- Research Article
6
- 10.1016/j.medengphy.2024.104181
Effects of dental implant diameter and tapered body design on stress distribution in rigid polyurethane foam during insertion
- May 18, 2024
- Medical Engineering and Physics
- Baixuan Yang + 3 more +3
Publications from 2021 to 2026
Showing 10 of 39 papers
Effects of dental implant diameter and tapered body design on stress distribution in rigid polyurethane foam during insertion
Does Fibular Displacement Predict Tibial Malrotation in Simulated Tibia-Fibula Fractures.
Tibial malrotation can occur with medullary nailing of diaphyseal tibial fractures. Fibular alignment has been proposed as a surrogate for axial plane reduction intraoperatively. The purpose of this study was to determine whether fibular alignment is a reliable marker of accurate tibial rotation. Deidentified CT scans of 50 patients with normal tibial anatomy were selected. Using ImageJ software, we simulated osteotomies at three sites (proximal third, mid-diaphysis, and distal third). We overlaid adjacent CT slices and rotated them around the central axis of the tibia in 5° increments of external rotation (ER) and internal rotation (IR). At each increment, measurements of fibular overlap (%) were obtained from anteroposterior (AP) and lateral views. To simulate fixation of the fibula, we repeated rotation around the axis of the fibula with and without a simulated medullary implant in the tibia. A total of 50 patients were included. The mean age was 62 years, average BMI was 25.8, and 28 of 50 patients (56%) were male. Earliest loss of fibular contact occurred at 24° ER and 22° IR at the proximal site. Contact was lost at 26° ER and 28° IR on the AP view and 42° ER and 29° IR on the lateral view. The mean fibular contact at each 5° increment was similar for ER and IR. Fibular contact was reduced to 50% at 10 to 15° of rotation in ER and IR at all sites. Tibial canal contact was lost at 24° in both ER and IR around the fibula. With a virtual medullary implant, the mean maximal rotation was 6°. Surgeons should be aware that 20° or more of malrotation is likely present when fibular contact is lost during medullary nailing of the tibia. Greater than 50% loss of contact should raise suspicion for malrotation. A fixed fibula and medullary tibial implant theoretically preclude significant tibial malrotation.
Read moreOrthopaedic Advances: Use of Three-Dimensional Metallic Implants for Reconstruction of Critical Bone Defects After Trauma.
Multiple successful strategies exist for the management of critical-sized bone defects. Depending on the location and etiology of an osseous defect, there are nuances that must be considered by the treating surgeon. The induced membrane technique and various modifications of the Ilizarov method (bone transport by distraction osteogenesis) have been the most common methods for biologic reconstruction. Despite the versatility and high union rates reported, they may not be practical for every patient. The rapid expansion of three-dimensional printing of medical devices has led to an increase in their use within orthopaedic surgery, specifically in the definitive treatment of critical bone defects. This article proposes indications and contraindications for implementation of this technology and reviews the available clinical evidence on the use of custom nonresorbable implants for the treatment of traumatic bone loss. Clinical cases are presented to illustrate the scenarios in which this approach is viable.
Read moreAlberta Collaborative Quality Improvement Strategies to Improve Outcomes of Moderate and Late Preterm Infants (ABC-QI) Trial: a protocol for a multicentre, stepped-wedge cluster randomized trial.
Evidence-based Practice for Improving Quality (EPIQ) is a collaborative quality improvement method adopted by the Canadian Neonatal Network that led to decreased mortality and morbidity in very preterm neonates. The Alberta Collaborative Quality Improvement Strategies to Improve Outcomes of Moderate and Late Preterm Infants (ABC-QI) Trial aims to evaluate the impact of EPIQ collaborative quality improvement strategies in moderate and late preterm neonates in Alberta, Canada. In a 4-year, multicentre, stepped-wedge cluster randomized trial involving 12 neonatal intensive care units (NICUs), we will collect baseline data with the current practices in the first year (all NICUs in the control arm). Four NICUs will transition to the intervention arm at the end of each year, with 1 year of follow-up after the last group transitions to the intervention arm. Neonates born at 32 + 0 to 36 + 6 weeks' gestation with primary admission to NICUs or postpartum units will be included. The intervention includes implementation of respiratory and nutritional care bundles using EPIQ strategies, including quality improvement team building, quality improvement education, bundle implementation, quality improvement mentoring and collaborative networking. The primary outcome is length of hospital stay; secondary outcomes include health care costs and short-term clinical outcomes. Neonatal intensive care unit staff will complete a survey in the first year to assess quality improvement culture in each unit, and a sample will be interviewed 1 year after implementation in each unit to evaluate the implementation process. The ABC-QI Trial will assess whether collaborative quality improvement strategies affect length of stay in moderate and late preterm neonates. It will provide detailed population-based data to support future research, benchmarking and quality improvement. ClinicalTrials.gov, no. NCT05231200.
Read morePRINCIPAIS ALTERAÇÕES DO HEMOGRAMA POTENCIALMENTE ASSOCIADAS AO COVID-19
American Academy of Orthopaedic Surgeons Appropriate Use Criteria: Early Screening for Psychosocial Risk and Protective Factors.
