Comparison of three different internal fixation implants in treatment of femoral neck fracture—a finite element analysis

Abstract Background Current surgical interventions for the femoral neck fracture are using either cannulated screws (CCS) or a single large screw at a fixed angle with a side-plate (i.e., a sliding hip screw, AKA dynamic hip screw, DHS). Despite these interventions, the need for reoperation remains high (10.0–48.8%) and largely unchanged over the past 30 years. Femoral neck fracture is associated with substantial morbidity, mortality, and costs. Methods In this study, our group designed a plate that combines the strength of both CCS and sliding hip screw, through providing three dynamic screws at a fixed angle with a side-plate, namely the slide compression anatomic place-femoral neck (SCAP-FN). Finite element analyses (FEA) were carried out to compare the outcomes of the combination of our SCAP-FN plate with DHS+DS (derotational screw) and to those of using cannulated screws alone. Results SCAP-FN produces more stable fixation with respect to the femur and the stress distributions, stress peaks, and rotational angles. Conclusions The FEA encouraged us that in the following biomechanical experiment, SCAP-FN may remain the strengths of both CCS and DHS+DS and show a better performance in resisting shearing and rotational forces, therefore achieving the best stability in terms of smallest displacement and rotational angle

Correction to: Comparison of three different internal fixation implants in treatment of femoral neck fracture—a finite element analysis

In the original publication of this article [1], the word “place” should be changed to “plate”

Exosome-Mediated Genetic Information Transfer, a Missing Piece of Osteoblast–Osteoclast Communication Puzzle

The skeletal system functions and maintains itself based on communication between cells of diverse origins, especially between osteoblasts (OBs) and osteoclasts (OCs), accounting for bone formation and resorption, respectively. Previously, protein-level information exchange has been the research focus, and this has been discussed in detail. The regulative effects of microRNAs (miRNAs) on OB and OC ignite the question as to whether genetic information could be transferred between bone cells. Exosomes, extracellular membrane vesicles 30–100 nm in diameter, have recently been demonstrated to transfer functional proteins, mRNAs, and miRNAs, and serve as mediators of intercellular communication. By reviewing the distinguishing features of exosomes, a hypothesis was formulated and evaluated in this article that exosome-mediated genetic information transfer may represent a novel strategy for OB–OC communication. The exosomes may coordinately regulate these two cells under certain physiological conditions by transferring genetic information. Further research in exosome-shuttered miRNAs in OB–OC communication may add a missing piece to the bone cells communication “puzzle.

A Single-Cell Survey of Cellular Heterogeneity in Human Great Saphenous Veins

Background: The great saphenous vein (GSV) is the most commonly used conduit for coronary arterial bypass graft. However, the status of the GSV, including metabolic dysfunction such as diabetes mellitus (DM) complication, is strongly associated with vein graft failure (VGF). To date, the molecular mechanism underlying VGF remains elusive. Detailed characterization of the cellular components and corresponding expression regulation in GSVs would be of great importance for clinical decision making to reduce VGF. Methods: To this end, we performed single-cell RNA sequencing to delineate cellular heterogeneity in three human GSV samples. Results: Scrutinization of cellular composition and expression revealed cell diversity in human GSVs, particularly endothelial cells (ECs). Our results unraveled that functional adaptation drove great expression differences between venous ECs and valvular ECs. For instance, cell surface receptor ACKR1 demarcated venous Ecs, whereas ACRK3/ACKR4 were exclusively expressed by valvular ECs. Differential gene expression analysis suggested that genes highly expressed in venous ECs were mainly involved in vasculature development and regulation of leukocyte adhesion, whereas valvular ECs have more pronounced expression of genes participating in extracellular matrix organization, ossification and platelet degranulation. Of note, pseudo-time trajectory analysis provided in silico evidence indicating that venous ECs, valvular ECs and lymphatic vessels were developmentally connected. Further, valvular ECs might be an importance source for lymphatic vessel differentiation in adults. Additionally, we found a venous EC subset highly expressing IL6, which might be associated with undesirable prognosis. Meanwhile, we identified a population of ANGPTL7+ fibroblasts (FBs), which may be profibrotic and involved in insulin resistance in human GSVs. Additionally, our data suggest that immune cells only accounted for a small fraction, most of which were macrophages. By assessing the intertwined remodeling in metabolic dysfunction that potentially increases the gene expression regulatory network in mural cells and leukocytes, we found that transcription factor KLF9 likely operated a proinflammatory program, inducing the transcription of metallothionein proteins in two mural cell subsets and proinflammatory immune cells. Lastly, cellular communication analysis revealed that proinflammatory signaling, including TRAIL, PVR, CSF and GDF, were uniquely activated in patients with metabolic dysfunction. Conclusions: Our results identified critical cell-specific responses and cellular interactions in GSVs. Beyond serving as a repertoire, this work illustrates multifactorial likelihood of VGF

Characterization of New Gambierones Produced by <i>Gambierdiscus balechii</i> 1123M1M10

