BACKGROUND:Finite element analysis is an advanced computer-based engineering technique that uses mathematical approximations to simulate the human body.This method accurately reflects the biomechanical characteristics within the knee,providing a powerful tool for understanding knee disease pathogenesis,optimizing surgical protocols,and developing new implant materials.OBJECTIVE:To review the establishment of finite element modelling of the knee joint and its application in the study of knee joint diseases,and look forward to the future development trend.METHODS:The first author searched the PubMed and EI databases in April 2024 by applying a computer with English search terms"finite element analysis,FEA,knee joint,finite element model,knee biomechanics,knee osteoarthritis,knee prosthesis,knee ligaments,meniscus"and searched CNKI and WanFang databases with Chinese search terms"finite element analysis,finite element model,knee joint,biomechanics,osteoarthritis,computational model,knee prosthesis,knee ligament,meniscus."Finally,75 papers were included in the analysis.RESULTS AND CONCLUSION:(1)Finite element analysis method uses medical imaging data to obtain a three-dimensional human model,simplifies the complex human joint structure into finite and interconnected units,and visually displays the internal stress distribution of the knee joint by applying external loads to the model.(2)The researchers deeply study the internal stress and strain distribution of the knee joint under different working conditions by means of finite element analysis,revealing the overloading of the articular cartilage and the decrease of load in some areas when the balance of the internal load distribution of the knee joint is changed,and that such long-term abnormal stresses cause deformation,wear and tear,and eventual loss of cartilage,which is crucial for understanding how biomechanical factors cause degenerative changes of the knee joint.(3)The effect of physical therapy methods such as Tai Chi and gait adjustment in patients with osteoarthritis of the knee joint was evaluated by finite element analysis,and the results showed that these treatments reduced the overloading of the cartilage,which provided a scientific theoretical basis for clinical treatment.(4)Clinicians are able to optimize surgical treatment strategies by performing three-dimensional reconstruction,data measurement,and simulation of surgery before surgery through finite element analysis.Furthermore,the mechanical characteristics of different prostheses can be simulated to improve the shape,material,and fixation of the prostheses,reduce patient complications,and improve patient outcomes.(5)The combination of artificial intelligence and finite element analysis makes the construction of finite element models more accurate and easy to operate,greatly contributing to the efficiency of clinicians'medical practice and patient outcomes.(6)Finite element analysis is only a digital simulation,which is still somewhat different from the real physical state.

BACKGROUND:Cervical disc herniation can cause pain in the neck and shoulder area,as well as radiating pain in the upper limbs.The incidence rate is increasing year by year and tends to affect younger individuals.Fully understanding the biomechanical characteristics of the cervical spine in adolescents is of great significance for preventing and delaying the onset of cervical disc herniation in this age group. OBJECTIVE:To reconstruct cervical spine models for both healthy adolescents and adolescent patients with cervical disc herniation utilizing finite element analysis techniques,to analyze the motion range of the C1-T1 cervical vertebrae as well as the biomechanical characteristics of the annulus fibrosus,nucleus pulposus,endplates,and the cartilage of the small joints. METHODS:A normal adolescent's cervical spine and an adolescent patient with cervical disc herniation were selected in this study.The continuous scan cervical spine CT raw image data were imported into Mimics 21.0 in DICOM format.The C1-T1 vertebrae were reconstructed separately.Subsequently,the established models were imported into the 3-Matic software for disc reconstruction.The perfected models were then imported into Hypermesh software for meshing of the vertebrae,nucleus pulposus,annulus fibrosus,and ligaments,creating valid geometric models.After assigning material properties,the final models were imported into ABAQUS software to observe the joint motion range of the C1-C7 cervical vertebrae segments under different conditions,and to analyze the biomechanical characteristics of the annulus fibrosus,nucleus pulposus,endplates,and small joint cartilage of each cervical spine segment. RESULTS AND CONCLUSION:(1)In six different conditions,the joint motion range of the C1 vertebra in the cervical spine models of both normal adolescent and adolescent patient with cervical disc herniation was higher than that of the other vertebrae.Additionally,the joint motion range of each cervical spine segment in normal adolescent was greater than that in adolescent patient with cervical disc herniation.(2)In the cervical spine model of normal adolescent,the maximum stress values in the annulus fibrosus and nucleus pulposus were found on the left side during C2-3 flexion conditions(0.43 MPa and 0.17 MPa,respectively).In the cervical spine model of adolescent patient with cervical disc herniation,the maximum stress values were found on the left side during C7-T1 flexion conditions(0.54 MPa and 0.18 MPa,respectively).(3)In the cervical spine model of normal adolescent,the maximum stress value on the endplate was found on the left side of the upper endplate of C3 during flexion conditions(1.46 MPa).In the model of adolescent patient with cervical disc herniation,the maximum stress value on the endplate was found on the left side of the lower endplate of C7 during flexion conditions(1.32 MPa).(4)In the cervical spine model of normal adolescent,the maximum stress value in the small joint cartilage was found in the C2-3 left rotation conditions(0.98 MPa).In adolescent patient with cervical disc herniation,the stress in the small joint cartilage significantly increased under different conditions,especially in C1-2,with the maximum stress found during left flexion(3.50 MPa).(5)It is concluded that compared to normal adolescent,adolescent patient with cervical disc herniation exhibits altered cervical curvature and a decrease in overall joint motion range in the cervical spine.In adolescent with cervical disc herniation,there is a significant increase in stress on the annulus fibrosus,nucleus pulposus,and endplates in the C7-T1 segment.The stress on the left articular cartilage of the C1-2 is notable.Abnormal cervical curvature may be the primary factor causing these stress changes.

