15 results on '"Richards, R Geoff"'
Search Results
2. General treatment principles for fracture-related infection: recommendations from an international expert group
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Metsemakers, Willem-Jan, Morgenstern, Mario, Senneville, Eric, Borens, Olivier, Govaert, Geertje AM, Onsea, Jolien, Depypere, Melissa, Richards, R Geoff, Trampuz, Andrej, Verhofstad, Michael HJ, Kates, Stephen L, Raschke, Michael, McNally, Martin A, Obremskey, William T, Athanasou, Nick, Atkins, Bridget L, Eckardt, Henrik, Egol, Kenneth A, Hungerer, Sven, Kuehl, Richard, Marais, Leonard, Mcfadyen, Ian, Foster, William, Fragomen, Austin T, Moriarty, T Fintan, Ochsner, Peter, Ramsden, Alex, Sancineto, Carlos, Zalavras, Charalampos, Zimmerli, Werner, and Surgery
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medicine.medical_specialty ,Consensus ,Standardization ,ORTHOPEDIC-SURGERY ,Periprosthetic ,ANESTHESIOLOGISTS PHYSICAL STATUS ,Implant removal ,SURGICAL-SITE INFECTION ,03 medical and health sciences ,Fracture Fixation, Internal ,Fractures, Bone ,HEALTH-CARE EPIDEMIOLOGY ,0302 clinical medicine ,Fracture fixation ,Diagnosis ,Medicine ,Humans ,Surgical Wound Infection ,COMPUTER ADAPTIVE TEST ,Orthopedics and Sports Medicine ,Sampling (medicine) ,030212 general & internal medicine ,POSTOPERATIVE COMPLICATIONS ,Intensive care medicine ,Outcome ,030222 orthopedics ,Fracture-related infection ,Science & Technology ,business.industry ,CHRONIC OSTEOMYELITIS ,General Medicine ,Evidence-based medicine ,Bacterial Infections ,Expert group ,ANTIBIOTIC STEWARDSHIP ,EXPOSED HARDWARE ,Orthopaedic Surgery ,Anti-Bacterial Agents ,Treatment ,Orthopedics ,Fracture ,HYPOVITAMINOSIS D ,Orthopedic surgery ,Practice Guidelines as Topic ,Surgery ,business ,Infection ,Life Sciences & Biomedicine - Abstract
Fracture-related infection (FRI) remains a challenging complication that creates a heavy burden for orthopaedic trauma patients, their families and treating physicians, as well as for healthcare systems. Standardization of the diagnosis of FRI has been poor, which made the undertaking and comparison of studies difficult. Recently, a consensus definition based on diagnostic criteria for FRI was published. As a well-established diagnosis is the first step in the treatment process of FRI, such a definition should not only improve the quality of published reports but also daily clinical practice. The FRI consensus group recently developed guidelines to standardize treatment pathways and outcome measures. At the center of these recommendations was the implementation of a multidisciplinary team (MDT) approach. If such a team is not available, it is recommended to refer complex cases to specialized centers where a MDT is available and physicians are experienced with the treatment of FRI. This should lead to appropriate use of antimicrobials and standardization of surgical strategies. Furthermore, an MDT could play an important role in host optimization. Overall two main surgical concepts are considered, based on the fact that fracture fixation devices primarily target fracture consolidation and can be removed after healing, in contrast to periprosthetic joint infection were the implant is permanent. The first concept consists of implant retention and the second consists of implant removal (healed fracture) or implant exchange (unhealed fracture). In both cases, deep tissue sampling for microbiological examination is mandatory. Key aspects of the surgical management of FRI are a thorough debridement, irrigation with normal saline, fracture stability, dead space management and adequate soft tissue coverage. The use of local antimicrobials needs to be strongly considered. In case of FRI, empiric broad-spectrum antibiotic therapy should be started after tissue sampling. Thereafter, this needs to be adapted according to culture results as soon as possible. Finally, a minimum follow-up of 12 months after cessation of therapy is recommended. Standardized patient outcome measures purely focusing on FRI are currently not available but the patient-reported outcomes measurement information system (PROMIS) seems to be the preferred tool to assess the patients' short and long-term outcome. This review summarizes the current general principles which should be considered during the whole treatment process of patients with FRI based on recommendations from the FRI Consensus Group.Level of evidence: Level V. ispartof: ARCHIVES OF ORTHOPAEDIC AND TRAUMA SURGERY vol:140 issue:8 pages:1013-1027 ispartof: location:Germany status: published
