scholarly journals Biomechanical Performance Analysis of the Monolateral External Fixation Devices with Steel and Composite Material Frames under the Impact of Axial Load

2022 ◽  
Vol 12 (2) ◽  
pp. 722
Author(s):  
Nedim Pervan ◽  
Elmedin Mešić ◽  
Adis J. Muminović ◽  
Muamer Delić ◽  
Enis Muratović ◽  
...  
Keyword(s):  
Composite Material ◽  
Axial Load ◽  
Biomechanical Properties ◽  
Steel Frame ◽  
Fixation Device ◽  
Control Zone ◽  
Fixation Devices ◽  
Critical Zones ◽  
The Impact ◽  
Frame Device

This paper describes comparative analysis of the biomechanical performances conducted on the external fixation devices whose frames are made out of two different material (stainless steel and composite material). Biomechanical properties were determined with experimental and FEM (finite element method) models which are used to study the movement of the fracture crack, establish stiffness of the design solutions and monitor generated stresses on the zones of interest. Geometric modeling of two fixation devices configurations B50 and C50 is used as a basis for structural analysis under the impact of axial load. Structural analysis results are confirmed with an experimental setup. Analyzed deflection values in the load and fracture zones are used to define the exact values of the stiffness for the construction design and fracture, respectively. The carbon frame device configuration has 28% lower construction stiffness than the one with the steel frame (for B50 configuration), i.e., 9% (for C50 configuration). In addition, fracture stiffness values for the composite frame application are approximately 23% lower (B50 configuration), i.e., 13% lower (C50 configuration), compared to steel frame. The carbon frame device has about 33% lower stresses at the critical zones compared to the steel frame at the control zone MM+ and, similarly, 35% lower stresses at the control zone MM-. With an exhausting analysis of the biomechanical properties of the fixation devices, it can be concluded that steel frame fixation device is superior, meaning it has better biomechanical characteristics compared to carbon frame fixation device, regarding obtained data for stresses and stiffnesses of the frame construction and fracture. Considering stresses at the critical zones of the fixation device construction, the carbon frame device has better biomechanical performances compared to steel frame devices.

scholarly journals Comparative analysis of modeled femoral fractures osteosynthesis stability

2014 ◽  
Vol 95 (3) ◽  
pp. 392-394
Author(s):  
O N Yamshchikov ◽  
D A Markov ◽  
S A Emelyanov ◽  
K P Zvereva ◽  
A E Bychkov
Keyword(s):  
External Fixation ◽  
Axial Load ◽  
Test Machine ◽  
Fixation Device ◽  
Intramedullary Nails ◽  
Fixation Devices ◽  
Bone Fragments ◽  
Angle Stability ◽  
External Fixation Device ◽  
The Stability

Aim. To perform the comparative analysis of osteosynthesis stability in splintered fractures on the example of modeled fractures of femur with metalwork. Methods. Bone fragments fixation methods using internal fixators, blocking intramedullary nails, external fixation devices. Round wooden rod with external diameter of 35 mm, internal diameter of 25 mm, which was saw in the middle with two cuts directed at an angle of 45° to the rod axis to form the triangle fragment, was picked for femur model for the purpose of experiment. The stability of bone fragments fixation using plates with angle stability, pin- and nail-type external fixation devices and blocking intramedullary nails was assessed. To test the stability of the «bone-fixing device» complex, torsional test machine КМ-50-1 №66, power press П-10 №92, pull test machine Р-10 №1677 were used. Results. Compared to external fixation device, fixation using plates with angle stability was 6 times more stable at axial load and by 43.5% at lateral load. The stability of blocking intramedullary nail at axial load was higher compared to external fixation device. At rotary load, the stability of blocking intramedullary nail was 2 times lower compared to external fixation device. Conclusion. On a model of splintered double-lever femur fractures, fixation using plates with angle stability was the most stable fixation mode.

scholarly journals Histological, Biomechanical, and Biological Properties of Genipin-Crosslinked Decellularized Peripheral Nerves

2021 ◽  
Vol 22 (2) ◽  
pp. 674
Author(s):  
Óscar Darío García-García ◽  
Marwa El Soury ◽  
David González-Quevedo ◽  
David Sánchez-Porras ◽  
Jesús Chato-Astrain ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Nerve Repair ◽  
Wistar Rat ◽  
Biomechanical Properties ◽  
Biological Properties ◽  
Suitable Alternative ◽  
Promising Alternative ◽  
Histological Pattern ◽  
The Impact

Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.

