Mathematical Modelling of Destabilization Stress Factors of Stable-Elastic Fixation of Distal Trans- and Suprasyndesmotic Fibular Fractures

Introduction. Specification of possible stress factors destabilizing the fibula stable osteosynthesis by the intramedullary nail with distal blocking and elastic fixation of distal syndesmosis by the thread with endobuttons by mathematical modelling of distal unstable ankle injuries. Material and Methods. We studied the thread tension during the combined stable-elastic fixation of unstable injuries of the ankle joint in cross-syndesmosis fractures of the fibula (B, C Danis–Weber classification), which includes a one-time stable minimally invasive fixation with the intramedullary nail and elastic fixation by the thread with endobuttons. We used a titanium alloy for the intramedullary nail and polyester for the thread. The deformed state was studied using the methods of mechanics. Results. A model of a fractured fibula blocked with the intramedullary nail and fixed with the elastic thread was developed. A formulation to specify the rational tension forces of the elastic thread depending on the parameters of the fibula and intramedullary blocking nail and on the location of the bone injury was obtained. The effect of foot rotation on the thread tension was investigated. The results of theoretical research should be implemented in medical practice. Conclusions. A mathematical model of the damaged fibula blocked by the intramedullary nail and fixed with the elastic thread was developed. Dependences for calculation of tension of the fixing thread were obtained. A slight increase in thread tension during foot rotation was found.

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Determination of vertical dynamics for a standard Ukrainian boxcar with Y25 bogies

Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu ◽

10.33271/nvngu/2021-5/067 ◽

2020 ◽

pp. 67-72

Author(s):

O. V Fomin ◽

A. O Lovska

Keyword(s):

Mathematical Modelling ◽

Dynamic Characteristics ◽

Center Of Mass ◽

Vertical Plane ◽

Field Tests ◽

The Body ◽

Dynamic Loads ◽

Theoretical Research ◽

Predominant Type ◽

Mathcad Software

Purpose. To determine the basic dynamic characteristics of a standard Ukrainian boxcar with the Y25 bogie by means of the mathematic modelling of dynamic loads in the vertical plane and to compare them with the dynamic characteristics obtained for a boxcar with the 18100 bogie. It can be used for substantiation of application of the Y25 bogie as more promising, which can improve the operational efficiency of rail transportation and foster integration of the Ukrainian transport system into the European transportation complex. Methodology. The authors used the mathematical modelling of a boxcar with the Y25 bogie. The research was made in the vertical plane. It was taken into account that an empty car passed over a joint irregularity. The research was made for an 11217boxcar as a predominant type to be used. The authors studied the motion of a car on the 18100 and Y25 bogies. The basic dynamic characteristics were determined for a boxcar with the nominal (design) dimensions of the carrying elements and a boxcar with the actual dimensions (after a long service life) on the basis of the field tests. The differential equations were solved by theRungeKutta method in MathCad software suite. The initial displacements and the speeds were taken equal to zero. The following dynamic characteristics of a boxcar were obtained: acceleration of the body in the center of mass, acceleration of the body in the areas of support on the bogies, forces in the spring suspension of the bogie, and dynamic coefficients of the bogies. Findings. The theoretical research showed that the basic dynamic characteristics of a boxcar with the nominal dimensions were improved by 3851% in comparison to a similar one with the 18100 bogie, and for a boxcar with the actual dimensions the dynamic characteristics were improved by 4350%. Originality. The authors substantiated the application of the Y25 bogie for a standard Ukrainian boxcar with the nominal and actual dimensions of the carrying elements by means of the mathematical modelling of the dynamic loads in the vertical plane. Practical value. Due to lower dynamic loads on the carrying structures of freight cars with the Y25 bogie, it is possible to improve the dynamic characteristics of the structures under the operational modes, to increase the fatigue strength and the operational resource, to decrease the total repair and maintenance costs, to ensure better security and reliability of freight transportation through lower loads on both carrying structures and lashing devices, to increase the speed of freight delivery thanks to better dynamic characteristics of cars, to improve the traffic security, and so on.

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Bosworth Dislocation without Associated Fracture

Case Reports in Orthopedics ◽

10.1155/2018/7284643 ◽

2018 ◽

Vol 2018 ◽

pp. 1-4

Author(s):

Austin D. Williams ◽

Matthew Blue ◽

Christian Douthit ◽

Cyrus Caroom

Keyword(s):

Intramedullary Nailing ◽

Treatment Option ◽

Intramedullary Nail ◽

Closed Reduction ◽

Open Reduction ◽

Ankle Injuries ◽

Fracture Dislocation ◽

Good Reduction ◽

Timely Manner ◽

Distal Fibula

One of the rarest ankle injuries is the Bosworth fracture-dislocation, whereby the distal fibula fractures and is lodged behind the tibia and is often unable to be reduced in a closed fashion. Even more rarely, a Bosworth dislocation without any accompanying fractures may occur. In this case, a 19-year-old male presented with a Bosworth dislocation, with the ipsilateral tibia having previously undergone intramedullary nailing. After closed reduction was attempted, open reduction and fixation was performed, directly reducing the fibula and fixing the unstable syndesmosis with 2 quadricortical screws. Bosworth injuries are rare, yet severe, and should be treated in a timely manner. We were able to provide good reduction and fixation without requiring removal of the intramedullary nail, and we support the use of 2 quadricortical screws as a valid treatment option for the fixation of Bosworth dislocations.

