83 research outputs found

    Preface and acknowledgements

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    This collection is the outcome of a Maastricht Research Based Learning Project (MARBLE) that took place at the Faculty of Arts and Social Sciences at Maastricht University in spring 2011. Under the guidance of Jens Lachmund (who is a lecturer at that faculty) a group of nine students worked on eight distinct case-studies on the culture and politics of product labelling

    Comparison of Functional and Clinical Outcomes between Minimally-Invasive and Conventional Approaches after Total Hip Replacement

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    Background: Total Hip Arthroplasty (THA) is one of the most commonly performed and successful orthopaedic surgeries. At the same time, the issue about the best surgical approach for THA remains controversial. This systematic review aims to evaluate the current evidence for the use of Minimally-Invasive Surgery (MIS) in THA. Methods: A systematic literature search of PubMed, Medline and Embase was conducted. Randomised controlled trials, comparative studies, and cohort studies were included in this systematic review. Main outcome measurements included incision length, blood loss, operating time, length of stay, complications, postoperative pain on a Visual Analogue Scale (VAS), Short Form 36/12 Health Survey (SF 36/12), Harris Hip Score (HHS) and cup inclination. Results: A total of 30 studies met the inclusion criteria. There was no significant difference between MIS and conventional approaches for THA with regards to complication rates and implant inclination angle. The average operating time in 10/24 (41%) studies was significantly (p<0.05) longer in the MIS group. MIS THA lead to an improvement, patient-centered results with reduced blood loss in 9/16 (56%), reduced use of analgesics in 4/4 (100%) and reduced myoglobin correlated muscle trauma in 3/4 (75%) of the analysed studies. Additionally, 10/10 (100%) studies reported less postoperative pain after MIS THA, 16/19 (84%) studies detected an improved postoperative Harris Hip score and 7/7 (100%) studies an improved SF36/12 score respectively. This resulted a reduced length of stay in 10/10 (100%) of the studies when compared to THA utilizing a conventional approach. Conclusion: MIS in THA is nowadays no longer seen as just cosmetically attractive but rather as a real improvement for the clinical outcome. There is evidence for improved patient related outcome following MIS THA

    The final implant position of a commonly used collarless straight tapered stem design (Corail®) does not correlate with femoral neck resection height in cement-free total hip arthroplasty: a retrospective computed tomography analysis

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    Background In total hip arthroplasty, inadequate femoral component positioning can be associated with instability, impingement and component wear and subsequently with patient dissatisfaction. In this study, we investigated the influence of femoral neck resection height on the final three-dimensional position of a collarless straight tapered stem (Corail®). We asked two questions—(1) is neck resection height correlated with version, tilt, and varus/valgus alignment of the femoral component, and (2) dependent on the resection height of the femoral neck, which area of the stem comes into contact with the femoral cortical bone? Materials and methods Three-dimensional computed tomography scans of 40 patients who underwent minimally invasive, cementless total hip arthroplasty were analyzed retrospectively. We analyzed the relationship between femoral neck resection height and three-dimensional alignment of the femoral implant, as well as the contact points of the implant with the femoral cortical bone. This investigation was approved by the local Ethics Commission (No.10-121-0263) and is a secondary analysis of a larger project (DRKS00000739, German Clinical Trials Register May-02-2011). Results Mean femoral neck resection height was 10.4 mm (± 4.8) (range 0–20.1 mm). Mean stem version was 8.7° (± 7.4) (range − 2° to 27.9°). Most patients had a varus alignment of the implant. The mean varus/valgus alignment was 1.5° (± 1.8). All 40 patients (100%) had anterior tilt of the implant with a mean tilt of 2.2° (± 1.6). Femoral neck resection height did not correlate with stem version, varus/valgus alignment, or tilt. Independent from femoral neck resection height, in most patients the implant had contact with the ventral and ventromedial cortical bone in the upper third (77.5%) and the middle third (52.5%). In the lower third, the majority of the implants had contact with the lateral and dorsolateral cortical bone (92.5%). Conclusion Femoral neck resection height ranging between 0 and 20.1 mm does not correlate with the final position of a collarless straight tapered stem design (Corail®). Level of evidence Level 3