Rupture by impact-induced fatigue of a copper foil strip embedded in a multifunctional composite material

2021 ◽  
pp. 002199832199432
Author(s):  
Yacine Ouroua ◽  
Said Abdi ◽  
Imene Bachirbey
Keyword(s):  
Composite Material ◽  
Mechanical Characteristics ◽  
Glass Fibers ◽  
Energy Levels ◽  
Fatigue Tests ◽  
Repeated Impact ◽  
Aeronautical Industry ◽  
Repeated Impacts ◽  
Cracking Mode ◽  
The Impact

Multifunctional composite materials are highly sought-after by the aerospace and aeronautical industry but their performance depends on their ability to sustain various forms of damages, in particular damages due to repeated impacts. In this work we studied the mechanical behavior of a layered glass-epoxy composite with copper inserts subjected to fatigue under repeated impacts with different energy levels. Damage evolution as a function of impact energy was carefully monitored in order to determine the effect of the copper inserts on mechanical characteristics of the multifunctional composite, such as endurance and life. Results of repeated impact tests show that electric current interruption in the copper inserts occurs prior to the total perforation of the composite material, and after about 75% of the total number of impacts to failure. This is the case for the three energy levels considered in this study, [Formula: see text] = 2, 3 and 4 Joules. The epoxy resin was dissolved chemically in order to preserve the mechanical structure of the damaged copper inserts and the composite fibers for further inspection and analysis. Scanning electron microscopy (SEM) of the fractured copper inserts revealed interesting information on the nature of the damage, including information on plastic deformation, strain hardening, cracking mode, temperature increase during the impacts, and most importantly the glass fibers and their roles during the impact-fatigue tests.

scholarly journals Fragility assessment of existing low-rise steel moment-resisting frames with masonry infills under mainshock-aftershock earthquake sequences

2021 ◽  
Vol 19 (6) ◽  
pp. 2483-2504
Author(s):  
Luigi Di Sarno ◽  
Jing-Ren Wu
Keyword(s):  
Seismic Vulnerability ◽  
Steel Frames ◽  
Steel Frame ◽  
Second Phase ◽  
Moment Frames ◽  
Damage Level ◽  
Masonry Infills ◽  
Aftershock Sequences ◽  
The Impact ◽  
Multiple Earthquakes

AbstractThis paper presents the fragility assessment of non-seismically designed steel moment frames with masonry infills. The assessment considered the effects of multiple earthquakes on the damage accumulation of steel frames, which is an essential part of modern performance-based earthquake engineering. Effects of aftershocks are particularly important when examining damaged buildings and making post-quake decisions, such as tagging and retrofit strategy. The procedure proposed in the present work includes two phase assessment, which is based on incremental dynamic analyses of two refined numerical models of the case-study steel frame, i.e. with and without masonry infills, and utilises mainshock-aftershock sequences of natural earthquake records. The first phase focuses on the undamaged structure subjected to single and multiple earthquakes; the effects of masonry infills on the seismic vulnerability of the steel frame were also considered. In the second phase, aftershock fragility curves were derived to investigate the seismic vulnerability of infilled steel frames with post-mainshock damage caused by mainshocks. Comparative analyses were conducted among the mainshock-damaged structures considering three post-mainshock damage levels, including no damage. The impact of aftershocks was then discussed for each mainshock-damage level in terms of the breakpoint that marks the onset of exceeding post-mainshock damage level, as well as the probability of exceeding of superior damage level due to more significant aftershocks. The evaluation of the efficiency of commonly used intensity measures of aftershocks was also carried out as part of the second phase of assessment.

scholarly journals The Evolving Approach to Treating Syndesmotic Injuries in the Elite Athlete: An International Perspective

