Дисертації з теми "PMMA cement"
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Pogula, Lavanya J. "Effect of Antibiotic Additives on the Fracture Toughness of Polymethyl Methacrylate Bone Cement." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1124339605.
Повний текст джерелаKim, Hong-Youl. "PMMA bone cement reinforced by plasma treated particles /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841158.
Повний текст джерелаAyre, Wayne Nishio. "Novel approaches to the development of PMMA bone cement." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/51101/.
Повний текст джерелаKulkarni, Swanand. "MODIFICATION IN PMMA BONE CEMENT BY ADDITION OF TiO2 NANOPARTICLES." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/749.
Повний текст джерелаMhatre, Devdatt. "Biomechanical Evaluation of Vertebral Augmentation to Compare Biocure Cement with PMMA." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1309390838.
Повний текст джерелаZezula, Miroslav. "Analýza tokových vlastností kostních cementů během tvrdnutí." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216580.
Повний текст джерелаFukuda, Chisako. "Bone bonding ability and handling properties of a titania?polymethylmethacrylate (PMMA) composite bioactive bone cement modified with a unique PMMA powder." Kyoto University, 2012. http://hdl.handle.net/2433/157423.
Повний текст джерелаSheafi, Emadeddin A. Mansur. "Effects of various test regimes on fatigue behaviour of PMMA bone cement : a comparative study." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6250/.
Повний текст джерелаHirvinen, Laura J. M. "Influence of bone cements on bone screw interfaces in the third metacarpal and metatarsal bones of horses." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1243434636.
Повний текст джерелаBarros, Carmem Aparecida Malaguti de. "Estudo comparativo da resistência à compressão do cimento ósseo nacional e do importado, preparados manualmente e a vácuo." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-08012003-144237/.
Повний текст джерелаThe bone cement used for the fixation of the prosthetic components in the surgeries of joint replacement, more resistant to the compression than to the traction, has its mechanical properties altered by several factors among those the commercial formulation and preparation employee's method. It is the objective of this work to evaluate the mechanical properties to the compression of the two commercial formulas of bone cement manually prepared and using vacuum, according to the manufacturer's instructions. A molding set was made in stainless steel and it allowed for the preparation of 48 bodies of proof for each experimental group, adding up to 192 proof bodies total which were tested in the Universal Rehearsal Machine, with the specifications based on the ISO 5833 and the ASTM F451-86 regulations. The elaboration of the diagram "tension vs. deformation" of each of the experimental group analyzed the mechanical properties of the bone cement in relation to the elasticity module, tension and deformation on the proportional limit among the groups with the same commercial formula and among the groups with the same mixture method. Analyzed statistically, by Kruskal-Wallis's method of the variation (p ≤0.001) and by the Dunns method (p ≤0.05). Regarding the elasticity, the group 2M was the one with the highest module, 1563 MPa, a statistically significant value (p ≤0.05) in relation to the groups 1M, 1V and 2V to the tension at the limit of the proportionality, there is no significant differences among them, but these differences were relevant when compared to groups 1V and 2M. The deformation at the limit of the proportionality of the highest percentage was to group 1M, 3.36%, being this the relevant statistical difference when compared to group 2M. The resistance tests to the compression of the national and international cement prepared manually and by vacuum show that there is no important difference between the two kind of bone cement, and neither between the two ways of mixing them.
Cimatti, Bruno. "Desenvolvimento e caracterização de um cimento ósseo esponjoso para preenchimento de falhas ósseas. Análise morfométrica e ensaio mecânico." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/17/17142/tde-13092012-095904/.
