1,720,957 research outputs found
In ‐house virtual surgical planning and guided mandibular reconstruction is less precise, but more economical and time‐efficient than commercial procedures
No full textAbstract
Background
To compare an in‐house and a commercially available surgical planning solution for mandibular reconstruction in terms of postoperative reconstruction accuracy and economic benefit.
Methods
Twenty‐nine consecutive patients with advanced oral squamous cell carcinoma (OSCC) requiring segmental mandibular reconstruction were enrolled. Fifteen patients underwent in‐house surgical planning and 14 patients underwent a commercially available planning solution. A morphometric comparison of preoperative and postoperative computed tomography (CT) data sets and a cost–benefit comparison were performed.
Results
Volumes of planned and reconstructed bone segments differed significantly for both in‐house planning (
p
= 0.0431) and commercial planning (
p
< 0.0001). Significant differences in osteotomy angles were demonstrated for in‐house planning (
p
= 0.0391). Commercial planning was superior to in‐house planning for total mandibular deviation (
p
= 0.0217), intersegmental space volumes (
p
= 0.0035), and lengths (
p
= 0.0007). No significant difference was found between the two planning solutions in terms of intersegmental ossification and the incidence of wound healing disorders. In‐house planning took less time than commercial planning (
p
< 0.0001). Component manufacturing costs (
p
< 0.0001) and total cumulative costs (
p
< 0.0001) were significantly lower for in‐house planning.
Conclusions
In‐house surgical planning is less accurate but has a cost advantage and could be performed in less time
Report on Prosthetic Fitting, Mobility, and Overall Satisfaction after Major Limb Amputation at a German Maximum Care Provider
No full textBackground: Satisfaction with prosthesis plays a key role in regaining mobility and is important for optimizing prosthetic usage, mobility, and increasing compliance with medical regimen. Despite unchangeable factors like age and comorbidities, other factors, like pain, received rehabilitation, satisfaction with assistive devices, service, and information, can be changed and might contribute to a better usage and acceptance of the prosthesis and amputees’ mobility. Objectives: The aim of the study was to analyze mobility, pain, supply of assistive devices, and additional therapies received after major limb amputations. Furthermore, a correlation of those parameters was evaluated. Methods: Retrospective identification of patients with major limb amputation (operation and procedures classification system (OPS)) and relevant related demographics within the clinical documentation system during a four-year observation time. In addition, we undertook prospective assessment of mobility (K-level), pain qualities, additional therapies, self-rated overall quality of life (QoL) and degree of adaptation to the life after amputation, dependency from caregivers, and satisfaction with the provided assistive devices (QUEST). Results: A total of 164 patients (mean age 68, age range: 19 to 97 years) underwent major limb amputation. A total of 27 questionnaires were returned and analyzed. All those traumatic and nontraumatic amputees received assistive devices. Although mobility and QoL decreased significantly after amputation, a high satisfaction with provided prosthetic and assistive devices and care was found. Conclusions: Amputation registries are becoming elementary to allow for nationwide comparisons of clinics, to identify the requirements of amputees, and to design an interdisciplinary care model for a successful comprehensive approach
Can Early Post-Operative Scoring of Non-Traumatic Amputees Decrease Rates of Revision Surgery?
No full textBackground and Objectives: Medical registries evolved from a basic epidemiological data set to further applications allowing deriving decision making. Revision rates after non-traumatic amputation are high and dramatically impact the following rehabilitation of the amputee. Risk scores for revision surgery after non-traumatic lower limb amputation are still missing. The main objective was to create an amputation registry allowing us to determine risk factors for revision surgery after non-traumatic lower-limb amputation and to develop a score for an early detection and decision-making tool for the therapeutic course of patients at risk for non-traumatic lower limb amputation and/or revision surgery. Materials and Methods: Retrospective data analysis was of patients with major amputations lower limbs in a four-year interval at a University Hospital of maximum care. Medical records of 164 patients analysed demographics, comorbidities, and amputation-related factors. Descriptive statistics analysed demographics, prevalence of amputation level and comorbidities of non-traumatic lower limb amputees with and without revision surgery. Correlation analysis identified parameters determining revision surgery. Results: In 4 years, 199 major amputations were performed; 88% were amputated for non-traumatic reasons. A total of 27% of the non-traumatic cohort needed revision surgery. Peripheral vascular disease (PVD) (72%), atherosclerosis (69%), diabetes (42%), arterial hypertension (38%), overweight (BMI > 25), initial gangrene (47%), sepsis (19%), age > 68.2 years and nicotine abuse (17%) were set as relevant within this study and given a non-traumatic amputation score. Correlation analysis revealed delayed wound healing (confidence interval: 64.1% (47.18%; 78.8%)), a hospital length of stay before amputation of longer than 32 days (confidence interval: 32.3 (23.2; 41.3)), and a BKA amputation level (confidence interval: 74.4% (58%; 87%)) as risk factors for revision surgery after non-traumatic amputation. A combined score including all parameters was drafted to identify non-traumatic amputees at risk for revision surgery. Conclusions: Our results describe novel scoring systems for risk assessment for non-traumatic amputations and for revision surgery at non-traumatic amputations. It may be used after further prospective evaluation as an early-warning system for amputated limbs at risk of revision
Comparative analysis of two surgical planning procedures for mandibular reconstruction with free bone grafts with regard to postoperative precision after extensive ablative surgery in the head and neck region