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0003
Author(s):  
Kenneth Hunt ◽  
Shanthan Challa ◽  
Pieter D’Hooghe ◽  
Pam Kumparatana ◽  
Phinit Phisitkul ◽  
...  
Keyword(s):  
Return To Sport ◽  
High Impact ◽  
Optimal Treatment ◽  
The Body ◽  
Return To Play ◽  
Considerable Variability ◽  
Fixation Device ◽  
Flexible Devices ◽  
Fixation Devices ◽  
Rehabilitation Protocols

Category: Ankle, Sports Introduction/Purpose: There exists little consensus regarding optimal treatment protocols for syndesmotic injuries. Orthopaedic clinicians have implemented a variety of treatment strategies, ranging from immobilization to screw fixation to new flexible fixation devices. While the body of literature is growing with regard to both the biomechanics and clinical outcomes for various constructs and rehabilitation protocols, there is little consensus on the optimal treatment and return to sport strategy for these injuries. We endeavored to assess current approaches to syndesmotic injures by orthopedic foot and ankle specialists around the world in 6 athlete scenarios with increasing degree of injury. Commensurate with the lack of available data to guide treatments, we hypothesize that there will be variability in the treatment and management strategies for syndesmotic injuries. Methods: A REDcap survey was created with 27 questions, including respondent demographics, indications for treatment of syndesmotic injuries, preferred treatment, preferred technique for repairing the syndesmosis and post-operative management. Respondents were asked to choose their preferred fixation device and post-operative return to play protocols in six different athlete scenarios (moderate impact, high impact and very high impact and each with/without complete deltoid injury). The survey was disseminated among the memberships of 18 North American and International medical societies. Society members were surveyed via three emails disseminated 2 weeks apart. Frequencies and percentages were calculated for all categorical responses. Results: A total of 596 providers responded to the survey, including 337 American surgeons and 259 members of various international societies. There was a 70% survey completion rate with a wide geographic distribution among respondents. Flexible devices were the preferred fixation construct (48.1%), followed by screws (27.5%), hybrid fixation (18.5%) and other (5.9%). There was a higher preference for flexible devices among sports medicine trained providers. 62% of respondents noted that their rehabilitation protocols would not change for each athlete scenario. Considerable variability was present in anticipated full return to sport, ranging from immediately following injury to 6 months post-op (Fig 1). One-third of respondents indicated that they repair the deltoid greater than 50% of the time when injured. Conclusion: We found a wide variety of indications and treatment constructs employed by orthopaedic surgeons for athletes with ligamentous syndesmotic injuries requiring fixation. Although, flexible fixation devices are the preferred among all respondents but there was a considerable variability in device choices. Fellowship training also appears to affect the preferred fixation device choice. There also exists substantial variability in expected return to play for every athlete scenario (Fig 1). The diversity in approaches and post-operative recommendations underscores the need for evidence-based guidelines to inform management of syndesmotic injuries.

Impact action on fiber and composite material based on it

2020 ◽  
Vol 6 ◽  
pp. 69-74
Author(s):  
V.V. Kudinov ◽  
◽  
I.K. Krylov ◽  
N.V. Korneeva ◽  
◽  
...  
Keyword(s):  
Composite Material ◽  
Deformation Behavior ◽  
Failure Mechanisms ◽  
Basic Mechanism ◽  
Impact Action ◽  
Uhmwpe Fiber ◽  
Mechanism Of Failure ◽  
First Moment ◽  
The Impact ◽  
Ib Method

The low-velosity impact properties and failure mechanisms of ultra-high molecular weight polyethylene (UHMWPE) fiber (Dyneema®SK-75) and a composite material (CM) based on it with the rigid and flexible matrices were investigated by the “Impact Break” (IB) method. A fundamental difference in deformation behavior and failure mechanisms upon impact on the UHMWPE-fiber and on the CM based on this fiber has been investigated experimentally. It is shown that impact has a little effect on the properties of UHMWPE-fiber, since it is an isotropic material. It has been established that upon impact, the properties of a fiber without a matrix were significantly higher than the properties of CM based on it. Impact action stimulates the interaction between CM components (fibers and matrix). Mechanism of stepwise deformation of anisotropic CM is occurred, which begins from the first moment of impact and ends with the destruction of the CM. A “stairway of deformation” behavior is observed in anisotropic materials. Stepwise deformation is the main form of deformation and the basic mechanism of failure of anisotropic composite materials upon impact.

scholarly journals Functional Outcomes and Complications of Intramedullary Fixation Devices for Midshaft Clavicle Fractures: A Systematic Review and Meta-Analysis.

