RESUMEN
BACKGROUND: Arthroscopic partial meniscectomy (APM) is widely applied for the treatment of degenerative meniscal lesions in middle-aged patients; however, such injury is often associated with mild or moderate osteoarthritis and has been reported by MRI in asymptomatic knees. Previous studies suggested, in most patients, a lack of benefit of surgical approach over conservative treatment, yet many controversies remain in clinical practice. Our aims were to assess the functional and pain scores between exercise therapy and arthroscopic surgery for degenerative meniscal lesions and to evaluate the methodological quality of the most recent systematic reviews (SRs). METHODS: Two authors independently searched PubMed and Google Scholar for SRs comparing the outcome (in knee pain and functionality) of arthroscopic treatment and exercise therapy or placebo for degenerative meniscal lesions. The timeframe set was from 2009 to 2019 included. RESULTS: A total of 13 SRs were selected. Two reviewers independently assessed the methodological quality of each paper using the AMSTAR 2 tool: seven scored as "moderate," four obtained a "low" grade while the remaining two were evaluated as "critically low." SRs agreed that in middle-aged patients with degenerative meniscal lesions arthroscopic surgery appears to grant no long-term improvement in pain and function over exercise therapy or placebo. CONCLUSIONS: Conservative treatment based on physical therapy should be the first-line management. However, most SRs revealed subgroups of patients that fail to improve after conservative treatment and find relief when undergoing surgery. In the future, randomized controlled trials, evidence should be looked for that APM can be successful in case of the unsatisfactory results after physical therapy.
Asunto(s)
Osteoartritis de la Rodilla , Lesiones de Menisco Tibial , Humanos , Persona de Mediana Edad , Artroscopía/métodos , Terapia por Ejercicio , Meniscos Tibiales/cirugía , Osteoartritis de la Rodilla/cirugía , Osteoartritis de la Rodilla/complicaciones , Dolor/etiología , Revisiones Sistemáticas como Asunto , Lesiones de Menisco Tibial/cirugíaRESUMEN
OBJECTIVE: Septic arthritis and osteomyelitis are rare in children, but they are difficult to treat and are associated with a high rate of sequelae. This paper addresses the main clinical issues related to septic arthritis and osteomyelitis by means of a systematic review of systematic reviews. MATERIALS AND METHODS: The major electronic databases were searched for systematic reviews/meta-analyses septic arthritis and osteomyelitis. The papers that fulfilled the inclusion/exclusion criteria were selected. RESULTS: There were four systematic reviews on septic arthritis and four on osteomyelitis. Independent assessment of their methodological quality by two reviewers using AMSTAR 2 indicated that its criteria were not consistently followed. CONCLUSIONS: Collectively, these works provide strong evidence regarding a large number of issues including classification, epidemiology and risk factors, causative organisms, clinical presentation, laboratory markers, imaging, diagnostic needle aspiration, antibiotic therapy, surgical therapy, and prognosis. A clinical summary based on the best evidence is supplied.
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Artritis Infecciosa , Osteomielitis , Enfermedad Aguda , Artritis Infecciosa/diagnóstico , Artritis Infecciosa/tratamiento farmacológico , Artritis Infecciosa/cirugía , Niño , Humanos , Osteomielitis/diagnóstico , Osteomielitis/tratamiento farmacológico , Osteomielitis/cirugíaRESUMEN
STUDY DESIGN: A prospective, randomized, controlled, multicenter clinical study. OBJECTIVE: To evaluate the safety and feasibility of osteogenic protein (OP)-1 in 1-level lumbar spine instrumented posterolateral fusions. SUMMARY OF BACKGROUND DATA: Instrumented posterolateral fusion with the use of autograft is a commonly performed procedure for a variety of spinal disorders. However, harvesting of bone from the iliac crest is associated with complications. A promising alternative for autograft are bone morphogenetic proteins. METHODS: As part of a larger prospective, randomized, multicenter study, 36 patients were included, who received a 1-level instrumented posterolateral fusion of the lumbar spine. All patients had a degenerative or isthmic spondylolisthesis with symptoms of neurologic compression. There were 2 treatment arms: OP-1 combined with locally available bone from laminectomy (OP-1 group) or iliac crest autograft (autograft group). The primary outcome was the fusion rate based on a computed tomography scan after 1-year follow-up. The clinical outcome was measured using the Oswestry Disability Index. Additionally, the safety of OP-1 was evaluated by comparing the number and severity of adverse events that occurred between both groups. RESULTS: Using strict criteria, fusion rates of 63% were found in the OP-1 group and 67% in the control group (P = 0.95). There was a decrease in Oswestry scores at subsequent postoperative time points compared with preoperative values (P > 0.001). There were no significant differences in the mean Oswestry scores between the study group and control group at any time point (P = 0.56). No product-related adverse events occurred. CONCLUSION: The results demonstrate that OP-1 combined with locally obtained autograft is a safe and effective alternative for iliac crest autograft in instrumented single-level posterolateral fusions of the lumbar spine. The main advantage of OP-1 is that it avoids morbidity associated with the harvesting of autogenous bone grafts from the iliac crest.
