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Tytuł:
Drilling resistance : A method to investigate bone quality
Autorzy:
Lughmani, W. A.
Farukh, F.
Bouazza-Marouf, K.
Ali, H.
Powiązania:
https://bibliotekanauki.pl/articles/306405.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chirurgia ortopedyczna
wiercenie
gęstość mineralna kości
jakość kości
bone drilling
orthopaedic surgery
screw pull-out strength
bone mineral density
bone quality
Opis:
Purpose: Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill-bit penetration and drill-bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. Methods: This study demonstrates that bone drilling force data if recorded in-vivo, during the repair of bone fractures, can provide information about the quality of the bone. To understand the variability and anisotropic behaviour of cortical bone tissue, specimens cut from three anatomic positions of pig and bovine were investigated at the same drilling speed and feed rate. Results: The experimental results showed that the drilling force does not only vary from one animal bone to another, but also vary within the same bone due to its changing microstructure. Drilling force does not give a direct indication of bone quality; therefore it has been correlated with screw pull-out force to provide a realistic estimation of the bone quality. A significantly high value of correlation (r 2 = 0.93 for pig bones and r 2 = 0.88 for bovine bones) between maximum drilling force and normalised screw pull-out strength was found. Conclusions: The results show that drilling data can be used to indicate bone quality during orthopaedic surgery.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 55-62
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the material’s stiffness on stress-shielding in osseointegrated implants for bone-anchored prostheses: a numerical analysis and initial benchmark data
Autorzy:
Prochor, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/27324152.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Young’s modulus
bone mass
bone remodelling
osseointegration
bone-anchored prosthesis
moduł Younga
masa kostna
przebudowa kości
osteointegracja
proteza zakotwiczona w kości
Opis:
This study attempted to establish the link between design of implants for bone-anchored prostheses and stress-shielding, affecting the stability of the bone-implant coupling using numerical approach. The objectives were to share a numerical model capable to evaluate the long-term stability of implants and to use this model to extract data sets showing how shape and material stiffness of threaded, press-fit and modular press-fit implants affect stress-shielding intensity. Methods: Three designs were considered: threaded, press-fit and modular press-fit. The effect of shape and material stiffness of each design on stress-shielding intensity was assessed using Young’s modulus (10 to 210 GPa). Furthermore, the impact of the diameter of percutaneous part (10 to 18 mm) and thickness of medullar part (5 to 1 mm) was investigated for the modular press-fit implant. Results: The threaded design generated 4% more bone mass loss at the distal femur but an overall loss of bone mass was by 5% lower to press-fit design. The influence of Young’s modulus on bone mass changes was noticeable for modular press-fit implant, depending on diameter of percutaneous or medullary part. A 20 GPa change of stiffness caused a bone mass change from 0.65% up to 2.45% and from 0.07% up to 0.32% for percutaneous parts with 18 mm and 10 mm diameter, respectively. Conclusions: Results suggested that threaded implant provides greater stability despite an increased bone loss at the distal femur. Altogether, this work provided an initial model that could be applied in subsequent studies on the long-term stability of current and upcoming implants.
Źródło:
Acta of Bioengineering and Biomechanics; 2020, 22, 2; 69--81
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An alternative method in fixation of tibial transverse fractures by intramedullar nailing : Biomechanical and histopathologic investigation
Autorzy:
Aksakal, B.
Varis, O.
Say, Y.
Kom, M.
Yilmaz, E.
Powiązania:
https://bibliotekanauki.pl/articles/951813.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bone fracture
intramedular nails
coating
fixation
biomechanics
biomechanika
złamanie kości
powłoka
Opis:
A new method was used in fixation of tibial bone fractures. Intramadular nailing (IMN) has been used into mid-diaphysis on left tibias of New Zeland rabbits (n = 5) via an in vivo work. To enable fixation of fracture, without causing too much screw damage on bone and avoiding malunion, nano- and micro-scale hydroxyapatite (HA) was coated at two ends (25 mm in length) of intramadular nails before implantation. After six weeks of survival period and sacrifizing, biomechanical tests and histopathologic examinations were executed. Such experiments have revealed that good stabilization and hence better fracture union for both treated IMN groups (NHA and MHA) over the standard IMN’. Pull-out tests showed the tensile strengths obtained to be significantly higher for the nano (NHA) and micro scale-MHA coated IMN compared to the uncoated standard IM nailing.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 2; 81-90
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface characterization of the raw and cooked bovine cortical metatarsal bone
Autorzy:
Petrovic, Bojan B.