No full textOral squamous cell carcinoma is one of the most common cancers worldwide. In advanced tumor stages, the tumor cells often grow invasively into the adjacent mandibular bone, making partial resection necessary. Both tumor progression and therapeutic measures are accompanied by a considerable loss of health-related quality of life, which makes functional and aesthetic reconstruction necessary. Today, mandibular reconstructions are planned and performed using preoperative virtual surgical planning (VSP) and the template-guided surgical implementation of this planning. The procedures described are both commercially available and can be performed in-house. In the present study, the advantages and weaknesses of a commercial and an in-house planning procedure were compared morphometrically with regard to postoperative precision. In this context, it was determined which factors are responsible for the deviations between planning and result and whether and how possible sources of error can be eliminated. The patient population consisted of a total of 29 patients with advanced oral squamous cell carcinoma and an indication for partial mandibular resection and reconstruction. In 15 patients, in-house surgical planning and execution was performed, in 14 patients a commercial procedure involving a patient-specific implant (PSI) was chosen. The analysis showed that the volumes of the planned and postoperatively reconstructed bone segments differed significantly in both in-house planning (p = 0.0431) and commercial planning (p < 0.0001). In addition, a significant deviation in the osteotomy angles was demonstrated in the in-house surgical planning (p = 0.0391). A direct comparison showed that commercial surgical planning was superior to in-house planning in the postoperative deviation of the entire mandible (p = 0.0217), the intersegmental space volumes (p = 0.0035) and the intersegmental space lengths (p = 0.0007). Only a few comparable studies are described in the current literature. Further multicentre studies with a large patient population and standardized measurement parameters would be desirable in this context. The following parameters were identified in this study as important influencing factors for postoperative precision: Intercondylar distance, osteotomy angle, surface overlay and volume and length comparison of the intersegmental spaces. The intersegmental spaces are of particular interest as they can have a major influence on graft ossification.2024-11-2
Amputationen der unteren Extremität: Postoperativer Verlauf und Analyse der Versorgungsabläufe
Full text linkRevisionen treten zu 25% bis 40% nach einer Amputation der unteren Extremität auf. Einige Faktoren erhöhen das Risiko für Revisionen und werden damit assoziiert. Ziel der durchgeführten Untersuchung war daher, anhand eines Kollektivs im Vier-Jahres-Verlauf zu erarbeiten, welche Faktoren möglicherweise mit einer chirurgischen Revision nach einer Amputation assoziiert sind. So wurde ein Score erstellt, der in einem weiteren geplanten Studiendesign überprüft werden soll.
Die vorliegende Arbeit erstellte im Rahmen einer retrospektiven Ausarbeitung eine Amputationsstatistik von Majoramputationen der unteren Extremität an der Uniklinik Göttingen im Zeitraum von 2013 bis einschließlich 2016. Insgesamt wurden 164 Patienten in die Studie eingeschlossen, durchschnittlich erfolgten 41 Majoramputationen pro Jahr. Innerhalb des Kollektivs erfolgte ein Vergleich zwischen traumatischen und nicht traumatischen Amputationen, wobei der Fokus auf den postoperativen Verlauf, insbesondere auf das Auftreten von Revisionen lag.
Für einen erfolgreichen Verlauf einer Amputation lassen sich folgende Erkenntnisse zusammenfassen: Sobald die Indikation zur Amputation steht sollte sie so zügig wie möglich, nach guter Vorbereitung des Patienten, durchgeführt werden. Eine direkte Versorgung verkürzt den Aufenthalt im Krankenhaus und reduziert die Mortalität.
Als Risikofaktoren für Revisionen nicht traumatischer Amputationen wurden Wundheilungsstörungen (Konfidenzintervall: 64,1% [47,18%;78,8%]), die Krankenhausverweildauer vor Amputation, länger als 32 Tage (Konfidenzintervall: 32,3 [23,2; 41,3]) und ein distales Amputationsniveau (Konfidenzintervall: 74,4% [58%;87%]) identifiziert.
Aus diesen Erkenntnissen wurde ein Score zur Einschätzung des Revisionsrisikos bereits amputierter Patienten entwickelt. So erhält man eine Risikobewertung und kann diese Patienten engmaschig nachbetreuen und daraus folgend Revisionen und damit verbundene Sekundärkomplikationen verhindern.
Die Scores ergeben anhand des untersuchten Patientenkollektivs signifikante Ergebnisse, bedürfen jedoch noch einer prospektiven klinischen Testung für eine evidenzbasierte Aussagekraft.
Des Weiteren wurde ein Fragebogen für die zukünftige Erstellung eines Prothesenregisters erstellt.Revisions occur 25% to 40% after lower extremity amputation. Some factors increase the risk of revision and are associated with it. The aim of the study was therefore to determine which factors might be associated with surgical revision after amputation on the basis of a collective over a four-year period. Thus, a score was created that will be reviewed in a further planned study design.
The present study compiled amputation statistics of major amputations of the lower extremity at the University Hospital of Göttingen in the period from 2013 to 2016 inclusive as part of a retrospective elaboration. A total of 164 patients were included in the study, with an average of 41 major amputations per year. Within the collective, a comparison was made between traumatic and non-traumatic amputations, with a focus on the postoperative course, especially on the occurrence of revisions.
The following findings can be summarized for a successful course of amputation: As soon as amputation is indicated, it should be performed as quickly as possible after good preparation of the patient. Direct care shortens the hospital stay and reduces mortality.
Risk factors identified for revisions of nontraumatic amputations were wound-healing disorders (confidence interval: 64.1% [47.18%;78.8%]), hospital length of stay before amputation, longer than 32 days (confidence interval: 32.3 [23.2; 41.3]), and distal amputation level (confidence interval: 74.4% [58%;87%]).
From these findings, a score was developed to assess the revision risk of previously amputated patients. This provides a risk assessment and allows close follow-up of these patients and consequent prevention of revisions and associated secondary complications.
The outcome of the scores are significant results based on the studied patient population, but still require prospective clinical testing for evidence-based validity.
Furthermore, a questionnaire was developed for the future creation of a prosthesis registry.2022-11-2
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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