Objective:To explore the application of the flipped classroom based on the production-oriented approach (POA) theory in the teaching of standardized training in the Department of Joint and Sports Medicine.Methods:A total of 37 standardized training physicians who rotated in the Department of Joint and Sports Medicine in Zhongnan Hospital of Wuhan University from January 2019 to December 2019 were selected as the control group, and the traditional teaching was adopted. Another 39 standardized training physicians who rotated from April 2020 to March 2021 were selected as the study group, and the flipped classroom based on POA theory was adopted. At the end of the rotation, the scores of theoretical knowledge and practical operation skills, the scores of mini-clinical evaluation exercise (Mini-CEX) and the teaching satisfaction were compared. SPSS 22.0 was used for t-test and Chi-square test. Results:The various scores and total score of theoretical knowledge and practical operation skills in the study group at the end of rotation were significantly higher than those in the control group ( P < 0.05). There was no significant difference in the various scores and total score of Mini-CEX between the two groups at the time of admission ( P > 0.05). The above scores in the two groups at the end of rotation were significantly higher than those at the time of admission ( P < 0.05), and the above scores of the study group were significantly higher than those of the control group ( P < 0.05). The overall teaching satisfaction rate of the study group was higher than that of the control group ( P < 0.05). Conclusion:The application of the flipped classroom based on POA theory in the teaching of standardized training in the Department of Joint and Sports Medicine can significantly improve the teaching effect and quality, and improve the clinical comprehensive ability and teaching satisfaction of the standardized training physicians, which is worthy of popularization and application.

Objective To investigate the efficacy of kinesio taping(KT)in the treatment of pain,function,range of motion and muscle strength in patients with knee articular osteoarthritis(OA).Method Forty patients with knee articular OA diagnosed in our hospital from January 2021 to January 2023 were selected.We randomly divided them into two groups,each with 20 cases.The observation group received KT therapy,while the control group received sham bandage therapy.Visual Analogue Scale/Score(VAS)was used to assess the degree of activity and nocturnal pain,KOOS score was used to assess the functional status of patients,digital goniometer was used to measure the range of activity and hand-held force meter was used to assess muscle strength.The evaluation time includes before treatment and on the 12th day of treatment.Result Compared with before treatment,the pain,function,range of motion,and muscle strength of patients in the control group and KT group were significantly improved after treatment.And compared with the control group,the KT group also significantly improved the above indicators after treatment.Conclusion KT therapy has significant efficacy in relieving short-term pain and improving functional limitations in knee osteoarthritis.

Insufficient myocardial perfusion is a common pathological feature in the early stage of various heart diseases,and quantitative evaluation of myocardial perfusion is of great significance for diagnosing and treating diseases and evaluating prognosis.Cardiac MR(CMR)perfusion imaging is non radiative,having high spatial resolution and being sensitive to local myocardial ischemia.Numerical simulation technology combined with computational biomechanics could simulate the process of myocardial blood flow perfusion.The research progresses of CMR and numerical simulation for quantitative evaluation of myocardial perfusion were reviewed in this article.