Повний текст джерелаIntroduction: Benign bone tumors are usually treated by intralesional curettage. The bone defect may be filled with synthetic or biological substitutes. Polymetylmethacrylate (PMMA) is the most popular synthetic substitute and the solid form is associated to thermal necrosis, aseptic loosening, bone remodeling prevention and distinct elasticity. Research of porous cement that solves these drawbacks and can be molded intraoperatively has encouraged many authors. For surgical purposes, porosity can be achieved by mixing hydrosoluble substances or by gas-foaming reactions. Objective: Development and physical and mechanical characterization of a bone cement with interconnecting pores and cancellous bone like structural aspect. Methods: Porous cement was produced by adding the effervescent components sodium bicarbonate and citric acid to PMMA. Six groups of fifteen cylindrical samples (40 mm height, 20 mm diameter) were compared. G1, G2 and G3 groups consisted of porous cement specimens of PMMA with 10%, 20% and 30% of effervescent components respectively. G4 consisted of solid PMMA cement specimens. G5 group consisted of porous ricinic polyurethane cement (Bioósteo®) with 20% effervescent components specimens. The control group G6 consisted of bovine cancellous bone samples. The porous cements were characterized in terms of porosity, density, pore interconnectivity and compressive strength. Macroscopic evaluation and measuring, methylene blue immersion, Scanning Electron Microscopy (SEM), mechanical testing and a special computed tomography reading software were employed for these evaluations. Results: The pilot study showed that adding effervescent components to PMMA was the best solution for porous cement production. The methylene blue immersion test showed that G2 and G3 groups had better pore interconnection. Scanning electron microscopy (SEM) showed a wide variation in pore size, from 50m to 3mm, and pore distribution. No significant differences between G1, G2 and G3porous cement groups were found regarding to mechanical strength and Young Modulus. Cancellous bovine bone, G6, was slightly stronger and less elastic than these groups. This property is potentially beneficial considering osteointegration as a consequence of Wolfs law. Solid PMMA is extremely strength and inelastic. These properties do not match with cancellous bone. The porous ricinic polyurethane cement (Bioósteo®) is unacceptably weak. Conclusion: Porous cement was developed by adding effervescent components, sodium bicarbonate and citric acid, to polymethylmetacrylate. Physical and mechanical properties are very similar to cancellous bone. Further investigations to evaluate its bone substitute potential should be encouraged. The porous ricinic polyurethane cement (Bioósteo®) is inadequate these purpose.
Shim, Jae-Bum. "Complexity in non-isothermal polymerization of PMMA based bone cement: thermal, chemical, and mechanical effects on polymerization fronts /." Related electronic resource:, 2007. http://proquest.umi.com/pqdweb?did=1342740171&sid=2&Fmt=2&clientId=3739&RQT=309&VName=PQD.
Повний текст джерелаBasgorenay, Burcu. "Preparation And Characterization Of Hydroxyapatite Containing Acrylic Bone Cements." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605675/index.pdf.
Повний текст джерелаC curing temperature. In order to decrease the curing temperature ammonium nitrate this gives endothermic reactions with water, was added into the formulations. Addition of 0.5 g NH4NO3 decreased curing temperature from 94°
C to 79.3°
C while compressive strength kept in acceptable range with 95.99 MPa. Experiments demonstrated that the proposed formulation is acceptable for workability, homogeneity, mechanical strength and thermal properties. Further studies especially on curing temperature and biocompatibility should be achieved.
Cyphert, Erika Leah. "Towards the creation of polymer composites which can be refilled with antibiotics after implantation for infection treatment." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1604071308469614.
Повний текст джерелаJimenez-Bescos, Carlos. "Dynamic finite element analysis of hip resurfacing arthroplasty and the influence of resting periods." Thesis, Anglia Ruskin University, 2013. http://arro.anglia.ac.uk/295483/.
Повний текст джерелаJimenez-Bescos, Carlos. "Dynamic finite element analysis of hip resurfacing arthroplasty and the influence of resting periods." Thesis, Anglia Ruskin University, 2013. https://arro.anglia.ac.uk/id/eprint/295483/1/Jimenez-Bescos%20PhD%20Thesis.pdf.
Повний текст джерелаPaulick, Mark Lloyd. "Effects of Reamer-Femoral Component Offset on Cement Mantle Penetration in Hip Resurfacing Arthroplasty." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/291.
Повний текст джерелаZhang, Juan. "A novel fuzzy digital image correlation algorithm for non-contact measurement of the strain during tensile tests." Thèse, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/8205.
