BACKGROUND:Bone mineral density is the clinical gold standard for determining bone strength,but bone mineral density is less sensitive to changes in bone mass,with large changes in bone mineral density only occurring when bone mass is significantly reduced,so bone mineral density has limited ability to predict changes in bone strength and fracture risk. OBJECTIVE:A model of the normal and osteoporotic hip joint was developed to analyze the stresses and deformation in the hip of normal and osteoporotic patients under single-leg standing conditions. METHODS:A healthy adult female volunteer at the age of 36 years was selected as the study subject.The CT data of the hip joint of this volunteer were obtained and saved in DICOM format.The hip joint model was reconstructed in three dimensions,and the material properties were assigned by the gray value assignment method to obtain the normal and osteoporotic hip joint models according to the empirical formula.The same boundary conditions and loads were set to simulate the stresses and deformation in the normal and osteoporotic hip joints in the single-leg standing position. RESULTS AND CONCLUSION:(1)In the finite element model of the normal and osteoporotic hip,the stress distribution was more concentrated in the medial region of the femoral neck.(2)In the hip bone,the stress distribution was mainly concentrated in the upper part of the acetabulum.(3)The stress peaks in the medial femoral neck and upper acetabulum were larger in the normal hip model than in the osteoporotic hip model,probably due to the reduced bone strength of the osteoporotic bone.(4)The peak Von Mises of both normal and osteoporotic hip models were concentrated on the medial femoral neck,and the peak Von Mises of the hip bone was smaller,indicating that the overall effect of osteoporosis on hip bone stresses was relatively small.(5)In terms of deformation in the single-leg standing position,the maximum deformation in the normal hip model was located at the acetabulum and femoral head,and the maximum deformation was located at the upper part of the greater trochanter of the femur.(6)It is suggested that the finite element analysis method to model the values of parameters related to bone tissue in osteoporosis may improve clinical prediction of bone strength changes and fracture risk.It is explained from the biomechanical view that the intertrochanteric femur and femoral neck are good sites for osteoporotic hip fractures.

Objective:To investigate the effect of 3D-printed customized flanged cup in hip revision with severe acetabular bone defects.Methods:Since February 2017, 10 cases of 3D-printed customized flanged cups were used in hip revision with severe acetabular bone defects, including 2 cases of Paprosky type IIIA and 8 cases of Paprosky type IIIB. There were 5 males and 5 females, mean age 73.6±8.1 yrs (range, 62-87 yrs), 5 left and 5 right cases. The preoperative thin-layer CT scan was preformed to reverse reconstruct digital pelvis. Five cases of one-piece flanged cups and 5 cases of decomposed flanged cups, including 3 cases of composite one-piece cups were designed by computer. The surgery was performed strictly according to the plan.Postoperative follow-up was performed to evaluate the Harris score. Operation time,intraoperative bleeding and other complications such as vascular and nerve injury, postoperative infection, and dislocation were counted. Pelvic X-ray was used to assess the height and horizontal position of the center of rotation and the stability of the prosthesis.Results:The surgical procedure was successful, with an average operative time of 147.9±48.3 min (range, 96-212 min) and an average intraoperative bleeding of 730.4±262.6 ml (range, 500-1 300 ml). The mean time of final follow-up was 40.8±18.7 months (range, 16-70 months) after surgery. At the last follow-up, the average Harris score was 83.80±6.73, with 4 cases excellent, 5 cases good, and 1 case fair. The excellent and good rate was 90%. The last Harris score was significantly higher than that before operation 28.60±8.40 ( t=16.84, P<0.001). The height of affected hip joint rotation center decreased from 46.24±7.74 mm before operation to 15.54±2.54 mm after operation with significant difference ( t=14.61, P<0.001). It was slightly higher than the opposite side (13.81±1.48 mm), which had no significant difference ( t=1.83, P=0.100). The horizontal distance of affected hip joint rotation center increased from 33.79±5.27 mm before operation to 40.53±4.50 mm after operation with significant difference ( t=3.62, P=0.006). It had no significant difference ( t=1.28, P=0.232) compared with the opposite side (38.54±3.46 mm). All incisions were healed in one stage without infection, vascular or nerve injury. During the following-up, all prostheses were in satisfied position without loosening, dislocation or screw breaks. Conclusion:Digitally assisted 3D-printed flanged cups can be used in hip revision with severe acetabular bone defect. It can not only improve hip joint function, but also restore the acetabular rotation center and the prosthesis stability, which can achieve good early and mid-term effect.

