Dysplasia of hip development: update

A terminologia "Displasia do Desenvolvimento do Quadril - DDQ" descreve o amplo espectro de alterações que atingem o quadril em crescimento, desde a displasia até a luxação da articulação, passando pelos diferentes graus de subluxação da coxofemoral. A incidência da DDQ é variável, dependendo de vários fatores, inclusive da localização geográfica. Aproximadamente um em cada 1.000 recém-nascidos poderá nascer com o quadril luxado e cerca de 10 em 1.000 com o quadril subluxado (instável). Em nosso meio podemos esperar a incidência de cinco por 1.000 quanto à positividade do sinal de Ortolani, que é o sinal clínico precoce de detecção da afecção. Os fatores de risco para a DDQ incluem: sexo feminino, raça branca, primiparidade, mãe jovem, apresentação pélvica ao nascimento, história familiar, oligohidrâmnio, recém-nascido com maiores peso e altura e com deformidades nos pés ou na coluna vertebral. O exame do quadril do recém-nascido deverá ser rotineiro e enfatizado nos berçários. No recém-nascido e nos bebês o diagnóstico da DDQ é eminentemente clínico e realizado com as manobras de Ortolani e de Barlow. A radiografia convencional tem um valor limitado na confirmação diagnóstica da DDQ nos recém-nascidos sendo a ultrassonografia do quadril o exame ideal. O tratamento da DDQ é desafiador tanto para o ortopedista pediátrico como para o generalista. Os objetivos do tratamento incluem o diagnóstico o mais precocemente possível, a redução da articulação e a estabilização do quadril em uma posição segura. Classicamente dividimos as possibilidades do tratamento de acordo com as diferentes faixas etárias, por ocasião do diagnóstico.The term "Developmental Dysplasia of the Hip - DDH" includes a wide spectrum of abnormalities in the immature hip, ranging range from subtle dysplasia to joint dislocation. The incidence of DDH is variable, and depends on a number of factors, such as geographical location. Approximately one in 1,000 newborn infants may present hip dislocation and 10 in 1,000 present hip instability. Brazil has an incidence of five per 1,000 in terms of the positive Ortolani signal, which is the early clinical signal for detecting the disorder. The risk factors for DDH include: female sex, Caucasian race, first labor, young mother, breech presentation on birth, family history, oligohydramnios , newborn with higher weight and height, and deformities of the feet or spine. Hip examination of the newborn should be routine, and should be emphasized in maternity units. In newborn infants and babies, the diagnosis of DDH is preeminently clinical and is carried out using the Ortolani and Barlow maneuvers. Conventional X-ray is of limited value for confirming the diagnosis of DDH in the newborn infant, and ultrasound of the hip is the ideal exam. The treatment of DDH is challenging, both for the pediatric orthopedist and for the general practitioner. The objectives of the treatment include early diagnosis, reduction of the articulation, and stabilization of the hip in a secure position. Classically, treatment options are divided according to the different age groups, at the time of diagnosis

The iterated auxiliary particle filter

We present an offline, iterated particle filter to facilitate statistical inference in general state space hidden Markov models. Given a model and a sequence of observations, the associated marginal likelihood L is central to likelihood-based inference for unknown statistical parameters. We define a class of "twisted" models: each member is specified by a sequence of positive functions psi and has an associated psi-auxiliary particle filter that provides unbiased estimates of L. We identify a sequence psi* that is optimal in the sense that the psi*-auxiliary particle filter's estimate of L has zero variance. In practical applications, psi* is unknown so the psi*-auxiliary particle filter cannot straightforwardly be implemented. We use an iterative scheme to approximate psi*, and demonstrate empirically that the resulting iterated auxiliary particle filter significantly outperforms the bootstrap particle filter in challenging settings. Applications include parameter estimation using a particle Markov chain Monte Carlo algorithm

Tratamiento de las complicaciones vasculares tras aplicación del método de Ilizarov: Aportación de tres casos

Entre 1987 y 1991 fueron intervenidos 209 pacientes mediante el método de Ilizarov en nuestra institución. Tres de los pacientes presentaron complicaciones vasculares durante el tratamiento. Todos ellos eran adultos y habían sido tratados por pseudoartrosis de un hueso largo. La lesión vascular ocurrió en la arteria femoral superficial en un caso, la arteria poplítea en otro y la arteria tibial posterior en el último de ellos. El signo clínico del problema vascular fue la presencia de la hemorragia en el punto de salida cutánea de las agujas de Kirschner de transfixión. Se realizó exploración arteriográfica en todos los casos, pero su interpretación fue difícil debido a la presencia del fijador externo. El tratamiento de la complicación vascular fue: en el caso de la lesión de la arteria femoral fue retirado el fijador y realizado un by-pass con un injerto invertido obtenido de la vena safena; en el caso de lesión de la arteria poplítea, se realizó la misma técnica pero sin retirar el fijador. En el último caso la lesión de la arteria tibial posterior se trató mediante ligadura de la misma. En todos los casos, la evolución del tratamiento vascular fue excelente, siendo posible finalizar el tratamiento ortopédico.From 1987 to 1991, 209 patients were operated on by the Ilizarov method in our institution. Among them, 3 patients presented vascular complications during the treatment. All were adults and have been treated for long bone pseudoarthrosis. The vascular lesion ocurred at the femoral superficial artery in one case, at the popliteal artery in other case, and at the posterior tibial artery in the third case. The clinical sign of vascular damage was bleeding through the cutaneous point of the Kirschnner transfixion wires in all cases. Arteriography was done in all cases but its interpretation was very difficult because of the presence of the external fixator. In the case of femoral artery, injury the external fixator was removed and a vascular by-pass was performed with an inverted graft of the saphenous vein. The same procedure was done in the case with a popliteal artery injury but without removal of the external fixator. The case with lesion of the posterior tibial artery was treated by arterial hgature. In all cases, outcome was satisfactory, allowing completion of the orthopaedic treatment

The iterated auxiliary particle filter and applications to state space models and diffusion processes.

