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Wyświetlanie 1-3 z 3
Tytuł:
Experimental analysis of insertion torques and forces of threaded and press-fit acetabular cups by means of ex vivo and in vivo measurements
Autorzy:
Vogel, D.
Rathay, A.
Teufel, S.
Ellenrieder, M.
Zietz, C.
Sander, M.
Bader, R.
Powiązania:
https://bibliotekanauki.pl/articles/307285.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
panewka
gwintowanie
kość
kość syntetyczna
insertion force
insertion torque
acetabular cup
press-fit
threaded
synthetic bone
Opis:
In THA sufficient primary implant stability is the precondition for successful secondary stability. Industrial foams of different densities have been used for primary stability investigations. The aim of this study was to analyse and compare the insertion behaviour of threaded and press-fit cups in vivo and ex vivo using bone substitutes with various densities. Methods: Two threaded (Bicon Plus®, Trident® TC) and one press-fit cup (Trident PSL®) were inserted by orthopaedic surgeons (S1, S2) into 10, 20 and 31 pcf blocks using modified surgical instruments allowing measurements of the insertion forces and torques. Furthermore, the insertion behaviour of two cups were analysed intraoperatively. Results:Torques for the threaded cups increased while bone substitute density increased. Maximum insertion torques were observed for S2 with 102 Nm for the Bicon Plus® in 20 pcf blocks and 77 Nm for the Trident® TC in 31 pcf blocks which compares to the in vivo measurement (85 Nm). The average insertion forces for the press-fit cup varied from 5.2-6.8 kN (S1) and 7.2-11.5 kN (S2) ex vivo. Intraoperatively an average insertion force of 8.0 kN was determined. Conclusions: Implantation behaviour was influenced by acetabular cup design, bone substitute and experience of the surgeon. No specific density of bone substitute could be favoured for ex vivo investigations on the implantation behaviour of acetabular cups. The synthetic bone blocks of high density (31 pcf) led to problems regarding cup orientation and seating. Therefore, bone substitutes used should be critically scrutinized in terms of the comparability to the in vivo situation.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 3; 155-163
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of three different preservative techniques on the mechanical properties of the ovine cortical bone
Autorzy:
Wieding, J.
Mick, E.
Wree, A.
Bader, R.
Powiązania:
https://bibliotekanauki.pl/articles/306558.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
właściwości mechaniczne
kość korowa
zamrażanie
mechanical properties
chemical preservatives
cortical bone
freezing
fresh bone samples
Opis:
Purpose: Preservative treatments are necessary for disinfection and long term storage when dealing with biological tissue. Freezing is a gold standard but infectious risk can only be eliminated by using chemical fluids that may alter the mechanical properties, depending on their composition. Therefore, we experimentally evaluated the influence of freezing and of two commonly used preservative fluids (formalin and alcohol) on the intrinsic mechanical properties of ovine cortical bone samples, compared to purely fresh samples. Methods: Prismatic specimens were prepared from the sheep’s metacarpal bones and were divided into four groups (fresh, fresh-frozen, formalin and alcohol). All samples underwent four-point-bending; fresh samples were tested immediately, preserved samples were tested after 14 days. Bending modulus, bending strength, yield strength and energy absorption for the elastic and plastic region were determined. Results: Significant differences were found for the plastic energy absorption for formalin (–41%) and alcohol (+37%) preservation compared to fresh samples. Formalin preservation revealed embrittlement of the cortical bone samples and alcohol preservation revealed higher ability of plastic energy absorption. Conclusions: Our results indicate that freezing has no influence on the mechanical properties of the ovine cortical bone. Preservation with chemical fluids (formalin and alcohol) showed no influence on the elastic properties but it was observed for the ability of plastic energy absorption. Therefore, these methods seem to be suitable for preservation without evident altering of the elastic mechanical properties.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 1; 137-146
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of electrophysical and structural properties of human cancellous bone and synthetic bone substitute material using impedance spectroscopy and X-ray powder diffraction
Autorzy:
Haba, Y.
Köckerling, M.
Shick, Ch.
Mittelmeier, W.
Bader, R.
Powiązania:
https://bibliotekanauki.pl/articles/306920.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kość syntetyczna
spektroskopia impedancyjna
dyfrakcja promieniowania rentgenowskiego
human cancellous bone
synthetic bone
impedance spectroscopy
X-ray powder diffraction
Opis:
Electrophysical stimulation is used to support fracture healing and bone regeneration. For design optimization of electrostimulative implants, in combination with applied human donor bone or synthetic bone scaffolds, the knowledge of electrophysical properties is fundamental. Hence further investigations of the structural properties of native and synthetic bone is of high interest to improve biofunctionality of bone scaffolds and subsequent healing of the bone defect. The investigation of these properties was taken as an objective of this study. Therefore, surgically extracted fresh cylindrical and consecutively ashed cancellous bone samples from human osteoarthritic femoral heads were characterized and compared to synthetic bone substitute material. Thereby, impedance spectroscopy is used to determine the electrophysical properties and X-ray powder diffraction (XRD) for analysis of structural information of the bone samples. Conductivity and permittivity of fresh and ashed cancellous bone amounted to 1.710–2 S/m and 7.5106 and 210–5 S/m and 7.2103 , respectively. Electrical conductivity and dielectric permittivity of bone scaffold resulted in 1.710–7 S/m and 49. Analysis of the structural properties showed that the synthetic bone scaffolds made of Brushite exhibited some reflections which correspond to the native bone samples. The information in present study of the bone material (synthetic and autologous) could be used for later patient individual application of electrostimulative implants.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 1; 11-19
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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