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- 2020
3. Small molecules of herbal origin for osteoarthritis treatment: in vitro and in vivo evidence
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Zhang, Penghui, Li, Kaihu, Kamali, Amir, Ziadlou, Reihane, Ahmad, Paras, Wang, Xinluan, Richards, R. Geoff, Alini, Mauro, Basoli, Valentina, Li, Zhen, and Grad, Sibylle
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Compound delivery ,Inflammation ,Traditional Chinese medicine ,Herbal medicine ,Herbal extraction ,Therapeutic target ,Anti-inflammatory ,Anabolic ,Anti-catabolic - Abstract
Osteoarthritis (OA) is one of the most common musculoskeletal degenerative diseases and contributes to heavy socioeconomic burden. Current pharmacological and conventional non-pharmacological therapies aim at relieving the symptoms like pain and disability rather than modifying the underlying disease. Surgical treatment and ultimately joint replacement arthroplasty are indicated in advanced stages of OA. Since the underlying mechanisms of OA onset and progression have not been fully elucidated yet, the development of novel therapeutics to prevent, halt, or reverse the disease is laborious. Recently, small molecules of herbal origin have been reported to show potent anti-inflammatory, anti-catabolic, and anabolic effects, implying their potential for treatment of OA. Herein, the molecular mechanisms of these small molecules, their effect on physiological or pathological signaling pathways, the advancement of the extraction methods, and their potential clinical translation based on in vitro and in vivo evidence are comprehensively reviewed., Arthritis Research & Therapy, 24, ISSN:1465-9905, ISSN:1465-9913, ISSN:1478-6362, ISSN:1478-6354
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- 2022
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4. An Exopolysaccharide Produced by Bifidobacterium longum 35624® Inhibits Osteoclast Formation via a TLR2-Dependent Mechanism
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Wallimann, Alexandra, Hildebrand, Maria, Groeger, David, Stanic, Barbara, Akdis, Cezmi A, Zeiter, Stephan, Richards, R Geoff, Moriarty, T Fintan, O’Mahony, Liam, Thompson, Keith, University of Zurich, and Thompson, Keith
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Diabetes and Metabolism ,2712 Endocrinology, Diabetes and Metabolism ,2732 Orthopedics and Sports Medicine ,Endocrinology ,10183 Swiss Institute of Allergy and Asthma Research ,610 Medicine & health ,Orthopedics and Sports Medicine ,1310 Endocrinology - Published
- 2021
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5. Experimental and numerical investigation of secondary screw perforation in the human proximal humerus
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Panagiotopoulou, Vasiliki C., Ovesy, Marzieh, Gueorguiev, Boyko, Richards, R. Geoff, Zysset, Philippe, and Varga, Peter
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600 Technology ,570 Life sciences ,biology ,610 Medicine & health - Abstract
Surgical treatment of proximal humerus fractures remains challenging, with a reported failure rate ranging from 15% to 35%. The dominant failure mode is secondary, i.e. post-operative screw perforation through the glenohumeral joint. A better understanding and the ability to predict this complication could lead to improved fracture fixation and decreased failure rate. The aims of this study were (1) to develop an experimental model for single screw perforation in the human humeral head and (2) to evaluate the ability of densitometric measures and micro finite element (microFE) analyses to predict the experimental failure event. Screw perforation was investigated experimentally in twenty cuboidal specimens cut from four pairs of fresh-frozen human cadaveric proximal humeral heads. A centrally inserted 3.5 mm screw was pushed quasi-statically at a constant displacement rate until perforation of the articular cartilage in each specimen. Force and displacement were recorded and evaluated at both initial screw loosening and perforation events. Bone volume was calculated