Parâmetros ósseos de codornas de corte suplementadas com diferentes níveis de vitamina A, de 15 a 35 dias de idade / [Parameters of bone of meat-type quail supplemented with different levels of vitamin A from 15 to 35 days of age]

Avaliou-se o efeito da utilização de níveis crescentes de vitamina A sobre os parâmetros ósseos de codornas de corte de 15 a 35 dias de idade. Foram utilizadas 1520 codornas, não sexadas, com peso médio inicial de 85±4,25g, distribuídas em um delineamento inteiramente ao acaso, totalizando oito tratamentos com cinco repetições e 38 codornas por unidade experimental. Os tratamentos consistiram de oito níveis de suplementação de vitamina A (0; 4.500; 6.000; 7.500; 9.000; 10.500; 12.000 e 13.500UI/kg da dieta). O período experimental foi de 15 a 35 dias de idade. Os ossos analisados apresentaram uma redução linear para o índice de Seedor, resistência óssea e teor de cinzas do fêmur e da tíbia de acordo com os níveis de suplementação de vitamina A. A suplementação de vitamina A para codornas de corte de 15 a 35 dias de idade mostrou resultados negativos para a qualidade óssea, com a necessidade de mais estudos sobre seu antagonismo com a vitamina D.(AU)

This study evaluated the effect of using increasing levels of vitamin A on bone parameters in meat-type quails from 15 to 35 days old. A total of 1520 unsexed quail with an average initial weight of 85g distributed in a completely randomized design, totaling eight treatments with five replicates and 38 quails per experimental unit were used. The treatments consisted of eight vitamin supplementation levels A (0; 4,500; 6,000; 7,500; 9,000; 10,500; 12,000 and 13,500IU / kg diet). The experimental period was 15 to 35 days of age. The bones analyzed showed a linear reduction to the Seedor index, bone strength and ash content of the femur and tibia according to vitamin supplementation levels Vitamin A supplementation for cutting quails from 15 to 35 days of age showed negative results for bone quality, with the need for more studies on its antagonism to vitamin D.(AU)

Effects of underwater lipus on the morphohistology of the CF-1 mice growth plate in late lactation stage / Efectos del ultrasonido subacuático sobre la morfohistología de la placa de crecimiento de ratones CF-1 en etapa de lactancia tardía

SUMMARY: Ultrasound is one of the most used tools in physiotherapy, its LIPUS modality allows to treat musculoskeletal injuries, but like the conventional ultrasound it is contraindicated its application in areas close to growth cartilage by a possible closure of this one. In the literature there is no conclusive evidence of this contraindication, so the objective of the present study is to evaluate the effects of doses equivalent to underwater LIPUS on the histomorphometry of the proximal tibial epiphysis growth plate in an animal model. LIPUS was applied in underwater mode in the right pelvic limb to 8 mice in p 15 for 4 days, 2 times a day. On completion of 8 sessions the histology of the stimulated limb growth plate was sacrificed and the histology. When evaluating the histomorphometry of the plaque, a significant increase in the thickness and area of the proliferative zone stimulated with LIPUS (p = 0.048) was observed. In the hypertrophic area were observed no significant differences in thickness or areas, but in the hypertrophic area there were significant changes in the histological organization, observing a significant increase of the entire columns in the stimulated plaque (p = 0.04). LIPUS in underwater modality modifies the histomorphometry of the proximal epiphyseal PC of the tibia of rodents in the late postnatal stage, promoting proliferation and columnar organization in the proliferative and hypertrophic zone, respectively.

