219 research outputs found

    An In Vitro Study Comparing Limited to Full Cementation of Polyethylene Glenoid Components

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    BACKGROUND: Glenoid component survival is critical to good long-term outcomes in total shoulder arthroplasty. Optimizing the fixation environment is paramount. The purpose of this study was to compare two glenoid cementing techniques for fixation in total shoulder arthroplasty. METHODS: Sixteen cadaveric specimens were randomized to receive peg-only cementation (CPEG) or full back-side cementation (CBACK). Physiological cyclic loading was performed and implant displacement was recorded using an optical tracking system. The cement mantle was examined with micro-computed tomography before and after cyclic loading. RESULTS: Significantly greater implant displacement away from the inferior portion of the glenoid was observed in the peg cementation group when compared to the fully cemented group during the physiological loading. The displacement was greatest at the beginning of the loading protocol and persisted at a diminished rate during the remainder of the loading protocol. Micro-CT scanning demonstrated that the cement mantle remained intact in both groups and that three specimens in the CBACK group demonstrated microfracturing in one area only. DISCUSSION: Displacement of the CPEG implants away from the inferior subchondral bone may represent a suboptimal condition for long-term implant survival. Cement around the back of the implant is suggested to improve initial stability of all polyethylene glenoid implants. CLINICAL RELEVANCE: Full cementation provides greater implant stability when compared to limited cementation techniques for insertion of glenoid implants. Loading characteristics are more favorable when cement is placed along the entire back of the implant contacting the subchondral bone

    Five-year publication rate of clinical presentations at the open and closed American shoulder and elbow surgeons annual meeting from 2005–2010

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    © 2016, The Author(s). Background: The purpose of this study was to evaluate the five-year publication rate of papers presented at both the open and closed American Shoulder and Elbow Surgeons’ (ASES) annual meetings from 2005 to 2010. Methods: Online abstracts of the presentations at the open and closed ASES annual meetings were independently screened for clinical studies and graded for quality using level of evidence. The databases PubMed (MEDLINE), Ovid (MEDLINE), and EMBASE were comprehensively searched for full-text publications corresponding to these presentations and any paper published within five years of the presentation date was counted. Results: Overall, 131/266 papers corresponding to the meeting presentations were identified for a five-year publication rate of 49.2 %. Sixty two (48 %) of the papers were published in The Journal of Shoulder and Elbow Surgeons, 23 (18 %) were published in The American Journal of Sports Medicine, and 20 (16 %) were published in The Journal of Bone and Joint Surgery. The mean patient sample size included in presentations with a subsequent full-text publication was higher (154; standard error =27) than the presentations not published (93; standard error = 13) (p = 0.039). There was no correlation (p = 0.248) between the publication rate and the level of evidence of the presentations. Conclusions: The publication rate of presentations at ASES meetings from 2005 to 2010 is similar to that reported from other orthopaedic meetings. Studies with large sample sizes should continue to be encouraged, and high quality presentations must consistently be followed up with full-text manuscript preparation in order to maximize the future clinical impact

    Level of clinical evidence presented at the open and closed American Shoulder and Elbow Surgeons annual meeting over 10 years (2005-2014)

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    © 2016 The Author(s). Background: The American Shoulder and Elbow Surgeons (ASES) annual scientific meetings are premier forums whereby orthopaedic surgeons are informed of the latest research advances in shoulder and elbow surgery. The purpose of the present study was to assess the Level of evidence (LOE) in the clinical papers presented at both the open and closed ASES annual scientific meetings from 2005 to 2014. Secondarily, the study evaluated whether there were any changes in the distribution of LOE over this period of time. Methods: Two reviewers independently evaluated the abstracts of 532 paper presentations at either the open or closed ASES annual meetings. The independent reviewers first screened the abstracts for clinical evidence and excluded cadaveric, biomechanical, technique, and review studies. The included abstracts were then independently graded for methodological quality using LOE from Level I (highest quality) to IV (lowest quality) based on the classification system created by The American Academy of Orthopaedic Surgeons (AAOS). Results: Overall, 421 presentations were included and graded for LOE. In general, 17% of the presentations were graded level I; 15% level II; 25% level III; and 43% assigned a LOE of IV. Chi-square analysis demonstrated a statistically significant improvement in the LOE of presentations at the open and closed ASES meetings combined (p = 0.028) between the years 2005 and 2014. In particular, the proportion of presentations graded as level IV significantly decreased over this period (p = \u3c0.001). Conclusions: While most presentations at the ASES annual scientific meetings were of lower LOEs the percentage of level I evidence is greater than that reported at other Orthopaedic meetings. There has been a significant improvement in the LOE of clinical research at open and closed ASES meetings from 2005 to 2014. Specifically, the proportion of level IV studies have dramatically decreased over time