2020 ◽  
Author(s):  
Paul Hoogervorst ◽  
Tess van Dam ◽  
Nico Verdonschot ◽  
Gerjon Hannink
Keyword(s):  
Systematic Review ◽  
Functional Outcomes ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Intramedullary Fixation ◽  
Common Complication ◽  
Fixation Device ◽  
Operative Strategy ◽  
Fixation Devices ◽  
Clavicle Fractures

Abstract Background An alternative to the current gold standard in operative treatment of displaced midshaft clavicle fractures (DMCF) using plate osteosynthesis, is internal fixation by means of intramedullary fixation devices. These devices differ considerably in their specifications and characteristics. The aim of this systematic review is to generate an overview of functional outcomes and complications in the management of DMCF per available intramedullary device.Methods A systematic review was conducted to identify all papers reporting functional outcomes, union rates and/or complications using an intramedullary fixation device for the management of midshaft clavicle fractures. Multiple databases and trial registries were searched from inception until February 2020. Meta-analysis was conducted based on functional outcomes and type of complication per type of intramedullary fixation device. Pooled estimates of functional outcomes scores and incidence of complications were calculated using a random effects model. Risk of bias and quality was assessed using the Cochrane risk of bias and ROBINS-I tools. The confidence in estimates were rated and described according to the recommendations of the GRADE working group.Results Sixty-seven studies were included in this systematic review. The majority of studies report on the use of Titanium Elastic Nails (TEN). At 12 months follow up the Titanium Elastic Nail and Sonoma CRx report an average Constant-Murley score of 94.4 (95%CI 93-95) and 94.0 (95%CI 92-95) respectively (GRADE High). The most common reported complications after intramedullary fixation are implant-related and implant-specific. For the TEN, hardware irritation and protrusion, telescoping or migration, with a reported pooled incidence 20% (95%CI 14-26) and 12% (95%CI 8-18), are most common (GRADE Moderate). For the Rockwood/Hagie Pin, hardware irritation is identified as the most common complication with 22% (95%CI 13-35) (GRADE Low). The most common complication for the Sonoma CRx was cosmetic dissatisfaction in 6% (95%CI 2-17) of cases (GRADE Very low). Conclusion Although most studies were of low quality, good functional results and union rates irrespective of the type of device are found. However, there are clear device-related and device-specific complications for each. The results of this systematic review and meta-analysis can help guide surgeons in choosing the appropriate operative strategy, implant and informing their patient.

Analysis of keratopographic and biomechanical corneal indicators with evaluation of the impact of diagnostic results on myopic refraction patient management tactics

2021 ◽  
pp. 196-199
Author(s):  
D.D. Sibakin ◽  
◽  
V.A. Breev ◽  
E.G. Solodkova ◽  
◽  
...  
Keyword(s):  
Patient Management ◽  
Screening Program ◽  
Clinical Stage ◽  
Biomechanical Properties ◽  
Corvis St ◽  
Stage Of Development ◽  
Biomechanical Parameters ◽  
The Impact ◽  
Biomechanical Measurements ◽  
Corneal Biomechanical Properties

Purpose. To analyse keratopographic and biomechanical corneal indicators with the diagnostic results assessment of the influence on the treatment tactics of myopic refraction patient. Materials and methods. Keratotopographic and biomechanical parameters of the cornea in a patient with mild myopia were evaluated. Results. The Belin/Ambrosio (Enchanced Ectasia Display) - BAD keratoconus screening program was used on Pentacam HR, which did not reveal corneal pathology. According to the results of CBI (Corvis biomechanical index) on Corvis ST (OD - 0.61, OS - 0.48), that was indicating poor corneal biomechanical properties and a high risk of keratectasia development. Conclusion. Ophthalmic examination, using The Corvis ST (Oculus, Germany) biomechanical measurements, makes possible to reveal with greater sensitivity subclinical signs of a keratectatic process at the pre-clinical stage of development. Key words: keratotopography, corneal biomechanics, keratoconus.