RESUMEN: El ultrasonido es una de las herramientas más utilizadas en fisioterapia, su modalidad LIPUS permite tratar lesiones músculo-esqueléticas, pero al igual que el ultrasonido convencional está contraindicada su aplicación en zonas próximas a cartílago de crecimiento por un posible cierre de éste. En la literatura no existe evidencia contundente de esta contraindicación, por lo cual el objetivo del presente estudio fue evaluar los efectos de dosis equivalentes a LIPUS subacuático sobre la histomorfometría de la placa de crecimiento de la epífisis proximal de tibia en un modelo animal. Metodología. Se aplicó LIPUS en modalidad subacuática en el miembro pélvico derecho a 8 ratones en p 15 por 4 días, 2 veces al día. Al cumplir 8 sesiones se sacrificaron y se evaluó la histología de la placa de crecimiento del miembro estimulado. Al evaluar la histomorfometría de la placa se observó un aumento significativo en el espesor y el área de la zona proliferiva estimulada con LIPUS (p=0.048). En la zona hipertrófica no se observaron diferencias significativas en el espesor ni en las áreas, pero si existieron cambios significativos en la organización histológica de la zona, observando un aumento significativo de las columnas completas en la placa estimulada (p=0,04). El LIPUS en modalidad subacuática modifica la histomorfometría de la PC epifisiaria proximal de la tibia de roedores en el etapa postnatal tardía, promoviendo la proliferación y la organización columnar en la zona proliferativa e hipertrófica, respectivamente.

Second hand tobacco smoke adversely affects the bone of immature rats

OBJECTIVES: To evaluate the influence of secondhand cigarette smoke exposure on longitudinal growth of the tibia of growing rats and some parameters of bone quality. METHODS: Forty female rats were randomly divided into four groups: control: rats were sham exposed; 30 days: rats were exposed to tobacco smoke for 30 days; 45 days: rats were exposed to tobacco smoke for 45 days; and 60 days: rats were exposed to tobacco smoke for 60 days. Blood samples were collected to evaluate the levels of cotinine and alkaline phosphatase. Both tibias were dissected and weighed; the lengths were measured, and the bones were then stored in a freezer for analysis of bone mineral content and mechanical resistance (maximal load and stiffness). RESULTS: Exposure of rats to tobacco smoke significantly compromised bone health, suggesting that the harmful effects may be time dependent. Harmful effects on bone growth were detected and were more pronounced at 60-day follow-ups with a 41.8% reduction in alkaline phosphatase levels (p<0.01) and a decrease of 11.25% in tibia length (p<0.001). Furthermore, a 41.5% decrease in bone mineral density was observed (p<0.001), leading to a 42.8% reduction in maximum strength (p<0.001) and a 56.7% reduction in stiffness (p<0.001). CONCLUSION: Second hand cigarette smoke exposure in rats affected bones that were weaker, deforming them and making them osteopenic. Additionally, the long bone was shorter, suggesting interference with growth. Such events seem to be related to time of exposure.

Osteotomía proximal en cuña abierta de tibia con injerto de peroné en la enfermedad de Blount / Ostéotomie tibiale proximale en chevron ouvert et greffon de péroné dans la maladie de Blount / Proximal osteotomy in tibia open wedge with fibular graft in Blount's disease

Introducción: La tibia vara es una enfermedad compleja que consta de varias deformidades en la rodilla y la pierna. Su tratamiento es controvertido. Con las técnicas quirúrgicas actuales se logra la corrección, pero la tendencia a la recidiva es elevada. Objetivo: Evaluar el uso de la osteotomía proximal de tibia en cuña abierta con injerto de peroné en la enfermedad de Blount. Métodos: Se realizó un estudio de intervención en 11 pacientes (18 miembros inferiores) con tibia vara, con edades entre 3 y 18 años, que acudieron a la consulta externa del Servicio de Miembro Inferior y Artroscopia del Complejo Científico Ortopédico Internacional Frank País del 1ro de junio de 2009 al 31 de mayo de 2011. A estos pacientes se les realizó una osteotomía proximal en cuña abierta medial de tibia. Se empleó un injerto estructural de peroné para corregir la deformidad. Se utilizaron los criterios clínico-radiográficos de Schoenecker PL y otros para la evaluación del procedimiento quirúrgico. Resultados: A partir de la propuesta de Schoenecker PL y otros, se pudo comprobar que 77,77 por ciento de los resultados fueron buenos; 16,66 por ciento, regulares, y 11,11 por ciento, malos, lo cual demuestra que el tratamiento con esta técnica fue efectivo. Se determinó además que un ángulo tibiofemoral mayor de 30º y un estadío radiográfico avanzado de la enfermedad son factores que afectan negativamente los resultados obtenidos. Conclusión: La osteotomía proximal en cuña abierta medial de tibia con injerto estructural de peroné ofreció buenos resultados clínicos y radiográficos en el tratamiento de la enfermedad de Blount(AU)