Kojic, Sanja
Peric, Tamara O.
Šipovac, Milica
Lazarevic, Jovana
Stefanovic, Sofija
Stojanovic, Goran
Powiązania:
https://bibliotekanauki.pl/articles/306722.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kości
właściwości elastyczne
SEM
nanoindentacja
bone
elastic properties
direct temperature exposure
nanoindentation
Opis:
The purpose of this study was to quantify the elastic properties and evaluate microscopical features of raw and boiled metatarsal bovine bone. Methods: The elastic modulus, hardness and microscopic surface of raw and cooked bovine metatarsal bone have been investigated using nanoindentation, SEM/EDX and Panasis microscope. Results: Regarding raw bovine bone, the average elastic modulus was 30.515 ± 6,769 GPa, while the average hardness was 0.5683 ± 0.211 GPa. When it comes to boiled bone corresponding values were 22.298 ± 7.0303 GPa and 0.408 ± 0.199 GPa, respectively. The values for investigated parameters were significantly higher ( p < 0.05) in raw bone specimens. Elastic modulus significantly correlated with hardness ( p < 0.05). EDX analysis revealed significant decrease in wt% of oxygen in boiled samples ( p < 0.05) No significant differences could be observed in SEM images particularly when analysing in smaller magnifications. Using higher magnification, additional branching of the existing voids as well as discrete reorganization and smoother edges of nutrient canals could be observed. The surface of boiled specimens was without the presence of crusts and layering, and no microscopical evidence of structural damage could be observed. Conclusions: This study provides detailed analysis of hardness, elastic modulus of raw and cooked bovine bone and their relation and changes during exposure to temperature. These results of elastic moduli and hardness could be comparable to similar studies of bovine and human bone tissue, but the careful analysis of experimental design, type of the bone as well as limitations of the employed techniques must be carried out before interpolation of the results to other theoretical, clinical, biomaterial and archeological studies.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 1; 13-21
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of various drilling parameters on bone during implantology : An in vitro experimental study
Autorzy:
Karaca, F.
Aksakal, B.
Powiązania:
https://bibliotekanauki.pl/articles/306864.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
orthopaedics
bone drilling
temperature
bone necrosis
implantologia medyczna
kości
temperatura
zabieg chirurgiczny
Opis:
Due to temperature increase during bone drilling, bone necrosis is likely to occur. To minimize bone tissue damage during drilling, a detailed in vitro experimental study by using fresh calf cortical bones has been performed with various combined drilling parameters, such as: drilling environment, drill diameter, drill speed, drill force, feed-rate and drill coating. Bone temperatures at the drilling sites were recorded with high accuracy using multi-thermocouples mounted around the tibial diaphyseal cortex. It was shown that temperatures increased with increased drill speeds. It also decreased with a higher feed-rate and drill force. It was also observed that TiBN coated drills caused higher temperatures in the bone than the uncoated drills and the temperatures increased with larger drill diameters. Although the influence of Simulated Body Fluid (SBF) on rising temperatures during drilling was higher for the TiBN coated drills, it was observed that these drills caused more damage to the bone structure. In order to minimize or avoid bone defects and necrosis, orthopaedic surgeons should consider the optimum drilling parameters.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 4; 25-32
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical comparison of straight DCP and helical plates for fixation of transverse and oblique bone fractures
Autorzy:
Aksakal, B.
Gurger, M.
Say, Y.
Yilmaz, E.