Повний текст джерелаAbstract : The present thesis is focused on the non-contact and efficient strain measurement using the Digital Image Correlation (DIC) method, which employs the tracking of random speckle pattern for accurate measurement of displacements on a surface of an object undergoing deformation. Specifically, a more efficient DIC algorithm was successfully developed, implemented, and validated. This thesis consists of five parts related to the novel DIC algorithm: (a) the development and implementation, (b) the numerical verification, (c) the experimental validation, for tensile loading, by comparing to the deformation measurements using the strain gauge technique, (d) the investigation of a novel atomization process to reproducibly generate the speckle pattern for accurate tracking, and (e) the analysis of the error sources in the DIC measurements. Specifically, the DIC algorithm was used to exemplarily examine the mechanical properties of polymethyl methacrylate (PMMA) used in skeletal reconstruction. In the DIC algorithm, images of an object are captured as it deforms. Nonlinear optimization techniques are then used to correlate the speckle on the surface of the objects before and after the displacement. This optimization process includes a choice of suitable initial displacement values. The more accurate the estimation of these initial displacement values are, the more likely and the more efficient the convergence of the optimization process is. The thesis introduced a novel, fuzzy logics based processing technique, approximation of the initial values of the displacement for initializing iterative optimization, which more accurately and efficiently renders the displacements and deformations as results. The mathematical formulation of the novel algorithm was developed and then successfully implemented into MATLAB programming language. The algorithmic verification was performed using computer-generated images simulating rigid body displacements and uniform tensile deformations. Specifically, the rigid motion images simulated (1) displacements of 0.1-1 pixel for the rigid body translation, (2) rotation angles of 0.5-5 ̊ for rigid body rotation and (3) large tensile deformations of 5000-300000µɛ, respectively. The verification processes showed that the accuracy of the novel DIC algorithm, for the simulated displacement types and levels above 99%. The experimental validation was conducted to examine the effectiveness of the novel technique under realistic testing conditions. Normalized PMMA specimens, in accordance to ASTM F3087, were produced, inspected and subjected to tensile loading until failure. The deformation of the specimen surface was measured using (a) the novel DIC, and (b) strain gauge rosette techniques. The mean maximum force and ultimate strength of four specimens were 882.2±108.3 N and 49.3±6.2 MPa, respectively. The mean ultimate deformation from the gauge and DIC groups were 15746±2567µɛ and 19887±3790µɛ, respectively. These large deformations are common in polymeric materials, and the DIC technique has thus far not been investigated for large deformation. The relative mean error of the DIC measurement, in reference to those of the strain gauge technique, was found to be up to 26.0±7.1%. Accordingly, the mean Young's modulus and Poisson's ratio of strain gauge measurement were 3.78±0.07 GPa and 0.374±0.02, and of the DIC measurements were 3.16±0.61 GPa and 0.373±0.08, respectively. The increasing difference of the DIC strain measurements relative to those of the strain gauge technique is likely related to the gradual distortion of the speckle pattern on the surface of the tensile specimen. Subsequently, a Correction Factor (CF) of 1.27 was introduced to correct for the systematic error in the deformation measurements of the DIC group. The corrected ultimate deformation of the DIC measurements became 15712±357µɛ with the relative mean error of -0.5±7.1%, if compared to those measurements of the strain gauge techniques. Correspondingly, the mean Young's Modulus and Poisson's ratio of the DIC and of the strain gauge measurements became 3.8±0.4 GPa and 0.368±0.025, respectively. Using an atomization process, paint speckles were reproducibly generated on the surface of an object. A factorial design of experiments was used to investigate the speckle pattern (grey value distribution and gradient) for the DIC measurement accuracy. Specifically, nine different speckle patterns were generated using the atomization process and tested for rigid body translation and rotation. The results showed the relative mean errors among the nine speckle patterns varied from 1.1±0.3% to -6.5±3.6%. The preferred speckle pattern, which was characterized by a wide range of sharp speckle and of grey values, produced a mean error of 1.1±0.3%. The analysis of errors and relating sources in the DIC measurement was conducted. Three categories of sources including algorithmic sources, processing parameters sources (subset size, number of pixels computed) and physical environment sources (specimen uniformity, speckle pattern, self-heating effect of the CCD camera and lens distortion of the camera, non-linearity error in strain gauge circuit) were investigated and discussed. Finally, the solutions were provided in order to help reduce the systematic and random errors relating to the aforementioned three categories of sources for errors. In conclusion, a novel DIC algorithm for a more accurate approximation of the initial guess and accordingly for an efficient and accurate convergence of the optimization was successfully formulated, developed, implemented and verified for relatively large deformations. The experimental validation surprisingly showed a systematic error of the DIC measurements, if compared to the measurements of the strain gauge technique. The larger the deformation applied to the specimen, the larger the error gradually became. Therefore, the gradual distortion of the speckles on the surface of the object was likely the underlying cause of the error. The error was systematic and therefore corrected. The atomization process allowed generating reproducible speckles on the surface of an object. Using the DIC measurements, the mechanical behavior of polymers, undergoing large deformations, such as polymethyl methacrylate used in skeletal reconstruction can be investigated and, once understood, the knowledge gained can help develop more effective materials.
