El cotilo de impactación en las artroplastias de cadera

Entre los diferentes sistemas de fijación de la cúpula acetabular entre las artroplastias no cementadas, la impactación tiene múltiples ventajas. Permite un mejor contacto entre implante y hueso y no necesita destrucción de la superficie ósea receptora. Los nuevos diseños para impactación están fabricados en aleaciones de titanio y poseen una superficie rugosa recubierta a su vez con hidroxiapatita. Algunos modelos como la artroplatia Bihapro poseen aletas estabilizadoras en su reborde externo para evitar la movilización rotatoria inicial. El sistema de impactación está mostrando buenos resultados de la experiencia conocida y aunque los periodos de seguimiento son aún cortos, la integración ósea conseguida es satisfactoria. Se presentan los resultados de 1107 cúpulas Bihapro con una evolución entre uno y siete años, que han seguido un protocolo de seguimiento informatizado. En sólo un caso se presentó movilización del componente que precisó cirugía de revisión.The acetabular fixation by impaction has advantages on other systems of fixing in the cementless arthroplaties of the hip. Permit a better contact between implant and bone and it does not need destruction of the receiving bony surface. The new designs for fixation by impaction are manufactured in titanium alloys and possess a rugged surface cover at the same time with hyrdoxiapatite-coated. Some models as the arthroplasty Bihapro possess fins for primary stability in your external curbing to avoid the initial rotary mobilization. This system of fixation is showing good results in the known experience and though the periods of follow-up are yet short, the obtained bony integration is satisfactory. We presented the results of 117 Bihapro cups implanted with a follow-up from one to seven years, that they have followed a computed protocol. In only a case was presented loosening of the component that specified review surgery

Los tornillos como método suplementario de fijación de las cúpulas acetabulares: Utilidad de la digitalización de imágenes

La fijación suplementaria con tornillos de los componentes acetabulares hemisféricos no cementados es utilizada para proporcionar estabilidad primaria al implante. No obstante su empleo se asocia a un mayor riesgo de lesiones neurovasculares, complicaciones propias de los tornillos e incremento de osteolisis. Se han estudiado retrospectivamente las radiografías de 30 cúpulas cotiloideas no cementadas modelo Bihapro, suplementadas con tornillos, con un seguimiento mínimo de 5 años. Se utilizó, además, un programa de análisis y procesamiento de imágenes por ordenador. No se produjeron lesiones neurovasculares o viscerales, no se apreció ninguna movilización de la cúpula y sólo se observó un caso e osteolisis alrededor de un tornillo en un paciente sometido a cirugía de revisión. La digitalización de imágenes es una técnica que permite entre otras ventajas graduar densidades óseas periprotésicas facilitando un diagnóstico precoz de zonas líticas y microdeslizamientos protésicos, eliminando la subjetividad del observador.The supplementary fixation with screws non-cemented acetabular hemispheric components is used to provide primary stability to the implants. However, their use has been associated to a bigger risk of neurological and vascular damage, characteristic complications of the screws and osteolysis. The X-rays of 30 non-cemented acetabular cups model Bihapro supplemented with screws have been studied retrospectively with a 5 year-old minimum follow-up. It was also used an analysis program and computer store of images. No neurological or vascular damage took place. Any mobilization of the cup was not appreciated and only in one case of an osteolytic area was observed around a screw in a patient who unfderwent revision surgery. The digitalization of images is a technique that allows among other advantages to graduate periprosthetic bone densities facilitating an early diagnose of lytic areas and prosthetic micromovements eliminating the observer's subjectivity

Hemangioma intramuscular: A propósito de un caso

Se presenta el caso de un tumor de partes blandas localizado en la unión de tercio proximal y medio de pierna derecha, en el espesor del músculo peroneo lateral largo. Los estudios preoperatorios consideraron como primera posibilidad un hemangioma que fue confirmado posteriormente en la anatomía patológica y tratado mediante resección completa. Se hace a su vez un recuerdo bibliográfico de este tipo de tumores.A soft-tissue located in the confluence of the proximal and middle third of the right leg, depth in the peroneus lateralis longus muscle is presented. Preoperative showed an intramuscular haemangioma and postoperative histological diagnosis was confirmed and complete excision was the treatment applied. The literature related to the condition is also reviewed

Molecular Aspects of Thyroid Hormone Actions

Cellular actions of thyroid hormone may be initiated within the cell nucleus, at the plasma membrane, in cytoplasm, and at the mitochondrion. Thyroid hormone nuclear receptors (TRs) mediate the biological activities of T3 via transcriptional regulation. Two TR genes, α and β, encode four T3-binding receptor isoforms (α1, β1, β2, and β3). The transcriptional activity of TRs is regulated at multiple levels. Besides being regulated by T3, transcriptional activity is regulated by the type of thyroid hormone response elements located on the promoters of T3 target genes, by the developmental- and tissue-dependent expression of TR isoforms, and by a host of nuclear coregulatory proteins. These nuclear coregulatory proteins modulate the transcription activity of TRs in a T3-dependent manner. In the absence of T3, corepressors act to repress the basal transcriptional activity, whereas in the presence of T3, coactivators function to activate transcription. The critical role of TRs is evident in that mutations of the TRβ gene cause resistance to thyroid hormones to exhibit an array of symptoms due to decreasing the sensitivity of target tissues to T3. Genetically engineered knockin mouse models also reveal that mutations of the TRs could lead to other abnormalities beyond resistance to thyroid hormones, including thyroid cancer, pituitary tumors, dwarfism, and metabolic abnormalities. Thus, the deleterious effects of mutations of TRs are more severe than previously envisioned. These genetic-engineered mouse models provide valuable tools to ascertain further the molecular actions of unliganded TRs in vivo that could underlie the pathogenesis of hypothyroidism