Three-dimensional finite element analysis of intramedullary nail with different materials in the treatment of intertrochanteric fractures

Intramedullary nails are the common treatment options for femoral intertrochanteric fractures. However, aseptic loosening is considered to be one of the primary forms of failure that can be caused by the stress shielding between the bone and implants. The matching in mechanical properties of implant and bone is a key issue to prevent this failure. Polyetheretherketone (PEEK) and Function-graded (FG) materials are widely used in clinical because of their excellent mechanical properties. In this study, to investigate the biomechanical behaviors of intramedullary nails made of Ti-6Al-4V alloy, Stainless Steel (SS), PEEK and two FG materials, three-dimensional finite element models of intertrochanteric fracture femur with intramedullary nail were constructed with ABAQUS. The maximum von Mises stress on the femoral fracture surface fixed by PEEK intramedullary nail was the largest, followed by FG intramedullary nail, which help stimulate bone growth and subsequently reduce fracture healing time. Compared with traditional metal intramedullary nails, PEEK and FG implants might increase von Mises stress along the same path in the proximal femur. The results showed that PEEK and FG intramedullary nails obviously changed the stress distributions in the bone and reduced stress shielding. This finding indicated that PEEK and FG intramedullary nails have the potential to become alternatives to the conventional metal intramedullary nails.     

Incidence,risk factors and clinical implications of postoperative urinary tract infection in geriatric hip fractures

IntroductionPostoperative urinary tract infection (UTI) is common in geriatric patients; however, little is known about the impact of UTI in orthopedic trauma. The present study was designed to determine the risk factors and clinical impact of postoperative urinary tract infection (UTI) in acute geriatric hip fractures.Patients and methodsGeriatric patients (≥65 years of age) undergoing hip fracture surgery were identified within the American College of Surgeons National Surgical Quality Improvement Program between 2016 and 2019. Patients presenting with UTI at the time of surgery were excluded. Baseline characteristics and outcomes were compared between patients with and without postoperative UTI. Multivariate logistic regression was performed, controlling for potential confounders.ResultsA total of 46,263 patients included in the study. Overall, 1,397 (3.02%) patients had postoperative UTI. Patients who developed postoperative UTI had higher rates of pneumonia (6.44% vs. 3.76%, p < 0.001), DVT (2.22% vs. 1.04%, p < 0.001), sepsis (7.73% vs. 0.62%, p < 0.001), and more frequently experienced postoperative hospital lengths of stay exceeding 6 days (37.94% vs. 20.33%, p < 0.001). Hospital readmission occurred more frequently in patients with postoperative UTI (24.55% vs. 7.85%, p < 0.001), but surprisingly, these patients had a lower mortality rate (1.36% vs. 2.2%, p < 0.001). Adjusted analysis demonstrated the following variables associated with postoperative UTI: age ≥ 85 (OR = 1.37, 95%CI = 1.08 - 1.73), ASA class ≥ 3 (OR = 1.59, 95%CI = 1.21 – 2.08,), chronic steroid use (OR = 1.451, 95%CI = 1.05 - 1.89), blood transfusion (OR = 1.24, 95%CI = 1.05 - 1.48), and >2 days delay from admission to operation (OR = 1.37, 95%CI = 1.05 - 1.79). Postoperative UTI was significantly associated with sepsis (OR = 7.65, 95%CI = 5.72 – 10.21), postoperative length of stay >2 days (OR = 1.83, 95%CI = 1.07 – 3.13), and readmission (OR = 3, 95%CI = 2.54 – 3.55).ConclusionsIn our study, postoperative UTI was found in 3% of geriatric hip fracture patients. Predictors of postoperative UTI were age ≥ 85, ASA class ≥ 3, chronic steroid use, blood transfusion, and time to operation > 2 days from admission. Results showed that postoperative UTI is independently associated with sepsis, postoperative length of stay beyond 2 days, and hospital readmission. To diminish the risk of UTI and its consequences, we recommend operating geriatric hip fractures in 24–48 hours after admission.     