Impact of Torque on Assessment of Syndesmotic Injuries Using Weightbearing Computed Tomography Scans

2019 ◽  
Vol 40 (6) ◽  
pp. 710-719 ◽  
Author(s):  
Nicola Krähenbühl ◽  
Travis L. Bailey ◽  
Maxwell W. Weinberg ◽  
Nathan P. Davidson ◽  
Beat Hintermann ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Axial Load ◽  
External Rotation ◽  
Ct Scans ◽  
Deltoid Ligament ◽  
Tibiofibular Syndesmosis ◽  
Tibiofibular Ligament ◽  
Distal Tibiofibular Syndesmosis ◽  
Axial Ct ◽  
The Impact

Background: The diagnosis of subtle injuries to the distal tibiofibular syndesmosis remains elusive. Conventional radiographs miss a large subset of injuries that present without frank diastasis. This study evaluated the impact of torque application on the assessment of syndesmotic injuries when using weightbearing computed tomography (CT) scans. Methods: Seven pairs of male cadavers (tibia plateau to toe-tip) were included. CT scans with axial load application (85 kg) and with (10 Nm) or without torque to the tibia (corresponding to external rotation of the foot and ankle) were taken during 4 test conditions. First, intact ankles (native) were scanned. Second, 1 specimen from each pair underwent anterior inferior tibiofibular ligament (AITFL) transection (condition 1A), while the contralateral underwent deltoid transection (condition 1B). Third, the lesions were reversed on the same specimens and the remaining intact deltoid or AITFL was transected (condition 2). Finally, the distal tibiofibular interosseous membrane (IOM) was transected in all ankles (condition 3). Measurements were performed to assess the integrity of the distal tibiofibular syndesmosis on digitally reconstructed radiographs (DRRs) and on axial CT scans. Results: Torque impacted DRR and axial CT scan measurements in almost all conditions. The ability to diagnose syndesmotic injuries using axial CT measurements improved when torque was applied. No significant syndesmotic morphological change was observed with or without torque for either isolated AITFL or deltoid ligament transection. Discussion: Torque application had a notable impact on two-dimensional (2-D) measurements used to diagnose syndesmotic injuries for both DRRs and axial CT scans. Because weightbearing conditions allow for standardized positioning of the foot while radiographs or CT scans are taken, the combination of axial load and torque application may be desirable. Clinical Relevance: Application of torque to the tibia impacts 2-D measurements and may be useful when diagnosing syndesmotic injuries by DRRs or axial CT images.

scholarly journals Study of the ballistic behaviour of UHMWPE composite material: experimental characterization and numerical simulation

2018 ◽  
Vol 183 ◽  
pp. 01051
Author(s):  
Hakim Abdulhamid ◽  
Paul Deconinck ◽  
Pierre-Louis Héreil ◽  
Jérôme Mespoulet
Keyword(s):  
Numerical Simulation ◽  
Composite Material ◽  
Damage Model ◽  
Material Model ◽  
Polyethylene Composite ◽  
Macro Scale ◽  
Out Of Plane ◽  
Peeling Strength ◽  
Scale Levels ◽  
The Impact

This paper presents a comprehensive mechanical study of UHMWPE (Ultra High Molecular Weight Polyethylene) composite material under dynamic loadings. The aim of the study is to provide reliable experimental data for building and validate the composite material model under impact. Four types of characterization tests have been conducted: dynamic in-plane tension, out-of-plane compression, shear tests and plate impact tests. Then, several impacts of spherical projectiles have been performed. Regarding the numerical simulation, an intermediate scale multi-layered model (between meso and macro scale levels) is proposed. The material response is modelled with a 3d elastic orthotropic law coupled with fibre damage model. The modelling choice is governed by a balance between reliability and computing cost. Material dynamic response is unconventional [1, 2]: it shows large deformation before failure, very low shear modulus and peeling strength. Numerical simulation has been used both in the design and the analysis of tests. Many mechanical properties have been measured: elastic moduli, failure strength and EOS of the material. The numerical model is able to reproduce the main behaviours observed in the experiment. The study has highlighted the influence of temperature and fibre slipping in the impact response of the material.

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