Background: Femoral head collapse is the key to the progress of osteonecrosis of the femoral head (ONFH), but the causes of collapse are not completely clear. The better understanding of the progress of femoral head collapse will guide the treatment strategy for ONFH patients. The purpose of this study was to evaluate the biomechanical influence of necrosis area on the collapse of the femoral head by finite element analysis. Methods: CT and MRI data from the hip joint of a healthy volunteer were collected to establish a finite element (FE) model of a normal hip. Subsequently, five categories of osteonecrosis FE models were established by using the normal model and computer software according to China-Japan Friendship Hospital (CJFH) classification for ONFH. The CJFH system includes five types based on the size and location of necrosis lesions in the femoral head (type M, C, L1, L2, and L3) and the stage of ONFH. The collapse indices of each model were analyzed by FE method, including the displacement, peak von Mises stress and stress index of the simulated necrotic area as well as the lateral pillar contact area of the femoral head to acetabular. Results: (1) The displacement increments in the simulated necrotic areas of type M, C, L1, L2, and L3 models were 3.75 μm, 8.24 μm, 8.47 μm, 18.42 μm, and 20.44 μm respectively; the peak von Mises stress decrements were 1.50 MPa, 3.74 MPa, 3.73 MPa, 4.91 MPa, and 4.92 MPa respectively; and the stress indices were 0.04, 0.08, 0.08, 0.27, and 0.27 respectively. (2) The displacement increments in the lateral pillar contact areas of five type models were significantly different (P < 0.001) and increased in sequence as follows: 1.93 ± 0.15 μm, 5.74 ± 0.92 μm, 5.84 ± 1.42 μm, 14.50 ± 3.00 μm, and 16.43 ± 3.05 μm. The peak von Mises stress decrements were also significantly different (P < 0.001) and increased in sequence as follows: 0.52 ± 0.30 MPa, 0.55 ± 0.12 MPa, 0.67 ± 0.33 MPa, 4.17 ± 0.59 MPa, and 4.19 ± 0.60 MPa. (3) The collapse indices including the displacement increments and peak von Mises stress decrements of type L2 and L3 models were markedly higher than those of type M, C, and L1 models (P < 0.001). Conclusions: The collapse indices of the femoral heads of type L2 and L3 FE models were significantly higher than those of type M, C, and L1. Different areas of necrosis result in varied impact on the femoral head collapse.

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Background. The number of articles of clinical and basic research for osteonecrosis of the femoral head (ONFH) is increasing, yet, to our knowledge, there is still a lack of bibliometric analysis on ONFH articles. The purpose of this study was to identify the top 100 cited (T100) articles related to ONFH research and to analyze the characteristics and qualities of these articles. Methods. The T100 articles on ONFH were retrieved from the Web of Science database. The information about each article including citations, titles, authors, journals, countries, institutions, and keywords was recorded for bibliometric analysis. Results. The T100 articles related to ONFH were mainly published from 1991 to 2010 ( n = 70 ) and were originated from 24 countries. The USA, China, and Japan were the most productive countries in this regard. The most prolific institution was the University of Pennsylvania from the USA with 6 publications and 742 citations. The most cited article was published in 1995 by Professor Steinberg ME. The five most frequently occurring keywords were “femoral head,” “osteonecrosis,” “core decompression,” “total hip arthroplasty,” and “follow up.” The keywords like “bone tissue engineering” and “extracorporeal shock wave” have emerged in recent years. Conclusions. The USA, China, and Japan contributed greatly in terms of the T100 articles. The outcomes of core decompression and total hip arthroplasty gathered the most research interests. In recent years, bone tissue engineering and extracorporeal shock wave have become new trends. However, the mechanism of ONFH is still unclear.

Intervertebral disc degeneration (IDD) is the primary cause of intervertebral disc (IVD) disease. With the increased ageing of society, an increasing number of patients are plagued by intervertebral disc disease. Ageing not only accelerates the decreased vitality and functional loss of intervertebral disc cells but also increases intracellular oxidative stress. Moreover, the speed of intervertebral disc ageing is also linked to high levels of reactive oxygen species (ROS) production. Not only is the production of ROS increased in ageing intervertebral disc cells, but antioxidant levels in degenerative intervertebral discs also decrease. In addition to the intervertebral disc, the structural components of the intervertebral disc matrix are vulnerable to oxidative damage. After chronic mitochondrial dysfunction, ROS can be produced in large quantities, while autophagy can eliminate these impaired mitochondria to reduce the production of ROS. Oxidative stress has a marked impact on the occurrence of IDD. In the future, IDD treatment is aiming to improve oxidative stress by regulating the redox balance in intervertebral disc cells. In summary, ageing and oxidative stress promote the degeneration of IVD, but further basic and clinical trials are needed to determine how to treat oxidative stress. At present, although there are many in-depth studies on the relationship between oxidative stress and degeneration of intervertebral disc cells, the specific mechanism has not been elucidated. In this paper, the main causes of intervertebral disc diseases are studied and summarized, and the impact of oxidative stress on intervertebral disc degeneration is studied.