around and in front of the screw and tip-to-joint distance was measured on the combined pre- and post-instrumentation micro computed tomography (microCT) scans. Implicit linear and explicit non-linear microFE models were created based on the microCT scans. The strength of these densitometric, geometrical and microFE methods to predict the experimental results was evaluated via correlation analysis. The bone volume measures were optimized in a parametric analysis to maximize correlation coefficients. The strongest and quantitatively correct predictions of perforation force (R2 = 0.93) and displacement (R2 = 0.77) were achieved using the explicit, non-linear microFE models. Linear microFE simulations provided the strongest predictions of loosening force (R2 = 0.90). Correlation strengths reached by optimized bone volume measures for predicting experimental force and by tip-to-joint distance for predicting displacement were only slightly inferior compared to the results of microFE models. The strong correlations achieved with densitometric and geometric measures indicate that monotonic perforation of single screws through the articular surface of the humeral head can be well predicted with these easily accessible measures. However, non-linear microFE models delivered even stronger correlations and quantitatively correct predictions of perforation force and displacement. This indicates that if computational resources are available, non-linear simulations may have a high potential to investigate more complex fixations and loading scenarios.
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- 2021
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6. Uncovering the secretome of mesenchymal stromal cells exposed to healthy, traumatic, and degenerative intervertebral discs: a proteomic analysis
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Wangler, Sebastian, Kamali, Amir, Wapp, Christina, Wuertz-Kozak, Karin, Häckel, Sonja, Fortes, Claudia, Benneker, Lorin M, Haglund, Lisbet, Richards, R Geoff, Alini, Mauro, Peroglio, Marianna, Grad, Sibylle, University of Zurich, and Grad, Sibylle
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musculoskeletal diseases ,Proteomics ,Mesenchymal stromal cells ,Medicine (miscellaneous) ,10071 Functional Genomics Center Zurich ,610 Medicine & health ,Genetics and Molecular Biology (miscellaneous) ,Intervertebral Disc Degeneration ,Secretome ,Intervertebral disc ,Conditioned medium ,intervertebral disc degeneration ,1301 Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Biochemistry ,1307 Cell Biology ,lcsh:Biochemistry ,Humans ,lcsh:QD415-436 ,Intervertebral Disc ,Cells, Cultured ,lcsh:R5-920 ,Research ,2701 Medicine (miscellaneous) ,Mesenchymal Stem Cells ,Cell Biology ,musculoskeletal system ,1313 Molecular Medicine ,570 Life sciences ,biology ,Molecular Medicine ,lcsh:Medicine (General) - Abstract
Background Mesenchymal stromal cells (MSCs) have been introduced as promising cell source for regenerative medicine. Besides their multilineage differentiation capacity, MSCs release a wide spectrum of bioactive factors. This secretome holds immunomodulatory and regenerative capacities. In intervertebral disc (IVD) cells, application of MSC secretome has been shown to decrease the apoptosis rate, induce proliferation, and promote production of extracellular matrix (ECM). For clinical translation of secretome-based treatment, characterization of the secretome composition is needed to better understand the induced biological processes and identify potentially effective secretomes. Methods This study aimed to investigate the proteome released by bone marrow-derived MSCs following exposure to a healthy, traumatic, or degenerative human IVD environment by mass spectroscopy and quantitative immunoassay analyses. Exposure of MSCs to the proinflammatory stimulus interleukin 1β (IL-1β) was used as control. Results Compared to MSC baseline secretome, there were 224 significantly up- or downregulated proteins following healthy, 179 following traumatic, 223 following degenerative IVD, and 160 proteins following IL-1β stimulus. Stimulation of MSCs with IVD conditioned media induced a more complex MSC secretome, involving more biological processes, compared to stimulation with IL-1β. The MSC response to stimulation with IVD conditioned medium was dependent on their pathological status. Conclusions The MSC secretome seemed to match the primary need of the IVD: homeostasis maintenance in the case of healthy IVDs, versus immunomodulation, adjustment of ECM synthesis and degradation disbalance, and ECM (re) organization in the case of traumatic and degenerative IVDs. These findings highlight the importance of cell preconditioning in the development of tailored secretome therapies., Stem Cell Research & Therapy, 12 (1)
