444 research outputs found

    Prevalence, incidence, and risk factors for shoulder and neck dysfunction after neck dissection: a systematic review

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    Introduction Shoulder pain and dysfunction may occur following neck dissection among people being treated for head and neck cancer. This systematic review aims to examine the prevalence and incidence of shoulder and neck dysfunction after neck dissection and identify risk factors for these post-operative complications. Methods Electronic databases (Pubmed, CINAHL, EMBASE, Cochrane) were searched for articles including adults undergoing neck dissection for head and neck cancer. Studies that reported prevalence, incidence or risk factors for an outcome of the shoulder or neck were eligible and assessed using the Critical Review Form – Quantitative Studies. Results Seventy-five articles were included in the final review. Prevalence rates for shoulder pain were slightly higher after RND (range, 10–100%) compared with MRND (range, 0–100%) and SND (range, 9–25%). The incidence of reduced shoulder active range of motion depended on surgery type (range, 5–20%). The prevalence of reduced neck active range of motion after neck dissection was 1–13%. Type of neck dissection was a risk factor for shoulder pain, reduced function and health-related quality of life. Conclusions The prevalence and incidence of shoulder and neck dysfunction after neck dissection varies by type of surgery performed and measure of dysfunction used. Pre-operative education for patients undergoing neck dissection should acknowledge the potential for post-operative shoulder and neck problems to occur and inform patients that accessory nerve preservation lowers, but does not eliminate, the risk of developing musculoskeletal complications

    Surface topography of hydroxyapatite affects ROS17/2.8 cells response

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    Hydroxyapatite (HA) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute. The aim of this investigation was to study the effect of surface topography produced by the presence of microporosity on cell response, evaluating: cell attachment, cell morphology, cell proliferation, total protein content, and alkaline phosphatase (ALP) activity. HA discs with different percentages of microporosity (< 5%, 15%, and 30%) were confected by means of the combination of uniaxial powder pressing and different sintering conditions. ROS17/2.8 cells were cultured on HA discs. For the evaluation of attachment, cells were cultured for two hours. Cell morphology was evaluated after seven days. After seven and fourteen days, cell proliferation, total protein content, and ALP activity were measured. Data were compared by means of ANOVA and Duncan’s multiple range test, when appropriate. Cell attachment (p = 0.11) and total protein content (p = 0.31) were not affected by surface topography. Proliferation after 7 and 14 days (p = 0.0007 and p = 0.003, respectively), and ALP activity (p = 0.0007) were both significantly decreased by the most irregular surface (HA30). These results suggest that initial cell events were not affected by surface topography, while surfaces with more regular topography, as those present in HA with 15% or less of microporosity, favored intermediary and final events such as cell proliferation and ALP activity

    Wear of composite ceramics in mixed-material combinations in total hip replacement under adverse edge loading conditions

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    Further development of ceramic materials for total hip replacement aim to increase fracture toughness and further reduce the incidence of bearing fracture. Edge loading due to translational mal positioning (microseparation) has replicated stripe wear, wear rates, and bimodal wear debris observed on retrievals. This method has replicated the fracture of early zirconia ceramic-on-ceramic bearings. This has shown the necessity of introducing microseparation conditions to the gait cycle when assessing the tribological performance of new hip replacement bearings. Two novel ceramic matrix composite materials, zirconia-toughened alumina (ZTA) and alumina-toughened zirconia (ATZ), were developed by Mathys Orthop€adie GmbH. In this study, ATZon- ATZ and ZTA-on-ZTA bearing combinations were tested and compared with alumina-on-alumina (Al2O3-on-Al2O3) bearings under adverse microseparation and edge loading conditions using the Leeds II physiological anatomical hip joint simulator. The wear rate (695% confidence limit) of ZTA-on-ZTA was 0.1460.10 mm3/million cycles and that of ATZ-on-ATZ was 0.0660.004 mm3/million cycles compared with a wear rate of 0.7461.73 mm3/million cycles for Al2O3- on-Al2O3 bearings. Stripe wear was evident on all bearing combinations; however, the stripe formed on the ATZ and ZTA femoral heads was thinner and shallower that that formed on the Al2O3 heads. Posttest phase composition measurements for both ATZ and ZTA materials showed no significant change in the monoclinic zirconia content. ATZon- ATZ and ZTA-on-ZTA showed superior wear resistance properties when compared with Al2O3-on-Al2O3 under adverse edge loading conditions. VC 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000–000, 2013

