuyan FENG ; Guang NING ; Yiming MU ; Hongyu KUANG ; Xiaoping XING ; Chunli PIAO ; Xingbo CHENG ; Zhifeng CHENG ; Yufang BI ; Yan BI ; Wenshan LYU ; Dalong ZHU ; Cuiyan ZHU ; Wei ZHU ; Fei HUA ; Fei XIANG ; Shuang YAN ; Zilin SUN ; Yadong SUN ; Liqin SUN ; Luying SUN ; Li YAN ; Yanbing LI ; Hong LI ; Shu LI ; Ling LI ; Yiming LI ; Chenzhong LI ; Hua YANG ; Jinkui YANG ; Ling YANG ; Ying YANG ; Tao YANG ; Xiao YANG ; Xinhua XIAO ; Dan WU ; Jinsong KUANG ; Lanjie HE ; Wei GU ; Jie SHEN ; Yongfeng SONG ; Qiao ZHANG ; Hong ZHANG ; Yuwei ZHANG ; Junqing ZHANG ; Xianfeng ZHANG ; Miao ZHANG ; Yifei ZHANG ; Yingli LU ; Hong CHEN ; Li CHEN ; Bing CHEN ; Shihong CHEN ; Guiyan CHEN ; Haibing CHEN ; Lei CHEN ; Yanyan CHEN ; Genben CHEN ; Yikun ZHOU ; Xianghai ZHOU ; Qiang ZHOU ; Jiaqiang ZHOU ; Hongting ZHENG ; Zhongyan SHAN ; Jiajun ZHAO ; Dong ZHAO ; Ji HU ; Jiang HU ; Xinguo HOU ; Bimin SHI ; Tianpei HONG ; Mingxia YUAN ; Weibo XIA ; Xuejiang GU ; Yong XU ; Shuguang PANG ; Tianshu GAO ; Zuhua GAO ; Xiaohui GUO ; Hongyi CAO ; Mingfeng CAO ; Xiaopei CAO ; Jing MA ; Bin LU ; Zhen LIANG ; Jun LIANG ; Min LONG ; Yongde PENG ; Jin LU ; Hongyun LU ; Yan LU ; Chunping ZENG ; Binhong WEN ; Xueyong LOU ; Qingbo GUAN ; Lin LIAO ; Xin LIAO ; Ping XIONG ; Yaoming XUE
Chinese Journal of Endocrinology and Metabolism 2025;41(11):891-907
Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.
3.Research progress on the application of intelligent medical treatment in abdominal war trauma
Si-Zhe WANG ; Xu SUN ; Ding-Chang LI ; Xian-Qiang LIU ; Wen-Xing GAO ; Wen ZHAO ; Hao LIU ; Guang-Long DONG
Medical Journal of Chinese People's Liberation Army 2025;50(1):22-27
Abdominal war trauma is a common and high-risk type of injury in the modern battlefield,with rapid changes in condition and a high mortality rate.There is an urgent need for emerging medical technologies to improve the efficiency and success rate of first aid for military casualties.With the development of artificial intelligence(AI),5G,and other emerging technologies,the concept of intelligent medical treatment is gradually forming and can assist in the diagnosis and treatment of abdominal trauma.This paper reviews the characteristics of abdominal war trauma in modern wars,discusses the application of intelligent medical treatment for abdominal war trauma and its drawbacks to be solved,aiming to provide reference for research related to abdominal war trauma.
4.Evaluation of antimicrobial activity of milk exosomes loaded with rifamycin S derivative
Zhanqun YANG ; Xiang LI ; Chenghua LIU ; Mengzhu ZHENG ; Shiyong FAN ; Yuchao DONG ; Zihao WANG ; Jian LIN ; Guang YANG ; Long CHEN
Chinese Journal of Pharmacology and Toxicology 2025;39(3):208-215
OBJECTIVE To design and synthesize rifamycin S derivatives and load them into milk exosomes to evaluate their in vitro antimicrobial activity.METHODS Rifamycin S derivatives were synthe-sized and characterized by mass spectrometry and NMR.Using the dilution assay method,the inhibitory activity of each rifamycin S derivatives molecule against Staphylococcus aureus and Pseudomonas aerugi-nosa was determined,and the IC50 was calculated.Derivatives molecules with excellent antimicrobial activity were selected and loaded into milk exosomes using the ultrasonication method,resulting in the preparation of milk exosome-loaded rifamycin S derivatives.The antimicrobial activity against Staphylo-coccus aureus was determined using the dilution assay method.The inhibitory effect of the exosome-loaded rifamycin S derivatives on Staphylococcus aureus residing within macrophages was detected using the plate colony counting method.RESULTS Three rifamycin S derivatives were successfully designed and synthesized,which demonstrated superior antimicrobial activity against Staphylococcus aureus(the parent compound's antimicrobial activity is merely from 1/20 to 1/80 of that of the three rifamycin S derivatives)and Pseudomonas aeruginosa(the parent compound's antimicrobial activity is only 1/14 and 1/9 of that of compound 1 and compound 3)compared to the parent compound.The loading of milk exosomes with the rifamycin S derivatives compound 3 was successfully achieved,with a loading efficiency of 10.9%.The antimicrobial activity of the compound after exosome loading was significantly enhanced against Staphylococcus aureus in vitro and against Staphylococcus aureus residing within macrophages(P<0.01).CONCLUSION The designed and synthesized derivatives of rifamycin S possess stronger anti-microbial activity,and their antibacterial efficacy against both extracellular and intracellular bacteria can be further enhanced after loading into exosomes.