Objective:To analyze the efficacy of the reconstruction of the proximal humerus by reverse shoulder arthroplasty with three-dimensional (3D) printing technology after tumor rescetion.Methods:A retrospective analysis was conducted on the data of eight patients undergoing semi-constrained reverse shoulder arthroplasty with 3D printing technology after the resection of bone tumors in proximal humeri at the Affiliated Wuxi People's Hospital of Nanjing Medical University from December 2017 to January 2021. There were four males and four females with an average age of 55.1 (range, 31-73) years, all of whom had unilateral onset, 2 on the left and 6 on the right. There was one case of leiomyosarcoma (Enneking IIB), two cases of chondrosarcomas (one Enneking IA and one Enneking IB), four cases of Campanacci grade 3 giant cell tumor of bone, and one case of bone metastasis of lung adenocarcinoma. Individualized prosthesis and implantation protocol were completed preoperatively in all patients. The glenoid baseplate was manufactured using 3D printing technology. During the surgery, Malawer type I tumor resection and semi-constrained reverse shoulder arthroplasty were performed, with 6 cases simultaneously using allograft-prosthetic composite reconstruction. The follow-up was scheduled, and the patient received X-ray examination of the shoulder. The range of motion of the shoulder was measured, the Constant-Murley score and musculoskeletal tumor society (MSTS) score were recorded.Results:All 8 patients successfully completed the surgery, with a surgical time of 173.8±46.7 min (range, 130-260 min), intraoperative blood loss of 487.5±334.6 ml (range 200-1,200 ml), and proximal humeral resection of 9.9±4.6 cm (range, 4.5-19.0 cm). All patients were followed up for a period of 45.6±12.5 months (range, 24-60 months). At the last follow-up, the abduction ranges of motion of the affected shoulders increased from 27.5°±14.4° pre-operatively to 106.3°±21.8° post-operatively, with a statistically significant difference ( t=11.37, P<0.001). The forward flexion ranges increased from 28.1°±12.8° pre-operatively to 115.6°±24.0° post-operatively, with a statistically significant difference ( t=11.49, P<0.001). The Constant-Murley score was improved from 40.5±14.3 pre-operatively to 79.3±11.2 post-operatively, with a statistically significant difference ( t=9.58, P<0.001). The MSTS score was 25.6±2.2 (range, 23-28), including 6 excellent cases and 2 good cases. At 2 weeks after surgery, one patient experienced joint dislocation that was successfully reduced manually. Up to the final follow-up, all patients had survived without local tumor recurrence, metastasis, prosthesis infection and loosening. Conclusion:3D printing technology assisted shoulder arthroplasty is helpful for effective reconstruction and shoulder joint function recovery after resection of proximal humeral tumors, with satisfactory outcomes in the early and middle stages.

Transcatheter tricuspid valve intervention is the new frontier of interventional cardiology. The LuX-Valve is a radial force-independent orthotopic tricuspid valve replacement device developed in China. The LuX-Valve Plus transcatheter tricuspid valve replacement (TTVR) system is changed from the trans-atrial to the transjugular approach, which further reduces trauma and pulmonary complications compared with the first generation LuX-Valve. The first-in-human study has been completed at Zhongshan Hospital, Fudan University and an exploratory multicentre clinical study is underway. Echocardiography plays an important role in pre-TTVR screening, intraoperative guidance and postoperative evaluation and follow-up, especially two-dimensional transoesophageal echocardiography (2D-TEE) and three-dimensional transoesophageal echocardiography (3D-TEE). However, there is a lack of appropriate intraoperative guidance and assessment protocols. In this study, we briefly described the protocols and imaging considerations for intraoperative 2D-TEE and 3D-TEE to ensure the successful implantation of TTVR.

Tricuspid regurgitation (TR) interventions are under rapid development. The K-Clip? system is the first domestic transcatheter tricuspid annuloplasty system with unique clamping procedure to achieve annular reduction.Intraoperative echocardiographic monitoring procedures for transcatheter tricuspid annuloplasty have not been reported yet in China. Thus, this review aimed to propose the standard two-dimensional and three-dimensional transesophageal echocardiographic workplanes and procedures to guide and monitor the implantation of K-Clip system based on our experience in Zhongshan Hospital, Fudan University to provide a reference point for the intraoperative echocardiographic monitoring of future transcatheter tricuspid annuloplasty devices in China.