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Comparison of Minimally Invasive Fixation of Mid‐Shaft Clavicular Fractures with Threaded Elastic Intramedullary Nail ( TEIN ) and Elastic Locking Intramedullary Nail ( ELIN )

Orthopaedic Surgery ◽

10.1111/os.13129 ◽

2021 ◽

Author(s):

Liang Ren ◽

Zhiqiang Yang ◽

Yongqing Wang ◽

Sapkota Basanta ◽

Bosong Du ◽

...

Keyword(s):

Minimally Invasive ◽

Intramedullary Nail ◽

Minimally Invasive Fixation

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Mathematical modelling for antibiotic resistance control policy: do we know enough?

BMC Infectious Diseases ◽

10.1186/s12879-019-4630-y ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 6

Author(s):

Gwenan M. Knight ◽

Nicholas G. Davies ◽

Caroline Colijn ◽

Francesc Coll ◽

Tjibbe Donker ◽

...

Keyword(s):

Antibiotic Resistance ◽

Mathematical Modelling ◽

Mathematical Models ◽

Control Policy ◽

Evidence Base ◽

Modern Medicine ◽

Theoretical Research ◽

Resistance Evolution ◽

Key Drivers ◽

The Right

Abstract Background Antibiotics remain the cornerstone of modern medicine. Yet there exists an inherent dilemma in their use: we are able to prevent harm by administering antibiotic treatment as necessary to both humans and animals, but we must be mindful of limiting the spread of resistance and safeguarding the efficacy of antibiotics for current and future generations. Policies that strike the right balance must be informed by a transparent rationale that relies on a robust evidence base. Main text One way to generate the evidence base needed to inform policies for managing antibiotic resistance is by using mathematical models. These models can distil the key drivers of the dynamics of resistance transmission from complex infection and evolutionary processes, as well as predict likely responses to policy change in silico. Here, we ask whether we know enough about antibiotic resistance for mathematical modelling to robustly and effectively inform policy. We consider in turn the challenges associated with capturing antibiotic resistance evolution using mathematical models, and with translating mathematical modelling evidence into policy. Conclusions We suggest that in spite of promising advances, we lack a complete understanding of key principles. From this we advocate for priority areas of future empirical and theoretical research.

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Anatomic Approach To The Removal Of A Bent Intramedullary Nail In A Refractured Tibia Minimising Soft Tissue And Bone Injury: A Rare Case Report.

The Internet Journal of Orthopedic Surgery ◽

10.5580/2b69 ◽

2012 ◽

Vol 19 (2) ◽

Keyword(s):

Case Report ◽

Soft Tissue ◽

Intramedullary Nail ◽

Rare Case ◽

Bone Injury ◽

Rare Case Report

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The use of the combined stable-elastic fixation for unstable injuries of the ankle joint in trans-syndesmotic fractures of the tibia

TRAUMA ◽

10.22141/1608-1706.3.22.2021.236323 ◽

2021 ◽

Vol 22 (3) ◽

pp. 43-47

Author(s):

A.V. Chuzhak

Keyword(s):

Ankle Joint ◽

High Efficiency ◽

Point Of View ◽

Tibial Fractures ◽

Ankle Injuries ◽

Treatment Results ◽

Ao Classification ◽

In Trans ◽

Poor Outcomes ◽

Elastic Fixation

The problem of complications and the frequency of poor outcomes in the surgical treatment of ankle fractures with ti-biofibular syndesmosis (TFS) rupture (4.8–36.8 % of cases) remains significant. It was interesting from a scientific and practical point of view to conduct a clinical study to determine the effectiveness of the newly developed method of metal osteosynthesis for tibial fractures with TFS rupture, which would combine stability of tibial fixation and not limit the elastic qualities of TFS. The aim of the study: to determine the effectiveness of combined stable-elastic fixation for unstable injuries of the ankle joint in trans-syndesmotic fractures of the tibia. Materials and methods. On the basis of own clinical researches and data of literature sources, the method of the combined stable-elastic fixation for unstable injuries of the ankle joint in trans-syndesmotic fractures of the tibia is developed. The effectiveness of the proposed technique was evaluated 6 months after surgery on the Kitaoka scale. We have examined 12 patients with tibial fractures type 44 B1, B2 and B3 according to the AO classification, who underwent surgery using our methods. Results. The high efficiency of using the technique of combined stable-elastic fixation for unstable injuries of the ankle joint due to trans-syndesmotic fractures of the tibia has been determined. Good and excellent treatment results 6 months after surgery were observed in all 12 people (100 %), with excellent outcomes observed in 75 % of cases. There were no satisfactory and unsatisfactory treatment results. Conclusions. The study proves the high efficiency of the proposed method for combined stable-elastic fixation of ankle injuries in unstable trans-syndesmotic fractures of the tibia with TFS damage. There were 75 % excellent and 25 % good results within 6 months after surgery. A wider introduction of this technique into the practice of traumatologists of Ukraine is proposed.

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