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- 2020
7. TightRight : augmenting screwdrivers to reduce bone stripping rates and optimise tightness when inserting non-locking screws
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Fletcher, James, Neumann, Verena, Silva-Henao, Juan, Mys, Karen, Panagiotopoulou, Vasiliki, Verschueren, Abigail, Gueorguiev, Boyko, Richards, R. Geoff, Whitehouse, Michael, Preatoni, Ezio, and Gill, Richie
- Abstract
Objectives Non-locking screws remain one of the most commonly used orthopaedic implants, however they are often poorly inserted. Exceeding the stripping torque for a screw hole reduces pullout strength. The aims of this study were firstly to quantify stripping rates and screw tightness for surgeons and secondly to assess how these change when using a screwdriver that indicates when optimum tightness is reached. Methods At the AO Davos Courses 2018 (Davos, Switzerland), 302 orthopaedic surgeons tightened 20 screws in two phases: Phase 1 - screws tightened to the surgeon’s perception of optimum tightness. Phase 2 - using an augmented screwdriver that indicated, by audibly alarming and vibrating, when a predetermined optimum tightness was reached (defined as 70% of the maximum stripping torque). Within each phase, 10 partially inserted 3.5 mm non-locking cortical screws were tightened through a 3.5 mm plate into 4 mm thick artificial bone analogue of 0.32 g/cm3. The stopping torque for each screw was recorded and compared to the stripping torque; if the stopping torque greatly exceeded the stripping torque, tightness values >100% were possible. A confidence value in each screw’s purchase was recorded, 1-10. Following tests of normality, Student t-tests were performed to compare different phases and insertion confidences. Results For phases 1 and 2 respectively, stripping rates were 58 ± 32% and 15 ± 25% (p
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- 2020
8. Innovative Tissue-Engineered Strategies for Osteochondral Defect Repair and Regeneration: Current Progress and Challenges
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Zhou, Liangbin, van Osch, G.J.V.M., Malda, Jos, Stoddart, Martin J., Lai, Yuxiao, Richards, R. Geoff, Ki-wai Ho, Kevin, and Qin, Ling
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tissue-engineered strategies ,scaffolds ,clinical applications ,osteochondral defect repair and regeneration - Abstract
Clinical treatments for the repair of osteochondral defects (OCD) are merely palliative, not completely curative, and thus enormously unfulfilled challenges. With the in-depth studies of biology, medicine, materials, and engineering technology, the conception of OCD repair and regeneration should be renewed. During the past decades, many innovative tissue-engineered approaches for repairing and regenerating damaged osteochondral units have been widely explored. Various scaffold-free and scaffold-based strategies, such as monophasic, biphasic, and currently fabricated multiphasic and gradient architectures have been proposed and evaluated. Meanwhile, progenitor cells and tissue-specific cells have also been intensively investigated in vivo as well as ex vivo. Concerning bioactive factors and drugs, they have been combined with scaffolds and/or living cells, and even released in a spatiotemporally controlled manner. Although tremendous progress has been achieved, further research and development (R&D) is needed to convert preclinical outcomes into clinical applications. Here, the osteochondral unit structure, its defect classifications, and diagnosis are summarized. Commonly used clinical reparative techniques, tissue-engineered strategies, emerging 3D-bioprinting technologies, and the status of their clinical applications are discussed. Existing challenges to translation are also discussed and potential solutions for future R&D directions are proposed.