Objective:To learn about the epidemic law of animal plague in natural plague focus of Himalayan Marmot in Yumen City of Gansu Province, to explore the epidemiological characteristics of plague in the area and to provide scientific basis for formulating prevention and control strategies of the plague. Methods:The animal plague surveillance data of natural plague focus of Himalayan Marmot in Yumen City, Gansu Province from 2014 to 2021 were collected, main host density, rate of infected with fleas, flea index, small rodent species, bacteriology, serology were studied. Excel 2007 software was used to analyze the plague epidemic situation in the focus. Results:From 2014 to 2021, the total average density was 0.06 per hm 2 of the marmots. A total of 19 300 traps were placed, and 209 rats were caught, with an average catch rate of 1.08%. Among them, Dipus sagitta (59.81%, 125/209) and Mongolian Five-toed Jerboa(31.10%, 65/209) were dominant small rodent species. Totally 877 marmots were checked, 184 with flea. The rate of infected with fleas of marmots was 20.98%, with a flea index of 1.00, Callopsylla dolabris (52.69%, 461/875) and Oropsylla silantiewi (47.20%, 413/875) were dominant species in vector. The rate of infected with fleas of burrow was 7.72% (173/2 241), with a flea index of 0.20. A total of 39 strains of Yersinia pestis were isolated from infected animals. Among them, 35 strains from the marmots, and 4 strains from vectors. Totally 913 serum samples were checked from marmots and shepherd dog, the positive serum was 34. Among them, the positive rate of shepherd dog was 13.98% (33/236). Conclusions:The plague epidemic situation in natural plague focus of Himalayan Marmot in Yumen City of Gansu Province is still serious. The monitoring of plague should be strengthened, and the comprehensive measures for prevention and control of the plague should be carried out to prevent a outbreak of the plague in human being.

The quality evaluation of X-ray protective clothing at home and abroad is mainly intended for the quality inspection of lead protective clothing. There is no unified standard to be developed for the test of lead protective clothing during use. When lead protective clothing with defective quality is used many times, this phenomenon will pose a greater safety hazard to radiation workers and patients. Therefore, in order to protect the health of radiation workers and patients, the implementation of regular testing and quality evaluation of lead protective clothing and the development of a standardized management system are important. This review introduces the domestic and international inspection method of X-ray lead protective clothing, summarizes the inspection and evaluation method in use, including shield transmission coefficient, defect detection and uniformity test, puts forward relevant suggestions to provide reference for the managers and practitioners of relevant institutions.

【Objective】 To analyze the metagenomics and microbiology of voluntary blood donors in China, so as to assess the potential threats of emerging infectious diseases to the safety of blood transfusion. 【Methods】 12 300 plasma samples (10 mL each) collected by central blood stations in Chongqing, Liuzhou, Urumqi, Mianyang, Wuhan, Nanjing, Mudanjiang, and Dehong Prefecture area from 2012 to 2018 were subjected to total DNA extraction after ultracentrifugation (32 000 rpm/min, centrifugal radius 91.9 mm) in minipools of 160 donations. The metagenomic library was constructed, and deep sequencing was conducted by Illumina Hiseq 4 500. By comparing with reference sequences of bacteria, fungi, parasites and viruses, metagenomic data were analyzed, classification of microbes were identified, and potentially harmful pathogens were evaluated. 【Results】 A total of 632 GB clean data were obtained by deep sequencing, and the top three pathogens were Pseudomonas(0.561 1%), Burkholderia(0.468 7%) and Serratia(4.242 0%). Pathogens with potential threat which could be transmitted by blood transfusion or blood products were found, such as human parvovirus B19(0.126 6%), Leishmania spp(1.348 5%) and Toxoplasma gondii(0.615 8%). 【Conclusion】 Our study analyzed metagenomics of voluntary blood donors in parts of China and revealed pathogens that may cause potential harm to blood safety, which were helpful for targeted prevention and control of emerging infectious diseases.

