227 research outputs found

    Fixation principles in metaphyseal bone—a patent based review

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    Osteoporotic changes start in cancellous bone due to the underlying pathophysiology. Consequently, the metaphyses are at a higher risk of "osteoporotic” fracture than the diaphysis. Furthermore, implant purchase to fix these fractures is also affected by the poor bone quality. In general, researchers and developers have worked on three different approaches to address the problem of fractures to osteoporotic bone: adapted anchoring techniques, improved load distribution as well as transfer with angular stable screws, and augmentation techniques using bone substitutes. A patent-based review was performed to evaluate which ideas were utilized to improve fixation in osteoporotic, metaphyseal bone, especially in the proximal femur, and to analyze whether the concept had entered clinical use. Anchoring devices that are either extramedullary or intramedullary have a long clinical history. However, demanding surgical techniques and complications, especially in poor quality bone, are justification that such implants and their corresponding surgical techniques need to be improved upon. Expanding elements have been evaluated in the laboratory. The results are promising and the potential of this approach has yet to be fully exploited in the clinics. Internal fixators with angular stable screws open the door for many new anchorage ideas and have great potential for further optimization of load distribution and transfer. Augmentation techniques may improve anchorage in osteoporotic bone. However, the properties of bone substitute materials will need to be modified and improved upon in order to meet the demanding requirements. If we summarise the development process and the clinical use of implants to date, we have to clearly state that more factors than simply biomechanical advantage will determine the clinical success of a new fixation principle or a new implant. Instead, fracture treatment of patients with osteoporosis really needs an interdisciplinary approach

    Age- and Gender-Specific Normative Data of Grip and Pinch Strength in a Healthy Adult Swiss Population

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    Assessment of hand strength is used in a wide range of clinical settings especially during treatment of diseases affecting the function of the hand. This investigation aimed to determine age- and gender-specific reference values for grip and pinch strength in a normal Swiss population with special regard to old and very old subjects as well as to different levels of occupational demand. Hand strength data were collected using a Jamar dynamometer and a pinch gauge with standard testing position, protocol and instructions. Analysis of the data from 1023 tested subjects between 18 and 96 years revealed a curvilinear relationship of grip and pinch strength to age, a correlation to height, weight and significant differences between occupational groups. Hand strength values differed significantly from those of other populations, confirming the thesis that applying normative data internationally is questionable. Age- and gender-specific reference values for grip and pinch strength are presented

    Universality of electron accumulation at wurtzite c- and a-plane and zinc-blende InN surfaces

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    Electron accumulation is found to occur at the surface of wurtzite (112¯0), (0001), and (0001¯) and zinc-blende (001) InN using x-ray photoemission spectroscopy. The accumulation is shown to be a universal feature of InN surfaces. This is due to the low Г-point conduction band minimum lying significantly below the charge neutrality level

    Implications for Fracture Healing of Current and New Osteoporosis Treatments: An ESCEO Consensus Paper

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    Osteoporotic fracture healing is critical to clinical outcome in terms of functional recovery, morbidity, and quality of life. Osteoporosis treatments may affect bone repair, so insights into their impact on fracture healing are important. We reviewed the current evidence for an impact of osteoporosis treatments on bone repair. Treatment with bisphosphonate in experimental models is associated with increased callus size and mineralization, reduced callus remodeling, and improved mechanical strength. Local and systemic bisphosphonate treatment may improve implant fixation. No negative impact on fracture healing has been observed, even after major surgery or when administered immediately after fracture. Experimental data for denosumab and raloxifene suggest no negative implications for bone repair. The extensive experimental results for teriparatide indicate increased callus formation, improved biomechanical strength, and greater external callus volume and total bone mineral content and density. Case reports and a randomized trial have produced mixed results but are consistent with a positive impact of teriparatide on clinical fracture healing. Studies with strontium ranelate in models of fracture healing indicate that it is associated with improved bone microstructure, callus volume, and biomechanical properties. Finally, there is experimental evidence for a beneficial effect of some of the agents currently being developed for osteoporosis, notably sclerostin antibody and DKK1 antibody. There is currently no evidence that osteoporosis treatments are detrimental for bone repair and some promising experimental evidence for positive effects on healing, notably for agents with a bone-forming mode of action, which may translate into therapeutic application