Introduction: Tibia vara is a complex disease consisting in several deformities in the knee and leg. The treatment is controversial. Correction is achieved with current surgical techniques, but the tendency to relapse is high. Objective: To evaluate the use of medial opening wedge proximal tibial osteotomy with fibular graft in Blount's disease. Methods: An intervention study was achieved in 11 patients (18 lower limbs) with tibia vara. The ages of these patients ranged from 3 to 18 years, and they were assisted in the outpatient clinic of the Lower Limbs and Arthroscopy Service at Frank País International Orthopedic Scientific Complex from June 1, 2009 to May 31, 2011. These patients underwent medial opening wedge proximal tibial osteotomy. A fibular structural graft was used to correct the deformity. The clinical and radiographic criteria of Schoenecker PL and others were used for the evaluation of the surgical procedure. Results: As of the proposal of Schoenecker PL and others, it was found that 77.77 percent of the results were good; 16.66 percent acceptable, and 11.11 percent poor, which shows this technique was effective for the treatment. It was also determined that a tibiofemoral angle larger than 30º and an advanced radiographic stage of the disease are factors that negatively affect the results. Conclusion: The medial opening wedge proximal tibial osteotomy with structural graft offered good clinical and radiographic results in the treatment of Blount's disease(AU)

Introduction: Le tibia vara est une maladie complexe comportant plusieurs déformations au niveau du genou et de la jambe. Son traitement est controversé. Elle peut être corrigée par les nouvelles techniques chirurgicales, mais la récidive tend à être élevée. Objectif: Évaluer l'utilisation de l'ostéotomie tibiale proximale en chevron ouvert et du greffon de péroné dans la maladie de Blount. Méthodes: Une étude interventionnelle de 11 patients (18 extrémités inférieures), âgés de 3 à 18 ans, atteints de tibia vara, et vus en consultation externe du 1 janvier 2009 au 31 mai 2011 au service des affections des extrémités inférieures et d'arthroscopie du Complexe scientifique internationale d'orthopédie «Frank Pais¼, a été réalisée. Ces patients ont été traités par une ostéotomie tibiale proximale en chevron ouvert médial. Un greffon structurel de péroné a été employé pour corriger la déformation. On a utilisé les critères cliniques et radiographiques de Schoenecker PL et al pour évaluer la procédure chirurgicale. Résultats: À partir de la proposition de Schoenecker PL et al, on a pu constater que les résultats ont été bons (77.77 pourcent); acceptables (16.66 %), et mauvais (11.11 pourcent), montrant ainsi que la technique était effective. On a aussi trouvé qu'une angulation tibio-fémorale de plus de 30° et un stade radiographique avancé de la maladie sont des facteurs influant négativement sur les résultats obtenus. Conclusions: L'ostéotomie tibiale proximale en chevron ouvert médial et le greffon structurel de péroné offrent de bons résultats cliniques et radiographiques dans le traitement de la maladie de Blount(AU)

Allometric relationships among body mass, MUZZLE-tail length, and tibia length during the growth of Wistar rats1