    Native femoral anteversion should not be used as reference in cementless total hip arthroplasty with a straight, tapered stem: a retrospective clinical study

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    Backround: Improper femoral and acetabular component positioning can be associated with instability, impingement, component wear and finally patient dissatisfaction in total hip arthroplasty (THA). The concept of "femur first"/" combined anteversion", incorporates various aspects of performing a functional optimization of the prosthetic stem and cup position of the stem relative to the cup intraoperatively. In the present study we asked two questions: (1) Do native femoral anteversion and anteversion of the implant correlate? (2) Do anteversion of the final broach and implant anteversion correlate? Methods: In a secondary analysis of a prospective controlled trial, a subgroup of 55 patients, who underwent computer-assisted, cementless THA with a straight, tapered stem through an anterolateral, minimally invasive (MIS) approach in a lateral decubitus position were examined retrospectivly. Intraoperative fluoroscopy was used to verify a "best-fit" position of the final broach. An image-free navigation system was used for measurement of the native femoral version, version of the final broach and the final implant. Femoral neck resection height was measured in postoperative CT-scans. This investigation was approved by the local Ethics Commission (No. 10-121-0263) and is a secondary analysis of a larger project (DRKS00000739, German Clinical Trials Register May-02-2011). Results: The mean difference between native femoral version and final implant was 1.9 degrees (+/-9.5), with a range from -20.7 degrees to 21.5 degrees and a Spearman's correlation coefficient of 0.39 (p < 0.003). In contrast, we observed a mean difference between final broach and implant version of -1.9 degrees (+/-3.5), with a range from -12.7 degrees to 8.7 degrees and a Spearman's correlation coefficient of 0.89 (p < 0.001). In 83.6 % (46/55) final stem version was outside the normal range as defined by Tonnis (15-20 degrees). The mean femoral neck resection height was 7.3 mm (+/-5.6). There was no correlation between resection height and version of the implant (Spearman's correlation coefficient 0.14). Conclusion: Native femoral version significantly differs from the final anteversion of a cementless, straight, tapered stem and therefore is not a reliable reference in cementless THA. Measuring anteversion of the final "fit and fill" broach is a feasible assistance in order to predict final stem anteversion intraoperatively. There is no correlation between femoral neck resection height and version of the implant

    Frequency chasing of individual megadalton ions in an Orbitrap analyser improves precision of analysis in single-molecule mass spectrometry

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    To enhance the performance of charge-detection mass spectrometry, we investigated the behaviour of macromolecular single ions on their paths towards and within the Orbitrap analyser. Ions with a mass beyond one megadalton reach a plateau of stability and can be successfully trapped for seconds, travelling a path length of multiple kilometres, thereby enabling precise mass analysis with an effective resolution of greater than 100,000 at a mass-to-charge ratio of 35,000. Through monitoring the frequency of individual ions, we show that these high-mass ions, rather than being lost from the trap, can gradually lose residual solvent molecules and, in rare cases, a single elementary charge. We also demonstrate that the frequency drift of single ions due to desolvation and charge stripping can be corrected, which improves the effective ion sampling 23-fold and gives a twofold improvement in mass precision and resolution. [Figure not available: see fulltext.

    Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary

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    This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions

    The Bose-Einstein Condensate and Cold Atom Laboratory

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    Microgravity eases several constraints limiting experiments with ultracold andcondensed atoms on ground. It enables extended times of flight withoutsuspension and eliminates the gravitational sag for trapped atoms. Theseadvantages motivated numerous initiatives to adapt and operate experimentalsetups on microgravity platforms. We describe the design of the payload,motivations for design choices, and capabilities of the Bose-Einstein Condensateand Cold Atom Laboratory (BECCAL), a NASA-DLR collaboration. BECCALbuilds on the heritage of previous devices operated in microgravity, featuresrubidium and potassium, multiple options for magnetic and optical trapping,different methods for coherent manipulation, and will offer new perspectives forexperiments on quantum optics, atom optics, and atom interferometry in theunique microgravity environment on board the International Space Station
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