ObjectiveTo investigate the awareness and clinical practice of guidelines for the prevention and treatment of chronic hepatitis B （2022 edition） among clinicians. MethodsFrom July 19 to December 31， 2024， a self-designed electronic questionnaire was distributed via the WeChat mini program to collect related data from 1 588 clinicians nationwide， including their awareness and practice based on 18 questions regarding testing and referral， diagnosis and treatment， and follow-up. ResultsAmong all respondents， only 350 clinicians correctly understood all the updated key points of antiviral indications and treatment for special populations in the 2022 edition of guidelines for the prevention and treatment of chronic hepatitis B， with an overall awareness rate of 22.0%. Only 20% ‍—‍ ‍40% of the patients with positive HBV DNA and an age of >30 years receive antiviral therapy， while 80% ‍—‍ ‍100% of the patients with positive HBV DNA and a family history of hepatitis B cirrhosis or hepatocellular carcinoma receive antiviral therapy. The median follow-up rates at 1 year， 3 years， and 5 years were 67.5% 57.5% and 47.5%，respectively， showing a trend of gradual reduction， which might be associated with the influencing factors such as insufficient time for follow-up management by clinicians， insufficient awareness of the disease among patients， and poor adherence to follow-up. ConclusionThere is a gap between the awareness and practice of guidelines for the prevention and treatment of chronic hepatitis B （2022 edition） among clinicians. It is recommended to further strengthen training and focus on the whole process of “detection， diagnosis， treatment， and management” for patients with chronic hepatitis B in healthcare institutions， in order to promote the implementation of the guidelines.

BACKGROUND:For dislocation of acromioclavicular joint induced by coracoclavicular ligament fracture,single EndoButton Plate reconstruction and double EndoButton Plates reconstruction are common repair methods.Further study on the stress distribution and fracture risk of the two repair methods is of great significance. OBJECTIVE:To study the biomechanical properties of the coracoclavicular ligament,and compare the fixation effect,stress distribution and failure mode of single and double EndoButton Plates reconstruction. METHODS:(1)Finite element simulation analysis:Mimics,Wrap and SolidWorks were used to establish normal coracoclavicular ligament,single EndoButton Plate reconstruction and double EndoButton Plates reconstruction.Ansys software was used to analyze the stress and deformation of the scapula and clavicle of each model under vertical load.(2)Sample experiment:Fifteen intact scapular-clavicle specimens were randomly grouped into five groups,with three specimens in each group.In group A,the acromioclavicular ligament was severed and the coracoclavicular ligament remained intact.In group B,acromioclavicular ligaments and trapeoid ligaments were severed,leaving intact conical ligaments.In group C,acromioclavicular ligaments and conical ligaments were cut off,and the intact traprex ligaments were retained.In group D,acromioclavicular and coracoclavicular ligaments were severed,and coracoclavicular ligaments were repaired by single EndoButton Plate reconstruction.In group E,acromioclavicular and coracoclavicular ligaments were severed,and the coracoclavicular ligaments were repaired by double EndoButton Plates reconstruction.The mechanical experiment was carried out by a mechanical testing machine to analyze the biomechanical status,stress distribution and failure patterns of the scapular-clavicle and clavicle. RESULTS AND CONCLUSION:(1)Finite element simulation analysis:The average stress of coracoclavicular ligament attached specimens was the lowest,and the risk of coracoclavicular fracture was less than that of single and double EndoButton Plates reconstruction.The mean stress of the coracoid process was similar in single and double EndoButton Plates reconstruction,and the fracture risk was similar.(2)Sample experiment:In groups A,B,C,D and E,the stiffness of specimens was(26.4±3.5),(19.8±2.8),(21.3±3.2),(57.7±4.1),and(46.2±2.8)N/mm,respectively;the ultimate loads were(545.5±53.7),(360.1±42.1),(250.9±44.4),(643.5±39.1),and(511.9±31.7)N,respectively;global stiffness in groups D and E was higher than that in group A(P=0.000 06,0.000 3);ultimate load in group D was higher than that in group A(P<0.05);the ultimate load was not significantly different between the group E and group A(P>0.05).Ligament fracture was observed in groups A,B and C and coracoid process fracture was found in groups D and E.(3)These results suggest that from the biomechanical analysis,Single EndoButton Plate reconstruction and double EndoButton Plates reconstruction are effective treatment techniques for coracoclavicular ligament fracture in acromioclavicular joint dislocation,but increase the risk of fracture.The double EndoButton Plates reconstruction dispersed the stress of the steel plate and reduced the contact force between the steel plate and bone,but slightly reduced the ultimate bearing capacity.Single and double EndoButton Plates reconstruction should be selected according to the actual clinical situation.