PURPOSE : To investigate allometric relationships among body mass (BM), muzzle-tail length (MTL), and tibia length (TL) in Wistar rats and establish their growth rate change parameters. METHODS : Eighteen male and 18 female Wistar rats were studied from the 3rd to the 21st week of age. BM, MTL, and TL were measured daily, and relative growth was compared using allometry. RESULTS : A positive correlation between BM and MTL (p<0.05) and BM and TL (p<0.05) was observed. Males and females showed comparable curves; however, females had turning points at a younger age. The allometric relationship between BM and MTL presented a regular increase until reaching a mass of 351 g (males) and 405 g (females). BM and TL showed an initial increase until 185 g (males) and 182 g (females), and then reached a plateau that finished at 412 g (males) and 334 g (females), to display another increase. CONCLUSIONS : The allometric relationship of body mass with animal length and tibia length was comparable for male and female rats, with female rats maturing earlier. Animal longitudinal growth occurred in a single stage. In contrast, tibia length depicted two stages of accelerated growth with an intermediate period of deceleration.

Análisis de las deformaciones de la tibia humana a consecuencia del genu varum / Analysis of the deformations of the human tibia as a result of genu varum

El Genu Varum (piernas arqueadas), corresponde a una alteración en el eje axial que presentan todos los niños durante su desarrollo. Desde el punto de vista de la Ingeniería de los materiales, el genu varum se lo considera como un desplazamiento de la articulación en sentido externo al eje de presión Esta investigación, mediante un riguroso análisis matemático de la geometría estructural de la tibia y la función física de sus elementos, plantea la determinación de los puntos críticos de flexionamiento. Un diagrama de esfuerzos con sus respectivas coordenadas, el tipo de esfuerzo que sufre y las fuerzas que deberían aplicarse para un alineamiento sin proceder con un corte de la misma. Este estudio también plantea una metodología de análisis mediante un diagrama vectorial de los vectores fuerza que actúan en los tendones externos (peroneo) e interno como así el vector de reacción de la tibia deformada a consecuencia del genu varum. Con este análisis se plantea una explicación del por qué el genu varum se detiene a causa de la reacción compensativa de la tibia ante el desplazamiento de la articulación. Para todo lo anteriormente planteado se considera la técnica de Ilizarov para la aplicación de este método de alineamiento.

Bone development trend in the knee joint of Tibetan teenagers in Aba Prefecture of Sichuan Province / 法医学杂志

OBJECTIVE@#To discuss bone development trend in the knee joint of Tibetan teenagers in Sichuan province and to effectively update the database for estimating the living age of Tibetan teenagers in terms of bone age of the knee joint.@*METHODS@#Radiographs including epiphysis of distal femur, proximal tibia and proximal fibula were taken from 483 Tibetan male and female teenagers aged from 14 to 19 years old in Aba prefecture of Sichuan province in order to observe epiphyseal growth situation. The descriptive data of the epiphyseal closure ages of these teenagers' knee joints were statistically analyzed by SPSS 16.0 software.@*RESULTS@#The distal femur epiphyseal closure occurred earliest, while the proximal fibula epiphyseal closure occurred latest. The epiphyseal growth of knee joints of females occurred about one year earlier than that of males.@*CONCLUSION@#The forensic information and data related to Tibetan teenagers' bone age identification should be updated regularly. These results provide potential value for the practice of forensic medicine, anthropology and clinical medicine.

relationship between normal intercondylar and intermaleolar distances and epidemiological factors in children 3-16 years of age

In evaluation of genu varum and genu valgum which are common in growth period of children, tibiofemoral [TF], intercondylar [1C] and intermaleolar [IM] distances are commonly measured. Normally, the legs of most newborns are slightly curved or have moderate curves medially when they are in standing position. During their growth, the extension of the lower limb changes. The aim of this study was to determine the relationship between normal intercondylar and intermaleoar distances and physiolgical factors among these subject groups. In this cross-sectional study a group of 850 children [452 females, 398 males] aged between 3 to 16 years old were studied. The samples were collected randomly from kindergartens, preschool care centers and schools in all 4 districts of Ahvaz, plus a few patients in Shafa hospital. The intercondylar and intermaleolar distance were examined in standing position, while the knee and hip joints were fully extended and the two medial maleolus or two medial condye of knees were in contact. In this study, descriptive statistics as well as t- and ANOVA tests were used for comparison. Pearson correlation for the survey were used data analysis by SPSS version 15. The mean of intercondylar distance among studied groups was 1.65 +/- 0.86: 1.5 in boys and 1.71 cm in girls respectively. The mean of intermaleolar distances was 2.31cm in males 2.05cm and in females 2.53 cm, the difference was significant [P<0.05]. There was a direct ralationship between intermaleolar distance and weight, height and length of leg, but relationship between Intercondylar distance and these factors is in reverse order

Age determination in girls of Jodhpur Region by epiphyseal union of bones at ankle joint.