Powiązania:
https://bibliotekanauki.pl/articles/307129.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
unieruchomienie
biomechanika
kości
Straight DC Plate
helical plate
biomechanics
fixation
bone fractures
Opis:
Purpose: Biomechanical comparison of straight DCP and helical plates for fixation of transversal and oblique tibial bone fractures were analyzed and compared to each other by axial compression, bending and torsion tests. Method: An in vitro osteosynthesis of transverse (TF) and oblique bone fracture (OF) fixations have been analysed on fresh sheep tibias by using the DCP and helical compression plates (HP). Results: Statistically significant differences were found for both DCP and helical plate fixations under axial compression, bending and torsional loads. The strength of fixation systems were in favor of DC plating with exception of the TF-HP fixation group under compression loads and torsional moments. The transvers fracture (TF) stability was found to be higher than that found in oblique fracture (OF) fixed by helical plates (HP). However, under torsional testing, compared to conventional plating, the helical plate fixations provided a higher torsional resistance and strength. The maximum stiffness at axial compression loading and maximum torsional strength was achieved at torsional testing for the TF-HP fixations. Conclusion: From in vitro biomechanical analysis, fracture type and plate fixation system groups showed different responses under different loadings. Consequently, current biomechanical analyses may encourage the usage of helical HP fixations in near future during clinical practice for transverse bone fractures.
Źródło:
Acta of Bioengineering and Biomechanics; 2014, 16, 4; 67-74
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
BoneCreo: a novel approach for generating a geometric model of the bone structure
Autorzy:
Wrona, A.
Powiązania:
https://bibliotekanauki.pl/articles/306211.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
model numeryczny
kości
symulacja komputerowa
numerical model
bone tissue
image analysis
computer simulation
Opis:
Bones, the fundamental part of the skeleton, are constantly subjected to many biological processes including growth, feeding and remodelling. Remodelling causes changes in bone structure that may be difficult to notice on a day-to-day basis but become significant over the longer time span. It acts on the cancellous and cortical bone tissue, causing alterations in thickness and spatial arrangement in the first and alternations in pore size in the second. In healthy individuals such changes are a part of the natural bone remodelling process explained by Wolff’s law. However, the direction of such changes is difficult to predict in patients in various pathological states in which bone health is affected. Here, we present a method to generate a computer based geometric model of the bone structure based on the cancellous tissue structure images. As a result we obtained a geometric model of the structure corresponding to the physical model of the cancellous bone. Such a model can be used in computer simulation to predict the remodelling changes in the healthy and pathological bone structures.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 3; 3-12
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pullout evaluation of sawbone experiment in different types of pedicle screws combined with bone cement augmentation for severe osteoporotic spine
Autorzy:
Yang, S.-C.
Liu, P.-H.
Tu, Y.-K.
Powiązania:
https://bibliotekanauki.pl/articles/307271.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
osteoporoza
kości
wytrzymałość
osteoporosis
bone cement augmentation
cannulated pedicle screw
sawbone
pullout strength
Opis:
Purpose: The conventional screw is unable to provide enough screw-bone interface strength for osteoporotic cencellous bone, and complications resulting from loosening or failure of the implants remain a significant clinical problem. Hence, the purpose of this study is to investigate pullout strength and energy in three types of the pedicle screws, including conventional solid pedicle screw, cannulated pedicle screw, and cannulated pedicle screw with a central pin, using osteoporotic sawbone test block with different bone cement volumes through pullout force testing. Methods: The control group (n = 15) of the osteoporotic sawbone test block includes groups A, B, and C to reflect three types of the pedicle screws without bone cement augmentation. The cemented group (n = 45) of the osteoporotic sawbone test block includes groups D1, D2, D3, E1, E2, E3, F1, F2, and F3 to reflect three types of the pedicle screws with PMMA bone cement of 2, 3, and 4 mL augmentation. Results: The results showed that the pullout strength and energy in the cemented group were significantly larger than that in the control group. Moreover, the best performances of the pullout strength and energy in the cemented group were evidenced obviously in the case of cannulated pedicle screw with a central pin with 4 mL bone cement augmentation. Conclusions: This study concludes that cement argumentation in the cannulated pedicle screw with a central pin can increase a pullout strength of pedicle screw for severe osteoporotic patients while bone cement of injective volume is limited.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 2; 55-64
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fixation of distal fibular fractures: A biomechanical study of plate fixation techniques
Autorzy:
Marvan, J.