BACKGROUND:Cervical rotation-traction manipulation is effective and safe in the treatment of cervical spondylotic radiculopathy,and has been widely used in clinical work.However,its effects on the biomechanics of cervical vertebra and intervertebral disc and the area of intervertebral foramen have not been systematically clarified. OBJECTIVE:Based on the finite element analysis technique,a relevant research and analysis were carried out to provide digital evidence for the mechanism of effect of cervical rotation-traction manipulation in the treatment of cervical spondylotic radiculopathy. METHODS:The CT image data of a volunteer with no neck diseases were selected as the finite element model material at its left-handed physiological limit position.The initial construction of the finite element model was completed by Mimics 19.0 software,Geomagic Studio 2013 software,Hypermash 14.0 software,and ANSYS Workbench 2020 R2 software,respectively.Based on the literature,the grid division of cervical structure and the assignment of elastic modulus and elastic coefficient were completed.Based on the previous work of the team,the mechanical effects of cervical rotation-traction manipulation were simulated on the model.Effects of cervical rotation-traction manipulation on the mechanical parameters of each vertebral body and intervertebral disc in C3-T1 segment and on the cervical lateral foramen area were analyzed. RESULTS AND CONCLUSION:(1)During cervical rotation-traction manipulation,the stress of bone structure was significantly higher than that of soft tissue such as intervertebral disc.(2)When operating the technique,the stress at the top of each cervical vertebra was higher,the stress at the bottom was lower,and the stress at the facet joint and transverse process was lower.The stress at the top of the intervertebral disc was lower,the stress at the bottom was higher,but the highest point of the intervertebral disc stress was outside the top.(3)In addition,after loading the lifting force,the projected area of the C6/C7 intervertebral foramen increased significantly compared with that before loading.(4)It is indicated that the cervical rotation-traction manipulation has the mechanical characteristics of changing the stress structure of the cervical spine itself,and can expand the C6/7 intervertebral cervical foramen area on the opposite side of the patient's cervical rotation,so as to achieve the purpose of treating cervical spondylotic radiculopathy.

Objective:To evaluate the validity of adventitial collagen cross-linking by glutaraldehyde(GA) to reduce intimal hyperplasia of vein graft in a rabbit carotid artery bypass graft model.Methods:Harvesting 36 segments of the external jugular vein and 6 segments of the internal carotid artery with 3 cm length from the New Zealand white rabbits. The veins were randomly divided into 6 groups and underwent adventitial collagen cross-linking by 0.3% glutaraldehyde for 0 min, 1 min, 2 min, 3 min, 4 min, and 5 min, respectively. All vessel segments were subjected to biomechanical tests and pathological tests. Carotid artery bypass graft models were established in 24 New Zealand white rabbits including crosslinked group(n=12) and non-crosslinked group(n=12). The vein grafts were obtained for pathological examination 4 weeks after models feeding, and the intimal hyperplasia of vein graft was evaluated.Results:Adventitial cross-linking increased fiber density of adventitia significantly, and increased the stiffness of the veins as the time of cross-linking increased. And in the high strain region(strain ratio 1.4-1.8), the mechanical curve of veins receiving 3min cross-linking was similar to that of the carotid artery. The patent rate of the vein grafts of rabbit models was 100% after 4 weeks. Comparing with non-crosslinked group, the intimal and medial thickness of vein grafts in crosslinked group were reduced remarkably[(78.83±9.02)μm vs.(140.19±19.90)μm, (43.75±5.05)μm vs.(58.35 ± 8.61) μm, P<0.01). Conclusion:Adventitial collagen cross-linking by GA can enhance the mechanical strength of the jugular vein, and reduce the intimal hyperplasia of the jugular vein grafts in rabbit models.