There is no statistical data to establish variation in epiphyseal fusion in Western Rajasthan populations. This significant oversight can lead to exclusion of persons of interest in a forensic investigation. Epiphyseal fusion of the distal tibia and fibula in sixty females was analyzed on radiological basis to assess the range of variation of epiphyseal fusion at each age. In the study the X ray films of the subjects were divided into three groups on the basis of degree of fusion. Firstly, those which were showing No Epiphyseal Fusion (N), secondly those showing Partial Union (P), and thirdly those showing Complete Fusion (C). Observations made were compared with the previous studies. Results indicate that complete fusion in females occurs as early as 14 years in the distal tibia and fibula. All females demonstrated complete fusion by 19 years with no significant differences between ancestral groups.

Fractura de la espina tibial en pacientes con fisis abierta: osteosintesis con pines biodegradables / Tibial eminence fracture with open physis: osteosynthesis with bioabsorbable pins

Introducción: El tratamiento de la fractura de las espinas tibiales en pacientes con fisis abierta es controversial. Dicha lesión puede evolucionar, en su estado secuelar, con inestabilidad residual y/o limitación funcional. El objetivo del presente trabajo consiste en analizar la experiencia adquirida en el tratamiento artroscópico de la fractura de las espinas tibiales en pacientes con fisis abierta practicando la osteosíntesis con pines biodegradables. Materiales y métodos: En el período comprendido entre junio de 2001 y junio de 2007 fueron tratados consecutivamente 6 pacientes con fisis abierta que presentaban fractura de espinas tibiales tipificadas según la clasificación de Meyers y Me Keever como Tipos II y III. Se practicó la osteosíntesis mediante el implante biodegradable SmartNail ® (ConMed, Línvatec), siendo características distintivas del mismo poseer cabeza y trama antideslizante. Se protocolizó la evaluación mediante: a) semiología clínica (maniobras de Lachman y Pívot), b) evaluación funcional mediante escalas de Lysholrn e IKDC y, e) valoración artrométrica de la laxitud antero posterior mediante artrómetro KT 1000. Se realizaron controles radiológico y mediante RM. Resultados: Se registró test de Lachman negativo en 5 casos y Lachman 1 en un caso. El Pivot fue negativo en todos los casos. Empleando el KT 1000 se registró un desplazamiento menor a 5 mm en todos los casos La valoración funcional resultó: a) "excelente" en el 90% de los casos según score de Lysholm y, b) "muy buena" en el 85% de los casos según el IKDC. Se documentó la consolidación fracturaria mediante RX y RMN en todos los casos. Discusión: El procedimiento descripto se considera original, habiéndose inspirado en la experiencia preliminar satisfactoria adquirida utilizando al Smart- ail ® ...

Effect of homocysteine and protective role of trimethylglycine on the structure of tibia in growing albino rats: histological and biochemical study

