31 research outputs found

    Bone remodeling around cementless tantalum cups

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    Purpose of the study.-Most studies have reported a significant decrease in periacetabular bone stock one year after implantation of a cementless cup. The purpose of this work was to study the bone-implant interface of the tantalum cup using plain X-rays and dual-energy X-ray absorptiometry (DEXA).Material and methods.-This retrospective analysis concerned 42 patients with a tantalum cup, Trabecular Metal (TM) (Zimmer, Warsaw, IN, USA). All hips had primary implantations, performed by one surgeon via the same approach and with the same postoperative rehabilitation protocol. Minimum follow-up was two years. The Harris clinical score, and radiographic (lucent lines and acetabular position) and densitometric (analysis of 3.3 mm of periacetabular bone in the three DeLee and Charnley zones) were recorded.Results.-At follow-up, the mean Harris score was 81. There were no implant malpositions (horizontal, vertical, inclination). Lucent lines were noted for 14% of the cups. Bone mineral density (BMD) was higher than generally observed with cementless cups (1.290 +/- 0.309g/cm(2)).Discussion.-The clinical and radiographic results are similar to data in the literature regarding correct implant position. The higher rate of lucent lines around the tantalum cup is also reported in the literature and is the result of the pressfit, resolving at one year. The greater BMD in zone 1 might reflect better force transfer to the weight-bearing zone.Conclusion.-As biomaterial recently introduced in orthopedic surgery, tantalum appears to provide a better force transfer to the central part of the iliac bone and thus possibly better preservation of pelvic bone stock. (C) 2008 Publie par Elsevier Masson SAS.</p

    Outcome of acute fulminant myocarditis in children

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    OBJECTIVES: To highlight clinical features and outcome of acute fulminant myocarditis (AFM) in children. METHODS: Diagnostic criteria were (1) the presence of severe and acute heart failure; (2) left ventricular dysfunction on echocardiography; (3) recent history of viral illness; and (4) no history of cardiomyopathy. RESULTS: Eleven children were included between 1998 and 2003, at a median age of 1 (0 to 9) year. Their mean left ventricular ejection fraction (LVEF) was 22 (SD 9)% at presentation. A virus was identified in five patients: human parvovirus B19 (n  =  2), Epstein–Barr (n  =  1), varicella zoster (n  =  1), and coxsackie (n = 1). The median intensive care unit course was 13 (2–34) days. Intravenous inotropic support was required by nine patients and eight were mechanically ventilated. All patients received corticosteroid, associated with intravenous immunoglobulin in seven. Five patients experienced cardiocirculatory arrest that was successfully resuscitated in four. At a median follow up of 58.7 (33.8–83.1) months, the 10 survivors are asymptomatic with normalised LVEF. CONCLUSION: Despite a severe presentation, the outcome of AFM is favourable. Aggressive symptomatic management is warranted and heart transplantation should be considered only when maximal supportive therapy does not lead to improvement

    Gas Stirling engine μCHP boiler experimental data driven model for building energy simulation

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    International audienceA dynamic model for the simulation of gas micro combined heat and power devices (μCHP boilers) has been developed in order to assess their energy performances. From a literature review and experimental investigations, the new model is designed with the aim of limiting the number of parameters which need to be easily accessible in order to be suitable with annual building energy simulations. At first, this paper focuses on the description of the μCHP boiler which has been tested, on the development of the test bench and on the experimental results. Then, it focuses on the model description, on its parameterization and on its validation. The modelling approach is based on an energy balance on the device and on empirical expressions for the main inputs and outputs. The model characterizes the μCHP boiler behaviour for different inlet water flow rates and temperatures. The dynamic phases with the start-up and cooling phases are taken into account. Finally, the models for the Stirling engine and the additional boiler are limited respectively to 28 and 24. Further experimental investigations led to simplify the μCHP model from 28 to 17 parameters without reducing the accuracy

    Dynamic model based on experimental investigations of a wood pellet steam engine micro CHP for building energy simulation

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    International audienceA wood pellet micro combined heat and power device (μCHP) has been tested in order to characterize its performances in steady and transient states. A dynamic model based on these experimental investigations has been developed in order to predict its energy performances and its pollutant emissions. The model is designed with a few parameters experimentally accessible. This model has been implemented in TRNSYS numerical environment. This work focuses on the experimental investigations and on the model description. The modelling approach is based on a physical part (an energy balance on the entire device and a combustion model), and on an empirical part (correlations for the fuel power input and for the thermal and electrical outputs). The model characterizes the μCHP behaviour for different part load ratios (PLR) (power modulation). The dynamic phases with start-up and cooling phases are also taken into account

    Adherence to treatment of osteoporosis: a need for study

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    Adherence to anti-osteoporosis medications is currently low and is associated with poor anti-fracture efficacy. This manuscript reviews the potential design of clinical studies that aim to demonstrate improved adherence, with new chemical entities to be used in the management of osteoporosis. Introduction Several medications have been unequivocally shown to decrease fracture rates in clinical trials. However, in real life settings, long-term persistence and compliance to anti-osteoporosis medication is poor, hence decreasing the clinical benefits for patients. Methods An extensive search of Medline from 1985 to 2006 retrieved all trials including the keywords osteoporosis, compliance, persistence or adherence followed by a critical appraisal of the data obtained through a consensus expert meeting. Results The impact of non-adherence on the clinical development of interventions is reviewed, so that clinicians, regulatory agencies and reimbursement agencies might be better informed of the problem, in order to stimulate the necessary research to document adherence. Conclusion Adherence to therapy is a major problem in the treatment of osteoporosis. Both patients and medication factors are involved. Adherence studies are an important aspect of outcomes studies, but study methodologies are not well developed at the moment and should be improved. Performing adherence studies will be stimulated when registration authorities accept the result of these studies and include the relevant information in Sect. 5.1 of the summary of product characteristics. Reimbursement authorities might also consider such studies as important information for decisions on reimbursement

    Time dependent risk of gastrointestinal complications induced by non-steroidal anti-inflammatory drug use: a consensus statement using a meta-analytic approach

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    Methods: An exhaustive systematic search was performed. Inclusion criteria were: RCT or controlled study, duration of 5 days at least, inactive control, assessment of minor or major NSAID adverse effects, publication range January 1985 to January 2003. The publications retrieved were assessed during a specifically dedicated WHO meeting including leading experts in all related fields. Statistics were performed conservatively. Meta-regression was performed by regressing NSAID adjusted estimates against study duration categories. Results: Among RCT data, indolic derivates provided a significantly higher risk of GI complications related to NSAID use than for non-users: RR = 2.25 (1.00; 5.08) than did other compounds: naproxen: RR = 1.83 (1.25; 2.68); diclofenac: RR = 1.73 (1.21; 2.46); piroxicam: RR = 1.66 (1.14; 2.44); tenoxicam: RR = 1.43 (0.40; 5.14); meloxicam: RR = 1.24 (0.98; 1.56), and ibuprofen: RR = 1.19 (0.93; 1.54). Indometacin users had a maximum relative risk for complication at 14 days. The other compounds presented a better profile, with a maximum risk at 50 days. Significant additional risk factors included age, dose, and underlying disease. The controlled cohort studies provided higher estimates: RR = 2.22 (1.7; 2.9). Publication bias testing was significant, towards a selective publication of deleterious effects of NSAIDs from small sized studies. Conclusion: This meta-analysis characterised the "compound" and "time" aspects of the GI toxicity of non-selective NSAIDs. The risk/benefit ratio of such compounds should thus be carefully and individually evaluated at the start of long term treatment
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