BACKGROUND:The stability of the pelvis is mainly determined by the posterior pelvic ring and the sacroiliac joint.The posterior pelvic ring injury and the dislocation of the sacroiliac joint caused by high energy impacts such as car accidents increase year by year.Surgical treatment is the best method,and there are many kinds of endophytorepair methods in clinical practice,but which treatment method has the best biomechanical properties is still controversial. OBJECTIVE:To compare the biomechanical properties of three kinds of internal implants:anterior double plates,posterior bridging plate and tension nail in the repair of unilateral unstable pelvic posterior ring injury,to provide a reference for the clinical treatment and development of a new pelvic tension screw. METHODS:(1)Finite element simulation:Mimics,Wrap and SolidWorks were used to establish normal pelvic model,unilateral injured pelvis model,and three kinds of internal implant repaired models(anterior double plates,posterior bridging plate and tension nail).Ansys was used to analyze the stress and deformation of the models.(2)Biomechanical test:A total of 15 intact pelvic specimens were randomly grouped into five groups,normal pelvic model,unilateral injured pelvis model,anterior double plates,posterior bridging plate and tension nail groups.The mechanical test was performed using an Instron E10000 testing machine. RESULTS AND CONCLUSION:(1)Simulation:In the normal pelvic model,the average displacement of the sacrum was 0.174 mm,and the maximum stress of the sacral iliac bone was 10.51 MPa,and the stress distribution was uniform.The mean sacral displacement of the unilateral injured pelvis model was 0.267 mm,and the stress concentration of the model was obvious.The mean displacement of the sacrum in the three repaired models was close to that in the normal pelvic model,and the stress distribution of the sacral iliac bone in the tension nail repaired model was uniform.(2)Mechanical test:The stiffness of the normal pelvic model was(226.38±4.18)N/mm,and that of the unilateral unstable pelvic model was the smallest(130.02±2.19)N/mm.The deviation of the normal pelvic model stiffness and the three repaired models'stiffness were all within(±10%),and the repair effect was obvious.(3)The simulation results were in agreement with the experimental results.(4)The biomechanics of the tension nail repaired model was the most similar to that of the normal pelvis,and this method was the best.The repairing stiffness of the anterior double plate was too large,and the stress shielding effect was more significant.The posterior bridging plate repair could not solve the compensatory effect of the normal side soft tissue and had defects.This study provides an optimal basis for clinical surgery.(5)The new type of pelvic tension nail should be improved from the point of view of the tension nail to retain the good biomechanical properties of the tension nail,while adding other advantages,such as being used for the osteoporotic pelvis.

Objective To investigate the biomechanical properties of a novel sacroiliac lag screw with a spiral blade.Methods Percutaneous sacroiliac lag screws were used as the controls.Polyurethane material was used to simulate the trabecular bone,and the pullout resistance performance was tested on an Instron mechanical testing machine.Subsequently,pelvic specimens were utilized to analyze the static stiffness and dynamic stability of the novel sacroiliac lag screw in repairing sacroiliac joint injuries under normal standing conditions,with normal pelvis,single-sided sacroiliac joint injury pelvis,percutaneous sacroiliac lag screw-single screw repair,and percutaneous sacroiliac lag screw-double screw repair as controls.Results The damage to the polyurethane material after screw extraction was smaller in the novel sacroiliac lag screw group.The average effective holding displacement of the novel sacroiliac lag screw was significantly greater than that of the percutaneous sacroiliac lag screw(P＜0.05).However,the maximum resistance to the pullout force for the percutaneous sacroiliac lag screw was significantly higher than that for the novel sacroiliac lag screw(P＜0.05).The stiffness after repair of sacroiliac joint injuries was significantly higher when using a single sacroiliac lag screw than when using two percutaneous sacroiliac lag screws(P＜0.05).The displacement amplitude was the highest in the sacroiliac joint injury group,followed by that in the normal group.The displacement amplitudes in the other groups were similar;however,the differences were statistically significant(P＜0.05).The dynamic stability of the sacroiliac lag screw repair group was the best,slightly better than that of the percutaneous sacroiliac lag screw-double screw repair group,and the dynamic stability of the sacroiliac joint injury group was the worst.The novel sacroiliac lag screw effectively repaired the sacroiliac joint injuries.Conclusions The novel sacroiliac lag screw can effectively hold the trabecular bone and has practical clinical utility.