Homocysteine [HCY] is an amino acid that is formed as an intermediate during the metabolism of methionine. Epidemiological studies have shown that too much homocysteine in blood plasma leads to a higher risk of coronary heart disease and strokes. It is also characteristic for homocystinuria. Trimethylglycine TMG [known as betaine] is a methyl donor that helps the quick conversion of homocysteine into methionine. Is to investigate the structural and the biochemical changes that occur in the articular cartilage, the growth plate and the bone structure of tibia in growing albino rats after being treated with oral supplement of HCY and possible protective role of TMG. Thirty two young male albino rats were used in this experiment. They were equally divided into four group. The control group received a balanced standard diet, HCY treated group received 0.6mg HCY/kg b.w/ day, TMG treated group [0.6gm TMG/kg b.w/day] and an interacting group received both HCY and TMG. Rats were sacrificed every 2 weeks up till the 8[th] week specimens from the tibias were obtained and processed for histological and biochemical study. Indicated that examination of rat bones of HCY group showed apparently abnormal radial and longitudinal bone growth. H and E stained sections of proximal ends of tibias showed changes in chondrocytes of proximal tibia. The growth plate of the proximal tibia showed a lack of the orderly chondrocytes columns arrangement. Examination of shafts of tibial bone of the same group showed many degenerative changes in periostum.The matrix contained many resorption cavities that were filled with granulation tissue. In addition there was evidence of abnormal biochemical patterns represented by low bone mineral density and bone mineral content. Statistically significant decrease in bone width compared to an increase in length and cross section area was detected. On the other hand TMG showed improved bone formation and inhibition of bone resorption. Was concluded that HCY produced profound histological changes in the articular cartilage, growth plate and bone structure of tibia of growing male albino rats. Mean while treatment with TMG markedly decreased the induced damage by HCY

Effects of Protein and Energy Restricted Diet During Lactation Leads to Persistent Morphological Changes on Tibia Growth in the Weaned Pups / Efectos de las Restricciones de Proteínas y de Energía Durante la Lactancia Provocan Cambios Morfológicos Persistentes en el Crecimiento de la Tibia de Crías Destetadas

The purpose of this study was to evaluate the effects of maternal protein and energy restriction during lactation on the body weight and tibiae dimensions of pups at aging. At parturition, Wistar rat dams were randomly assigned to the following groups: 1) control group (C) - free access to a standard laboratory diet containing 23% protein, 2) protein-energy restricted group (PR) - free access to an isoenergetic, protein-restricted diet containing 8% protein, and 3) energy-restricted group (ER) - fed restricted amounts of a standard laboratory diet. At weaning, all pups were separated of dams and received free access to a standard laboratory diet containing 23% protein until 180 days when the rats were anesthetized and sacrificed. The dimensions of excised pup tibia were measured directly using pre-established anatomical points. Morphometrical analysis of the tibia showed that most of the measurements in the ER and PR groups were significantly lower than in the control group, with the greatest reductions occurring in the PR group. These results show that protein and energy restriction during lactation have an important influence on pup tibia development.

Los objetivos de este estudio fueron evaluar los efectos de la restricción materna de proteínas y de energía durante la lactancia y sus efectos en el peso corporal y las dimensiones de las tibias de crías en ratas. En el parto, las crías de ratas Wistar fueron agrupadas aleatoriamente en los grupos siguientes: 1) grupo control (C) - con acceso libre a una dieta estándar del laboratorio, que contenía 23% de proteínas; 2) grupo con restricción de proteínas y energía (PR) - acceso libre a una dieta isoenergética, con restricción de proteínas, conteniendo un 8% de éstas y 3) grupo con restricción de energía, alimentado con restricción en la cantidad de alimento de la dieta estándar del laboratorio (ER). Al destete, todas las crías fueron separadas y recibieron la dieta estándar del laboratorio, conteniendo 23% de proteínas, hasta los 180 días, cuando fueron anestesiadas y sacrificadas. El análisis morfométrico de la tibia demostró que la mayoría de las mediciones en los grupos ER y PR, fueron significativamente menores que las del grupo control, con mayores reducciones en el grupo PR. Estos resultados muestran que las restricciones de energía y proteínas durante la lactancia tienen una influencia importante en el desarrollo de la tibia de las crías.

Multifocal giant cell tumour of bone in a skeletally immature patient--a case report.

Giant cell tumor of bone is usually seen in adults affecting a single bone. Multiple giant cell tumour of bone occurring in skeletally immature patients is extremely rare. Multifocal giant cell tumor of bone in a ten year old boy involving upper end of humerus and tibia is being reported for its extreme paucity in literature.