5.Evaluation of antimicrobial activity of milk exosomes loaded with rifamycin S derivative
Zhanqun YANG ; Xiang LI ; Chenghua LIU ; Mengzhu ZHENG ; Shiyong FAN ; Yuchao DONG ; Zihao WANG ; Jian LIN ; Guang YANG ; Long CHEN
Chinese Journal of Pharmacology and Toxicology 2025;39(3):208-215
OBJECTIVE To design and synthesize rifamycin S derivatives and load them into milk exosomes to evaluate their in vitro antimicrobial activity.METHODS Rifamycin S derivatives were synthe-sized and characterized by mass spectrometry and NMR.Using the dilution assay method,the inhibitory activity of each rifamycin S derivatives molecule against Staphylococcus aureus and Pseudomonas aerugi-nosa was determined,and the IC50 was calculated.Derivatives molecules with excellent antimicrobial activity were selected and loaded into milk exosomes using the ultrasonication method,resulting in the preparation of milk exosome-loaded rifamycin S derivatives.The antimicrobial activity against Staphylo-coccus aureus was determined using the dilution assay method.The inhibitory effect of the exosome-loaded rifamycin S derivatives on Staphylococcus aureus residing within macrophages was detected using the plate colony counting method.RESULTS Three rifamycin S derivatives were successfully designed and synthesized,which demonstrated superior antimicrobial activity against Staphylococcus aureus(the parent compound's antimicrobial activity is merely from 1/20 to 1/80 of that of the three rifamycin S derivatives)and Pseudomonas aeruginosa(the parent compound's antimicrobial activity is only 1/14 and 1/9 of that of compound 1 and compound 3)compared to the parent compound.The loading of milk exosomes with the rifamycin S derivatives compound 3 was successfully achieved,with a loading efficiency of 10.9%.The antimicrobial activity of the compound after exosome loading was significantly enhanced against Staphylococcus aureus in vitro and against Staphylococcus aureus residing within macrophages(P<0.01).CONCLUSION The designed and synthesized derivatives of rifamycin S possess stronger anti-microbial activity,and their antibacterial efficacy against both extracellular and intracellular bacteria can be further enhanced after loading into exosomes.
6.Guideline for Adult Weight Management in China
Weiqing WANG ; Qin WAN ; Jianhua MA ; Guang WANG ; Yufan WANG ; Guixia WANG ; Yongquan SHI ; Tingjun YE ; Xiaoguang SHI ; Jian KUANG ; Bo FENG ; Xiuyan FENG ; Guang NING ; Yiming MU ; Hongyu KUANG ; Xiaoping XING ; Chunli PIAO ; Xingbo CHENG ; Zhifeng CHENG ; Yufang BI ; Yan BI ; Wenshan LYU ; Dalong ZHU ; Cuiyan ZHU ; Wei ZHU ; Fei HUA ; Fei XIANG ; Shuang YAN ; Zilin SUN ; Yadong SUN ; Liqin SUN ; Luying SUN ; Li YAN ; Yanbing LI ; Hong LI ; Shu LI ; Ling LI ; Yiming LI ; Chenzhong LI ; Hua YANG ; Jinkui YANG ; Ling YANG ; Ying YANG ; Tao YANG ; Xiao YANG ; Xinhua XIAO ; Dan WU ; Jinsong KUANG ; Lanjie HE ; Wei GU ; Jie SHEN ; Yongfeng SONG ; Qiao ZHANG ; Hong ZHANG ; Yuwei ZHANG ; Junqing ZHANG ; Xianfeng ZHANG ; Miao ZHANG ; Yifei ZHANG ; Yingli LU ; Hong CHEN ; Li CHEN ; Bing CHEN ; Shihong CHEN ; Guiyan CHEN ; Haibing CHEN ; Lei CHEN ; Yanyan CHEN ; Genben CHEN ; Yikun ZHOU ; Xianghai ZHOU ; Qiang ZHOU ; Jiaqiang ZHOU ; Hongting ZHENG ; Zhongyan SHAN ; Jiajun ZHAO ; Dong ZHAO ; Ji HU ; Jiang HU ; Xinguo HOU ; Bimin SHI ; Tianpei HONG ; Mingxia YUAN ; Weibo XIA ; Xuejiang GU ; Yong XU ; Shuguang PANG ; Tianshu GAO ; Zuhua GAO ; Xiaohui GUO ; Hongyi CAO ; Mingfeng CAO ; Xiaopei CAO ; Jing MA ; Bin LU ; Zhen LIANG ; Jun LIANG ; Min LONG ; Yongde PENG ; Jin LU ; Hongyun LU ; Yan LU ; Chunping ZENG ; Binhong WEN ; Xueyong LOU ; Qingbo GUAN ; Lin LIAO ; Xin LIAO ; Ping XIONG ; Yaoming XUE
Chinese Journal of Endocrinology and Metabolism 2025;41(11):891-907
Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.
