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Strain stress analysis of BS splint
Řehák, Kamil ; Fuis, Vladimír (referee) ; Florian, Zdeněk (advisor)
This master‘s thesis deals with strain-stress analysis of hip joint together with the final applied total endoprosthesis with Burch-Schneider cage. The main point of my work was to find the solution of stress–strain analysis state, which has been mentioned before in connection with Burch-Schneider cage. I describe the technique of geometric creation of whole body system, component´s materials or conditions which are neccessary for calculation. In coclusion there are results achieved in variants. In the first option the case of bone tissue was considered, which don’t reach degradation mechanical properties effect straining under Burch-Schneider cage. In some cases when the bone tissue is untimely forced, the necrosis of bone tissue takes place under Burch-Schneider cage. This possibility is described in the second option of type. For every option there was a case which was calculated with applied screw or without it. In all option mechanical features of cancellous bone tissue and their change influence on achieved results were considered. This problem was solved computational simulation in commercial software Ansys Workbench 12.0.
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The effect of surface modification of acetabular cup on friction coefficient of hip implant
Cahová, Aneta ; Valena, Martin (referee) ; Nečas, David (advisor)
This bachelor’s thesis is focused on limited longevity of hip joint replacements. In order to extend the longevity of replacements effect of microtexture application on surface of artificial acetabulum cup on coefficient of friction was investigated. Attention was paid to composition of model synovial fluid and geometry and layout of texture. For joint simulation, a pendulum hip joint simulator was employed. In first part three femoral heads, two acetabulum cups and five fluids were tested, respectively two heads, four acetabulum cups and one fluid in second part. Significant effect of fluid composition and geometry and layout of texture was observed during measurement. Compared smooth and textured cup the highest decline of friction was 78 %. Results can be used for further research of micortextures. Friction reduction and prolonging lifespan of implants may eventually improve life quality of many patients.
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Stress-strain analysis of tumorous total endoprosthesis of hip joint
Vystrk, Tomáš ; Konvalinka, Jan (referee) ; Marcián, Petr (advisor)
Tumorous total endoprosthesis of hip joint is used for reconstruction of the limb affected by bone tumor and to regain its functnion. Longterm load conditions must be considered by the reconstruction and the joint mobility must be enabled. Suitability of the endoprosthesis depends on its construction considering shape, material and with this related mechanical properties. This thesis deals with creation of computational model and stress-strain analysis of tumorous total endoprosthesis of hip joint. There are two different types of endoprosthesis modeled in this thesis, each with three different length of resected bone replacement. Based on stress-strain analysis an assessment of possible limit states is made.
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Biomechanics study of hip join
Ebringerová, Veronika ; Marcián, Petr (referee) ; Florian, Zdeněk (advisor)
This work deals with the description of physiological joint resultant force and the subsequent comparison with patology of the hip. Then here is described the basic anatomy of the hip. Finally, ANSYS software was used to display the results both contact pressure and total mechanical strain intensity.
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Research study of tumorous total endoprosthesis of knee and hip joint
Věžníková, Tereza ; Florian, Zdeněk (referee) ; Marcián, Petr (advisor)
The presented bachelor’s thesis deals with tumorous total endoprosthesis of knee and hip joint. Tumorous replacement is used in patients with bone losts due to bone tumors and for these patients it means the salvage of their limb and the possibility to live full lives. This work includes the description of the developement, types and currently used replacement after bone tumors. The significiant part of patients with bone tumors are children for whom there are growing endoprosthesis containing the expandable mechanism and thanks to this the length of the limb can be regulated. In the last part of this work the stress-strain analysis of tumorous total hip endoprosthesis is performed using computational modeling.
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Wear analysis of extracted polyethylenes of total hip replacements using optical methods
Přikryl, Adam ; Morovič, Ladislav (referee) ; Vrbka, Martin (advisor)
An experimental methodology for wear assessment of extracted polyethylene hip implants was designed in this diploma thesis. Methodology uses optical 3D scanner and optical profilometer for analysis of wear. Designed methodology for wear analysis was validated by gravimetric method. The results of validation were in good agreement with the increase of wear rate. Validation results show that the methodology is not suited for wear assessment of metal and ceramic implants which have small wear rates. On the other hand the methodology is more than useful for wear assessment of polyethylene implants. Designed methodology for wear assessment was applied on the set of thirteen extracted polyethylene hip implants. Results of the wear analysis were wear volumes and linear wear noted in the wear maps. Roughness of the surface was measured on explanted cups and results were noted in the roughness map. On articulating surface of the cups different areas were observed for measured roughness. Those areas were described as area with machining marks from manufacturing process, polished area from combination of abrasive and adhesive wear, polished area from micro-contact fatigue and area including plastic deformation.