    Using a machine learning model to risk stratify for the presence of significant liver disease in a primary care population

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    Background: Current strategies for detecting significant chronic liver disease (CLD) in the community are based on the extrapolation of diagnostic tests used in secondary care settings. Whilst this approach provides clinical utility, it has limitations related to diagnostic accuracy being predicated on disease prevalence and spectrum bias, which will differ in the community. Machine learning (ML) techniques provide a novel way of identifying significant variables without preconceived bias. As a proof-of-concept study, we wanted to examine the performance of nine different ML models based on both risk factors and abnormal liver enzyme tests in a large community cohort.Methods: Routine demographic and laboratory data was collected on 1,453 patients with risk factors for CLD, including high alcohol consumption, diabetes and obesity, in a community setting in Nottingham (UK) as part of the Scarred Liver project. A total of 87 variables were extracted. Transient elastography (TE) was used to define clinically significant liver fibrosis. The data was split into a training and hold out set. The median age of the cohort was 59, mean body mass index (BMI) 29.7 kg/m2, median TE 5.5 kPa, 49.2% had type 2 diabetes and 20.3% had a TE >8 kPa.Results: The nine different ML models, which included Random Forrest classifier, Support Vector classification and Gradient Boosting classifier, had a range of area under the curve (AUC) statistics of 0.5 to 0.75. Ensemble Stacker model showed the best performance, and this was replicated in the testing dataset (AUC 0.72). Recursive feature elimination found eight variables had a significant impact on model output. The model had superior sensitivity (74%) compared to specificity (60%).Conclusions: ML shows encouraging performance and highlights variables that may have bespoke value for diagnosing community liver disease. Optimising how ML algorithms are integrated into clinical pathways of care and exploring new biomarkers will further enhance diagnostic utility

    Intraosseous foreign body granuloma in rotator cuff repair with bioabsorbable suture anchor

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    Biodegradable implants lead to problems such as cyst formation, soft-tissue inflammation, loose implant fragments or local osteolysis. This report represents the first published case of an intraosseous foreign body granuloma in the humeral head after arthroscopic rotator cuff tear fixation with a poly-l-lactide (PLLA) suture anchor. A 48-year-old female patient presented with pain in her right shoulder. A refixation of her right supraspinatus tendon with a biodegradable suture anchor was performed 11 months ago at an external hospital. Laboratory tests showed normal values for C-reactive protein, leukocytes and the erythrocyte sedimentation rate. No signs of infection or instability were noted. The visual analogue scale (VAS) was 8, the simple shoulder test (SST) was 4 and the American shoulder and elbow surgeons score (ASES) was 44. Plain radiographs showed high lucency in the area of the tuberculum majus. MRI showed an intra- and extraosseous mass surrounded by fluid in this area. Surgical care involved arthroscopic debridement and removal of the suture anchor. Histological examination revealed a foreign body granuloma. At the 18-month follow-up the patient was nearly pain-free. The VAS was 2, SST was 10 and ASES was 88. Foreign body granulomas are a well known but rarely described complication that arises after the use of biodegradable suture anchors in shoulder surgery. Every patient presenting with shoulder pain after usage of a biodegradable fixation material should be evaluated closely. Orthopaedic surgeons should be aware of the possibility of delayed foreign body reactions, especially after using PLLA anchors

    Basic mechanisms of urgency: roles and benefits of pharmacotherapy

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    Introduction Since urgency is key to the overactive bladder syndrome, we have reviewed the mechanisms underlying how bladder filling and urgency are sensed, what causes urgency and how this relates to medical therapy. Materials and methods Review of published literature. Results As urgency can only be assessed in cognitively intact humans, mechanistic studies of urgency often rely on proxy or surrogate parameters, such as detrusor overactivity, but these may not necessarily be reliable. There is an increasing evidence base to suggest that the sensation of ‘urgency’ differs from the normal physiological urge to void upon bladder filling. While the relative roles of alterations in afferent processes, central nervous processing, efferent mechanisms and in intrinsic bladder smooth muscle function remain unclear, and not necessarily mutually exclusive, several lines of evidence support an important role for the latter. Conclusions A better understanding of urgency and its causes may help to develop more effective treatments for voiding dysfunction