7.Clinical study of intensity-modulated radiation therapy combined with camrelizumab in the treatment of advanced hepatocellular carcinoma
Guang-Long SHI ; Xue-Dong XU ; Rui HUANG ; Na CHAI
Journal of Regional Anatomy and Operative Surgery 2024;33(1):43-46
Objective To investigate the efficacy and safety of intensity-modulated radiation therapy combined with camrelizumab in the treatment of advanced hepatocellular carcinoma(HCC).Methods A total of 84 patients with advanced HCC admitted to our hospital from January to December 2020 were selected as the study objects,and were randomly divided into the observation group and the control group,with 42 cases in each group.Patients in the observation group received intensity-modulated radiation therapy combined with carrelli-zumab,and patients in the control group received intensity-modulated radiation therapy.The short-term efficacy,immune function and long-term survival rate of patietns in the two groups were compared,and the incidence of adverse reactions was recorded.Results The total effec-tive rates of the observation group 1 month and 3 months after treatment were significantly higher than those of the control group(P<0.05).The levels of CD3+,CD4+ and CD4+/CD8+ 1 month and 3 months after treatment were all increased in the two groups,while the levels of CD8+ in both two groups were decreased(P<0.05),and the levels of CD3+,CD4+ and CD4+/CD8+ in the observation group were higher than those in the control group(P<0.05),and the levels of CD8+ in the observation group were lower than those in the control group(P<0.05).The median survival time of patients in the observation group was significantly longer than that of patients in the control group(P<0.05).The incidence of cutaneous capillary hyperplasia in the observation group was higher than that in the control group(P<0.001),and there was no significant difference in the incidence of other adverse reactions between the two groups(P>0.05),and all of adverse reactions were grades 1 to 2.Conclusion Intensity-modulated radiation therapy combined with camrelizumab has a good effect on HCC,it can improve the immune function of the body,and control the development of the disease,with good safety.
8.Efficacy and safety analysis of early surgical treatment for spinal thoracolumbar fracture without nerve injury
Zheng-Guang JIAN ; Hai-Long WANG ; Xiao-Dong SU ; Guan-Xing LI ; Ji-Hui JU
Journal of Regional Anatomy and Operative Surgery 2024;33(7):599-603
Objective To explore the clinical efficacy and safety of early surgical treatment for spinal thoracolumbar fracture without nerve injury.Methods The clinical data of 80 patients with spinal thoracolumbar fracture without nerve injury who were admitted to the department of spinal surgery in our hospital were retrospectively analyzed.According to the different operation timing,those who underwent surgery within 72 hours after fracture were included in the early operation group(n=41),and those who underwent surgery 72 hours to 2 weeks after fracture were included in the elective operation group(n=39).All operations were performed through the Wiltse approach for short-segment pedicle screw fixation on the injured vertebra.The operation time,intraoperative blood loss,hospital stay and incidence of complication of the two groups were compared.The visual analogue scale(VAS)scores,Oswestry disability index(ODI),compression rate of the anterior edge height of the injured vertebra,and the Cobb angle in the sagittal position of the injured vertebra before surgery,1 week after surgery and 1 year after surgery were compared between the two groups.The improvement rates of the anterior edge height compression and the Cobb angle in the sagittal position of the injured vertebra 1 week and 1 year after surgery were compared between the two groups.Results There was no significant difference in the operation time,intraoperative blood loss or total incidence of complications between the two groups(P>0.05).The hospital stay in the early operation group was shorter than that in the elective operation group,and the difference was statistically significant(P<0.05).The VAS scores and ODI 1 week and 1 year after surgery of the two groups were better than those before surgery,and the differences were statistically significant(P<0.05).There was no significant difference in the VAS scores or ODI at each time point before and after surgery between the two groups(P>0.05).The compression rate of the anterior edge height and Cobb angle in the sagittal position of the injured