    Teriparatide improves early callus formation in distal radial fractures: Analysis of a subgroup of patients within a randomized trial

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    Background Teriparatide (parathyreoid hormone; PTH 1-34) increases skeletal mass in humans and improves fracture healing in animals. A recent randomized multicenter trial of nonoperated distal radial fractures showed a moderate shortening of the time to restoration of cortical continuity by treatment with 20 μg (low-dose) teriparatide per day, but not with 40 μg (high-dose). As radiographic cortical continuity appears late in the healing process, perhaps too late for clinical relevance, we studied the qualitative appearance of the callus 5 weeks after fracture

    Empirical evidence to understand the human factor for effective rapid testing against SARS-CoV-2

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapid antigen point-of-care and home tests are available to laypeople. In four cross-sectional mixed-methods data collections conducted between December 2020 and March 2021 (n = 4,026), we showed that a majority of subjects were willing to test despite mistrust and ignorance regarding rapid tests’ validity. Experimental evidence shows that low costs and access to events could increase testing intentions. Mandatory reporting and isolation after positive results were not identified as major barriers. Instead, assuming that testing and isolation can slow down the pandemic and the possibility to protect others were related to greater willingness to get tested. While we did not find evidence for risk compensation for past tests, experimental evidence suggests that there is a tendency to show less mask wearing and physical distancing in a group of tested individuals. A short communication intervention reduced complacent behavior. The derived recommendations could make rapid testing a successful pillar of pandemic management

    Unpacking the black box: Empirical evidence to understand the human factor for effective rapid testing against SARS-CoV2

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    SARS-CoV-2 rapid antigen point-of-care (PoC) and home tests are available to laypeople. This raises questions regarding the drivers and barriers of people’s willingness to use tests, their understanding of test results and the psychological and behavioural consequences of positive and negative test results. Four cross-sectional data collections, including survey items, open text answers and three experiments, were therefore conducted between December 2020 and March 2021, involving 4,026 German participants. The majority was willing to use PoC or home tests. People will be more likely to use tests when they are inexpensive and easy to use or when they are a necessary (given low infection rates) for obtaining access to public and social life. However, people urgently need information about what a test result means and how they should behave. Recommendations based on the present findings could make rapid testing a successful pillar of pandemic management

    Survival, Social Cohesion and Rock Art: The Painted Hands of Western Arnhem Land, Australia

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    This paper explores the complex story of a particular style of rock art in western Arnhem Land known as ‘Painted Hands’. Using new evidence from recent fieldwork, we present a definition for their style, distribution and place in the stylistic chronologies of this region. We argue these motifs played an important cultural role in Aboriginal society during the period of European settlement in the region. We explore the complex messages embedded in the design features of the Painted Hands, arguing that they are more than simply hand stencils or markers of individuality. We suggest that these figures represent stylized and intensely encoded motifs with the power to communicate a high level of personal, clan and ceremonial identity at a time when all aspects of Aboriginal cultural identity were under threat.Sally K. May, Luke Taylor, Catherine Frieman, Paul S.C. Taçon, Daryl Wesley, Tristen Jones, Joakim Goldhahn, Charlie Munguld

    Prediction of grip and key pinch strength in 978 healthy subjects

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    <p>Abstract</p> <p>Background</p> <p>Hand strength is an important independent surrogate parameter to assess outcome and risk of morbidity and mortality. This study aimed to determine the predictive power of cofactors and to predict population-based normative grip and pinch strength.</p> <p>Methods</p> <p>A representative population survey was used as the basis for prediction analyses (n = 978). Bivariate relationships between grip/pinch strengths of the dominate hand were explored by means of all relevant mathematical functions to maximize prediction. The resulting best functions were combined into a multivariate regression.</p> <p>Results</p> <p>Polynoms (up to the third degree) were the best predictive functions. On the bivariate level, height was best correlated to grip (46.2% explained variance) and pinch strength (37.7% explained variance) in a linear relationship, followed by sex, age, weight, and occupational demand on the hand. Multivariate regression provided predicted values close to the empirical ones explaining 76.6% of the variance for grip strength and 67.7% for pinch strength.</p> <p>Conclusion</p> <p>The five easy-to-measure cofactors sex, age, body height, categorized occupational demand on the hand, and body weight provide a highly accurate prediction of normative grip and pinch strength.</p
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