INTRODUCTION: Visual impairment and obesity remain the major public health issues among school-age students in rural areas of China. Obesity is an underlying risk of vision problems. This study aimed to assess the association between visual impairment and body mass index (BMI) among school-age students in rural northwest China. METHODS: This study included 39,385 students from the 4 th to 9 th grade in rural northwest China. From 2018 to 2020, students underwent an assessment of visual acuity (VA) and completed a questionnaire on family demographics, and height and weight measurements. Multiple logistic regression analyses were used to analyse the data. RESULTS: The association between visual impairment and BMI groups was significant in the study population ( P = 0.002) and in different groups (at the different educational, provincial and national levels) ( P < 0.001, separately). Multiple logistic regression analyses revealed a positive relationship between visual impairment and obesity in the study population, including those attending primary school, Han students and the residents of Ningxia autonomous region. CONCLUSION The association between visual impairment and obesity was significant among school-age students in rural northwest China. There should be implementation of policies to address the problem about visual impairment and obesity among school-age students in rural areas.
Humans ; China/epidemiology* ; Body Mass Index ; Male ; Female ; Rural Population ; Vision Disorders/complications* ; Child ; Adolescent ; Students ; Surveys and Questionnaires ; Logistic Models ; Obesity/complications* ; Visual Acuity ; Cross-Sectional Studies

In response to the new requirements for course instruction outlined in the revised training program for medical imaging program, this study integrated medical imaging technology courses based on the principle of outcome-oriented education and by leveraging self-developed digital resources, with imaging methods as the entry point. The core elements of the course teaching were re-optimized and reorganized to transcend the temporal and spatial limitations of course delivery, enabling the rational application of diverse teaching methods. This approach facilitated the integration of knowledge across three specialized courses, namely medical imaging physics, medical imaging equipment, and medical imaging examination techniques, and achieved full-dimensional and whole-process teaching evaluation. While reducing the number of hours allocated to theoretical instruction, the teaching objectives were achieved with high quality, providing a reference for the integration of digital technologies into the teaching of medical imaging and related disciplines.

BACKGROUND:Finite element analysis is an advanced computer-based engineering technique that uses mathematical approximations to simulate the human body.This method accurately reflects the biomechanical characteristics within the knee,providing a powerful tool for understanding knee disease pathogenesis,optimizing surgical protocols,and developing new implant materials.OBJECTIVE:To review the establishment of finite element modelling of the knee joint and its application in the study of knee joint diseases,and look forward to the future development trend.METHODS:The first author searched the PubMed and EI databases in April 2024 by applying a computer with English search terms"finite element analysis,FEA,knee joint,finite element model,knee biomechanics,knee osteoarthritis,knee prosthesis,knee ligaments,meniscus"and searched CNKI and WanFang databases with Chinese search terms"finite element analysis,finite element model,knee joint,biomechanics,osteoarthritis,computational model,knee prosthesis,knee ligament,meniscus."Finally,75 papers were included in the analysis.RESULTS AND CONCLUSION:(1)Finite element analysis method uses medical imaging data to obtain a three-dimensional human model,simplifies the complex human joint structure into finite and interconnected units,and visually displays the internal stress distribution of the knee joint by applying external loads to the model.(2)The researchers deeply study the internal stress and strain distribution of the knee joint under different working conditions by means of finite element analysis,revealing the overloading of the articular cartilage and the decrease of load in some areas when the balance of the internal load distribution of the knee joint is changed,and that such long-term abnormal stresses cause deformation,wear and tear,and eventual loss of cartilage,which is crucial for understanding how biomechanical factors cause degenerative changes of the knee joint.(3)The effect of physical therapy methods such as Tai Chi and gait adjustment in patients with osteoarthritis of the knee joint was evaluated by finite element analysis,and the results showed that these treatments reduced the overloading of the cartilage,which provided a scientific theoretical basis for clinical treatment.(4)Clinicians are able to optimize surgical treatment strategies by performing three-dimensional reconstruction,data measurement,and simulation of surgery before surgery through finite element analysis.Furthermore,the mechanical characteristics of different prostheses can be simulated to improve the shape,material,and fixation of the prostheses,reduce patient complications,and improve patient outcomes.(5)The combination of artificial intelligence and finite element analysis makes the construction of finite element models more accurate and easy to operate,greatly contributing to the efficiency of clinicians'medical practice and patient outcomes.(6)Finite element analysis is only a digital simulation,which is still somewhat different from the real physical state.