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Proteína Morfogenética Ósea 7/administración & dosificación , Proteína Morfogenética Ósea 7/efectos adversos , Trasplante Óseo/métodos , Vértebras Lumbares , Fusión Vertebral/efectos adversos , Fusión Vertebral/instrumentación , Espondilolistesis , Adulto , Anciano , Trasplante Óseo/efectos adversos , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Hematoma/inducido químicamente , Hematoma/etiología , Humanos , Ilion/trasplante , Vértebras Lumbares/patología , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Fusión Vertebral/métodos , Espondilolistesis/tratamiento farmacológico , Espondilolistesis/cirugía , Trasplante Autólogo , Resultado del TratamientoRESUMEN
Palmar fascia tissue and cultured cells from patients with Dupuytren's contracture and from normal subjects were characterized and analyzed for androgen receptor expression. Androgen receptors have never been studied in Dupuytren's myofibroblasts and may have a role in its high male predominance. Surgical samples were collected from eight patients undergoing surgery for Dupuytren's contracture and from four patients with carpal tunnel syndrome, used as control tissue. Immunohistochemical analysis was performed on tissue samples and on cell cultures with anti-androgen receptor, anti-alpha-smooth muscle actin, anti-fibronectin, and anti-type I and III collagen antibodies using the biotin avidin peroxidase method as revelatory system. Immunostaining for androgen receptors in tissue samples and cultured cells revealed nuclear reaction in many Dupuytren's myofibroblasts, but in few fibroblasts of the normal palmar fascia. In a double-labeling study, androgen receptors were seen to co-localize with alpha-actin in both cell cultures and tissue samples. We present the first evidence that the palmar fascia is a target tissue for androgen action and that the expression of androgen receptors in Dupuytren's contracture is considerably higher than in the normal palmar fascia. Further studies will need to evaluate whether the androgen-responsive state of the tissue is related to the high incidence of Dupuytren's contracture in the male sex.
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Contractura de Dupuytren/metabolismo , Fascia/química , Receptores Androgénicos/análisis , Actinas/análisis , Anciano , Células Cultivadas , Colágeno Tipo I/análisis , Contractura de Dupuytren/patología , Fascia/citología , Femenino , Humanos , Inmunohistoquímica , MasculinoRESUMEN
Osteoblast-like cells isolated from human bone bioptic specimens were established in culture. Their osteoblast-like phenotype was studied by biochemical, histochemical and immunohistochemical methods and by electron microscopy examination. Third-passage cell cultures exhibited high level of alkaline phosphatase activity and the exposure to human parathyroid hormone produced an increase of intracellular cAMP. Cultured cells were immunoreactive for type I and type III collagen, osteonectin, and fibronectin; when ascorbic acid and beta-glycerophosphate were added, they synthesized a rich extracellular matrix. This characterization ensures the reliability of osteoblast-like cultures when they are used as experimental models.