Anti-neutrophil antibodies (anti-MPO-ANCAs) are associated with poor prognosis in breast cancer patients

Anti-neutrophil antibodies are capable of activating neutrophils in sterile environments, releasing extracellular traps containing myeloperoxidase (MPO) and anti-MPO antibodies (MPO-ANCAs or anti-MPO-ANCAs), which have been implicated in the pathogenesis of several diseases. The present study evaluated systemic and tumor tissue levels of anti-MPO-ANCAs breast cancer patients, and its relation to clinicopathological characteristics. Anti-MPO-ANCAs were measured in serum and tissue samples of 150 patients by enzyme-linked immunoassay. Samples were pooled according to clinicopathological characteristics of patients. Higher anti-MPO-ANCAs levels were detected in groups presenting negative clinicopathological characteristics, such as high histological grade tumors and risk factors such as body mass index, menopausal status and early onset at diagnosis. The present data highlights anti-MPO-ANCAs as associated to poor prognosis in breast cancer, a role beyond its actually discussed role in autoimmunity and vasculitis.     

Hypertension is a risk factor for adverse outcomes in patients with coronavirus disease 2019: a cohort study

Abstract

Background

Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19.     

Use of intravoxel incoherent motion MR imaging to assess placental perfusion in patients with placental adhesion disorder on their third trimester

ObjectiveOur primary aim was to investigate if women with placenta accreta can be differentiated with women without using IVIM quantitative assessment of the placental perfusion. A second aim was to investigate if IVIM parameters could be used to differentiate placenta accreta from increta.MethodsThe study population included 17 patients with placenta accreta, 29 patients with placenta increta and 16 patients without placenta accreta between 28 + 0 to 41 + 6 weeks. All women underwent a MRI examination including an IVIM sequence at 1.5 T. The perfusion fraction (f), pseudodiffusion coefficient (D*) and standard diffusion coefficient (D) were calculated. Results Women with placenta accreta and increta had a smaller placenta perfusion fraction (P < 0.05) than patients without placenta accreta, placental perfusion fraction didn't differ between placenta accreta and increta (p > 0.05). Differences of D and D* in three groups showed no statistical significance (p > 0.05).ConclusionPlacenta accreta and increta differ in placental perfusion fraction from women without the disease. The perfusion fraction can be used as a feasible index to evaluate placenta perfusion.     

Exploration and validation of the effects of robust co-expressed immune-related genes on immune infiltration patterns and prognosis in laryngeal cancer

ObjectivesLaryngeal cancer is a common malignant tumor that originates from the larynx, yet its molecular mechanisms have not been thoroughly explored. The purpose of this study was to identify and evaluate immune-related genes in laryngeal cancer through gene co-expression networks, which may serve as biomarkers for its immunotherapy.MethodsWe applied ESTIMATE to evaluate the immune-infiltration landscape of tumor microenvironment. The co-expression networks were constructed by weighted gene co expression network analysis (WGCNA) and compared with the existing human immune related genes (IRGs) to determine the co-expressed IRGs. GSVA combined with CIBERSORT and ssGSEA illustrated the correlation of hub genes and immune infiltration patterns. TIDE algorithm and Subclass mapping evaluated the function of hub genes in predicting immune function and immunotherapeutic sensitivity. The pRRophetic was employed in the sensitivity prediction of chemotherapeutic drugs.ResultsA total of 23 co-expressed IRGs were identified and showed robust expression characteristics. These genes were significantly related to immune infiltration patterns, immune function and sensitivity prediction of immunotherapy and chemotherapeutic drugs for laryngeal cancer patients. Genetic alteration in somatic mutation level and related pathways were also revealed.ConclusionThe 23 co-expressed IRGs may act as immunotherapeutic biomarkers and potential therapeutic targets for laryngeal cancer with certain expression robustness. The molecular mechanisms deserve further investigation, which will guide clinical treatment in the future.     

儿童外科教学方法实践及探讨

目的探讨儿童外科的教学特点及教学方法,提高儿外科医生的总体执业水平,促进儿童外科学的发展。方法通过分析四川大学华西医院多年儿童外科疾病的临床教学实践经验,总结出适合医学生、初级儿童外科专科医生的实用的教学方法及经验。结果结合儿童外科特有的疾病特点所总结出的故事式讲述教学、典型病例教学、漫画形式学习、比较学习法及多媒体素材教学五种方式是非常适合儿童外科教学的方法。能够加深记忆,提高兴趣,轻松快捷,事半功倍的掌握相关医学专业知识。结论独特有趣的儿童外科教学方法可提高医学生及儿童外科初级从业者的学习兴趣、专业知识和执业水平。