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Strain Stress Study of Burch-Schneider Split
Řehák, Kamil ; Horyl, Petr (referee) ; Janíček, Přemysl (referee) ; Florian, Zdeněk (advisor)
This thesis deals with problems of the hip endoprosthetics area, namely total endoprosthesis (TEP) with Burch-Schneider (BS) split, in which there are many problems in clinical practice. The hip joint load depends on the patient weight and the performed activity. Sedentary job, little exercise, a lot of stress or poor eating habits and overweight associated with it affect negatively hip joint. Increasing hip joint wear and its pain in movement is necessary in several cases to be solved by a surgical procedure in which TEP is applied. When selecting and subsequently applying individual TEP, it is important to pay attention to creating conditions which will allow good fixation. In case of worse mechanical properties of bone tissue, it is very problematic to ensure stability of the implant. Based on several classifications which assess the degree of hip joint damage, it is possible to select a suitable TEP. The BS split, on which this work is focused, is dominantly used in cases of large defects in the acetabulum area. The use of this cage allows to bridgelarge defects and create a new centre of rotation of the hip. Knowledge of the mechanical properties of hip bone tissue can significantly affect the prediction of BS split damage. For this purpose, it was necessary to perform a biomechanical study, which is focused on the influence of worse mechanical properties of bone tissue on BS split failure. The computational modelling using finite element method implemented in the ANSY S software was used for the solution, which enables to solve the mechanical interaction between bone tissue and TEP with BS split. Due to the absence of bone tissue data before application of TEP with BS split, the variants before application of TEP and after application of resurfacing and standard TEP were solved. All variants were solved with the material properties of bone tissue that were determined based on CT images. In addition, all variants were solved for the case of degraded mechanical properties. Based on the numerical simulations results and the Mechanostat hypothesis, a bone tissue analysis of the hip joint was performed before and after application of TEP and TEP with BS split. The results show the influence of the computational model level, which considers the distribution of bone tissue through the inhomogeneous model of the material. Therefore, the degraded mechanical properties have a major impact on the stability and strain of the BS split, particularly in the cranial part of the acetabulum.
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Friction analysis of hip joint replacements with coated surface
Nosek, Matěj ; Streďanská, Alexandra (referee) ; Nečas, David (advisor)
This bachelor thesis focuses on the effect that results from applying a coating to hip joint replacement based on the friction coefficient. The aim of this thesis was to conclude a comparison between individual combinations with and without coating in three types of fluids. Experimental measurements were conducted in configuration ball-on-head in a pendulum hip joint simulator. For these measurements, DEWEsoft, MATLAB, and MS Excel were used. During the measurements, four balls, two cups, and three fluids were used. The coating is a polymer-based solution made out of PEGMA-360 a PEGDMA-550. With the usage of the coating, gathered results point out that the coefficient of friction declines by a maximum of 5,4 % and increases by a maximum of 16,1 % compared to those without any coating. Results presented by this thesis may be in the service of further research of coatings and their application on hip joint replacement, which might increase the potency of those implants.
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Design and Development of Experimental Device for Testing the TEP Acetabula and Wear Identification using Optical Method
Houfek, Martin ; Kratochvíl, Ctirad (referee) ; Hortel, Milan (referee) ; Hlaváčková, Milada (referee) ; Florian, Zdeněk (advisor)
Today is the implantation of joint replacements, although a radical, but very functional restoration frequent way ill joint. The implants are placed high demands on their biocompatible and long-term function, which is directly related to wear of joint replacements in the human body. Therefore, analysis of the complex behavior of the implant in the human body is a fundamental problem of biomechanics of implants. This issue is dedicated, this dissertation thesis. Dissertation thesis deals with the solution design and development of experimental device for testing the TEP acetabula and wear identification using optical method. The proposed device allows the joint burden hole TEP physiological manner, but by working with the acetabulum burdened by Power resultant joint axis passes through the hole. The physiological loading of articular wells and evaluating the size of the loss of polyethylene is currently intensively addressed. The results of this study may in the near future, serving as information for assessing the conduct of wear prosthetic hip joint in vivo. The work is devoted to solving the problem of the size required to detect the loss of polyethylene for joint replacement arthroplasty: Design and development of experimental equipment for testing the acetabulum of the hip joint arthroplasty. Identify wear using optical methods. Design and development of experimental equipment was made in the system Inventor Professional 2010 at the level of 3D modeling. Great attention was paid to the design fit into the acetabulum TEP testing machines and gripping the acetabulum into an optical device. Management options were tested with combinations of experimental equipment engines. Suggestions were made and then tests for fixing the acetabulum into an optical device. Has the possibility of depth analysis and identification of wear joined with innovative solutions to evaluate the loss of polyethylene acetabulum arthroplasty. Identification of abrasion (loss of polyethylene) joint arthroplasty holes were carried out experimental measurements using an optical holographic interferometry. The comprehensive analysis of the results of experimental measurement of the loss of polyethylene shows that this method can identify both the size but also an area where there is even to small changes in the surface, which depend on the abrasion. One can also say that using this method we are able to affect the will or displacements that affect the size of the loss of polyethylene in joint arthroplasty hole. Despite the number of known and lessons learned arising from the results of solving the problem of design and development of experimental equipment for testing the acetabulum and hip arthroplasty wear identification using optical methods, this work is that the initial study to identify problematics wear of joint replacements. Complete resolution of this issue is beyond the scope of one doctoral thesis.
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Specifics of nursing care for a paediatric patient after hip surgery
Husárová, Katarína ; Tomová, Šárka (advisor) ; Klokočková, Šárka (referee)
Background: This bachelor thesis deals with the specifics of nursing care for a child patient after hip joint surgery. Objectives: The aim of the research was to find out the specifics of nursing care for a patient after hip surgery in orthopedic departments or clinics located in Slovakia or Czech Republic. Subsequently the findings were evaluated and compared. Methods: The self-constructed questionnaire prepared for the bachelor's thesis was anonymous and non-standardized. A total of 37 nurses working in orthopedic departments or clinics participated in the research exploration. From a geographical point of view, they were employees of 2 Slovak and 2 Czech hospitals.For statistical analysis, given the stated hypotheses and the nature of the data, we used the test of agreement of two proportions, Chi - square association with Yates correction, Cohran's test of equality of pooled proportions and a series of McNamar's tests with Bonferroni correction for multiple comparisons Results: Nurses working in the orthopedic department with children's patients in Slovakia and the Czech Republic prepare their patients for surgery and for what awaits them after it. They also focus on meeting the needs of children's patients, of which they perceive psychological needs the most. Psychological support,...
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