Horak, Z.
Vilimek, M.
Horny, L.
Kachlik, D.
Baca, W.
Powiązania:
https://bibliotekanauki.pl/articles/306556.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
analiza FEM
osteosynteza
złamanie kości
fibular fracture
finite element analysis
osteosynthesis
fracture fixation
fibula
Opis:
Ankle fractures are complex injuries with variable prognoses that depend upon many factors. The aim of the treatment is to restore the ankle joint biomechanical stability with maximum range of motion. Most ankle fractures are fibular fractures, which have a typical oblique fracture line in the distal fibula located in the area of the tibiofibular syndesmosis. The aim of this study was to simulate numerically several fixation techniques of the distal fibular fractures, evaluate their stability, determine their impact on surrounding tissue load, and correlate the results to clinical treatment experience. The following three models of fibular fracture fixation were used: (a) plate fixation with three screws attached above/below and lag screws, (b) plate fixation with two screws attached above/below and lag screws, and (c) three lag screws only. All three fracture fixation models were analyzed according to their use in both healthy physiological bone and osteoporotic bone tissue. Based on the results of Finite Element Analysis for these simulations, we found that the most appropriate fixation method for Weber-B1 fibular fractures was an unlocked plate fixation using six screws and lag screws, both in patients with physiological and osteoporotic bone tissue. Conversely, the least appropriate fixation method was an unlocked plate fixation with four screws and lag screws. Although this fixation method reduces the stress on patients during surgery, it greatly increased loading on the bone and, thus, the risk of fixation failure. The final fixation model with three lag screws only was found to be appropriate only for very limited indications.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 33-39
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal selection of dental implant for different bone conditions based on the mechanical response
Autorzy:
Roy, S.
Das, M.
Chakraborty, P.
Biswas, J. K.
Chatterjee, S.
Khutia, N.
Saha, S.
Roychowdhury, A.
Powiązania:
https://bibliotekanauki.pl/articles/307549.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wytrzymałość kości
implanty stomatologiczne
analiza FEM
pacjent
bone condition
porous dental implant
FE Analysis
patient specific
Opis:
Bone quality varies from one patient to another extensively; also, Young’s modulus may deviate up to 40% of normal bone quality, which results into alteration of bone stiffness immensely. The prime goal of this study is to design the optimum dental implant considering the mechanical response at bone implant interfaces for a patient with specific bone quality. Method. 3D model of mandible and natural molar tooth were prepared from CT scan data while, dental implants were modelled using different diameter, length and porosity and FE analysis was carried out. Based on the variation in bone density, five different bone qualities were considered. First, failure analysis of implants, under maximum biting force of 250N had been performed; next, the implants, those survived were selected for observing the mechanical response at bone implant interfaces under common chewing load of 120N. Result. Maximum Von Mises stress did not surpass the yield strength of the implant material (TiAl4V). However, factor of safety of 1.5 was considered and all but two dental implants survived the design stress or allowable stress. Under 120N load, distribution of Von Mises stress and strain at the bone-implant interface corresponding to the rest of the implants for five bone conditions were obtained and enlisted. Conclusion. Implants, exhibiting interface strain within 1500-3000 microstrain range show the best bone remodelling and osseointegration. So, implant models, having this range of interface strains were selected corresponding to the particular bone quality. A set of optimum dental implants for each of the bone qualities were predicted.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 2; 11-20
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
αBSM failed as a carrier of rhBMP-2 to enhance bone consolidation in a sheep model of distraction osteogenesis
Autorzy:
Floerkemeier, T.
Thorey, F.
Wellmann, M.
Hurschler, C.
Budde, S.
Windhagen, H.