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- 2020
9. Biomechanical evaluation of three different plating techniques for fixation of displaced midshaft clavicle factures
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Zderic, Ivan, Yanev, Parvan, Pukalski, Yavor, Enchev, Dian, Rashkov, Mihail, Richards, R. Geoff, Gueorguiev, Boyko, and Baltov, Asen
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musculoskeletal diseases ,locking compression plate ,surgical procedures, operative ,dynamic compression plate ,reconstruction plate ,ddc: 610 ,mechanical testing ,clavicle ,610 Medical sciences ,Medicine ,equipment and supplies ,musculoskeletal system ,midshaft fracture - Abstract
Objectives: Displaced midshaft fractures are the most common surgically treated clavicle fractures. However, they are still associated with high complication rates after plating due to fixation failure in terms of plate breakage, screw breakage or screw loosening. The aim of this biomechanical study[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2019)
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- 2019
10. Heterodimeric BMP-2/7 for nucleus pulposus regeneration-In vitro and ex vivo studies
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Li, Zhen, Lang, Gernot, Karfeld-Sulzer, Lindsay S, Mader, Kerstin T, Richards, R Geoff, Weber, Franz E, Sammon, Chris, Sacks, Hagit, Yayon, Avner, Alini, Mauro, Grad, Sibylle, University of Zurich, and Grad, Sibylle
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2732 Orthopedics and Sports Medicine ,610 Medicine & health ,Orthopedics and Sports Medicine ,10069 Clinic of Cranio-Maxillofacial Surgery - Published
- 2017
11. Biomechanical comparison of two plating systems for medial column fusion in foot
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Gueorguiev, Boyko, Sommerer, Theresia, Klos, Kajetan, Zderic, Ivan, Richards, R. Geoff, and Simons, Paul
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musculoskeletal diseases ,body regions ,Medial Column Fusion ,ddc: 610 ,Foot ,Plating ,Motion Tracking ,Biomechanics ,610 Medical sciences ,Medicine - Abstract
Objectives: Arthrodesis of the Os naviculare, Os cuneiforme I and Os metatarsale I (medial column) is performed for reasons such as Charcot arthropathy, arthritis, posttraumatic reconstruction or severe pes planus. The complication rate is still high and mainly resulting from inadequate fixation. Special[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2016)
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- 2016
12. Monitoring immune responses in a mouse model of fracture fixation with and without Staphylococcus aureus osteomyelitis
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Rochford, Edward T J, Sabaté Brescó, Marina, Zeiter, Stephan, Kluge, Katharina, Poulsson, Alexandra, Ziegler, Mario, Richards, R Geoff, O'Mahony, Liam, Moriarty, T Fintan, University of Zurich, and Moriarty, T Fintan
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2712 Endocrinology, Diabetes and Metabolism ,10183 Swiss Institute of Allergy and Asthma Research ,610 Medicine & health ,1314 Physiology ,2722 Histology - Published
- 2016
13. Der osteoporotische Knochensubstanzverlust führen am proximalen Humerus zu einer deutlichen Abnahme der kortikale Dicke und Zunahme der Porosität: Eine Analyse der mikrostrukturellen Umbauprozessen
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Schmidutz, Florian, Helfen, Tobias, Eberli, Ursula, Müller, Peter. M., Richards, R. Geoff, Gueorguiev, Boyko, and Sprecher, Christoph
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Frakturrisiko ,ddc: 610 ,Kortikalis ,Porosität ,610 Medical sciences ,Medicine ,Humerus ,Osteoporose - Abstract
Fragestellung: Proximale Humerusfrakturen stehen in direktem Zusammenhang zum Knochensubstanzverlust im höheren Lebensalter. Studien am Radius und der Tibia zeigen, dass neben dem trabekulären Substanzverlust auch die mikrostrukturellen Umbauprozesse an der Kortikalis eine wichtige Rolle spielen.[zum vollständigen Text gelangen Sie über die oben angegebene URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2015)
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- 2015
14. Does Metaphyseal Cement Augmentation in Fracture Management Influence the Adjacent Subchondral Bone and Joint Cartilage?