    Method for volumetric assessment of edge-wear in ceramic-on-ceramic acetabular liners

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    This paper details a novel method to characterize and quantify edge wear patterns in ceramic-on-ceramic acetabular liners using a roundness measurement machine to measure the post-wear surface. A 3D surface map is produced which encompasses the measured surface covering the wear patch, the uncontrolled edge geometry and form of the bearing surface. The data is analysed to quantify linear penetration and volume. The developed method was applied in a blind study to a set of six 36 mm ceramic- on-ceramic acetabular cup liners that were measured and analysed to characterise the edge wear. The in-vitro linear wear penetration ranged from 10 μm to 30 μm. The computed volumetric wear results obtained from the blind roundness measurement study were compared against the measured gravimetric results indicating a strong correlation between the results (0.9846). This study has also highlighted that measured liners exhibited an area of localised edge wear locates above the bearing surface as well as a smearing effect on the bearing surface caused by debris from edge wear. A study was carried out to test the repeatability of the measurement method and the inter-operator variability of the analysis. The results of the study show a standard deviation for the entire measurement and analysis process of 0.009 mm3 for first user and 0.003 mm3 for second user over twenty datasets. Hence the method displays high repeatability of the measurement and analysis process between users. This method allows for the delineation of form and wear through the determination of local geometry changes on what is essentially a freeform surface. The edge geometry is only partially controlled from a GD&T perspective and its geometry relative to the bearing surface varies from part-to-part. This method whilst being subjective allows for the determination of wear in this area with a high level of repeatability. However the limitation of this method is that it can only measure 5mm wide band of the liner due to the limited gauge travel range of 2mm

    Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene

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    The Amundsen Sea Low (ASL) plays a major role in the climate and environment of Antarctica and the Southern Ocean, including surface air temperature and sea ice concentration changes. Unfortunately, a relative dearth of observational data across the Amundsen and Bellingshausen seas prior to the satellite era (post-1979) limits our understanding of the past behaviour and impact of the ASL. The limited proxy evidence for changes in the ASL are primarily restricted to the Antarctic where ice core evidence suggests a deepening of the atmospheric pressure system during the late Holocene. However, no data have previously been reported from the northern side of the ASL. Here we report a high-resolution, multi-proxy study of a 5000-year-long peat record from the Falkland Islands, a location sensitive to contemporary ASL dynamics which modulates northerly and westerly airflow across the southwestern South Atlantic sector of the Southern Ocean. In combination with climate reanalysis, we find a marked period of wetter, colder conditions most likely the result of enhanced southerly airflow between 5000 and 2500 years ago, suggesting limited ASL influence over the region. After 2500 years ago, drier and warmer conditions were established, implying more westerly airflow and the increased projection of the ASL onto the South Atlantic. The possible role of the equatorial Pacific via atmospheric teleconnections in driving this change is discussed. Our results are in agreement with Antarctic ice core records and fjord sediments from the southern South American coast, and suggest that the Falkland Islands provide a valuable location for reconstructing high southern latitude atmospheric circulation changes on multi-decadal to millennial timescales

    Textured shoe insoles to improve balance performance in adults with diabetic peripheral neuropathy: study protocol for a randomised controlled trial

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    IntroductionPeripheral neuropathy is a major risk factor for falls in adults with diabetes. Innovative footwear devices which artificially manipulate the sensory environment at the feet, such as textured shoe insoles, are emerging as an attractive option to mitigate balance and walking problems in neuropathic populations. This study aims to explore whether wearing textured insoles for 4 weeks alters balance performance in adults with diabetic peripheral neuropathy.Methods and analysisA prospective, single-blinded randomised controlled trial with parallel groups will be conducted on 70 adults with diabetic peripheral neuropathy. Adults with a diagnosis of peripheral neuropathy (secondary to type 2 diabetes), aged ≥18 years, ambulant over 20 m (with/without an assistive device), will be recruited. Participants will be randomised to receive a textured insole (n=35) or smooth insole (n=35), to be worn for 4 weeks. During baseline and post intervention assessments, standing balance (foam/firm surface; eyes open/closed) and walking tasks will be completed barefoot, wearing standard shoes only, and two different insoles (smooth, textured). The primary outcome measure will be centre of pressure (CoP) velocity, with higher values indicating poorer balance. Secondary outcome measures include walking quality (gait velocity, base of support, stride length and double-limb support time), physical activity levels, foot sensation (light-touch pressure, vibration) and proprioception (ankle joint position sense), and other balance parameters (CoP path length, anteroposterior and mediolateral excursion). Patient-reported outcomes will be completed evaluating foot health, frequency of falls and fear of falling. Data will be analysed using a repeated measures mixed models approach (including covariates) to establish any differences between-groups, for all outcome measures, over the intervention period.Ethics and disseminationEthical approval has been obtained from the institutional Human Research Ethics Committee (#2017000098). Findings will be disseminated at national and international conferences, through peer-reviewed journals, workshops and social media.Trial registration numberACTRN12617000543381; Pre-results.</jats:sec