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Células Cultivadas , Osteoblastos , Adulto , Fosfatasa Alcalina/análisis , Ácido Ascórbico/farmacología , Matriz Ósea/metabolismo , Colágeno/análisis , AMP Cíclico/metabolismo , Fibronectinas/análisis , Glicerofosfatos/farmacología , Histocitoquímica , Humanos , Inmunohistoquímica , Microscopía Electrónica de Rastreo , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Osteoblastos/ultraestructura , Osteonectina/análisis , Hormona Paratiroidea/farmacologíaRESUMEN
To investigate the pathogenesis of the degenerative changes of the ligamentum flavum occurring in lumbar spine stenosis, yellow ligament cells from patients with lumbar spine stenosis were cultured for the first time and subjected to biochemical, histochemical and immunohistochemical study. Stenotic ligamentum flavum (SLF) cells were seen to express high levels of alkaline phosphatase (ALP) activity and to produce a matrix rich in type I and III collagen, fibronectin and osteonectin. The matrix mineralized only following beta-glycerophosphate (betaGP) and ascorbic acid supplementation. Stimulation with human parathyroid hormone (PTH) increased intracellular cAMP concentration. These findings indicate that there was significant evidence of osteoblast-like activity in these cells. SLF cells also stained for S100 protein, type II and type X collagen, and co-localized type II collagen and ALP labelling, reflecting the presence of hypertrophic chondrocyte-like cells. Cultures from control patients showed neither osteoblastic nor chondrocytic features: they expressed type I and type III collagen and fibronectin, but did not stain for osteonectin, nor were bone-like calcifications observed in presence or absence of betaGP. Normal ligamentum flavum (NLF) cells did not synthesized S100 protein or type II or type X collagen, and showed a weaker response to PTH stimulation. Our data demonstrated the presence of hypertrophic chondrocytes with an osteoblast-like activity in the ligamentum flavum of patients with spinal stenosis suggesting that they could have a role in the pathophysiology of the heterotopic ossification of ligamentum flavum (OLF) in lumbar spine stenosis.
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Ligamento Amarillo/patología , Estenosis Espinal/patología , Fosfatasa Alcalina/metabolismo , Matriz Ósea/metabolismo , Células Cultivadas , Colágeno/metabolismo , AMP Cíclico/metabolismo , Fibronectinas/metabolismo , Humanos , Inmunohistoquímica , Ligamento Amarillo/efectos de los fármacos , Ligamento Amarillo/metabolismo , Región Lumbosacra , Persona de Mediana Edad , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Osteonectina/metabolismo , Hormona Paratiroidea/farmacología , Valores de Referencia , Proteínas S100/metabolismo , Fracturas de la Columna Vertebral/metabolismo , Fracturas de la Columna Vertebral/patología , Estenosis Espinal/metabolismoRESUMEN
Osteoblast-like cells isolated from human bone bioptic specimens were characterized and analysed for the presence of type II estrogen receptor (type II EBS). The amount of type II EBS was measured by a whole-cell assay at 4 degrees C for 2.5 h using [(3)H]-estradiol as tracer. Saturation analysis, used to investigate the binding characteristic of type II EBS, resulted in a sigmoid curve. Scatchard analysis showed the binding affinity of the estrogen receptor, yielding a concave plot. The dissociation constant (K(d)), determined from the [(3)H]-estradiol concentration required for half saturation was about 12+/-2 nM (SD). The number of type II EBS, estimated at maximum binding, was 197,000+/-8800 sites per cell. If the regulation of the receptor by flavonoids would be confirmed, the evidence of type II EBS in osteoblast-like cells could suggest a direct action of ipriflavone and others flavonoids on bone density in postmenopausal osteoporosis.
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Huesos/metabolismo , Osteoblastos/metabolismo , Receptores de Estrógenos/metabolismo , Adulto , Fosfatasa Alcalina/metabolismo , Unión Competitiva/efectos de los fármacos , Huesos/citología , Huesos/efectos de los fármacos , Células Cultivadas , Colágeno/metabolismo , AMP Cíclico/metabolismo , Citoplasma/enzimología , Estradiol/farmacocinética , Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Humanos , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Osteonectina/metabolismo , Hormona Paratiroidea/farmacología , Quercetina/farmacocinética , Especificidad por Sustrato/efectos de los fármacos , TritioRESUMEN
Bone morphogenetic protein (BMP), associated with N,N-dicarboxymethyl chitosan, is used to induce or facilitate the repair of articular cartilage lesions. This association is intended for the synergistic potentiation of the respective biological effects. Data show that BMP-7 enhances the in vivo proliferation of cells with chondrocytes phenotype in the articular environment, leading to partial healing of the articular surface of the lesions. N,N-dicarboxymethyl chitosan is found to be useful as a molecular carrier or drug delivery agent.