Objective: To explore the value of chest CT features and clinical indexes in the differential diagnosis between suspected COVID-19 with two or more negative nucleic acid tests and confirmed COVID-19. Methods: The clinical data and chest CT images of 105 cases withconfirmedCOVID-19 (55 males and 50 females, aged from 2 month to 88 years) and 97 cases with suspected COVID-19(59 males and 38 females, aged from 1 month to 93 years) were analyzed retrospectively in Shiyan Taihe Hospital from January 21 to February 10, 2020. χ²test and two independent sample t test were used to analyze the clinical data and CT signs of the two cases, with P<0.05 for the difference statistically significant. Results: Compared with the suspected patients, the average age of diagnosis of covid-19 was higher (t = 2.460, P = 0.01). The main pathological changes were pure ground glass (68 cases) and mixed ground glass density (53 cases) (χ² = 50.016, P< 0.01). Interstitial thickening (83 cases) (χ² = 55.395, P< 0.01), vascular thickening (73 cases) (χ² = 57.527, P< 0.01), air bronchoscopic sign or bronchiectasis Zhang (67 cases) (χ² = 17.899, P< 0.01), cord focus (54 cases) (χ² = 5.500, P = 0.02), easily distributed under the pleura and the long axis of the lesion was parallel to the pleura (89 cases) (χ² = 23.597, P< 0.01), most of them had no pleural effusion (χ² = 7.017, P< 0.01); both lesions were mainly distributed in patches (89 cases were confirmed, 87 suspected) (χ² = 19.573, P< 0.01). In addition, the lesions of patients with confirmed covid-19 showed progress in short term (72 / 87, 82.76%), and those with suspected covid-19 showed remission in short term (63 / 89, 70.78%). The difference was statistically significant (χ² = 51.114, P< 0.01). There was no significant difference in gender and distribution of pulmonary lobes (χ² = 1.462, P= 0.23; χ² = 7.381, P= 0.19). The number of white blood cells (χ² = 17.891, P< 0.01) and the percentage of lymphocytes (χ² = 11.151,P< 0.01) of covid-19 were mostly normal or decreased, creatine kinase (χ² = 9.589, P< 0.01) were mostly normal, and erythrocyte sedimentation rate was mostly normal or increased (χ² = 4.240, P= 0.04). Conclusions The imaging features and biochemical indexes of diagnosed COVID-19 are different from those of suspected COVID-19. The comparative analysis of imaging features, clinical indexes and reexamination are helpful for the differential diagnosis of COVID-19 and suspected COVID-19.

Objective To evaluate the role of transthoracic echocardiography ( T T E ) and transesophageal echocardiography( T EE) in the process of transapical mitral valve repair using a novel edge‐to‐edge device( ValveClamp) and this device′s efficacy and safety in a preliminary clinical trial . Methods Six patients with moderate to severe or severe degenerative mitral regurgitation ( DM R) confirmed by T T E and T EE were enrolled . T T E was performed pre and post procedure as well as 30 days post procedures . Related cardiac structure and hemodynamic parameters ,including mitral regurgitation area ( MRA‐max ) , vena contracta width ( VCW ) ,mitral valve effective orifice area ( M VEOA ) ,left ventricular end diastolic diameter ( LVEDD ) , left ventricular end systolic diameter ( LVESD ) , left ventricular ejection fraction ( LVEF) ,max and mean mitral valve pressure gradient ( M VPG‐max and M VPG‐mean) were recorded and evaluated in a central core laboratory . Results All the procedures were successfully performed .M RA‐max , VCW and M VEOA decreased significantly post procedures ( all P ＜ 0 .000 ) , and they remained no significant changes within 30 days post procedures ( all P ＞ 0 .05 ) . M eanwhile ,M VPG‐max and M VPG‐mean slightly increased ( all P ＜0 .01 ) and left atrial anterior‐posterior dimension attenuated 30 days post procedures( P ＜0 .05) ,but all M VPG‐mean were lower than 5 mm Hg ( 1 mm Hg＝0 .133 kPa) . T here were no significant changes in other hemodynamic parameters ( all P ＞ 0 .05) . Conclusions T ransapical mitral valve repair using ValveClamp can be performed safely and a significant reduction in mitral regurgitation can be achieved in patients with DM R . T EE and T T E facilitate the patient selection for ValveClamp procedures as well as perioperative navigation and assessment .