The benthic dinoflagellate genus Gambierdiscus is the primary producer of toxins responsible for ciguatera poisoning (CP), a food intoxication endemic in tropical and subtropical areas of the world. We used high-performance liquid chromatography tandem high-resolution mass spectrometry (HPLC-HRMS) to investigate the toxin profile of Gambierdiscus balechii 1123M1M10, which was obtained from Marakei Island (2°01′N, 173°15′E), Republic of Kiribati, located in the central Pacific Ocean. Four new gambierone analogues including 12,13-dihydro-44-methylgambierone, 38-dehydroxy-12,13-dihydro-44-methylgambierone, 38-dehydroxy-44-methylgambierone, and desulfo-hydroxyl gambierone, and two known compounds, gambierone and 44-methylgambierone, were proposed by analyzing their fragmentation behaviors and pathways. Our findings provide new insights into the toxin profile of Gambierdiscus balechii 1123M1M10, which can be used as a biomarker for species identification, and lay the foundation for further toxin isolation and bioactivity studies of gambierones

Correlation between Parameters of Calcaneal Quantitative Ultrasound and Hip Structural Analysis in Osteoporotic Fracture Patients.

Calcaneal quantitative ultrasound (QUS), which is used in the evaluation of osteoporosis, is believed to be intimately associated with the characteristics of the proximal femur. However, the specific associations of calcaneal QUS with characteristics of the hip sub-regions remain unclear.A cross-sectional assessment of 53 osteoporotic patients was performed for the skeletal status of the heel and hip.We prospectively enrolled 53 female osteoporotic patients with femoral fractures. Calcaneal QUS, dual energy X-ray absorptiometry (DXA), and hip structural analysis (HSA) were performed for each patient. Femoral heads were obtained during the surgery, and principal compressive trabeculae (PCT) were extracted by a three-dimensional printing technique-assisted method. Pearson's correlation between QUS measurement with DXA, HSA-derived parameters and Young's modulus were calculated in order to evaluate the specific association of QUS with the parameters for the hip sub-regions, including the femoral neck, trochanteric and Ward's areas, and the femoral shaft, respectively.Significant correlations were found between estimated BMD (Est.BMD) and BMD of different sub-regions of proximal femur. However, the correlation coefficient of trochanteric area (r = 0.356, p = 0.009) was higher than that of the neck area (r = 0.297, p = 0.031) and total proximal femur (r = 0.291, p = 0.034). Furthermore, the quantitative ultrasound index (QUI) was significantly correlated with the HSA-derived parameters of the trochanteric area (r value: 0.315-0.356, all p<0.05) as well as with the Young's modulus of PCT from the femoral head (r = 0.589, p<0.001).The calcaneal bone had an intimate association with the trochanteric cancellous bone. To a certain extent, the parameters of the calcaneal QUS can reflect the characteristics of the trochanteric area of the proximal hip, although not specifically reflective of those of the femoral neck or shaft

Frailty Factors and Outcomes in Patients Undergoing Orthopedic Surgery: Protocol for a Systematic Review and Meta-analysis

BackgroundFrailty is an aggregate expression of susceptibility to adverse health outcomes because of age- and disease-related deficits that accumulate across multiple domains. Previous studies have found the presence of preoperative frailty is associated with an increased risk of adverse outcomes. The number of older adults undergoing orthopedic surgery is rapidly increasing. However, there has been no evidence-based study on the relationship between frailty and outcomes in patients undergoing orthopedic surgery. ObjectiveThe aims of this study are to investigate the association between frailty and outcomes in patients who underwent orthopedic surgery as well as patient factors associated with frailty. MethodsThe methods to be used for this systematic review are reported according to the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-analysis Protocols) 2015 checklist. An extensive search will be conducted in PubMed, Embase, the Cochrane Library, and other mainstream databases. Any study where patients undergoing orthopedic surgery were assessed using a defined or validated measure of frailty and the association of frailty with patient factors and/or outcomes was reported will be included. A total of 2 researchers will independently screen articles for inclusion, with disagreements resolved by a third reviewer. We will perform a narrative synthesis of the factors associated with frailty, prevalence of frailty, effect of frailty on patient outcomes, and interventions for patients who are frail. A meta-analysis focusing on individual factors associated with frailty and the effect of frailty on patient outcomes will be performed, if applicable. The risk of bias will be evaluated. A subgroup analysis and sensitivity analysis will be performed. ResultsLiterature searches were conducted in September 2021 and the review is anticipated to be completed by the end of July 2022. ConclusionsThis systematic review and meta-analysis will provide an overview of frailty and investigate the relationship between frailty and patient outcomes as well as the relationship between patient factors and frailty in patients undergoing orthopedic surgery. This study could potentially increase patients’ awareness of the outcomes associated with frailty, compel clinical specialties to further acknowledge the concept of frailty, and enhance the development of assessment instruments and tools for frailty. Trial RegistrationPROSPERO CRD42020181846; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=181846 International Registered Report Identifier (IRRID)DERR1-10.2196/2833