1,720,981 research outputs found
Predictors of failure of two-stage revision in periprosthetic knee infection: a retrospective cohort study with a minimum two-year follow-up
No full textPurpose: Despite the standardization of two-stage knee revision protocols, a high percentage of failures still occurs. Identifying the predictors of failure is necessary to determine appropriate management and counsel for patients with a periprosthetic knee infection. This study aimed to identify risk factors predicting the failure, to describe implant survival, and to report the mid-term clinical outcomes of patients undergoing two-stage revision for periprosthetic knee infection. Methods: Data of patients who underwent two-stage knee revision from 2012 to 2016 were analyzed, and 108 patients were included. The mean age was 66.6 ± 9.2 years. The mean follow-up was 52.9 ± 15.6 months. Logistic regression was conducted to identify predictors of treatment failure. Kaplan–Meier curves were generated to assess implant survival. Preoperative functional outcomes were compared to those registered at the final follow-up. Results: Difficult-to-treat infections (OR = 4.2, 95% CI 1.2–14.5, p = 0.025), the number of previous surgeries (OR = 1.8, 95% CI 1.2–2.6, p = 0.005), and the level of tibial bone defect (OR = 2.3, 95% CI 1.1–4.7, p = 0.027) significantly predicted the failure of two-stage knee revision. Survivorship of implants was significantly lower for patients presenting these risk factors (p < 0.05). Mean Knee Society Score improved from 49.0 ± 12.0 to 80.2 ± 13.6 (p < 0.001). Mean Oxford Knee Score improved from 22.2 ± 4.9 to 36.1 ± 6.0 points (p < 0.001). Conclusion: Difficult-to-treat pathogens, the number of previous surgeries, and the level of tibial bone defect were independent risk factors of two-stage knee revision failure. Overall, the two-stage protocol provided a good survival rate and functional outcome
Acetabular custom-made implants for severe acetabular bone defect in revision total hip arthroplasty: a systematic review of the literature.
No full textPurpose: The management of acetabular bone loss is a challenging problem in revision total hip arthroplasty (rTHA). The aim of this systematic review is to summarize and critically analyze indications, complications, clinical and radiological outcomes of custom-made acetabular components in rTHA.
Methods: A systematic review of English literature was performed on Medline. Retrospective or prospective studies with minimum 2 years of follow-up (FU) were included. The PRISMA 2009 flowchart and checklist were considered to edit the review. Rates of intra- or post-operative complications, aseptic loosening (AL), periprosthetic joint infection (PJI), reopera- tions and re-revisions rates were extrapolated.
Results: 18 articles with a level of evidence of IV were included. Six hundred and thirty-four acetabular custom components (627 patients) with a mean FU of 58.6 ± 29.8 months were analyzed. The studies showed good clinical and functional out- comes. Custom-made acetabular components allowed a stable fixation with 94.0 ± 5.0% survival rate. The estimated rate of re-operations and re-revisions were 19.3 ± 17.3% and 5.2 ± 4.7%, respectively. The incidence of PJI was 4.0 ± 3.9%.
Conclusions: The acetabular custom-made implants represent a reliable solution for pelvic discontinuity and particular cases of bone loss classified as Paprosky Type IIIA-B or type III–IV according to American Academy of Orthopaedic Surgeons system where the feature of the defect cannot be handled with standard implants. This strategy allows to fit the implant to the residual host bone, bypassing the bony deficiency and restoring hip biomechanics. Satisfactory clinical and radiological outcomes at mid-term follow-up are reported in literature
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
Clinical radiographic outcomes and survivorship of medial pivot design total knee arthroplasty: a systematic review of the literature
No full textBackground: Total knee arthroplasty is a reliable procedure able to reduce pain and disability in patients suffering from osteoarthritis. However, a considerable percentage of patients still experiences unsatisfactory results. Medial pivot total knee arthroplasty has been introduced in the clinical practice to overcome problems related with classic design implants and better mimic native knee kinematics. The aim of this study was to analyze survivorship and clinical and radiographic outcomes of medial pivot implants. Methods: A systematic research was conducted in eight different databases. Thirty-four studies met the inclusion criteria and were included in the analysis. Data on objective and patients-reported outcomes, radiographic alignment, and survivorship were collected and analyzed. Revision rate was expressed as revision per 100 components years. Result: A total of 3377 procedures were included. Mean follow-up was 85.7 months (range, 12–182). The revision per 100 components years was 0.19, which corresponds to a revision rate of 1.9% after 10 years. Mean post-operative range of motion was 117.3 ± 0.4°. Mean clinical and functional Knee Society Score were, respectively, 85.9 ± 1.1 and 84.7 ± 3.5 at final follow-up. Post-operative femorotibial alignment was 177.1 ± 0.5°. Alfa and beta angles were 95.7 ± 0.1° and 89.2 ± 0.1°, respectively. Gamma and delta angles were 2.3 ± 0.6° and 86.7 ± 0.4°. Conclusion: Medial pivoting implants provided excellent survivorship and low revision rate, as well as good-to-excellent results in term of objective and patient-reported clinical outcomes, and reliable correction of radiographic parameters. More high-quality studies with long-term follow-up are needed to clarify the role of medial pivoting implants
Primary cementless stems in septic hip revision: Indications and results
No full textPurpose: The aim of our work is to evaluate results obtained from a cohort of patients affected by periprosthetic joint infection and treated with a primary cementless stem in a two-stage technique framework. Methods: Eighty-four patients were evaluated at a mean follow-up of 37.4 months. The main demographic, surgical, clinical, and radiographic data were recorded. A femoral window for stem removal was performed in 33 patients. Results: Statistically significant improvement was noted for both the Harris Hip score and the Oxford Hip score. Postsurgical complications included thigh pain in three patients, subsidence (>2 mm) in one patient, implant dislocation in two patients, cup revision in one patient, implant revision for septic failure in two patients, and stem revision for varus position in one patient. The stem survivorship rate was 96.3%. There were no significant differences between the groups in which a cortical window was created or not. Conclusion: Femoral stem revision with primary cementless stems is a viable option in selected patients undergoing two-stage hip revision surgery. Correct indication is a cornerstone of good outcome. The use of a cortical window does not affect the final outcome or implant survivorship rate
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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