López, Alejandro. "Injectable Biomaterials for Spinal Applications." Doctoral thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-215606.
Повний текст джерелаFerreira, Bárbara Joana Martins Leite. "PMMA-co-EHA cements for osteoprotheses." Doctoral thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7500.
Повний текст джерелаThe main purpose of this thesis was to produce new formulations of PMMA-co- EHA and study its feasibility as being an alternative to traditional PMMA bone cements. Thus, were originally produced several co-polymers of PMMA-co-EHA and its mechanical properties and in vitro behaviour were evaluated. The copolymers were obtained by radical polymerization and several formulations were produced by partial replacement of MMA (up to about 50%) for EHA. Overall, the results suggest that the partial replacement of MMA by EHA decreased the modulus of the materials and, consequently, increased its flexibility. Then, PMMA commercial beads were added to PMMA-co-EHA formulations (to get bone cement) and the general properties of the resulting bone cements were evaluated. In general, the results revealed that the partial replacement of MMA by EHA led to beneficial changes in curing parameters (there was a reduction of the peak temperature and an increase of curing/setting time), in the in vitro behaviour (the water capacity increased) and in the mechanical properties (the bending strength increased) of new cements. The in vitro cellular response of new formulations of PMMA-co-EHA was compared with that of traditional PMMA bone cement. To this end, we tested the cell adhesion and proliferation of osteoblast-like MG63 cells and human cells from bone marrow. The results revealed that both types of cells were able to attach and proliferate in both formulations. The only exception was observed for the formulation prepared with the highest percentage of EHA, where a few cells that adhere failed to proliferate. Moreover, it was found that increasing the amount of EHA in cement led to an increasing inhibition of cell growth, especially during the first week of culture. This was related to increased water uptake capacity by the new formulations and consequent release of some of its toxic components. Finally, PMMA commercial beads were partially replaced by HA particles and the influence of this substitution on the curing parameters, the mechanical properties and in vitro behaviour of the resulting composites was also evaluated. Incorporation of HA into the bone cements induced a number of significant changes in its final properties: 1) decrease the peak temperature; 2) increase of curing time, 3) increasing the value of elastic modulus accompanied by decrease of the strength/tension. This last finding was related to poor interfacial adhesion between the various components of the bone cements and a heterogeneous distribution (possible agglomeration) of HA particles.
