1,720,976 research outputs found
Pathology of bone lesions associated with congenital pseudarthrosis of the leg.
No full textCongenital pseudarthrosis of the leg remains one of the most controversial pediatric entities in terms of etiopathogenesis, pathology, treatment, and prognosis. The authors reviewed the pathologic material of 24 patients with congenital pseudarthrosis of the leg along with clinical and radiographic data. The tibia was affected in 22 patients; in two patients the disease was limited to the fibula. Fifteen patients were male and nine were female. Age at surgery ranged from 1 to 26 years. Nineteen patients were classified as having dysplastic type, one cystic, and four mixed. Clinical evidence of neurofibromatosis type I (NF-I) was found in 17 patients. The main histopathologic change observed was the growth of a highly cellular, fibromatosis-like tissue. In the dysplastic type, such tissue was associated with the periosteum. In the cystic type, a closely similar tissue occupied the lytic area. In case classified as of mixed type, the coexistence of endosteal/medullary and periosteal involvement by the fibromatosis-like tissue was observed. In the cystic lesion, evidence of de novo bone formation within the lesional tissue was obvious. Overall, the histologic features of the cystic lesion were similar to those of osteofibrous dysplasia. In the dysplastic type, the proliferation of the fibrovascular tissue was associated with active osteoclastic resorption of the cortex, which remodeled into a trabecular rather than a compact type of structure. Histologic comparison of the pathologic samples of patients with and without NF-I revealed no significant differences. The pseudarthrosis gap was continuous with periosteal soft tissues and filled by fibrous tissue, fibrocartilage, and hyaline cartilage with features of enchondral ossification. The authors suggest that the clinical diversity of congenital pseudarthrosis of the leg results from the diverse location of a single pathologic process--namely the growth of an abnormal, fibromatosis-like tissue either within the periosteum or within the endosteal/marrow tissues. It is tempting to suggest that such an "osteofibromatosis" represent a skeletal expression of neurofibromatosis, either within the fully expressed syndrome (patients with known neurofibromatosis) or as isolated lesion (patients with unknown/cryptic neurofibromatosis)
Functional results at the end of skeletal growth in 30 patients affected by congenital pseudoarthrosis of the tibia
No full textFrom a multicentric study on Congenital Pseudoarthrosis of the tibia (CPT) conducted on 340 patients, we evaluated the functional results on a group of thirty patients who were at the end of skeletal growth (age less than or equal to 16 years). The prognosis of CPT is very much related to the radiologic classification. Crawford type 2 and Crawford type 4 pseudoarthrosis have a worse prognosis, with a lower percentage of fusion at the site of pseudoarthrosis. Crawford 4 patients have the worst functional results. Most of them showed a severe leg length discrepancy, needed a permenent brace, with an ankle joint function fair or poor. The presence of fibula pseudoarthrosis seems to be responsible for most of the worst functional results. The level of deformity caused by either the natural course of the disease or its treatment, is decisive in the evalution of the functional results
Congenital pseudarthrosis of the tibia: history, etiology, classification, and epidemiologic data
No full textCongenital pseudarthrosis of the tibia is a rare disease with a variable history. The pseudarthrosis is usually not present at birth (and therefore is not truly congenital) but occurs during the first decade of life. Paget in 1891 was the first to describe a case. The etiology is unknown. Neurofibromatosis plays a role in approximately 50% of patients. In the others, hereditary and mechanical factors are debated. Various (morphologic) classification systems have been proposed (Andersen, Boyd, Crawford). Because the appearance changes during the course of the disease, all classification systems have limited value: the determining factor is the stage of the disease at which it was classified. Because of the rarity of the disease and the variability of its history, the European Pediatric Orthopaedic Society decided to carry out a multicenter study on this disease. This paper presents the epidemiologic data on the patients involved. Data have been gathered on 340 patients from 13 countries. Two hundred patients were male (58.8%), 140 were female (41.2%). The right side was affected in 165 patients (48.5%) and the left side in 172 (50.6%); 3 patients had bilateral disease. Symptoms of neurofibromatosis were present in 54.7%. Histologic examinations in 192 patients showed a nonspecific appearance in 45.3%; in 15.6% the ultrastructure resembled fibrous dysplasia, and in 39% there was histologic evidence of neurofibromatosis. Most of the lesions were initially localized in the middle or distal third of the tibia. In 29% the localization changed during the course of the disease
Treatment approaches for congenital pseudarthrosis of tibia: results of the EPOS multicenter study. European Paediatric Orthopaedic Society (EPOS)
No full textThis study was designed to analyze the different therapeutic methods used by European Paediatric Orthopaedic Society members from 13 countries for congenital pseudarthrosis of tibia. The treatment data of 340 patients who underwent 1287 procedures for this condition were analyzed. The essential findings were that the method of choice needed to approach the biological problem with the aims of: (1) resecting the pseudarthrosis to provide stability, the basic requirement for bony consolidation; (2) correcting length discrepancy and axial deformity; (3) achieving fusion; and (4) solving the additional problems around the main deformity such as alignment, leg length discrepancy and ankle valgus. The Ilizarov technique emerged as being the optimal method, having the highest rate of fusion (75.5%) of pseudarthrosis and rate of success in correction of the additional deformities. There was also consensus that surgery should be avoided before the third year of life
Atlanto-axial joint involvement as exclusive manifestation of juvenile idiopathic arthritis (JIA).
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Free vascular fibular transfer in congenital pseudoarthrosis of the tibia: results of the EPOS multicenter study. European Paediatric Orthopaedic Society (EPOS)
No full textThis paper presents a review of the literature, describes the principal author's (B.R.) personal experience and provides the results of the European Paediatric Orthopaedic Society (EPOS) multicenter study. The objective is to evaluate the present status and future role of free vascular fibular transfer in treating congenital pseudoarthrosis of the tibia. Variables such as the selection of cases, age at operation, technical surgical details and postoperative results will be considered. The data on the EPOS study were incomplete at the time of writing, but the considerable amount of information already amassed is a valuable contribution to this updated report
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
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