    First evidence for human occupation of a lava tube in Arabia: The archaeology of Umm Jirsan Cave and its surroundings, northern Saudi Arabia

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    Recent advances in interdisciplinary archaeological research in Arabia have focused on the evolution and historical development of regional human populations as well as the diverse patterns of cultural change, migration, and adaptations to environmental fluctuations. Obtaining a comprehensive understanding of cultural developments such as the emergence and lifeways of Neolithic groups has been hindered by the limited preservation of stratified archaeological assemblages and organic remains, a common challenge in arid environments. Underground settings like caves and lava tubes, which are prevalent in Arabia but which have seen limited scientific exploration, offer promising opportunities for addressing these issues. Here, we report on an archaeological excavation and a related survey at and around Umm Jirsan lava tube in the Harrat Khaybar, north-western Saudi Arabia. Our results reveal repeated phases of human occupation of the site ranging from at least the Neolithic through to the Chalcolithic/Bronze Age. Pastoralist use of the lava tube and surrounding landscape is attested in rock art and faunal records, suggesting that Umm Jirsan was situated along a pastoral route linking key oases. Isotopic data indicates that herbivores primarily grazed on wild grasses and shrubs rather than being provided with fodder, while humans had a diet consistently high in protein but with increasing consumption of C3 plants through-time, perhaps related to the emergence of oasis agriculture. While underground and naturally sheltered localities are globally prominent in archaeology and Quaternary science, our work represents the first such combined records for Saudi Arabia and highlight the potential for interdisciplinary studies in caves and lava tubes

    Effects of different lower-limb sensory stimulation strategies on postural regulation – A systematic review and meta-analysis

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    Systematic reviews of balance control have tended to only focus on the effects of single lower-limb stimulation strategies, and a current limitation is the lack of comparison between different relevant stimulation strategies. The aim of this systematic review and meta-analysis was to examine evidence of effects of different lower-limb sensory stimulation strategies on postural regulation and stability. Moderate- to high- pooled effect sizes (Unbiased (Hedges’ g) standardized mean differences (SMD) = 0.31 – 0.66) were observed with the addition of noise in a Stochastic Resonance Stimulation Strategy (SRSS), in three populations (i.e., healthy young adults, older adults, and individuals with lower-limb injuries), and under different task constraints (i.e., unipedal, bipedal, and eyes open). A Textured Material Stimulation Strategy (TMSS) enhanced postural control in the most challenging condition – eyes-closed on a stable surface (SMD = 0.61), and in older adults (SMD = 0.30). The Wearable Garments Stimulation Strategy (WGSS) showed no or adverse effects (SMD = -0.68 – 0.05) under all task constraints and in all populations, except in individuals with lower-limb injuries (SMD = 0.20). Results of our systematic review and meta-analysis revealed that future research could consider combining two or more stimulation strategies in intervention treatments for postural regulation and balance problems, depending on individual need

    The effects of prolonged wear of textured shoe insoles on gait, foot sensation and proprioception in people with Multiple Sclerosis: protocol for a randomised controlled trial

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    Background: Many people with multiple sclerosis experience problems with walking, which can make daily activities difficult and often leads to falls. Foot sensation plays an important role in keeping the body balanced whilst walking; however, people with multiple sclerosis often have poor sensation on the soles of their feet. Wearing a specially designed shoe insole, which enhances plantar sensory information, could help people with multiple sclerosis to walk better. This study will explore whether long-term wear of a textured insole can improve walking in people with multiple sclerosis
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