O principal objectivo desta tese foi produzir novas formulações de PMMA-co- EHA e estudar a sua viabilidade como alternativa aos tradicionais cimentos ósseos de PMMA. Assim sendo, foram inicialmente produzidos vários co-polímeros de PMMA-co- EHA e as suas propriedades mecânicas e comportamento in vitro foram avaliados. Os co-polímeros foram obtidos por polimerização radicalar e diversas formulações foram produzidas por substituição parcial do MMA (até cerca de 50 %) por EHA. Globalmente, os resultados sugerem que a substituição parcial do MMA por EHA diminuiu o módulo de elasticidade dos materiais e, consequentemente, aumentou a sua flexibilidade. Posteriormente, foram adicionados grânulos de PMMA pré-polimerizado (para se obter um cimento ósseo) às várias formulações de PMMA-co-EHA e as propriedades gerais dos cimentos resultante foram avaliadas. De um modo geral, os resultados obtidos revelaram que a substituição parcial do MMA pelo EHA levou a alterações benéficas dos parâmetros de cura (houve uma redução da temperatura máxima de polimerização e um aumento do tempo de cura), do comportamento in vitro (verificou-se um aumento da capaciadade de retenção de água) e das propriedades mecânicas (aumento da capacidade de flexão) dos novos cimentos. A resposta celular in vitro das novas formulações de PMMA-co-EHA foi comparada com a dos cimentos tradicionais. Para o efeito, foram avaliadas a adesão e proliferação celular de células tipo-osteoblastos MG63 e de células humanas provenientes de medula óssea. Os resultados revelaram que os dois tipos de células foram capazes de aderir e proliferar em ambas as formulações. A única excepção foi observada para a formulação preparada com maior percentagem de EHA, onde as poucas células que aderiram não conseguiram proliferar. Para além deste facto, verificou-se que o aumento da quantidade de EHA nos cimentos conduziu a uma crescente inibição do crescimento celular, sobretudo durante a primeira semana de cultura. Este facto foi relacionado com a crescente capacidade de retenção de água por parte das novas formulações e consequente libertação de alguns dos seus componentes tóxicos. Por último, os grânulos de PMMA foram parcialmente substituídos por partículas de HA e a influência desta substituição nos parâmetros de cura, nas propriedades mecânicas e no comportamento in vitro dos compósitos resultantes foi também avaliada. A incorporação de HA nos cimentos induziu uma série de alterações importantes nas suas propriedades finais: 1) diminuição da temperatura máxima de polimerização; 2) aumento significativo do tempo de cura; 3) aumento do valor do módulo elástico acompanhado de uma dimuição da sua força/tensão. Este último resultado foi relacionado com a baixa adesão interfacial entre os vários componentes e com uma distribuição heterogénea (possível aglomeração) das partículas de HA.
Crne, Matija. "Stereocomplex poly (methyl methacrylate) fibers and self-reinforced composites and structural color of butterflies and beetles - characterization, replication and mimicry." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/34827.
Повний текст джерелаOrmsby, Ross William. "Investigation of orthopaedic PMMA bone cements with multi-walled carbon nanotubes." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534598.
Повний текст джерелаMicoli, Antonio. "Studio del rischio di termonecrosi nelle fratture ossee dell'arto superiore ricostruite con cemento acrilico." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
Знайти повний текст джерелаDe, Donno Giulia. "Three dimensional strain analysis of vertebrae with artificial metastases through digital volume correlation." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/19911/.
Повний текст джерелаLou, Yin-Wei, and 羅尹蔚. "Study of Calcium Sulfate/PMMA Bone Cement Composites." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/10354358734137876353.
Повний текст джерела龍華科技大學
化工與材料工程系碩士班
104
PMMA bone cement had been used widely in medical materials filling material, and also with good mechanical properties and also used as. The defect of PMMA is non-degradable. When PMMA mixed with MMA, it will produce high temperature and mortify the tissues around. We prepare five different w/w ratio, of with 10%w/w, 20%w/w, 30%w/w, 40%w/w, 50%w/w calcium sulfate respectively. These ratio sample were assed different volume of MMA to find out mechanical properties. It comes out that the results of analysis change obviously after soaking CSPBC in the phosphate buffered saline. Where the pH value of the immersion test, the pH value turn from neutral to weak acid and it meets the pH value of human body. In the curing test, when 6 ml MMA added into PMMA, we found that the temperature of mixture sample 50%w/w fall to 51.1℃, and compared with another condition, it was clear down. The average compressive strength of sample 50%w/w is up to 85.95 MPa. The results show that 10%w/w samples have stable and high mechanical strength.
hao, Liao chih, and 廖志豪. "Research of PMMA bone cement modified by organic clay." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/64392758895133079148.
Повний текст джерела東海大學
化學工程學系
94
Recently, studies attempted to decrease the bone cement curing exotherm. The new PEMA/nBMA bone cement system is chosen to achieve this goal. However, due to the fact that it is weaker in mechanical strength, organic nano-sized clay will be added. This composite system of bone cement/clay is expected to be better than commercial product nowadays in the following ways: 1. low exotherm during cure, 2. viability in adjusting mechanical strength between human bone and prosthesis, and 3. low shrinkage. In this research, a nanocomposites of PMMA/clay was made by melt intercalation and supposed to be an additive for the preparation of bone cement. Expansion of the inter-layer space by PMMA was examined by XRD and TEM. The thermal properties of nanocomposites were tested by both TGA and DMA. And the results were correlated with the preparation parameter, molecular weight of PMMA, clay concentration and operation temperature when preparing. The tensile and storage modulus of the nanocomposites was found to improve with respect to raw PMMA. And also, the decomposing temperature and glass transition temperature were increased with clay adding concentrations.