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Goetzen, Michael, Hofmann-Fliri, Ladina, Arens, Daniel, Zeiter, Stephan, Stadelmann, Vincent, Nehrbass, Dirk, Richards, R. Geoff, and Blauth, Michael
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Cartilage, Articular ,Sheep ,Bone Cements ,Clinical Trial/Experimental Study ,Osteoarthritis, Knee ,Stifle ,Article ,Injections, Intra-Articular ,Disease Models, Animal ,Fractures, Bone ,Risk Factors ,Animals ,Polymethyl Methacrylate ,Female ,Glycosaminoglycans - Abstract
Augmentation of implants with polymethylmethacrylate (PMMA) bone cement in osteoporotic fractures is a promising approach to increase implant purchase. Side effects of PMMA for the metaphyseal bone, particularly for the adjacent subchondral bone plate and joint cartilage, have not yet been studied. The following experimental study investigates whether subchondral PMMA injection compromises the homeostasis of the subchondral bone and/or the joint cartilage. Ten mature sheep were used to simulate subchondral PMMA injection. Follow-ups of 2 (4 animals) and 4 (6 animals) months were chosen to investigate possible cartilage damage and subchondral plate alterations in the knee. Evaluation was completed by means of high-resolution peripheral quantitative computed tomography (HRpQCT) imaging, histopathological osteoarthritis scoring, and determination of glycosaminoglycan content in the joint cartilage. Results were compared with the untreated contralateral knee and statistically analyzed using nonparametric tests. Evaluation of the histological osteoarthritis score revealed no obvious cartilage damage for the treated knee; median histological score after 2 months 0 (range 4), after 4 months 1 (range 5). There was no significant difference when compared with the untreated control site after 2 and 4 months (P = 0.23 and 0.76, respectively). HRpQCT imaging showed no damage to the metaphyseal trabeculae. Glycosaminoglycan measurements of the treated joint cartilage after 4 months revealed no significant difference compared with the untreated cartilage (P = 0.24). The findings of this study support initial clinical observation that PMMA implant augmentation of metaphyseal fractures appears to be a safe procedure for fixation without harming the subchondral bone plate and adjacent joint cartilage.
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- 2015
15. An in vitro investigation of bacteria-osteoblast competition on oxygen plasma-modified PEEK
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Rochford, Edward T. J., Subbiahdoss, Guruprakash, Moriarty, T. Fintan, Poulsson, Alexandra H. C., van der Mei, Henny C., Busscher, Henk J., Richards, R. Geoff, Man, Biomaterials and Microbes (MBM), and Personalized Healthcare Technology (PHT)
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EXPRESSION ,Staphylococcus ,BIOFILM FORMATION ,biomaterial-associated infections ,osteoblasts ,ADHESION ,bacterial adhesion ,IMPLANTS ,PEEK ,plasma treatment ,XDLVO THEORIES ,CELLS ,INFECTION ,AUREUS ,STAPHYLOCOCCUS-EPIDERMIDIS ,coculture ,BIOMATERIAL SURFACE-CHEMISTRY ,surface modification - Abstract
Polyetheretherketone (PEEK) films were oxygen plasma treated to increase surface free energy and characterized by X-ray photoelectron microscopy, atomic force microscopy, and water contact angles. A parallel plate flow chamber was used to measure Staphylococcus epidermidis, Staphylococcus aureus, and U-2 OS osteosarcomal cell-line adhesion to the PEEK films in separate monocultures. In addition, bacteria and U-2 OS cells were cocultured to model competition between osteoblasts and contaminating bacteria for the test surfaces. Plasma treatment of the surfaces increased surface oxygen content and decreased the hydrophobicity of the materials, but did not lead to a significant difference in bacterial or U-2 OS cell adhesion in the monocultures. In the S. epidermidis coculture experiments, the U-2 OS cells adhered in greater numbers on the treated surfaces compared to the untreated PEEK and spread to a similar extent. However, in the presence of S. aureus, cell death of the U-2 OS occurred within 10 h on all surfaces. The results of this study suggest that oxygen plasma treatment of PEEK may maintain the ability of osteoblast-like cells to adhere and spread, even in the presence of S. epidermidis contamination, without increasing the risk of preoperative bacterial adhesion. Therefore, oxygen plasma-treated PEEK remains a promising method to improve implant surface free energy for osseointegration. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 4427-4434, 2014.
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- 2014
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