In response to the new requirements for course instruction outlined in the revised training program for medical imaging program, this study integrated medical imaging technology courses based on the principle of outcome-oriented education and by leveraging self-developed digital resources, with imaging methods as the entry point. The core elements of the course teaching were re-optimized and reorganized to transcend the temporal and spatial limitations of course delivery, enabling the rational application of diverse teaching methods. This approach facilitated the integration of knowledge across three specialized courses, namely medical imaging physics, medical imaging equipment, and medical imaging examination techniques, and achieved full-dimensional and whole-process teaching evaluation. While reducing the number of hours allocated to theoretical instruction, the teaching objectives were achieved with high quality, providing a reference for the integration of digital technologies into the teaching of medical imaging and related disciplines.

Objective:To translate the quality of life tool for patients with aplastic anaemia and paroxysmal nocturnal haemoglobinuria (QLQ-AA/PNH) into Chinese, and to test its reliability and validity.Methods:According to the scale translation principle, the Chinese version of QLQ-AA/PNH was formed through translation, back translation and cross-cultural adaptation. A cross-sectional survey method was used to conveniently select 58 patients with aplastic anemia who were treated in the hematology department of the Second Affiliated Hospital of Dalian Medical University from January 2018 to September 2023 for investigation, and to evaluate the reliability and validity of the scale.Results:The Chinese version of QLQ-AA/PNH retains 36 items, and 5 common factors (psychological status dimension, life burden dimension, physical condition dimension, illness anxiety dimension and other symptom dimension) were extracted through exploratory factor analysis. The cumulative variance contribution rate reached 71.33%, and the factor load of each entry was greater than 0.5 on corresponding common factors. The Cronbach α coefficient of the scale as a whole was 0.971, the broken half reliability coefficient was 0.985, the Cronbach α coefficient of each common factor was 0.637 to 0.954, and the broken half reliability coefficient was 0.637 to 0.930. Conclusions:The Chinese version of QLQ-AA/PNH has been proved to be valid and reliable. It is a valuable tool for evaluating the quality of life among patients with aplastic anaemia.

Objective:To translate the quality of life tool for patients with aplastic anaemia and paroxysmal nocturnal haemoglobinuria (QLQ-AA/PNH) into Chinese, and to test its reliability and validity.Methods:According to the scale translation principle, the Chinese version of QLQ-AA/PNH was formed through translation, back translation and cross-cultural adaptation. A cross-sectional survey method was used to conveniently select 58 patients with aplastic anemia who were treated in the hematology department of the Second Affiliated Hospital of Dalian Medical University from January 2018 to September 2023 for investigation, and to evaluate the reliability and validity of the scale.Results:The Chinese version of QLQ-AA/PNH retains 36 items, and 5 common factors (psychological status dimension, life burden dimension, physical condition dimension, illness anxiety dimension and other symptom dimension) were extracted through exploratory factor analysis. The cumulative variance contribution rate reached 71.33%, and the factor load of each entry was greater than 0.5 on corresponding common factors. The Cronbach α coefficient of the scale as a whole was 0.971, the broken half reliability coefficient was 0.985, the Cronbach α coefficient of each common factor was 0.637 to 0.954, and the broken half reliability coefficient was 0.637 to 0.930. Conclusions:The Chinese version of QLQ-AA/PNH has been proved to be valid and reliable. It is a valuable tool for evaluating the quality of life among patients with aplastic anaemia.