林博中. "Preparation of PMMA/bentonite nanocomposites and its application on bone cement." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/90537094721336625180.
Повний текст джерелаChen, Shen Yao, and 陳伸曜. "The Control of Environment Temperature of PMMA Bone Cement for Vertebroplasty." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/21370461365258051491.
Повний текст джерела長庚大學
醫療機電工程研究所
101
Abstract Background: Vertebroplasty has been widely accepted in treatment of osteoporotic vertebral fractures. In this procedure, PMMA bone cement is percutaneously injected under pressure into a vertebra. Polymerization of bone cement stabilizes the fractured vertebra by increasing its mechanical strength, thereby providing symptomatic pain relief. Many factors affect the reaction of polymerization of polymethylmethacrylate and, therefore, the reaction rate and injection permeability of bone cement. This may increase the probability of a surgeon missing the crucial period, leading to the increase of the risks of uneven cement distribution, cement leakage and premature hardening of cement. Lowering the environmental temperature during cement polymerization is expected to reduce reaction rate and hence, extending the handling time. Nonetheless, in a manner of reducing the environmental temperature of bone cement, there are still uncertainties about the impact on handling time, distribution pattern, cement viscosity and injection permeability. This study is thus designed to investigate the efficacy of temperature control for enhancing applicability and safety of bone cement. Methods: The experiments were categorized based on the different types of hypothermic manipulation that were used. Room temperature group (sham group), the syringes were kept at 22°C after mixing the bone cement. Precooling group (cement powder and monomer are stored at 4 ℃ before mixing) and ice bath cooling group (the mixture was immediately submerged in ice water after mixing the bone cement). Two types of commercially available test blocks with density of 7.5 pcf and 15 pcf are used to mimic different degrees of osteoporotic bone. The influence of cement hypothermic manipulation on handling time, distribution pattern, viscosity and injection permeability are investigated. Results: 1) The average handling time for room temperature, precooling and ice bath groups are 8.5 ± 0.8, 15.2 ± 1.2 and 112.5 ± 11.3 min, respectively. 2) For bone cement injected into test block with lower density, cement tends to distribute at lower position of the test block due to gravity. However, this phenomenon is not obvious for bone cement injected into high density test block. Besides, a similar cement distribution pattern is found for room temperature, precooling and ice bath groups when bone cement is injected into test blocks at 3, 6 and 40 min, respectively. 3) The injection resistance of bone cement for room temperature, precooling and ice bath groups at 4, 11 and 40 min are 125.9 ± 13.7 N, 155.9 ± 15.2 N, 141.4 ± 3.3 N, respectively. 4) For bone cement with high viscosity, the injection permeability is enormously affected by degree of osteoporosis. However, regardless of the degree of osteoporosis, high permeability is achieved for bone cement with lower viscosity. Conclusion: Based on this laboratory model, both the precooling and ice bath methods can effectively increase the polymerization time of PMMA bone cement. Precooling is easy for clinical applications, while ice bath cooling can notably extend the handling time and might be more suitable for multiple-level vertebroplasty. However, earlier injection of bone cement treated with hypothermic manipulation should be performed with caution to avoid cement leakage.
Chen, Zheng-Xing, and 陳政行. "Biomechanical Evaluation of the Volume and Location of PMMA bone cement in Vertebroplasty." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/dsscsk.