vertebra 1 week and 1 year after surgery in the two groups were lower/smaller than those before surgery,with statistically significant differences(P<0.05).There was no statistically significant difference in the compression rate of the anterior edge height or Cobb angle before surgery in the sagittal position of the injured vertebrae between the two groups(P>0.05).The compression rate of the anterior edge height and Cobb angle in the sagittal position of the injured vertebra 1 week and 1 year after surgery in the early operation group were lower/smaller than those in the elective operation group,and the differences were statistically significant(P<0.05).The improvement rates of the anterior edge height compression and the Cobb angle in the sagittal position of the injured vertebra 1 week and 1 year after surgery in the early operation group were better than those in the elective operation group,and the differences were statistically significant(P<0.05).Conclusion Early surgical treatment for spinal thoracolumbar fracture without nerve damage is safe,it can significantly shorten hospitalization time,obtain good fracture reduction quality and definite therapeutic effects.However,a comprehensive preoperative evaluation of the patients' condition is necessary to ensure surgical safety.
9.Research progress of traditional Chinese medicine in treatment of benign prostatic hyperplasia.
Sheng-Long LI ; Gang-Gang LU ; Guang-Wei JIN ; Peng-Dong YIN ; Mei-Sheng GONG ; Hui LI ; Xu MA ; Xi-Xiang LI ; Yuan-Bo ZHAO ; Da-Cheng TIAN ; Yong-Lin LIANG ; Yong-Qiang ZHAO
China Journal of Chinese Materia Medica 2024;49(21):5817-5828
Benign prostatic hyperplasia(BPH) is a common disease in middle-aged and elderly men, with lower urinary tract symptoms as the main manifestation, severely affecting the quality of life of patients. The pathogenesis of BPH is not yet fully understood, and there are still some challenges and limitations in western medicine treatment for BPH. Therefore, finding new and more effective treatment strategies is urgent. In recent years, many basic and clinical studies have confirmed the important role of traditional Chinese medicine in the treatment of BPH. This article reviews the progress of basic and clinical research in the treatment of BPH with traditional Chinese medicine, and believes that basic research mainly focuses on the active ingredients of Chinese medicine [regulating pathways such as NF-E2-related factor 2(Nrf2)/antioxidant response element(ARE), nuclear factor κB(NF-κB), epidermal growth factor receptor(EGFR)/signal transducer and activator of transcription 3(STAT3), phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR), p38 mitogen-activated protein kinase(p38 MAPK)/forkhead box O subtype(FOXO3a), etc.], single Chinese herbs(regulating inflammatory factors, oxidative stress-related proteins, cell cycle-related proteins, and apoptotic factors, etc.), and Chinese herbal compounds and patent medicines [regulating extracellular signal-regulated kinase(ERK1/2), transforming growth factor-β(TGF-β)/Smad, mitogen-activated protein kinase(MAPK), PI3K/Akt, Nrf2, trefoil factor 2(TFF2)/Wnt, interleukin-6(IL-6)/Janus kinase 2(JAK2)/STAT3, hypoxia-inducible factor 1α(HIF-1α)/vascular endothelial growth factor receptor(VEGFR), etc.], and then play a therapeutic role by inhibiting BPH cell proliferation, oxidative stress, inflammatory response, promoting apoptosis, and inhibiting epithelial-mesenchymal transition. Clinical studies mainly focus on internal treatment, external treatment, combined internal and external treatment, and integrated Chinese and western medicine treatment as the main methods, aiming to improve traditional Chinese medicine syndrome scores, prostate symptom scores, residual urine volume, effective bladder volume, sexual quality of life, increase average urine flow rate, maximum urine flow rate, and promote balance of sex hormone secretion. Through this research, it is hoped to provide some reference ideas for clinical research and drug development for BPH.
Prostatic Hyperplasia/metabolism*
;
Male
;
Humans
;
Drugs, Chinese Herbal/therapeutic use*
;
Animals
;
Signal Transduction/drug effects*
;
Medicine, Chinese Traditional
;
NF-E2-Related Factor 2/genetics*
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
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Weight-Bearing
;
Biomechanical Phenomena
;
External Fixators
;
Tibial Fractures/physiopathology*
;
Fracture Fixation/instrumentation*
;
Male

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