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Light microscopic histology of achilles tendon ruptures. A comparison with unruptured tendons.
No full textWe studied biopsies from the Achilles tendons of patients undergoing open repair for a subcutaneous rupture of their Achilles tendons (27 men, 11 women; mean age, 45.3 +/- 13.8 years) and specimens of Achilles tendons from persons with no known tendon ailments (43 men, 3 women; mean age, 64.2 +/- 9.7 years). Histologic examination was performed using stained slides that were interpreted using a semiquantitative grading scale assessing fiber structure and arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability, hyalinization, and glycosaminoglycan. We gave up to three marks for each of these variables, with 0 being normal and 3 being maximally abnormal. All the histology slides were assessed twice in a blinded manner; the agreement between two readings ranged from 0.56 to 0.87 (kappa statistics). The score of ruptured tendons was significantly greater than the average score of control tendons (20.5 +/- 3.6 versus 6.5 +/- 2.1), and there was significantly higher degeneration in the ruptured tendons. Nonruptured Achilles tendons, even at an advanced age, and ruptured Achilles tendons are clearly part of two distinct populations. Using these staining techniques, light microscopic degeneration is not a feature of tendons from healthy, older persons
Quantitative review of operative and nonoperative management of achilles tendon ruptures.
No full textBACKGROUND:
There is no consensus on the best method for management of acute Achilles tendon ruptures. Individual preferences, drawn from experience and study, determine whether treatment is operative or nonoperative.
PURPOSE:
Our goal was to review the literature to try to determine what management method was the most popular and effective. We wanted to ascertain the best results in terms of complication rates and patient outcomes.
STUDY DESIGN:
Retrospective review of retrospectively and prospectively collected data.
METHODS:
We analyzed 125 articles in peer-reviewed journals for year of publication, patient numbers, sex, management method, follow-up complications, and patient satisfaction. Each article was graded using a validated methods score. Methods, patient satisfaction, and complication rates were correlated with the year each article was published.
RESULTS:
Skin-healing complications were lowest in conservatively managed patients (3 of 578, 0.5%) and highest in open repair and immobilized patients (543 of 3718, 14.6%). General complication rates were lowest in open repair and early-mobilization groups (16 of 238, 6.7%) and highest in percutaneous and early-mobilization groups (19 of 122, 15.6%). Rerupture rates were highest in immobilized conservative management groups (62 of 578, 10.7%) and lowest in groups with external fixation (0%).
CONCLUSIONS:
In general, the number of publications reporting Achilles tendon ruptures is increasing, the quality of articles is increasing, and the trend for the number of reported complications is decreasing. The published articles had a low methods score (mean, 50.9; range, 25 to 77) and showed a trend toward earlier mobilization. Open repair and early mobilization give the best functional recovery and an acceptable complication rate
Tenocytes from ruptured and tendinopathic achilles tendons produce greater quantities of type III collagen than tenocytes from normal achilles tendons. An in vitro model of human tendon healing.
No full textType I collagen is the main collagen in tendons; type III collagen is present in small amounts. Ruptured Achilles tendons contain a significantly greater proportion of type Ill collagen, which predisposes them to rupture. We used an in vitro model to determine whether tenocytes from Achilles tendons that were ruptured (N = 22), nonruptured (N = 7), tendinopathic (N = 12), and fetal (N = 8) show different behavior. Samples of Achilles tendon were digested with collagenase and the released tenocytes were collected. Primary tenocyte cultures were established and subsequently cultured onto glass coverslips. Once a confluent monolayer was obtained, the cell populations were "wounded" by scraping a pipette tip along the surface. The cultures were further incubated for either 1, 4, 8, 12, 16, or 24 hours, and production of types I and II collagen was assessed by immunostaining. In cultures from ruptured and tendinopathic tendons, there was increased production of type Ill collagen. Athletic participation places excess stress on the Achilles tendon, which could potentially lead to areas of microtrauma within the tendon. These areas may heal by the production of type III collagen, which is an abnormal healing response. Accumulation of such episodes of microtrauma could resuit in a critical point where the resistance of the tissue to tensile forces is compromised and tendon rupture occurs
Conservative management, percutaneous or open repair of acute Achilles tendon rupture: a retrospective study.
No full textBACKGROUND AND AIMS:
To ascertain the differences in patients' perceived outcomes between conservative, percutaneous or open repair of Achilles tendon ruptures.
METHODS:
We studied 111 patients who had been managed for a unilateral closed Achilles tendon rupture. We excluded patients with open Achilles tendon lesions, patients whose tear had occurred more than seven days from operation, patients with diabetes, inflammatory disease, systemic corticosteroids or fluoroquinolones. Patients were contacted by telephone and asked to answer a questionnaire.
RESULTS:
There was no difference in effects on working life, patient satisfaction, sports performance, muscle strength, swelling and fear of re-rupture. Pain on weight bearing and cramps were signficantly more frequent in the patients managed conservatively. Re-rupture and complication rates were comparable to published rates.
CONCLUSION:
Treatment should be individualised according to the demands and health of the patient
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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