Desnutrição em crianças de 6 a 30 meses induz maior retardo de crescimento na tíbia do que no corpo / Malnutrition in 6-30 months children induces a more intense growth delay in the tibia than in the body

A diferença nos padrões de crescimento dos órgãos permite estabelecer relações entre as suas dimensões e as do corpo como um todo, determinando o que se chama crescimento, diferencial ou alométrico. Desde que estudos desta natureza ainda não foram realizados em desnutridos é oportuno testar a hipótese de que a desnutrição causa distorções naquelas relações. A presente pesquisa objetivou investigar as relações alométricas tíbia/altura em crianças eutróficas e desnutridas com 6 a 30 meses de idade. 125 crianças eutróficas (Percentil 10-97) e 125 desnutridas (Percentil <3), (Padrão NCHS) do sexo masculino, foram distribuídas em 26 grupos com 5 indivíduos para cada mês e cada condição nutricional, sendo medidas sua altura (comprimento do corpo) e comprimento da tíbia. Baseado na equação alométrica y: ax e mediante a logaritmização dos valores destas medidas e ajustamento dos dados a uma equação de regressão linear (y = a + bx) onde y é o logaritmo do comprimento da tíbia, x o logaritmo da altura e b (velocidade de crescimento da tíbia em relação à altura), os resultados mostraram que: nos desnutridos o rítmo de crescimento relativo da tíbia é significativamente menor (p < 0,01) do que nos eutróficos (desnutridos, b = 1.242; eutróficos, b = 1.508). Os dados indicam que nessa faixa etária os desnutridos, comparados aos eutróficos, apresentam uma redução na velocidade de crescimento mais pronunciada para a tíbia que para o corpo como um todo

Osteogénesis imperfecta. Experiencia del Hospital Shriners, Unidad Ciudad de México / Osteogenesis imperfecta. Experience in the Shriners Hospital from Mexico City

Desde su primera descripción en 1751, la osteogénesis imperfecta (OI) es una enfermedad de gran interés para el ortopedista; múltiples han sido los médicos e investigadores que han tratado de explicar la etiología, por lo que se han propuesto varias clasificaciones. De 1979 a 1993, se encontraron 57 expedientes de pacientes con OI en nuestro hospital, de los cuales sólo 39 se incluyeron en este estudio. La edad varió desde recién nacidos hasta 16 años, con un promedio de ocho años. Veinte eran del sexo masculino y 19 del femenino. Usando la clasificación de Seedorf encontramos que nueve pacientes eran del tipo I, 17 al tipo II y 3 del tipo III. La presencia de fracturas fue la manifestación clínica más frecuente, siendo el fémur el hueso predominante, con un promedio de 4.4 fracturas por paciente. Dentro del estudio encontramos que la OI tipo tarda gravis es la más frecuente; las deformidades óseas más frecuentes son en las extremidades inferiores: angulación anterolateral del fémur y tibia en sable. Es ideal la correción temprana de las angulaciones óseas, para permitir la deambulación temprana y mediante la ferulización interna prevenir la presentación de nuevas deformidades

Efectos tóxicos del uranio: modelos experimentales / Toxic effects of uranium: experimental models

Se presenta una revisión de los estudios realizados por el grupo de trabajo en relación a la acción tóxica del uranio desde un punto de vista químico. Los compuestos del uranio tienen una fácil absorción percutánea y lo hacen entre los espacios intercelulares del epitelio malpighiano. Se comprobó que el tejido óseo es particularmente sensible a la acción del uranio con una franca disminución de la osteoformación. Las tetraciclinas y los difosfonatos anulan el efecto del uranio sobre la inhibición de la formación ósea. Mientras que las tetraciclinas no tienen efecto marcado sobre la mortalidad, los bifosfonatos previenen la mortalidad producida por diferentes dosis y vías de aplicación del uranio. Estos datos sugieren la necesidad de completar estos estudios para su aplicación en casos de intoxicación en seres humanos y en distintas condiciones de contaminación.