BackgroundThe morbidity and mortality of cardiovascular diseases (CVD) in patients with rheumatoid arthritis (RA) is significantly higher than those in the general population, leading to RA-related CVD has attracted broad attention and numerous articles have been published. However, no study has systematically examined this area from a scientometric perspective. This study aimed to visualize the knowledge structure and identify emerging research trends and potential hotspots in this field.Materials and methodsArticles and reviews on RA-CVD published from 2001 to 2021 were extracted from the Web of Science Core Collection database. CiteSpace and VOSviewer software were used to visualize the knowledge network of countries, institutions, authors, references and keywords in this field. SPSS and Microsoft Excel software were used for curve fitting and correlation analysis.ResultsA total of 2,618 articles and reviews were included. The number of publications about RA-related CVD significantly increased yearly. Publications were mainly concentrated in North America, Europe and East Asia. The United States contributed most with 699 publications, followed by the United Kingdom and Italy. Gross Domestic Product was an important factor affecting scientific output. University of Manchester and Professor Kitas George D. were the most prolific institutions and influential authors, respectively. Journal of Rheumatology was the most productive journal for RA-related CVD research. The research hotspots switched in the order of clinical features (cardiovascular events), mechanism exploration, anti-tumor necrosis factor therapy, risk factors, and antirheumatic drug safety, which can be observed from the keyword analysis and co-cited reference cluster analysis.ConclusionsThis study found that research on RA-related CVD is flourishing. The safety and cardiovascular pharmacological mechanisms of anti-rheumatoid drugs, especially targeted synthetic DMARDs, would be the focus of current research and developmental trends in future research.

Purpose: Information about risk factors can be used to target preventive measure on susceptible patient subgroups. The purpose of study was to determine the risk factors for infection following primary knee replacement. Methods: Between April 2014 and January 2016, total 1599 primary total knee replacements were carried out in 1374 patients, among them 1161 (933 female and 228 male) cases were available for final study. Patients were divided into without infection and had deep infection. Patients-related risk factors and provider-related risk factors were determined. Results: Out of 1161 patients, 16 patients had deep infection with infection rate was 1.38 %. There was no significant statistically between age, diagnosis, obesity and malnutrition with infection. Total 16.6 % were smoker, among infected group 37.5% patients were smoker with odds ratio 3.01 and P value 0.013 (<0.05). In study 12.4% patients had diabetics mellitus, in infected group 25% had with odds ratio 2.35 and p value 0.016 (<0.05). Total 2.6% patients had history of steroid use, among infected group 12.5% patients with odds ratio 5.39 and p value less than 0.05. Regarding the provider-related risk factors, mean duration of surgery was 130.9 min and mean duration of hospital stay was 10.95 days with both had no significant statistically. Mean blood loss during surgery was 751.47 ml and mean amount of blood transfusion was 596.08 ml with both had association with infection (p<0.05). Conclusions: Smoking, diabetes mellitus, steroid use, total blood loss and blood transfusion were significance risk factors for infection after total knee replacement.

BackgroundVenous thromboembolism (VTE) after hip or knee arthroplasty has attracted increasing attention over the past few decades. However, there is no bibliometric report on the publications in this field. The purpose of this study was to analyze the global research status, hotspots, and trends in VTE after arthroplasty.MethodsAll articles about VTE research after hip or knee arthroplasty from 1990 to 2021 were retrieved from the Web of Science Core Collection database. The information of each article including citation, title, author, journal, country, institution, keywords, and level of evidence was extracted for bibliometric analysis.ResultsA total of 1,245 original articles from 53 countries and 603 institutions were retrieved. The USA contributed most with 457 articles, followed by England and Canada. McMaster University in Canada was the leading institution for publications. The journals with the highest output and citation were the Journal of Arthroplasty and the Thrombosis and Haemostasis, respectively. The median number of citations was significantly different among the levels of evidence (F = 128.957, P &lt; 0.001). The research hotspots switched from VTE diagnosis and heparin to factor Xa inhibitors (fondaparinux, rivaroxaban, apixaban) and direct thrombin inhibitors (dabigatran etexilate, ximelagatran), and finally to aspirin, risk factor studies, which can be observed from the keyword analysis and co-cited reference cluster analysis.ConclusionsThis study observed an increasing trend of research articles on VTE after arthroplasty. Publications with higher levels of evidence gained further popularity among researchers and orthopedic surgeons. Additionally, individualized VTE prevention and the development of new, safe, effective, and inexpensive oral agents would be emerging trends in the future.

Background: The number of articles of clinical and basic research for osteonecrosis of the femoral head (ONFH) is increasing, to our knowledge, there is still a lack of bibliometric analysis on ONFH articles. The purpose of this study was to identify the top 100 cited (T100) articles related to ONFH research and analyze the characteristics and qualities of these articles.Methods: The T100 articles on ONFH were retrieved from the Web of Science database. The information about each article including citations, titles, authors, journals, countries, institutions, and keywords, was recorded for bibliometric analysis. Results: The T100 articles related to ONFH were mainly published from 1991 to 2010 (n=70), and originated from 24 countries. The USA, China, and Japan were the most productive countries in this regard. The most prolific institution was the University of Pennsylvania from the USA with 6 publications and 742 citations. The most-cited article was published in 1995 by Professor Steinberg ME. The five most frequently occurring keywords were “femoral head”, “osteonecrosis”, “core decompression”, “total hip arthroplasty” and “follow up”. The keywords like "bone tissue engineering" and "extracorporeal shock wave" have emerged in recent years.Conclusions: The USA, China, and Japan contributed greatly in terms of the T100 articles. The outcomes of core decompression and total hip arthroplasty gathered most research interests. In recent years, bone tissue engineering and extracorporeal shock wave have become new trends. However, the mechanism of ONFH is still unclear.