1,720,958 research outputs found
Microsurgical reconstruction with vascularized fibula and massive bone allograft for bone tumors
No full textIntroduction: Combining massive bone allograft and vascularized fibula in intercalary reconstruction following resection of bone tumors represents a complex reconstructive procedure that requires specialists in microvascular surgery as well as orthopedic surgery. The purpose of our study was to examine the outcomes using this surgical technique in patients with bone tumors in terms of oncologic results, complications related to surgery, Musculoskeletal Tumor Society (MSTS) scores and duration of surgery. Materials and methods: We analyzed 81 patients with femoral or tibial sarcomas who underwent intercalary resection and microsurgical reconstruction with massive bone allograft and vascularized fibula. There were 56 boys and 25 girls with a mean age of 13.4 years at the time of surgery. The patients’ medical records were reviewed for clinical and functional outcomes as well as postoperative complications. The study group was comprised of 33 patients who underwent reconstruction of the femur with massive bone allograft and free vascularized fibula and 48 patients who underwent reconstruction of the tibia with massive bone allograft and free or pedicle vascularized fibula. The mean length of resection was 15.9 cm (8–31 cm). The functional evaluation of the patients was done at the end of the follow-up using MSTS score for the lower limb. All patients had at least a 2-year follow-up. Results: The overall limb salvage rate was 94%, although many patients required re-operation after the procedure. Complications occurred in 24 patients, 18 of which underwent additional surgical procedures. They included fractures of the massive bone allograft-vascularized fibula construct with or without implant failure (19) and deep infection (5). After surgical or conservative treatment, all the fractures successfully healed. The overall MSTS functional score was good to excellent in 91% of patients. Conclusions: The combination of massive bone allograft and vascularized fibula seems to be a reasonable option for reconstruction of diaphyseal defects following intercalary resection of bone tumors. Although there was a high rate of complications and therefore re-operations, the biology of vascularized fibula was able to save the reconstruction in most of the cases that had complications
Is There Benefit to Free Over Pedicled Vascularized Grafts in Augmenting Tibial Intercalary Allograft Constructs?
No full textBackground: Intercalary reconstruction of tibial sarcomas with vascularized fibula autografts and massive bone allografts is reliable with predictable long-term results. However, inadequate data exist comparing free and pedicled vascularized fibula autografts in combination with a massive bone allograft in patients undergoing intercalary tibia reconstructions. Questions/Purposes: Among patients undergoing large-segment intercalary allografting, we sought to compare supplemental free vascularized fibular autografts with supplemental pedicled vascularized fibular autografts, in terms of (1) oncologic results, (2) complications associated with surgery, (3) Musculoskeletal Tumor Society (MSTS) scores, and (4) surgical time. Methods: Between 1994 and 2013, we treated 320 patients, younger than 40 years, with tibial sarcomas. Thirty-five patients (11%) underwent amputations. One hundred ninety-five patients (61%) were treated with intraarticular resection of the tibia, which constituted 104 tumor endoprostheses, 63 proximal tibia allograft prosthetic composites, 21 osteoarticular allografts, and seven arthrodeses with allografts. Ninety patients (28%) underwent joint-sparing intercalary reconstruction. Forty-one (13%) of these 90 patients were treated with allografts alone, two (1%) with vascularized fibula grafts, and 47 (15%) with intercalary allografts supplemented by autografts (free fibular autografts, 22 patients, 7%; pedicled fibular autografts, 25 patients, 8%). During the study period, we used free vascularized fibular autografts in association with massive bone allograft for a resection longer than 12 cm with a very small periarticular residual segment. The choice for using a pedicled fibula harvested in the ipsilateral leg initially was for patients having only diaphyseal resections and the indication was later extended to intraepiphyseal osteotomies with a small periarticular residual segment. The goals of this study are to present the long-term results in this group of patients and compare their results based on the type of vascularized fibula harvest. There were 33 male and 14 female patients with mean age of 14 ± 6 years. The median followup was 84 months (range, 7–231 months). No patients were lost to followup before 1 year. Four patients died and were not available for followup after 18 months. The mean tibia resection length was 15 ± 4 cm and mean length of the harvested vascularized fibula was 18 ± 4 cm. Results: Overall 5- and 10-year oncologic survival rates in this study were 87% ± 5% and 83% ± 6% respectively. With the numbers available, we observed no difference in survivorship free from death from disease between the study groups (85% ± 8% [95% CI, 174–232 months] of the free vascularized group versus 82% ± 8% [95% CI, 148–206 months] of the pedicled fibula graft group; p = 0.741). At last followup, 40 patients had no evidence of disease and seven had died of disease. Local recurrence was observed in two patients in the supplemental free vascularized fibula group and three patients in the supplemental pedicled vascularized fibula group, whereas metastases was observed in eight patients. With the numbers available, we observed no difference in the proportion of patients experiencing surgical complications between those treated with free vascularized fibula grafts and those treated with pedicled grafts (eight of 22 [36%] versus nine of 25 [36%] respectively; p = 0.605). With the numbers available, we observed no difference in mean MSTS scores between patients treated with free vascularized fibula grafts and those treated with pedicled grafts (24 ± 9 versus 25 ± 8; mean difference, 0.48; 95% CI, 0.54–4.6; p = 0.858). Mean surgical time was longer in the free vascularized fibula and massive bone allograft group at 9.4 ± 1.7 hours compared with that of the pedicled vascularized fibula and massive bone allograft group at 5.7 ± 1.3 hours (mean difference, 3.73 hours; 95% CI, 2.8–4.6 hours; p ≤ 0.001). Conclusions: Intercalary reconstruction of tibia sarcomas with massive bone allografts supplemented with vascularized fibula grafts provide predictable results. Complications occur as expected in a biologic reconstruction, but are salvageable, preserving the original construct. The pedicled fibula can be an alternative to a free contralateral fibula for intraepiphyseal resections. Comparative technical ease, shorter surgical time, avoidance of additional microvascular anastomosis, and avoidance of surgery on the contralateral leg are notable advantages of pedicled vascularized fibula over free fibula grafts to supplement allografts when indicated in intercalary tibia resections. Level of Evidence: Level III, therapeutic study
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Reconstruction of large posttraumatic skeletal defects of the forearm by vascularized free fibular graft
No full textVascularized bone graft is most commonly applied for reconstruction of the lower extremity; indications for its use in the reconstruction of the upper extremity have expanded in recent years. Between 1993-2000, 12 patients with segmental bone defects following forearm trauma were managed with vascularized fibular grafts: 6 males and 6 females, aged 39 years on average (range, 16-65 years). The reconstructed site was the radius in 8 patients and the ulna in 4. The length of bone defect ranged from 6-13 cm. In 4 cases, the fibular graft was harvested and used as a vascularized fibula osteoseptocutaneous flap. To achieve fixation of the grafted fibula, plates were used in 10 cases, and screws and Kirschner wires in 2. In the latter 2 cases, an external skeletal fixator was applied to ensure immobilization of the extremity. The follow-up period ranged from 10-93 months. Eleven grafts were successful. The mean period to obtain radiographic bone union was 4.8 months (range, 2.5-8 months). Fibular grafts allow the use of a segment of diaphyseal bone which is structurally similar to the radius and ulna and of sufficient length to reconstruct most skeletal defects of the forearm. The vascularized fibular graft is indicated in patients with intractable nonunions where conventional bone grafting has failed or large bone defects, exceeding 6 cm, are observed in the radius or ulna. © 2004 Wiley-Liss, Inc
- …