The novel research work presented in this thesis consists of an offline, iterated particle filter to facilitate statistical inference in general state space hidden Markov models. Given a model and a sequence of observations, the associated marginal likelihood L is central to likelihood-based inference for unknown statistical parameters. We define a class of “twisted” models: each member is specified by a sequence of positive functions ψ and has an associated ψ - auxiliary particle filter that provides unbiased estimates of L. We identify a sequence ψ* that is optimal in the sense that the ψ* -auxiliary particle filter’s estimate of L has zero variance. In practical applications, ψ* is unknown so the ψ* - auxiliary particle filter cannot straightforwardly be implemented. We use an iterative scheme to approximate ψ*, and demonstrate empirically that the resulting iterated auxiliary particle filter significantly outperforms the most popular competitors in some challenging settings. Applications include parameter estimation using a particle Markov chain Monte Carlo algorithm. An adaptation of the iAPF for statistical inference in the context of diffusion processes along with a number of examples and applications in this setting is provide

La consolidación de las fracturas diafisarias del radio en el adulto : resultados del tratamiento con osteosíntesis por autocompresión

Los autores presentan un análisis de la consolidación de las fracturas de diáfisis del radio tratadas mediant e osteosíntesis de autocompresión tipo "Bagby", en 30 pacientes atendidos en el Departamento de Ortopedia y Traumatología del "Hospital das Clínicas" de la F.M.U.S.P., en el período de 1975 a 1985. 24 (80%) paciente s eran hombre s y 6 (20%) mujeres, con edade s comprendidas entr e 18 y 47 años (edad media 30.1 años). Se utilizaron placas "Bagby" de 4 y 6 agujeros (4 en 18 casos y 6 en 12 casos). Los resultados fueron buenos en 24 casos, regulares en 4 y malos en 2 casos. No se produjeron pseudoartrosis, sin embargo, si se observaron 2 retardos de consolidación. El tiempo medio de consolidación fue de 9 semanas (rango 6-16 semanas). No hubieron infecciones. En un pacient e hubo dehiscencia de sutura, en otro una reacción alérgica al metal y en dos paciente s se produjo un paresia del nervio radial con recuperación espontánea . En tre s casos, despué s de la retirada de la placa hubo espongialización subyacente. No hubo refracturas en esta serie.The author s carried out an analysis of healing in shaft fractures of radius treated by compression bone plating (Bagby System). 30 patients treated in the Department of Orthopaedi c Surgery of "Hospital das Clínicas" (F.M.U.S.P.) betwee n 1975 and 1985 wer e includedin this study. 24 (80%) of patients wer e men and 6 (20%) women; average of age was 30.1 year s (rangel8-47). Bagby plate s with 4 and 6 screws (18 and 6 case s respectively) wer e used by the authors. Good results wer e obtained in 24 patients, fair in 4 cases of delayed union wer e observed. The average of healing was 9 week s (6-16). One patient showed dehiscenc e of the wound, and othe r allergic reaction to metal. Two patients had paresia of radial nerve resolved spontaneously. In three cases, showed local osteoporosis after the plat e wa s removed. No case s of refractur e wer e observed in this series

Helminth biocoenosis of Lepus europaeus meridiei (Hilzheimer, 1906) from Pianosa island, Italy

Pianosa is a 10 km(2) Italian island in the Tyrrhenian Sea which is part of the Tuscan Archipelago National Park. In this island lives a brown hare population which, according to the literature, belongs to the ancestral taxon Lepus europaeus meridei that offers a unique opportunity to observe how the parasite biocoenosis shapes in condition of isolation, limited space availability and high population density. The aim of this work is to describe the helminth component community of a non-managed, isolated, and dense hare population, evaluating host-parasite relationship and parasite community structure. All 26 analyzed hares (13 males and 13 females) were in good physical conditions, and all of them harboured exclusively the nematode Protostrongylus oryctolagi only. This is the first report of this lungworm species in Italy. The estimated overall abundance was 48.15 worms per examined hare (range 3-258, median 50) and the parasites were unevenly distributed across host population, with few hosts having most parasites (aggregated or overdispersed distribution). No significant relationship was detected between the number of isolated parasites and hare sex and weigh. The effect of the isolation of Pianosa's hare population seems to have acted reducing parasite richness, while the high host density is probably the cause of the high prevalence and abundance of the single helminth species collected. In conclusion, despite the low impact of parasites confirmed also by the overdispersed parasite distribution, the low diversity of the studied parasite community sounds a warning for the management of the hare population and the whole Pianosa's ecosystem