Powiązania:
https://bibliotekanauki.pl/articles/306674.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
czynniki wzrostu
kości
test biomechaniczny
DXA
rhBMP-2
growth factors
αBSM
bone consolidation
biomechanical testing
Opis:
One of the problems associated with callus distraction is a long time period needed for consolidation of the newly formed bone. The goal of this study was to determine whether percutaneous injections of rhBMP 2 in BSM would enhance bone consolidation. Methods: A unilateral tibial osteotomy combined with external stabilization was performed in 20 adult sheep. After a latency of four days, distraction was conducted for 20 days. Sheep were divided into three groups: group 1 received rhBMP-2/αBSM injections at day 23 and 30, group 2 buffer/BSM injections at day 23 and 30 and group 3 did not receive any injection. The radiographs and in-vivo torsional stiffness measurements were obtained weekly during the following 50 days. Post-mortem bone densitometry (DXA) and mechanical testing were performed. Results: In-vivo stiffness assessments, DXA values and the maximum torsional moment of the sheep tibia treated with two rhBMP-2 injections were not significantly greater than those of both control groups. Conclusions: Presented application of rhBMP-2 in BSM failed to enhance bone consolidation in distraction osteogenesis.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 4; 55-62
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A tensomeric and planimetric evaluation of the durability of the bond between an orthodontic bracket and enamel
Autorzy:
Pawlus, B.
Dyszkiewicz, A.
Špidlen, M.
Powiązania:
https://bibliotekanauki.pl/articles/306966.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
dental adhesives
dental brackets
tensometric testing of bond
planimetric testing of bond
ARI index
tensometria
kości
ortodoncja
Opis:
The development of orthodontics has improved thanks to the introduction of adhesives which are physically and chemically akin to tooth enamel and brackets. These materials often fall short of the required durability standards. The objective was to evaluate the real strength of the adhesives and to introduce a proprietary device, generating multiple vectors of strength between dental brackets and the surface of enamel. 11 types of adhesive materials have been studied. 990 applications have been made using removed teeth, followed by a randomised creation of 11 groups containing 90 samples each. The threshold values of the strength needed to break the brackets off were determined in torsional, shear and tension strength tests. A comparison between tensometric and planimetric methods was made by means based on ARI index. Resistance was highest for torsional stress, weaker for shear stress and the weakest for tension stress. A correlation was found between tensometric results. The study attempted to systematise the methodology of direct tests.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 4; 33-42
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of initial density distribution in simulations of bone remodeling around dental implants
Autorzy:
Nutu, E.
Powiązania:
https://bibliotekanauki.pl/articles/307275.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
energia odkształcenia
kość
warunki początkowe
przebudowa kości
strain energy density
bone quantity
initial conditions
bone remodeling simulation
Opis:
In this paper, the effect of initial density distribution upon the predicted density via numerical simulations of bone remodeling was evaluated. The main purpose was to correlate the numerical results with clinical data according to which the initial bone quantity is an essential factor for long term survival of dental implants. Methods: Two-strain energy density-based bone remodeling theories were employed, one which accounts for overload resorption and the second one, which does not. The remodeling parameters were derived from the mechanostat theory. Bone remodeling around an osseointegrated dental implant was simulated based on finite element method using a generic mandible plane model. A variable time step was introduced to increase the speed of the remodeling simulations by keeping the truncation errors small. The simulations were performed for several initial density distributions correlated with values from clinical classifications of bone quality. For each density value, the occlusal load was defined in two ways so that to consider normal and overload mastication forces, respectively. Results: The results showed that the initial density distribution influences the predictions of bone remodeling simulations. For the analyzed model, the remodeling algorithm predicted overload resorption only in the case of low initial density, which can be associated with low bone quality, which, from clinical perspective, may probably lead to implant loss. Conclusions: The paper demonstrated that when simulating bone remodeling around dental implants using finite element method, it is important to account for initial density distribution in correlation with the bone quantity.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 4; 23-31
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mandibular reconstruction : biomechanical strength analysis (FEM) based on a retrospective clinical analysis of selected patients
Autorzy:
Jędrusik-Pawłowska, M.
Kromka-Szydek, M.
Katra, M.
Niedzielska, I.