Objective To study mechanical properties of the novel micro-movement elastic implant of distal tibiofibular syndesmosis in dorsiflexion position.Methods A combination of simulation and experiment was used. The normal ankle dorsiflexion model, the bone nail repaired model and the micro-movement elastic implant repaired model were established by using Mimics and CT data. Besides, ANSYS Workbench was used for finite element analysis. Mechanical experiments on lower limb specimens were conducted on Instron E10000 mechanical test instrument, and five sets of experimental data were measured and analyzed.Results Mechanical properties of the micro-movement elastic implant repaired model were closer to those of the normal ankle dorsiflexion model, but stress of the micro-movement elastic implant repaired mode was greater than that of the bone nail repaired model. The results of two-sample heteroscedasticity t test indicated that there was no significant difference in resistance torque between the micro-movement elastic implant repaired model and the normal ankle dorsiflexion model.Conclusions For dorsiflexion position, repairing mechanical properties of the novel micro-movement elastic implant are much better than those of the bone nail, and there is still room for optimizing the micro-movement elastic implant.

Objective To study the effect of interlocking intramedullary nail on fixing transverse olecranon fracture. Methods Nine pairs of fresh ulna specimens were collected and the transverse fracture model of olecranon was established. Kirschner wire tension band and interlocking intramedullary nail were used to repair the fracture. Cyclic dynamic tension loads with amplitude of 25 N, mean value of 45 N and frequency of 05 Hz were applied to the triceps tendon under simulated elbow flexion conditions of 30°, 45° and 60°, respectively. The fracture displacements of specimens within 300 cycles were recorded in three groups. ResultsAt 30° flexion angle, the fracture displacement of interlocking intramedullary nail group and Kirschner wire tension band group was (1.831±0.333) mm and (3.723±2.390) mm, respectively. At 45° flexion angle, the fracture displacement of interlocking intramedullary nail group and Kirschner wire tension band group was (1.167±0.374) mm and (2.455±0.609) mm, respectively. At 60° flexion angle, the fracture displacement of interlocking intramedullary nail group and Kirschner wire tension band group was (1.407±0.342) mm and (3.112±1.025) mm, respectively. The fracture displacement of interlocking intramedullary nail was smaller. Conclusions The mechanical properties of interlocking intramedullary nail are better than those of Kirschner wire tension band, and the interlocking intramedullary nail is more stable and firmer for fixing transverse olecranon fracture. Moreover, the interlocking intramedullary nail is installed with the operating tool, thus the operation is more accurate and faster, and the operation efficiency is greatly improved.

Osteoporotic vertebral compression fracture (OVCF) can lead to lower back pain and may be even accompanied by scoliosis, neurological dysfunction and other complications, which will affect the daily activities and life quality of patients. Vertebral augmentation is an effective treatment method for OVCF, but it cannot correct unbalance of bone metabolism or improve the osteoporotic status, causing complications like lower back pain, limited spinal activities and vertebral refracture. The post-operative systematic and standardized rehabilitation treatments can improve curative effect and therapeutic efficacy of anti-osteoporosis, reduce risk of vertebral refracture, increase patient compliance and improve quality of life. Since there still lack relevant clinical treatment guidelines for postoperative rehabilitation treatments following vertebral augmentation for OVCF, the current treatments are varied with uneven therapeutic effect. In order to standardize the postoperative rehabilitation treatment, the Spine Trauma Group of the Orthopedic Branch of Chinese Medical Doctor Association organized relevant experts to refer to relevant literature and develop the "Guideline for postoperative rehabilitation treatment following vertebral augmentation for osteoporotic vertebral compression fracture (2022 version)" based on the clinical guidelines published by the American Academy of Orthopedic Surgeons (AAOS) as well as on the principles of scientificity, practicality and advancement. The guideline provided evidence-based recommendations on 10 important issues related to postoperative rehabilitation treatments of OVCF.

Objective:To determine the mechanical properties of our self-designed novel cross-locking intramedullary nails and the impact of number of conical locking nails on the fixation through a finite element analysis and specimen experiments.Methods:Mimics 19.0 and SolidWorks 2014 were used to create transverse fracture models of the olecranon which were subjected to fixation with respectively K-wire tension band (KTB) and our self-designed novel cross-locking intramedullary nails (NIN). The strengths of KTB and NIN fixation were analyzed by Ansys. Fifteen human ulna specimens were used to construct a transverse fracture model of the olecranon; an Instron E10000 mechanical testing machine was used to determine mechanical properties in fixation respectively with KTB, one NIN (NIN-1) and 3 NINs (NIN-3).Results:In the finite element analysis, in simulation of the forearm flexed at 45° under a 100 N load, the deformation of the fracture surface of the olecranon in fixation with KTB, NIN-1 and NIN-3 was respectively 0.131 mm, 0.123 mm and 0.121 mm. In the specimen experiments, in simulation of the forearm flexed at 45°, the maximum failure loads for fixation with KTB, NIN-1 and NIN-3 were (313.38±27.68) N, (528.56±53.58) N and (871.04±94.95) N, respectively, showing significant differences among the 3 groups ( P<0.05). The maximum failure load for NIN-3 fixation was significantly greater than that for KTB or NIN-1 fixation, and the maximum failure load for NIN-1 fixation was significantly greater than that for KTB fixation ( P<0.05). Conclusions:Compared with KTB fixation, NIN fixation is more convenient in operation and has better mechanical properties. NIN-3 fixation has the best mechanical properties.

