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The electromyographic activity characteristics of the gluteus medius muscle before and after total hip arthroplasty

Kopeć Konrad, Bereza Przemysław, Sobota Grzegorz, Hajduk Grzegorz, Kusz Damian

Acta of Bioengineering and Biomechanics

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2021

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Vol. 23, no. 1

187--195

EN

Purpose: The clinical outcomes of total hip arthroplasty are influenced by the correct muscle function that determines good, longterm and proper function of the artificial joint. The aim of the study was to analyze the electromyographic activity of the gluteus medius muscle in patients with hip osteoarthritis and after arthroplasty in various static weight bearing conditions, both on the affected and contralateral side. Methods: The prospective study involved 70 patients qualified for hip replacement. Patients underwent a surface electromyography of the gluteus medius muscle which involved the Trendelenburg test. The normalized results were obtained for both hips, preoperatively and 6 months after arthroplasty. Results: The only muscle activity differences were found at a full load condition of lower limb. In the preoperative assessment, the activity of the gluteus medius muscle was greater on the side qualified for surgery. After arthroplasty and the rehabilitation period, the muscle activity on the operated side decreased and significantly increased on the contralateral side. Detailed analysis of the contralateral side revealed relationship with osteoarthritis. Previous hip arthroplasty of that side resulted in lower muscle activity, similar to fully functional joints. Conclusion: The activity characteristics of the gluteus medius muscle vary depending on the condition of the joint, and the characteristics change as a result of the surgical procedure performed on both the operated and contralateral sides. These dependencies should be taken into account in the rehabilitation process, especially at the side opposite to the operated one.

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Effect of elliptical deformation of the acetabulum on the stress distribution in the components of hip resurfacing surgery

Stempin R., Dragan S. Ł., Kulej M., Filipiak J., Dragan S.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 4

35--41

EN

Hip resurfacing surgery is a matter of controversy. Some authors present very good late results of 99% survival outcomes. However, national records of implants point to the series of complications connected with biomechanical flaws of the implant. These results implicate the experimental research on biomechanical properties of HRS. The aim of the research was to define the nature of cooperation between the components of hip resurfacing surgery (HRS) and the influence of the deformation of acetabulum, the size of the implant and the nature of the bone surface on the stress distribution in the acetabulum and the femoral component. The calculations were run with the use of the finite element method (FEM), using the ANSYS bundle for this purpose. Four decrete models of the studied system were made: a model with the elements of the system connected with glue, a perfect spherical model with cooperating surfaces, a model reflecting an elliptical deformation of the acetabulum, and a model with different sizes of the implant. The results indicate that the stress values obtained for models with the ideally spherical acetabulum cannot cause significant deformation of cooperating implants. In the case of loads of the elliptically deformed acetabulum significant point stress concentrations can be observed in the spots of joint. The size of the acetabular and femoral components of HRS has influence on the stress concentration on the internal surface of the acetabulum as well as in the bone tissue surrounding the madrel of the femoral component. Moreover, physical properties of the base surface surrounding the HRS components have influence on the size of stress in the acetabulum and the femoral component.

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Aplikacja do projektowania indywidualnego narzędzia prowadzącego do kapoplastyki stawu biodrowego

Żołądź M., Skalski A., Śmigielski A., Socha A.

Pomiary Automatyka Kontrola

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2013

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R. 59, nr 3

223--226

PL

Alloplastyka stawu biodrowego jest jedną z poważniejszych operacji ortopedycznych wykonywanych przy zmianach zwyrodnieniowych stawu biodrowego. Jedną z jej wersji jest kapoplastyka, która polega na wymianie części głowy kości udowej oraz panewki stawu biodrowego. Od prawidłowego przeprowadzenia operacji zależy czas dochodzenia pacjenta do zdrowia jak i komfort późniejszego życia. Postęp w tomografii komputerowej, komputerowych metodach obróbki obrazu oraz metodach szybkiego prototypowania umożliwił wytwarzanie indywidualnych (dopasowanych do konkretnego pacjenta) narzędzi wspomagających chirurga podczas operacji. W artykule omówiona zostanie procedura wytwarzania indywidualnego narzędzia prowadzącego do operacji kapoplastyki.