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Proteínas Morfogenéticas Óseas/administración & dosificación , Cartílago Articular/lesiones , Quitina/administración & dosificación , Regeneración , Factor de Crecimiento Transformador beta , Animales , Proteína Morfogenética Ósea 7 , Proteínas Morfogenéticas Óseas/uso terapéutico , Cartílago Articular/efectos de los fármacos , Cartílago Articular/patología , Quitina/análogos & derivados , Portadores de Fármacos , Masculino , ConejosRESUMEN
Ultrastructural difractometric and chemical evaluations of calcium partially stabilized zirconium (Ca-PSZ) implants were performed in an in vivo study on animals in order to evaluate its biological behaviour. The chemical-morphological investigations demonstrated the presence of an osteogenetic activity at the bone-biomaterial interface. The new-osteogenesis was preceded by the formation of a loose connective tissue around the implants. This mesenchymal-type tissue without a capsular organization, allowing modulation of the mechanical forces to which the implant is subject, could be considered a positive event in the osteogenetic process and not a sign of future failure of the implant. Finally, microanalytical investigations carried out on non-implanted and implanted Ca-PSZ tools suggested that the surface of this ceramic material does not undergo modification once it has been inserted in the biological environment (12 months).
RESUMEN
Eleven subungual exostoses of the foot (10 on the hallux, 1 on the third toe) were studied. The initial symptom was subungual pain. When a subungual mass of fibrous tissue appeared, the nail was pushed up and in one case the mass became infected. X-rays exhibited a bone mass protruding from the terminal phalanx on the dorsomedial aspect of the toe in all cases. All patients underwent surgical excision of the lesions with partial onychectomy. Three layers were identified in five cases: a cap of fibrous tissue, a middle zone of hyaline cartilage with enchondral ossification, and a deep zone of cancellous bone. In three other cases, the histological pattern was pleomorphic and poorly characterized. The study shows that most subungual bone masses exhibited the pathological features of conventional osteochondromas. Nonetheless, a small number of lesions were pleomorphic and differed from osteochondromas, with abundant fibrous tissue merging irregularly into scattered islets of cartilage that was not organized in columns. Radical excision of the mass achieved complete relief of symptoms and recovery without recurrences in all cases.
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Neoplasias Óseas/patología , Enfermedades del Pie/patología , Osteocondroma/patología , Adolescente , Adulto , Neoplasias Óseas/diagnóstico , Neoplasias Óseas/cirugía , Femenino , Enfermedades del Pie/diagnóstico , Enfermedades del Pie/cirugía , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Osteocondroma/diagnóstico , Osteocondroma/cirugía , Radiografía , Dedos del Pie/diagnóstico por imagen , Dedos del Pie/patologíaRESUMEN
Three types of elastic fibers have been described: mature elastic fibers, elaunin fibers, and oxytalan fibers. To our knowledge, their location in the immature epiphysis has never been previously reported. The aim of the present study was to use histochemistry, immunohistochemistry, and electron microscopy to demonstrate the distribution of each type of elastic fiber in the epiphyseal region of growing humans and rabbits. Histological samples were collected from the knees of 10 immature New Zealand White rabbits and four children of various ages. The Weigert resorcin-fuchsin, Gomori aldehyde-fuchsin, Verhoeff iron haematoxylin, and Fullmer-Lillie methods were used for histochemistry; anti-elastin monoclonal antibodies, for immunohistochemistry; and tannic acid, uranyl acetate, and lead citrate stain, for transmission electron microscopy analysis. Elastic fibers were detected in the perichondrium, the epiphyseal vessels, and the outer and middle zones of Ranvier's groove. Their orientation was longitudinal in the outer zone and circumferential in the middle zone of the groove. Oxytalan fibrils (i.e., bundles of filaments of 10-12 nm in diameter that do not contain elastin) and elaunin fibers (i.e., filaments that cross discontinuous aggregates of elastin) were more plentiful in the middle zone and decreased with age, whereas mature fibers were more numerous in the outer zone and increased with age. This organization of elastic fibers seems to indicate an age-related process of maturation of the elastic network. The contribution of these fibers to the mechanical properties of the epiphyseal plate and to the growth process remains to be determined.