    Stressful situation if CENP-A not front and CENter

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    The exclusive localization of the histone H3 variant CENP-A to centromeres is essential for accurate chromosome segregation. Ubiquitin-mediated proteolysis helps to ensure that CENP-A does not mislocalize to euchromatin, which can lead to genomic instability. Consistent with this, overexpression of the budding yeast CENP-A(Cse4) is lethal in cells lacking Psh1, the E3 ubiquitin ligase that targets CENP-A(Cse4) for degradation. To identify additional mechanisms that prevent CENP-A(Cse4) misincorporation and lethality, we analyzed the genome-wide mislocalization pattern of overexpressed CENP-A(Cse4) in the presence and absence of Psh1 by chromatin immunoprecipitation followed by high throughput sequencing. We found that ectopic CENP-A(Cse4) is enriched at promoters that contain histone H2A.Z(Htz1) nucleosomes, but that H2A.Z(Htz1) is not required for CENP-A(Cse4) mislocalization. Instead, the INO80 complex, which removes H2A.Z(Htz1) from nucleosomes, promotes the ectopic deposition of CENP-A(Cse4). Transcriptional profiling revealed gene expression changes in the psh1Δ cells overexpressing CENP-A(Cse4). The down-regulated genes are enriched for CENP-A(Cse4) mislocalization to promoters, while the up-regulated genes correlate with those that are also transcriptionally up-regulated in an htz1Δ strain. Together, these data show that regulating centromeric nucleosome localization is not only critical for maintaining centromere function, but also for ensuring accurate promoter function and transcriptional regulation

    Quantitative Microscopy Reveals Centromeric Chromatin Stability, Size, and Cell Cycle Mechanisms to Maintain Centromere Homeostasis

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    The deposited item is a book chapter and is part of the series "Centromeres and Kinetochores" published by the publisher Springer Verlag. The deposited book chapter is a post-print version and has been submitted to peer reviewing. There is no public supplementary material available for this publication. This publication hasn't any creative commons license associated.Centromeres are chromatin domains specified by nucleosomes containing the histone H3 variant, CENP-A. This unique centromeric structure is at the heart of a strong self-templating epigenetic mechanism that renders centromeres heritable. We review how specific quantitative microscopy approaches have contributed to the determination of the copy number, architecture, size, and dynamics of centromeric chromatin and its associated centromere complex and kinetochore. These efforts revealed that the key to long-term centromere maintenance is the slow turnover of CENP-A nucleosomes, a critical size of the chromatin domain and its cell cycle-coupled replication. These features come together to maintain homeostasis of a chromatin locus that directs its own epigenetic inheritance and facilitates the assembly of the mitotic kinetochore.There are no funders and sponsors indicated explicitly in the document.info:eu-repo/semantics/publishedVersio

    Automatic Detection of User Abilities through the SmartAbility Framework

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    This paper presents a proposed smartphone application for the unique SmartAbility Framework that supports interaction with technology for people with reduced physical ability, through focusing on the actions that they can perform independently. The Framework is a culmination of knowledge obtained through previously conducted technology feasibility trials and controlled usability evaluations involving the user community. The Framework is an example of ability-based design that focuses on the abilities of users instead of their disabilities. The paper includes a summary of Versions 1 and 2 of the Framework, including the results of a two-phased validation approach, conducted at the UK Mobility Roadshow and via a focus group of domain experts. A holistic model developed by adapting the House of Quality (HoQ) matrix of the Quality Function Deployment (QFD) approach is also described. A systematic literature review of sensor technologies built into smart devices establishes the capabilities of sensors in the Android and iOS operating systems. The review defines a set of inclusion and exclusion criteria, as well as search terms used to elicit literature from online repositories. The key contribution is the mapping of ability-based sensor technologies onto the Framework, to enable the future implementation of a smartphone application. Through the exploitation of the SmartAbility application, the Framework will increase technology amongst people with reduced physical ability and provide a promotional tool for assistive technology manufacturers
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