EN

Hip replacement is one of the major orthopedic surgery, performed with osteoarthritis of the hip. One of the versions is hip resurfacing, which involves replacing a part of femoral head and the acetabulum. The time of patient recovery and comfortable later life depends on a proper conduct of the surgery. Progress in the computed tomography, computerized methods of image processing and rapid prototyping, enabled the production of the individual (tailored to individual patient) tools to assist a surgeon during the operation. This paper presents an application for design of an individual guid-ing tool for hip resurfacing. The first volumetric model based on a series of TC is created. It is made with using the thresholding method combined with simple morphological operations (erosion, dilatation). The key issue is to separate the femur model from the pelvis one. It is carried out with the software user assistance. The final step of bone model creation is conversion of the volumetric model to the polygonal mesh model. It is performed with the marching cubes algorithm. To avoid the quantization artifacts related to finite resolutions of the volumetric model and to reproduce the bone shape as accurately as possible, smoothing with a Gaussian filter is applied to the volumetric model before application of the marching cubes algorithm. A software module directly related to the Guider design allows the user to manually adjust the position of the key Guider elements. Positioning of the auxiliary elements of the Guider is automatically made. The output of the presented module is a set of polygonal mesh models corresponding to the Guider components. The final stage of the Guider creation process is assembling the Guider solid by using Boolean operations.

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Badania własności warstwy węglowej na powierzchni implantów z odlewniczego stopu Co-Cr-Mo.

Paszenda Z.

Inżynieria Materiałowa

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1999

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R. XX, nr 2

66-71

PL

W pracy skoncentrowano się nad pokryciami węglowymi, które jak wykazały badania ostatnich lat cechują się korzystnymi własnościami fizykochemicznymi w środowisku tkanek i płynów ustrojowych. Zbadano wpływ struktury odlewniczego stopu Witalium oraz sposobu przygotowania jego powierzchni na własności fizykochemiczne warstwy nanokrystalicznego węgla wytworzonej w procesie RF CVD. Badaniom poddano stop w stanie lanym oraz przesyconym. Zróżnicowanie sposobu przygotowania powierzchni próbek osiągnięto poprzez proces szlifowania, polerowania elektrolitycznego oraz pasywacji. Wyniki przeprowadzonych badań odporności na korozję wżerową metodą potencjodynamiczną w roztworze fizjologicznym Tyrode'a stopu Witalium z naniesioną warstwą węglową wskazują na jej współzależność ze strukturą stopu. Warstwa węglowa naniesiona w warunkach opracowanych w pracy zwiększa prawie dwukrotnie odporność badanego stopu na korozję wżerową w roztworze fizjologicznym Tyrode'a oraz charakteryzuje się dużą przyczepnością warstwy węglowej do metalicznego podłoża. Warunkiem uzyskania warstwy o optymalnych własnościach fizykochemicznych jest odpowiednia struktura stopu składająca się z roztworu Co beta z dużą ilością wydzieleń węglików. Obróbka cieplna, ujednorodniająca skład chemiczny stopu i zmniejszająca ilość wydzieleń węglików, zmniejsza adhezję warstwy węglowej oraz jej odporność na korozję w roztworze fizjologicznym Tyrode'a.

EN

The focuses of this work are the carbon coatings that - as it was shown by results of investigations carried out in last years - have advantageous physical and chemical properties in the tissue and body fluids environment. Influence of the Vitallium casting alloy structure and method of its surface preparation, on physical and chemical properties of the nanocrystalline carbon coating applied in the RF CVD process was investigated. The as cast and saturated alloy was investigated. Diversification of surface preparation methods was obtained by grinding, electrolytic polishing and pasivation. Results of the pitting corrosion resistance tests of the Vitallium alloy with the carbon coating applied carried out using the potentiodynamic method in the Tyrodes physiological solution, indicate its relationship with the alloy structure. Carbon coating applied in conditions worked out in the project, nearly doubles the pitting corrosion resistance of the investigated alloy in the Tyrode's physiological solution, and has a significant adherence to the metallic substrate. The suitable alloy structure consisting of the Co beta solution with multiple carbide precipitations features the condition of obtaining a coating with the optimum physical and chemical properties. Heat treatment, homogenising the alloy chemical composition and decreasing the number of carbide precipitations, decreases the adherence of the carbide coating and its corrosion resistance in the Tyrode's physiological solution.