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Tejido Elástico/crecimiento & desarrollo , Fémur/química , Fémur/crecimiento & desarrollo , Factores de Edad , Animales , Animales Recién Nacidos , Cartílago/química , Cartílago/crecimiento & desarrollo , Cartílago/ultraestructura , Niño , Preescolar , Proteínas Contráctiles/análisis , Tejido Elástico/química , Tejido Elástico/ultraestructura , Elastina/análisis , Epífisis/química , Epífisis/crecimiento & desarrollo , Epífisis/ultraestructura , Fémur/ultraestructura , Histocitoquímica , Humanos , Inmunohistoquímica , Lactante , Recién Nacido , Microscopía Electrónica , ConejosRESUMEN
The aim of this study was the histochemical, immunohistochemical and ultrastructural analysis of reparative fibrillogenesis in experimental lesions of Achilles' tendon. Subtotal tenotomy of Achilles' tendon was performed in twenty Wistar rats. The scar tissue was analysed 2, 4, 7, 14, 21, 30, 45 and 60 days post-operatively. Histochemical, (resorcin-fuchsin, aldehyde-fuchsin, iron haematoxylin and Fullmer and Lillie's methods) immunohistochemical (antibody against collagen I, II and elastin) and ultrastructural analyses were performed. Three phases in the healing process were distinguished: 1) inflammatory, 2) proliferative, and 3) remodelling phase. The inflammatory phase was characterised by haematoma, fibrin deposition, inflammatory cells, fibroblasts, beginning of collagen fibrillogenesis (200-400 A ø fibrils) and oxytalan fibrils. The proliferative phase was characterised by angiogenesis and fibroblast proliferation. Collagen fibres displayed a random arrangement and had a diameter of 400-600 A. Immature elastic fibres reached maximum tissutal concentration. In the remodelling phase, hypocellularity, normal vascularisation, tendon crimps, collagen fibres (800-1,000 A ø), elastic fibres with increased elastin deposition and reduction in oxytalan fibres were observed. In the course of the healing process collagen and elastic fibre fibrillogenesis exhibited consistent quantitative and qualitative variations (i.e. differences in the type and diameter of fibrils). The present study suggests that, together with other matrix macromolecules, also elastic fibres (oxytalan, elaunin and mature) are synthesised in significantly higher amounts during reparative fibrillogenesis and play a role in cell-matrix interaction.
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Tendón Calcáneo/lesiones , Colágeno/ultraestructura , Cicatrización de Heridas , Tendón Calcáneo/patología , Animales , Histocitoquímica , Ratas , Ratas WistarRESUMEN
Lesions of the articular cartilage were bilaterally induced in the patella and the femoral condyle of adult NZW rabbits. A fresh fetal chondral homograft was implanted in one side, the untreated side serving as control. Fetal chondral tissue appeared to survive when implanted at the site of articular injury in adult animals, with no histological evidence of cell-mediated immune response. Fetal chondroblasts showed some signs of maturation and induced endochondral ossification at the base of the graft, with sound anchoring of the graft to the host tissue. In most cases, the homograft fused directly with the adjacent articular cartilage restoring the continuing of the articular surface. However, at implantation the graft could not be easily kept in place, and therefore some grafts had poor mechanical stability. Condylar grafts were incorporated better than patellar grafts. The healing process seemed to be related to the mechanical stability of the graft and to the anatomical site of injury.