Objective:To investigate effects of bone-resorptive lesion on stress distribution of femoral head and on progression in patients with osteonecrosis of the femoral head (ONFH).Methods:From April 2014 to September 2018, a total of 155 femoral heads from 94 patients diagnosed with ARCO stage II and III ONFH were retrospectively reviewed, including 77 males and 17 females with aged 39.90±10.45 years old (ranged from 18-64 years). The hips were divided into two groups according to whether there were bone-resorptive lesions. Further, we compared whether there was statistical difference between the two groups in staging. Then, a case of ARCO II hip joint without bone-resorptive lesion was selected from the included patients. Six femoral head with different diameters of spherical bone-resorptive lesion of 5 mm, 7 mm, 10 mm, 14 mm, 18 mm, and 23 mm were simulated. The influence of bone-resorptive lesion on the stress distribution of necrotic area and a spherical shell extending 1 mm radially around the bone-resorptive lesion was investigated by finite element method in slow walking conditions.Results:Of the 155 ONFH hips, 67 hips are complicated by bone-resorptive lesions, of which 17 were ARCO II, 50 were ARCO III. A total of 88 hips did not contain bone-resorptive lesions, of which 58 were ARCO II, ARCO III 30 cases. The proportion of ARCO stage II in the group with bone-resorptive lesions was significantly higher than that in the group without bone-resorptive lesions (χ 2=25.03, P=0.000). The finite element stress distribution cloud diagram showed that there was a stress concentration area around the bone-resorptive lesions. The maximum von Mises stress around bone-resorptive lesions in the models that contained a synthetic bone-resorptive lesions were significantly higher than those reported in the matched, non-synthetic bone-resorptive lesions finite element models ( t=3.139, P=0.026). The values for maximum von Mises stress around bone-resorptive lesions were 6.94±1.78 MPa and 5.01±0.35 MPa for the group with synthetic bone-resorptive lesions and the group non-synthetic bone-resorptive lesions, respectively. There was a positive correlation between the diameter of bone-resorptive lesions and the maximum and mean von Mises stress of necrotic areas as well as the maximum von Mises stress around bone-resorptive lesions. Conclusion:Bone-resorptive lesions can increase the maximum stress and average stress in the necrotic area. The larger the bone-resorptive lesion, the more the stress increases. There is a stress concentration area around the bone-resorptive lesions, which may accelerate the collapse of the femoral head.

Objective:A residual false lumen progress risk prediction model was constructed based on computational fluid dynamics and biomechanical parameters were calculated to assess the factors affecting the long-term reintervention after the first operation.Methods:Patients with Stanford type A aortic dissection admitted to Fuwai hospital were retrospectively collected and divided into control group and thoracoabdominal aortic replacement group according to long-term prognosis or history of reintervention. The fluid parameters of the descending aorta were calculated based on the early CTA imaging data after first operation. The differences of parameters between the two groups were compared to explore the risk factors.Results:A total of 24 patients were included from January 2015 to May 2021. The average age was(47.88±9.84) years old, 21(87.5%) male, and 3 female. The balance position of luminal pressure difference in the descending aorta was closer to the opening of the left subclavicular artery[(22.00±3.91)cm vs.(36.00±1.77)cm, P<0.001], and the false lumen pressure was greater than the true lumen pressure in the thoracoabdominal aortic replacement group. Conclusion:The computational fluid dynamics method can simplify and visualize the complex human blood flow and postoperative structure based on the mathematical model. The lumen pressure balance point moving to the proximal are the risk factors for poor remodeling of the descending aorta and reintervention.

Objective To investigate the pathogenesis of type-B aortic dissection by using morphological analysis and computational fluid dynamics (CFD) method, so as to provide evidence for the effective prediction of type-B aortic dissection. Methods Six primary type-B dissection cases scanned by CT (dissection group) and six normal cases applied to black-blood MRI (control group) were included in this study and patient-specific three-dimensional (3D) models of aorta were established through image segmentation and 3D reconstruction. The pre-type-B dissection aortas were constructed by applying the scaling algorithm to shrink the dissection and then compared with subjects in control group. The differences between morphological parameters and hemodynamic parameters of the two groups were compared. Results Compared with the normal cases, the area of the descending aorta increased dramatically in dissection group ［(892.03±263.78) mm2 vs (523.67±64.10) mm2, P=0.036］. A significant decrease in angle of the left subclavian artery occurred (66.62°±20.11° vs 100.40°±15.35°, P=0.036). The tortuosity of the aorta also had an obvious increase (0.37°±0.07° vs 0.21°±0.51°, P=0.011). The time-averaged wall shear stress (TAWSS) in dissection group was obviously higher than that in control group; the flow in the dissection region was vortex flow at low speed and the oscillating shear index (OSI) was higher. Conclusions The results of this study can be used to provide guidance for the early diagnosis and treatment of type-B aortic dissection.