Повний текст джерела中原大學
醫學工程研究所
91
Osteoporotic vertebral compression fracture is one of the most common diseases that attack the elder population especially in postmenopausal women. Most of these patients received conservative treatment such as medication, bracing and rest, but sometimes in vain. Instrumentation and fusion surgery can be used in some cases, but most of these patients are older and with higher operative risk that are not eligible for these operations. Vertebroplasty involves inserting bone cement (PMMA) into the center of the collapsed spinal vertebra in order to stabilize and strengthen the crushed bone. The two objectives of this study are, (1) to develop a set of instruments used for vertebroplasty with disposable parts (trocar, needle, and syringe), and reusable part (introducer) and to reduce the expense for vertebroplasty, (2) to use a validated finite element model to evaluate the effects of bone cement with different volumes and locations in vertebroplasty and the stress distribution of the vertebral bodies after vertebroplasty. According to our analysis, there is no significant difference between 6-ml, one-sided and 10-ml, two-sided models. The effect of 6-ml, one-sided model was similar to 6-ml, two-sided and even better, but no significant difference. On the biomechanical viewpoint, vertebroplasty is an effective method in increasing biomechanical strength of vertebral bodies. The effects were related to the volumes of bone cement, but not totally proportional to them. There were similar results between the same volumes but different distributions (one-sided, two-sided). One-sided approach seems to be a safer method. We established another model with five motion segments to evaluate the effect of vertebroplasty on the adjacent vertebrae. The result showed that there was no significant effect on the adjacent vertebrae if the height of the injured vertebral body was recovered to the initial height. The introducer we designed is easy-to-use, less expensive and we can effectively control the amount of PMMA to be injected.
Lee, Yen-Chen, and 李彥震. "Biomechanical Evaluation for Control of PMMA Bone Cement Mechanical Properties in Application of Vertebroplasty." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/91589118545808236110.
Повний текст джерела長庚大學
醫療機電工程研究所
99
Polymethylmethacrylate (PMMA) bone cement has been widely used as bone substitute material for vertebroplasty. As PMMA exhibits significant higher stiffness than that osteoporotic vertebral cancellous bone, the use of PMMA cement to reinforce fragile or broken vertebral bodies (vertebroplasty) leads to extensive bone stiffening, fractures in the adjacent vertebrae may be the consequence of this procedure. Consequently, modified by addition of castor oil, vertebroplasty with a low-modulus PMMA may be more suitable. The goal of this study is thus to produce and characterize a low stiffness PMMA bone cements. Low-modulus PMMA bone cement was prepared by combining commercial PMMA with various volume fractions of a castor oil. For PMMA with three different volume fractions of castor oil (5%, 10% and 15%), the peak polymerization temperature, time to achieve peak polymerization temperature, porosity, density and mechanical properties of the modified cements were investigated on conditions that PMMA was stored in room temperature (25 ℃) or in pre-cooling condition (3 ℃). The results indicated the followings: 1) Peak polymerization temperature of PMMA decreased from 102 ℃ (0% volume of castor oil combined with RT storage) to 59 ℃ (15 % volume of castor oil combined with 3 ℃ storage). 2) Time to achieve peak polymerization temperature of PMMA increased from 5.5 min (0% volume of castor oil combined with RT storage) to 28 min (15 % volume of castor oil combined with 3 ℃ storage). 3) PMMA density decreased from 1112 Kg/m3 for PMMA with 0% castor oil to 1017 Kg/m3 with 15% volume of castor oil. 4) Young’s modulus and compression strength decreased from 1739 MPa to 474 MPa and from 75 to 17 MPa for PMMA without and with 15% volume of castor oil, respectively. 5) PMMA with addition of 15 % volume of castor oil presented an increase of porosity up to 20% as compared to that of pure PMMA. In conclusion, the addition of castor oil into PMMA facilitated the formation of pores, which lowered the stiffness of the modified PMMA and let to a more compliant configuration in performing vertebroplasty.
Lin, Sheng-Chih, and 林聖智. "The Investigation of Stability in Different Pilot Hole Type and PMMA Bone Cement Transpedicular Screw Augmentation for Pedicle Screw Loosening." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/n5d8k7.