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Cartílago Articular/cirugía , Cartílago/trasplante , Trasplante de Tejido Fetal , Miembro Posterior/cirugía , Animales , Cartílago/citología , Cartílago/embriología , Cartílago Articular/patología , Femenino , Cabeza Femoral/patología , Cabeza Femoral/cirugía , Trasplante de Tejido Fetal/métodos , Supervivencia de Injerto , Miembro Posterior/patología , Rótula/patología , Rótula/cirugía , ConejosRESUMEN
The distribution and histochemical properties of elastic fibers in the knee of newborn, young, adult, and old New Zealand White rabbits were studied. In the growing rabbit, elastic fibers, especially oxytalan fibers, are abundant in the perichondrium and the fibrous layer of the periosteum. They are homogeneously distributed in tendons, ligaments, and menisci, and are absent in the epiphyseal cartilage and growth plate and at the enthesis. In mature rabbits, the articular capsule, the synovial membrane, the peritenon, the periosteum, the perimysium, and the perivascular connective tissue are rich with elastic fibers. They are rarer in the tendon and are absent at the enthesis, in bone and articular cartilage. In the meniscus, the fibers are distributed centripetally. The distribution of elastic fibers is probably related to the different functional role and biomechanical behavior of each tissue. Finally, the type of elastic fiber in the various tissues changes with age; younger animals have more oxytalan fibers than adult animals. A gradual process of maturation and specialization of the network of elastic fibers takes place with age.
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Envejecimiento , Cartílago Articular/ultraestructura , Proteínas Contráctiles/ultraestructura , Tejido Elástico/ultraestructura , Animales , Animales Recién Nacidos , Proteínas Contráctiles/fisiología , Articulación de la Rodilla/citología , Ligamentos Articulares/ultraestructura , Meniscos Tibiales/ultraestructura , Periostio/ultraestructura , Conejos , Tendones/ultraestructuraRESUMEN
Forty patients with Sudeck's atrophy were assessed in order to evaluate the diagnostic accuracy of x-ray, scintigraphy and telethermography in staging the 3 phases of the disease. The dynamic and early static phases of scintigraphy were the most sensitive and specific instrumental tests for detecting the early stage, whereas telethermography was fairly sensitive but not very specific. Radiographic examination was not sensitive in detecting slight changes in bone density, but it was the most reliable index for recognizing the transition to stage II of the disease. Moreover, it was possible to confirm that the late static phase of scintigraphy is the index which is best related to bone metabolism.
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Diagnóstico por Imagen , Distrofia Simpática Refleja/diagnóstico , Adulto , Fosfatasa Alcalina/análisis , Calcio/análisis , Fractura de Colles/complicaciones , Femenino , Humanos , Hidroxiprolina/análisis , Masculino , Fosfatos/análisis , Cintigrafía/métodos , Distrofia Simpática Refleja/etiología , Medronato de Tecnecio Tc 99m , Termografía/métodosRESUMEN
A retrospective study was carried out to evaluate the results of intramedullary fixation by Ender nailing in the treatment of intertrochanteric fractures. During the period 1980-1989, 85 patients were treated with this method at the Orthopedic Department of the Università Cattolica in Rome. Evaluation of the cases took into account the patient's characteristics (age, sex, weight, height, obesity, previous or concomitant illness, level of autonomy, mental condition, type of fracture, time elapsed before operation and laboratory tests), details of the operation (length, accuracy of reduction and mechanical fixation stability, post-operative hospitalization period and general and local complications) and follow-up evaluation (X-ray examination, functional examination and evaluation of the results). Analysis of the observations showed that, although it induced less surgical trauma, internal fixation by the Ender method did not ensure a stable reduction, particularly with highly comminuted and basicervical fractures. As a result, the elective indication for this method should be restricted to stable intertrochanteric fractures, particularly in patients with a generally poor condition.
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Fijación Intramedular de Fracturas/métodos , Fracturas de Cadera/cirugía , Anciano , Anciano de 80 o más Años , Estudios de Evaluación como Asunto , Femenino , Fijación Intramedular de Fracturas/efectos adversos , Fracturas de Cadera/complicaciones , Fracturas de Cadera/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Four cases are described of solitary spinal neurofibroma, a rare tumour of the spinal cord or nerve roots. Computerised tomography provided an accurate topographical definition of the tumour. Magnetic resonance imaging showed an increased T2-weighted signal and multiple areas of decreased T1- and T2-weighted signals centrally. The MR signals matched the histological examination which showed hyperplastic interfascicular connective tissue, pleomorphic cells, and tightly packed nerve fibres compressed by the surrounding loose connective tissue. Electron microscopy showed three types of cell: Schwann cells, fibroblast-like cells, and mast cells. The histological findings suggests that solitary spinal neurofibroma is a distinct pathological entity which could be diagnosed preoperatively from the MR images.