Objective:To investigate the nutritional risk, incidence of malnutrition, and intake of three major energy-supplying nutrients, analyze changes in their body composition and the possible influencing factors in patients with stomach neoplasms during perioperative period in order to provide a theoretical basis for the nutritional management of patients with stomach neoplasms during perioperative period.Methods:This was a cross-sectional study. A total of 105 patients who underwent gastric cancer radical surgery in the Gastrointestinal Department of Zhongshan Hospital Affiliated to Xiamen University from June 2021 to May 2023 were taken as the research subjects using fixed-point continuous sampling method. They were recruited for screening and assessment using Nutritional Risk Screening 2002 (NRS 2002) and Patient-Generated Subjective Global Assessment (PG-SGA). Nutrients intake during the perioperative period were investigated using the 24-h recall method and dietary diary method, etc. Body compositions were measured using the bioelectrical resistance method.Results:Among the 105 patients, there were 78 males and 27 females, with an average age of (61.5 ± 10.3) years. About 83.8% (88/105) gastric cancer patients were at nutritional risk and 82.9% (87/105) were malnourished. The preoperative and postoperative energy intake were (1 646.1 ± 321.5) and (1 317.2 ± 365.8) kcal (1 kcal=4.184 kJ), respectively, which were significantly lower than the target amount of (1 896.7 ± 262.9) kcal, the difference was statistically significant ( t=6.23, 8.29, both P<0.05).The preoperative body mass, muscle mass, skeletal muscle, fat mass, and skeletal muscle index were (51.5 ± 9.6), (40.8 ± 6.0), (23.6 ± 4.0), (8.3 ± 4.9) kg, and 6.7 ± 0.8 respectively, while the postoperative values were (50.0 ± 9.1), (39.8 ± 6.0), (22.8 ± 3.6), (7.8 ± 5.2) kg, and 6.5 ± 0.8 respectively, with statistically significant differences between the two groups ( t values were 2.89-10.61, all P<0.05). Logistic multivariate regression analysis showed that the operation time ( OR=3.984, 95% CI 1.433-11.080, P<0.05) and energy satisfaction ( OR=0.053, 95% CI 0.005-0.610, P<0.05) were independent influencing factors for the degree of skeletal muscle loss. Conclusions:During perioperative period, the gastric cancer patients had poor nutritional status with insufficient nutrient intake and accelerated loss of body muscle and fat. Therefore, it was necessary to conduct a comprehensive nutritional evaluation for patients with stomach neoplasms during perioperative period in time and take steps to promote recovery by providing individualized nutritional therapy.

BACKGROUND:Ankylosing spondylitis is a chronic inflammatory disease with chronic rheumatic immunity.Soft tissue ossification and fusion and spinal stiffness can cause biomechanical changes. OBJECTIVE:To reconstruct the lumbar-sacral intervertebral disc in ankylosing spondylitis patients with lumbar kyphosis by finite element analysis,and to study the range of motion of each segment of T11-S1 and the biomechanical characteristics of annulus fibrosus and nucleus pulposus. METHODS:The imaging data were obtained from an ankylosing spondylitis patient with lumbar kyphosis.The original CT image data of continuously scanned spine were imported into Mimics 21.0 in DICOM format,and T11-S1 was reconstructed respectively.The established model was imported into 3-Matic software in the format of"Stl"to reconstruct the intervertebral disc,and the fibrous intervertebral disc model was obtained.The improved model was further imported into Hypermesh software,and the vertebra,nucleus pulposus,annulus fibrosus and ligament were mesh-divided.After the material properties were given,the model was imported into ABAQUS software to observe the range of motion of each vertebral body in seven different working conditions of T11-S1,and analyze the biomechanical characteristics of each segment of annulus fibrosus and nucleus pulposus. RESULTS AND CONCLUSION:(1)The range of motion of L1 vertebrae was higher than that of other vertebrae under six different working conditions:extension,forward flexion,rotation(left and right),and lateral flexion(left and right).The maximum range of motion was 2.18° during L1 vertebral flexion,and the minimum range of motion was 0.12° during L5 vertebral extension.(2)The annular fiber flexion at L2-L3 segments was greater than the extension(P<0.05),and the annular fiber flexion at L3-L4 and L4-L5 segments was less than the extension(P<0.05).The left rotation of L1-L2 annular fibers was greater than the right rotation(P<0.05).The left flexion of the annulus was greater than the right flexion in L1-L2,L2-L3,L3-L4,L4-L5 and L5-S1 segments(P<0.05).(3)The nucleus pulposus stresses of T11-L12,L1-L2,L2-L3,L3-L4 and L4-L5 segments in forward flexion were greater than in extension(P<0.05).The left rotation of T12-L1 and L3-L4 segments was smaller than the right rotation(P<0.05),and that of T11-T12,L1-L2,and L2-L3 segments was larger than the right rotation(P<0.05).The left flexion was larger than the right flexion in the T11-S1 segment.(4)It is concluded that in ankylosing spondylitis patients with lumbar kyphosis,the minimum range of motion of the vertebral body is located at the L5 vertebral body in extension.To prevent fractures,it is recommended to avoid exercise in the extension position.During the onset of lumbar kyphosis in patients with ankylosing spondylitis,the maximum stress of the annulus fibrosus and nucleus pulposus is located in the L1-L2 segment,which is fixed and will not alter with the change of body position.The late surgical treatment and correction of deformity should focus on releasing the pressure of the annulus fibrosus and nucleus pulposus in this segment to avoid the rupture of the annulus fibrosus and the injury of the nucleus pulposus.