Повний текст джерела國立陽明大學
生物醫學工程學系
106
There are many kinds of methods to treat spinal disease in clinical case. One of the methods is using pedicle screw system, becoming a common spinal surgery. The pedicle screw which is inserted into the vertebrae may be repeat sustain cyclic loading until loosening. It lead to the necessity of the secondary spinal surgery in clinical. There are two ways to enhance the stability of spinal, one is inserting pedicle screw, the other is injecting PMMA bone cement prior to screw insertion. However, the effects of pedicle screw fixation in two kinds of the secondary spinal surgery are not clear. Therefore, the aim of this study is to investigate the pedicle screw stabilization to compare with or without PMMA bone cement augmentation, via in-vitro biomechanical experiment and observe characteristics of pedicle screw at the bone-screw interface failure. The specimen is simulated with the fixation method of secondary spinal surgery by porcine thoracic spine ranging from T10 to T14. Stryker Xia series of mono-axial pedicle screw with an outer diameter of 4.5 mm were used for testing. The experiment setting is based on ASTM F1717 standard fatigue test and the loading cycle is half million which is represented to the loading condition in postoperative 3 months. Finally, via microscope to examine the characteristics of pedicle screw at the bone-screw interface failure. According to the results of this study, the group without bone cement passed fatigue loading at 70%, but the group with bone cement passed at 85%. However, in sliced part, failure has not happened in 55% fatigue loading in both groups. Both of groups were no significant difference.
Schunck, Antje. "Freisetzung des Röntgenkontrastmittels Zirkoniumdioxid an der implantatzugewandten Seite von PMMA-Zementköchern - REM-Analyse und -Charakterisierung bei zementierten Hüftendoprothesenschäften vom Typ CF-30." Doctoral thesis, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-1454-6.
Повний текст джерелаBai, Shao Han, and 白少涵. "Biomechanical Study for Treatment of Unstable Trochanteric Fractures with Osteoporotic Bone- Comparison between a PMMA Cemented DHS and an Intramedullary Device." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/13121303302144789807.
Повний текст джерела長庚大學
醫療機電工程研究所
101
Interochanteric fractures associated with severe osteoporosis and comminution remain a considerable challenge to orthopedic surgeon. The standard treatment of these fractures is by osteosynthesis with a dynamic hip screw (DHS). However, in unstable intertrochanteric fractures, complications of cut-out and excessive sliding of the lag screw occurred frequently. Another device frequently used to treat these unstable intertrochanteric fractures is the use of a intramedullary nail. Although PMMA bone cement has been widely applied as a secondary fixation to facilitate fracture stability, there has been few biomechanical studies regarding the significance of bone cement in unstable fracture patterns with osteoporotic bone, therefore this study was conducted to compare the biomechanical behavior between a PMMA cemented DHS and an intramedullary device in treatment of interochanteric fractures associated with severe osteoporosis. Methods: Both finite element analysis (FEA) and In vitro experiment were conducted in current study. For FEA study, CT images obtained from standardized composite femur was used to create 3-D finite element model simulating unstable interochanteric fracture. The solid model and finite element model of DHS and intramedullary device were created by actual measurement. Loading condition simulating single leg stance was performed. Femora with three different degree of density (normal, osteoporotic and augmented with cemented) were compared. For experiment study, postoperative stability for femora with unstable interochanteric fracture treated with DHS and intramedullary device were compared. Results: The results of finite element analysis indicated that, for femur treated with DHS, the maximal femoral head displacement for normal, osteoporotic and cemented femur were 7.143 mm, 8.714 mm and 6.889 mm, respectively; whereas for femur implanted with intramedullary device, the maximal femoral head displacement for normal, osteoporotic and cemented femur were 1.869 mm, 2.207 mm and 1.859 mm, respectively. Regardless of DHS or intramedullary device, unstable interochanteric fractures associated with severe osteoporosis exhibited the highest femoral head displacement. In addition, the maximal von Mises stress of DHS device for normal, osteoporotic and cemented femur were 2,112 MPa, 2,006 MPa and 2,084 MPa, respectively; whereas for femur implanted with intramedullary device, the maximal von Mises stress of intramedullary device for normal, osteoporotic and cemented femur were 1,444, 1,452, and 1,616 MPa, respectively. Regardless of DHS or intramedullary device, the application of bone cement increases the von Mises stress of fixation device. Furthermore, the results of in vito experiment indicated, under 2000 N compressive loading, the vertical displacement of femoral head for femora implanted with DHS and intramedullary device are 11.3 mm and 4.6 mm, respectively Conclusion: The intramedullary device may be suitable to treat unstable interochanteric fractures associated with severe osteoporosis due to the lower displacement and stresses. DHS treated femur exhibits a higher risk of screw cut-out. The application of bone cement reduces the risk of screw cut-out, however, it increases the risk of implant damage.