Objective To analyze factors that affect axial mechanical performance of the posterior pedicle fixation system. Methods The mechanical model for axial mechanical properties of the posterior pedicle fixation system was established to perform mechanical analysis. By referring to the Standard YY/T 0961-2014, tests on axial ejection force and axial clamping torque of JHL-I multi-axis components, JHL-I single-axis components, JHL-V multi-axis components and JHL-V single-axis components were performed by using Instron E3000 and Instron E10000 mechanical testing machines. Results The ejection rigidity of the single-axis component of vertebral nail system was significantly higher than that of the multi-axis component of vertebral nail system; the torsion rigidity of JHL-V was higher than that of JHL-I. The type and size of the locking bolt as well as its locking torque were the main factors affecting axial ejection force of the posterior spinal pedicle fixation system; the size of the locking bolt and the diameter of the connection rod were the main factors affecting axial clamping torque of the system; axial mechanical properties of the system could be improved by increasing the diameter of the connecting rod, the coefficient of friction between each connecting element, and the pitch diameter of the locking bolt. Conclusions The research findings provide references for optimizing and improving axial mechanical properties of the posterior pedicle fixation system.

Objective To investigate the main cell types expressed brain-derived neurotrophic factor (BDNF) in the posterior cortical infarction area in cerebral infarction rats after early vein allograft of bone marrow mesenchymal stem cells (BM-MSCs) and the effect of BM-MSCs transplantation on their ce11 numbers and percentages.Methods (1) Fifteen SD rats were randomly divided into sham-operated group 1,ischemia control group 1,and BM-MSCs transplantation group 1 (n=5);distal middle cerebral artery occlusion (dMCA) models were used in the later two groups;1 × 106 CM-DiI labeled BM-MSCs were intravascularly transplanted into the tail vein of rats from the transplantation group 1 at one h after ischemia;all rats were sacrificed 48 h after ischemia;BM-MSCs with co-existence of CM-Dil and BDNF in the ischemia cortex areas were detected by immunofluorescence staining.(2)Fifteen SD rats were randomly divided into sham-operated group 2,ischemia control group 2,and BM-MSCs transplantation group 2 (n=5);dMCAO models were used in the later two groups;1 ×106 non-labeled BM-MSCs were intravascularly transplanted into the tail vein of rats from the transplantation group 2 at one h after ischemia;48 h after ischemia onset,all rats were sacrificed;the number of BDNF+ and CD68+ microglia cells,BDNF+ and Iba-1+ microglia cells,and BDNF+ and neuron-specific nucleoprotein (NeuN)+ neurons were measured by immunofluorescence staining.Results (1) CM-Dil red fluorescence labeled allogeneic BM-MSCs were only found in BM-MSCs transplantation group 1;the labeled cells scattered in the infarct and peri-infarct cortices;9.70％±3.47％ CM-Dil labeled BM-MSCs expressed BDNF,accounting for 13.32％±4.48％ of all BDNF+ cells in the infarct brain cortex.(2) In the brain tissues of cortex infarct area of BM-MSCs transplantation group 2,38.40％±9.04％ BDNF+ cells were Iba-1+ microglia cells,11.65％±2.76％ BDNF+ cells were CD68+ microglia cells,and 28.96％±6.99％ BDNF+ cells were NeuN+ neurons;the Iba-1+ cell numbers and Iba-1+/BDNF+ double positive cell percentages in the BM-MSCs transplantation group 2 ([92.06±36.52]/mm2 and 79.21％±12.27％) were significantly increased as compared with those in the ischemia control group 2 ([31.13±10.23] mm2 and 60.15％±28.20％,P＜0.05).Conclusion Allogeneic BM-MSCs is capable of migrating into the infarct cortex when intravenous transplantation of BM-MSCs is performed at the early stage after ischemia;the main sources of BDNF in these areas are microglias cells and neurons;these BM-MSCs increase both number and percentage of Iba-1+/BDNF+ double positive cells,which may be one of the underlying mechanisms of therapeutic effects.