142 research outputs found

    Mechanical analysis of cranial distractor attachment with three different resorbable fixation systems

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    Distraction osteogenesis (DO) has become increasingly popular to correct craniosynostosis. Disadvantages of DO include the secondary operation needed for device removal and titanium screw related dura injury. To reduce invasiveness of the secondary device removal operation and to overcome titanium-related problems, fixation of the cranial distractor with resorbable materials is a potential alternative. New resorbable fixation methods, such as ultrasound-activated pins (UAPs) or heat-activated pins (HAPs), allow faster attachment on thinner bone than conventional resorbable screws (CRSs) since tapping is not required. However, resorbable materials are designed to be attached with a resorbable plate, not with a titanium distractor. We evaluated the suitability of CRSs, HAPs and UAPs for the cranial distractor fixation in a laboratory setting with a mechanical testing machine. Fracture tests were conducted in two directions with respect to the longitudinal axis; vertical i.e. axial pull-out strength, and horizontal i.e. shear strength. Mean maximum pull-out strength for CRS, HAP and UAP was 48.9 N, 32.5 N and 14.7 N, respectively. Mean maximum shear strength for CRS, HAP and UAP was 40.8 N, 77.9 N and 38.9 N, respectively. According to our in vitro tests, the cranial distractor attachment with four CRSs or six HAPs per footplate would provide sufficient fixation stability. (C) 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Promoting ossification of calvarial defects in craniosynostosis surgery by demineralized bone plate and bone dust in different age groups

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    Correction of calvarial defects after calvarial vault reconstruction (CVR) is challenging in craniosynostosis patients of advanced age and typically employs autologous bone. Demineralized bone matrix (DBM) is a potential alternative material for autologous bone, but its use has not been extended to correct calvarial defects. CVR patients operated at the Department of Plastic Surgery, Helsinki University Hospital, during 2008-2010 were retrospectively reviewed. Inclusion criteria of the study were CVR patients who received DBM plate, with or without bone dust, on calvarial defects and who had suitable uncovered defect on the contralateral side as control. This study included 17 craniosynostosis and one positional plagiocephaly patient, whose mean age was 6.9 years (range 0.9-19 years). The mean follow-up time was 5.6 years. The fusion degree of all defects was measured from 1 week to 1 year postoperatively using three-dimensional computed tomography (3D CT) images by the OsiriX (R) method. Medical records were reviewed for DBM-related complications. A total of 26 defects were covered with a DBM plate (mean area 11.1 cm(2)) and 26 control defects were identified (mean area 7.8 cm2). The mean fusion degree of the DBM defects was 74% and 54% for the controls (p 30 months) than in younger patients or when used with bone dust. (C) 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Force measurements during posterior calvarial vault osteodistraction : A novel measurement method

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    Posterior calvarial vault osteodistraction (PCVO) has become increasingly popular in the correction of craniosynostosis. When compared to cranioplasty, PCVO offers a shorter, less invasive operation, greater intracranial volume advancement and a lower rate of relapse. In general, distraction protocols are based primarily on clinical observations rather than systematic research. Faster distraction protocols may reduce complications. However, distraction protocols producing higher forces can increase complications. Thus, we need to understand these forces in order to improve distraction protocols and devices. We developed a force measurement method that can be used on PCVO devices. Here, we present preliminary data about the forces developed during PCVO. We measured the forces in four bicoronal craniosynostosis patients during PCVO. We observed a linear-like trend between the force increase and the distraction distance within distraction sessions. We also observed a step-wise force increase between distraction sessions and found that the distraction force relaxed rapidly shortly after the distraction session. The mean maximum pre distraction force for one distracter was 20.4 N, while the mean maximum end-distraction force for one distracter was 57.6 N. Our data suggests that current treatment protocols might be re-evaluated favouring shorter distraction distances and more frequent distraction sessions. (C) 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Comparison of postoperative skeletal stability of maxillary segments after Le Fort I osteotomy, using patient-specific implant versus mini-plate fixation

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    Background: Three-dimensionally (3D) designed osteotomies and customised osteosynthesis are rapidly becoming standard in maxillofacial reconstructive and deformity surgery. Patient-specific implants (PSIs) have been in use for a few years in orthognathic surgery as well. In Le Fort I osteotomy, wafer-free fixation of the maxillary segment can be performed by individually manufactured cutting and drill guides together with PSIs. Aim: This retrospective study was performed to compare the postoperative skeletal stability of the maxillary segment fixed by patient-specific implants versus mini-plates after Le Fort I osteotomy. Patients: Fifty-one patients were divided into subgroups according to the fixation method and the advancement of the sub-spinal point. The postoperative skeletal stability of the maxillary segment was evaluated from lateral cephalometric radiographs one year postoperatively. Results: No statistically significant differences were found between the postoperative skeletal stability of the PSI and mini-plate fixed maxillae. Prospective studies, possibly with 3D fusion analysis, are warranted to confirm the results. Conclusion: The choice between the two fixation methods does not seem to affect the postoperative skeletal stability of the maxillary segments. (C) 2019 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Cost-Effectiveness Modelling of Sequential Biologic Strategies for the Treatment of Moderate to Severe Rheumatoid Arthritis in Finland