Powiązania:
https://bibliotekanauki.pl/articles/306994.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bone grafts
mandibular reconstruction
finite element method
reconstruction plates
bone healing
kości
metoda elementów skończonych
przeszczep kostny
Opis:
Restoration of mandible discontinuity defects continues as a challenge for maxillofacial surgeons. Despite the development of algorithms for reconstruction plates fixation and autogenous grafting techniques, complications are still encountered including screw loosening, bone resorption or delayed/incomplete union. The aim of the study was to analyze the possibility of obtaining bone union in the aspect of biomechanical conditions of two mandible reconstructions using an autogenous iliac crest bone graft stabilized with a reconstruction plate, and to attempt to predict patient outcomes based on strength parameters obtained by the finite element analysis. The authors of the present paper were trying to determine to what extent the reconstruction model and changes occurring in hard tissues of the bone and autogenous graft (simulated by changes in material properties) might help predict individual patient courses. The effort of reconstruction plates was defined using the values of the von Mises stress (σHMH) while the effort of bones was determined based on the values of strain intensity εint. The results of the above mentioned simulations are presented in the form of bar graphs and strain/stress distribution maps. Our strength analyses indicate that uncomplicated healing of grafts fixed with reconstruction plates requires that the initial loading of the stomatognatic system should not result in strain intensity exceeding 20–40 [×10–4]. This range of strain intensity evokes an increase in the mineral phase. The state of nonunion between the mandibular bone and the graft might result from prolonged periods of insufficient loading of the mandible during treatment.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 2; 23-31
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Results and biomechanical consideration of treatment of congenital lower limb shortening and deformity using the Ilizarov method
Autorzy:
Morasiewicz, P.
Morasiewicz, L.
Stępniewski, M.
Orzechowski, W.
Morasiewicz, M.
Pawik, Ł.
Wrzosek, Z.
Dragan, S.
Powiązania:
https://bibliotekanauki.pl/articles/307355.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bone elongation
congenital deformity
hybrid external fixator
Ilizarov external fixator
wydłużenie kości
stabilizator zewnętrzny Ilizarowa
biomechanika
deformacja
Opis:
One of the applications of the Ilizarov apparatus is the correction of congenital shortening and deformities. Ilizarov external fixator produces biomechanical structure with surrounding tissue, which is the reason why very important is correct stability of fixator. Large distraction in the case of high value of lengthening, and large deformity corection result in shear stresses that occur additionally in the regenerate, which can potentially lead to damage of the regenerating nutritive microcirculation of bone tissue and bone fragment displacements. Our objective was to assess the results of the Ilizarov method in the treatment of congenital shortening taking into account treatment strategy and the size of the axis of lengthening and correction. Our research problems include presenting the effects of biomechanics of musculoskeletal deformations on treatment results, presenting complications and their treatment. Between 1989 and 2009, 62 patients underwent surgery to correct congenital lower limb deficiencies at our Clinic; 33 patients were followed-up. In total, there were 70 surgeries (2.12/patient). Axial correction was performed in 26 patients (78.79%). Average age at the start of the treatment was 15.58 years. Mean follow-up was 8.58 years. Mean lengthening per surgery was 3.17 cm with the lengthening index of 50.7 day/cm. Results were very good for 23 patients, good for 7 patients, satisfactory for 3 patients. Complications appeared in 24 patients, problems occurred in 74.42% of the cases, obstacles in 4.65% of cases, and true complications in 20.93% of the cases. The best results were achieved in the treatment of patients with two-stage and two-segment lengthening with a total elongation of less than 7 cm, and without correction of the axis. Congenital shortening of the lower limb should be treated comprehensively because the shortening applies to all segments, and disturbs biomechanics of all lower limb. In the case of axial correction and large amount of elongation high soft tissue forces counteract the distraction forces. Hybrid construction may help to shorten treatment time, increase fixator stability and decrease rate of complications. We suggest use of hybrid Ilizarov fixator, especially when large elongation and axis corection are planned.
Źródło:
Acta of Bioengineering and Biomechanics; 2014, 16, 1; 133-140
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 21

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