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Neurofibroma/ultraestructura , Neoplasias de la Médula Espinal/ultraestructura , Adulto , Diagnóstico por Imagen , Femenino , Humanos , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Neurofibroma/diagnóstico , Neurofibroma/cirugía , Neoplasias de la Médula Espinal/diagnóstico , Neoplasias de la Médula Espinal/cirugíaRESUMEN
An in vitro study was performed assessing the pharmacologic properties of polymethylmethacrylate (PMMA)-antiblastic agent (doxorubicin and cisplatinum) mixtures in normal and neoplastic cell lines cultures. The study's aim was to analyze the polymerization capacity of PMMA in the presence of doxorubicin and cisplatinum, the release of drug from the mixture, the kinetics of release, and the effect of the released drugs in normal and neoplastic cell cultures. Our data show that even at high concentrations neither doxorubicin nor cisplatinum inhibit the polymerization of PMMA. Moreover, mixtures in vitro can release the antiblastic drug which maintains its pharmacologic activity on sensitive neoplastic cells. Therefore, the PMMA-antiblastic drug mixtures, along with current anti-cancer therapy (systemic chemotherapy and radiation therapy), may provide better local control of the metastatic lesion and of some bone tumors.
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Neoplasias Óseas/secundario , Cisplatino/administración & dosificación , Doxorrubicina/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Metilmetacrilatos/farmacología , Neoplasias Óseas/tratamiento farmacológico , Preparaciones de Acción Retardada , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
Ultrastructural analysis was conducted on samples of articular cartilage taken from both load-bearing and non-load-bearing areas with the aim of evaluating the morphologic adaptation of the articular cartilage to mechanical stimulation and identifying the mechanisms of interaction of the chondrocyte and the matrix. Through this analysis we were able to better define the adaptation process of the cartilage as well as the modalities of mechanical stress transmission. We believe that the complex formed by the chondrocyte, the pericellular matrix, and the pericellular capsule constitutes the biomechanical unit of the articular cartilage which serves as the sensor and transducer of mechanical stress. The arrangement of the collagen fibers and the proteoglycans which make up the pericellular capsule and membrane around the chondrocyte can be compared, from a mechanical standpoint, to a dynamic structure constructed in order to absorb the load stresses and protect the internal environment. From a biological standpoint, these are comparable to an extracellular-scaffold constructed with the aim of mediating the interaction between the chondrocyte and the territorial and inter-territorial compartments.
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Cartílago Articular/ultraestructura , Adaptación Fisiológica , Animales , Cartílago Articular/fisiología , Matriz Extracelular/ultraestructura , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Conejos , Estrés MecánicoRESUMEN
The authors analyze the ultrastructure of mast cells and perineurial cells when both are present in neurofibroma of the nerve sheath. Samples of pathologic tissue taken from three patients with neurofibroma of a peripheral nerve sheath were analyzed by light and transmission electron microscopy. The observations document the characteristics of the tumor cells (Schwann cells and perineurial cells) as well as the presence of numerous mast cells, typically in close contact with the perineurial cells and never with the Schwann cells. Many electron-dense vesicles were found between the cells; these vesicles are created when the cell membrane of the mast cell buds, and then they come into contact with the adjacent perineurial cell. Endocytosis vesicles are often present in the cytoplasm of perineurial cells. Analysis of these observations led the authors to assume the existence of a metabolic interaction between the two cell type in contact with each other and an active role of the mast cells in the evolution of the tumor. The following two theories are plausible: either the mast cells actively stimulate tumor growth, or they alter the phenotype of the tumor cell. These findings could have interesting clinical applications. The use of treatment protocols which inhibit mast cell activity could, in theory, stop either the proliferation of the neurofibroma or its malignant transformation.