The Major Extremity Trauma and Rehabilitation Consortium and the American Academy of Orthopaedic Surgeons (AAOS) have developed Appropriate Use Criteria for the Early Screening for Psychosocial Risk and Protective Factors. Evidence and clinical expertise were used to develop criteria for addressing mental and social health opportunities to help people recover from musculoskeletal injuries to the extremity, spine, and pelvis. The criteria were developed by identifying observable symptoms and results of screening that suggest mental and social health challenges among patients with lower extremity trauma in clinical practice. The 32 patient scenarios and three interventions (evaluate for psychological distress, evaluate for social health opportunities, and evaluate coping and resilience strategies) were developed by the writing panel of clinicians who are specialists in mental and social health in musculoskeletal illness. Next, a separate, multidisciplinary, voting panel made up of specialists and nonspecialists rated the appropriateness of treatment for each patient scenario using a 9-point scale to designate a treatment as "appropriate" (median rating, 7 to 9), "may be appropriate" (median rating, 4 to 6), or "rarely appropriate" (median rating, 1 to 3). Notably, with a high level of agreement, the voting panel determined that interventions to address mental and social health were appropriate in all scenarios as follows: 86% were rated appropriate, 14% were rated possibly appropriate, and none were rated rarely appropriate.
Read moreOpen and Arthroscopic Triangular Fibrocartilage Complex (TFCC) Repair.
Triangular fibrocartilage complex (TFCC) tears, whether acute or chronic, can result in persistent ulnar-sided wrist pain. Although diagnosis and nonsurgical management of TFCC tears is well described, there remains ongoing discussion about the optimal surgical technique, specifically open or arthroscopic. This article reviews the most up-to-date literature regarding TFCC injury including demographics, risk factors for TFCC injury, classification of acute and chronic TFCC tears, history and physical examination, appropriate diagnostic imaging, surgical indications, pertinent surgical anatomy, open and arthroscopic TFCC repair, fixation biomechanics and techniques, postoperative rehabilitation, and clinical outcomes.
Read moreEine Online-Plattform für Digitale Zwillinge
Zunehmend suchen Komponentenhersteller nach Lösungen zur Bereitstellung von digitalen Abbildern ihrer realen Komponenten. Ziel ist es, dass Kunden damit ihre Automatisierungskonzepte virtuell validieren und Steuerungssysteme im Entwicklungsprozess anhand einer virtuellen Inbetriebnahme eingehend testen und optimieren können. Simulationswerkzeuge für die virtuelleInbetriebnahme bieten mittlerweile vielfältige Schnittstellen zur Einbindung bestehender Teilmodelle bei der Modellierung eines digitalen Zwillings einer Maschine oder Anlage. In diesem Beitrag wird die Online-Plattform „TwinStore“ für den Austausch von Simulationsmodellen zur virtuellen Inbetriebnahme vorgestellt.
Read moreGut Microbiota-Dependent Trimethylamine N-Oxide Predicts Risk of Cardiovascular Events in Patients With Stroke and Is Related to Proinflammatory Monocytes.
Objective- Gut microbiota-dependent metabolites, in particular trimethylamine N-oxide (TMAO), have recently been reported to promote atherosclerosis and thrombosis. Here, we examined for the first time the relation of TMAO and the risk of incident cardiovascular events in patients with recent first-ever ischemic stroke in 2 independent prospective cohorts. Moreover, the link between TMAO and proinflammatory monocytes as a potential contributing factor for cardiovascular risk in stroke patients was studied. Approach and Results- In a first study (n=78), higher TMAO plasma levels were linked with an increased risk of incident cardiovascular events including myocardial infarction, recurrent stroke, and cardiovascular death (fourth quartile versus first quartile; hazard ratio, 2.31; 95% CI, 1.25-4.23; P<0.01). In the second independent validation cohort (n=593), high TMAO levels again heralded marked increased risk of adverse cardiovascular events (fourth quartile versus first quartile; hazard ratio, 5.0; 95% CI, 1.7-14.8; P<0.01), and also after adjustments for cardiovascular risk factors including hypertension, diabetes mellitus, LDL (low-density lipoprotein) cholesterol, and estimated glomerular filtration rate (hazard ratio, 3.3; 95% CI, 1.2-10.9; P=0.04). A significant correlation was also found between TMAO levels and percentage of proinflammatory intermediate CD14++CD16+ monocytes ( r=0.70; P<0.01). Moreover, in mice fed a diet enriched with choline to increase TMAO synthesis, levels of proinflammatory murine Ly6Chigh monocytes were higher than in the chow-fed control group (choline: 9.2±0.5×103 per mL versus control: 6.5±0.5×103 per mL; P<0.01). This increase was abolished in mice with depleted gut microbiota (choline+antibiotics: 5.4±0.7×103 per mL; P<0.001 versus choline). Conclusions- The present study demonstrates for the first time a graded relation between TMAO levels and the risk of subsequent cardiovascular events in patients with recent prior ischemic stroke. Our data support the notion that TMAO-related increase of proinflammatory monocytes may add to elevated cardiovascular risk of patients with increased TMAO levels.
Read moreRegulation of neuronal survival by DNA methyltransferases
The limited regenerative capacity of neuronal cells requires tight orchestration of cell death and survival regulation in the context of longevity, age-associated diseases as well as during the development of the nervous system. Subordinate to genetic networks epigenetic mechanisms like DNA methylation and histone modifications are involved in the regulation of neuronal development, function and aging. DNA methylation by DNA methyltransferases (DNMTs), mostly correlated with gene silencing, is a dynamic and reversible process. In addition to their canonical actions performing cytosine methylation, DNMTs influence gene expression by interactions with histone modifying enzymes or complexes increasing the complexity of epigenetic transcriptional networks. DNMTs are expressed in neuronal progenitors, post-mitotic as well as adult neurons. In this review, we discuss the role and mode of actions of DNMTs including downstream networks in the regulation of neuronal survival in the developing and aging nervous system and its relevance for associated disorders.
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