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    Abstract: Objective: The main objective was to compare the cost-effectiveness of therapeutic options in moderate or severe rheumatoid arthritis (RA) when a clinical response to a first TNF-blocker, either etanercept (ETA), adalimumab (ADA), or infliximab (INF), is insufficient. Methods: Effectiveness criteria were defined as remission (RS), low disease activity (LDAS), and moderate to high disease activity (MHDAS). Cost-effectiveness was derived as cost per day in RS and in LDAS using simulation modelling to assess six sequential biologic strategies over 2 years. Each sequential treatment strategy was composed of three biologic agents and included a first anti-TNF agent, ETA, ADA or INF, followed by either abatacept (ABA) or rituximab (RTX) as a second therapeutic option in case of an insufficient response, followed by another anti-TNF agent in case of further insufficient response. Results: Over two years and taking into account biologic costs, the following estimated mean costs per day in RS and LDAS were respectively of �829 and �428 for the biologic sequence composed of ADA-ABA-ETA, �1292 and �516 for the sequence ADA-RTX-ETA, �829 and �429 for the sequence ETA-ABA-ADA, �1292 and �517 for the sequence ETA-RTX-ADA, �840 and �434 for the sequence INF-ABA-ETA, and �1309 and �523 for the sequence INF-RTX-ETA. Conclusion: The treatment sequences including ABA as the second biologic option appear more cost-effective than those including RTX in a patients with moderate to severe RA and an insufficient response to a first anti-TNF agent. Keywords: Cost-effectiveness, rheumatoid arthritis, biologics, modelling

    Of all foods bread is the most noble: Carl von Linné (Carl Linneaus) on bread1

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    Carl von Linné was interested in dietetics, which in his time covered all aspects of a healthy life. As a utilitarian he understood the importance of private economy and paid attention to bread in many of his publications. Two texts, Ceres noverca arctoum and De pane diaetetico, were wholly devoted to bread and bread-making. Linné classified different types of bread, and described their nutritional value and health-related aspects, as well as milling, baking and storing, in detail. While discussing the food habits of social classes Linné accepted as a fact that the peasants and the poor should eat less tasty bread than the rich. The less palatable bread had, however, many nutritional and health advantages. Linné paid much attention to substitutes for grain to be used in times of famine, an important topic in eighteenth century Sweden. He regarded flour made of pine bark or water arum roots as excellent famine food, was enthusiastic about the new plant, maize, but considered potato only as a poor substitute for grain. Linné and his followers praised bread not only as the core component of diet, but also for its versatile role both in health and in disease

    A Photo Score for Aesthetic Outcome in Sagittal Synostosis:An ERN CRANIO Collaboration

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    European Reference Network (ERN) CRANIO is focused on optimizing care for patients with rare or complex craniofacial anomalies, including craniosynostosis and/or rare ear, nose, and throat disorders. The main goal of ERN CRANIO is to collect uniform data on treatment outcomes for multicenter comparison. We aimed to develop a reproducible and reliable suture-specific photo score that can be used for cross-center comparison of phenotypical severity of sagittal synostosis and aesthetic outcome of treatment. We conducted a retrospective study among nonsyndromic sagittal synostosis patients aged &lt;19 years. We included preoperative and postoperative photo sets from 6 ERN CRANIO centers. Photo sets included bird's eye, lateral, and anterior-posterior views. The sagittal synostosis photo score was discussed in the working group, and consensus was obtained on its contents. Interrater agreement was assessed with weighted Fleiss' Kappa and intraclass correlation coefficients.The photo score consisted of frontal bossing, elongated skull, biparietal narrowness, temporal hollowing, vertex line depression, occipital bullet, and overall phenotype. Each item was scored as normal, mild, moderate, or severe. Results from 36 scaphocephaly patients scored by 20 raters showed kappa values ranging from 0.38 [95% bootstrap CI: 0.31, 0.45] for biparietal narrowness to 0.56 [95% bootstrap CI: 0.47, 0.64] for frontal bossing. Agreement was highest for the sum score of individual items [intraclass correlation coefficients agreement 0.69 [95% CI: 0.57, 0.82]. This is the first large-scale multicenter study in which experts investigated a photo score to assess the severity of sagittal synostosis phenotypical characteristics. Agreement on phenotypical characteristics was suboptimal (fair-moderate agreement) and highest for the summed score of individual photo score items (substantial agreement), indicating that although experts interpret phenotypical characteristics differently, there is consensus on overall phenotypical severity.</p

    A forest typology for monitoring sustainable forest management: The case of European Forest Types

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    Sustainable forest management (SFM) is presently widely accepted as the overriding objective for forest policy and practice. Regional processes are in progress all over the world to develop and implement criteria and indicators of SFM. In continental Europe, a set of 35 Pan-European indicators has been endorsed under the Ministerial Conference on the Protection of Forests in Europe (MCPFE) to measure progress towards SFM in the 44 countries of the region. The formulation of seven indicators (forest area, growing stock, age structure/diameter distribution, deadwood, tree species composition, damaging agents, naturalness) requires national data to be reported by forest types. Within the vast European forest area the values taken by these indicators show a considerable range of variation, due to variable natural conditions and anthropogenic influences. Given this variability, it is very difficult to grasp the meaning of these indicators when taken out of their ecological background. The paper discusses the concepts behind, and the requirements of, a classification more soundly ecologically framed and suitable for MCPFE reporting than the three (un-informative) classes adopted so far: broadleaved forest, coniferous forest, mixed broadleaved and coniferous forest. We propose a European Forest Types scheme structured into a reasonably higher number of classes, that would improve the specificity of the indicators reported under the MCPFE process and its understanding.L'articolo è disponibile sul sito dell'editore www.tandf.co.uk/journals
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