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A Tomografia Computadorizada de Energia Dupla (DECT em inglês) é um dos campos das imagens tomográficas que mais evoluiu nos últimos anos. O DECT usa dois espectros para irradiar pacientes e é capaz de diferenciar tecidos com base na sua composição elementar. Apesar de serem semelhantes aos dispositivos padrão de tomografia, para essa modalidade é necessário o desenvolvimento de ferramentas específicas que permitam o estudo de suas propriedades de imagem. O objetivo deste trabalho era construir um sistema simulado de Tomografia Computadorizada (TC) com a capacidade de produzir imagens semelhantes às obtidas em dispositivos DECT reais. O TC simulado também permitiria explorar as propriedades das imagens de materiais de teste antes de sua construção física. Este trabalho presenta a simulação do processo de aquisição de imagens de um dispositivo DECT que funciona a partir da troca rápida de kV, o GE Discovery CT 750 HD. A geometria simulada foi baseada num dispositivo atualmente disponível no InRad (Instituto de Radiologia da Faculdade de Medicina da Universidade de São Paulo). As simulações foram realizadas usando o código Monte Carlo PENELOPE/penEasy para simular o transporte de radiação através dos materiais e detectores. Também é apresentada uma comparação entre as imagens obtidas no dispositivo real e nas simulações. Para isso, foi preparado um objeto simulador cilíndrico contendo concentrações de materiais equivalentes a iodo e cálcio. As imagens de tal objeto simulador foram adquiridas no equipamento GE Discovery CT 750 HD. Um objeto simulador equivalente foi modelado e as suas imagens foram simuladas com o código PENELOPE/penEasy. As imagens foram adquiridas e reconstruídas de acordo com as possibilidades do equipamento clínico de tomografia. Imagens de concentração de material e imagens monoenergéticas foram obtidas a partir do dispositivo CT clínico e das simulações. O algoritmo BMD (Basis Material Decomposition em Inglês) baseado nas projeções foi implementado usando os coeficientes de atenuação mássicos da água e do iodo. Consequentemente, imagens de concentração dos materiais água e iodo foram obtidas. A concentração medida nos cilindros de iodo foi equivalente às esperadas tanto no dispositivo real quanto nas imagens simuladas. Foram observados artefatos de endurecimento de feixe nas imagens de concentração de material. Imagens monoenergéticas foram obtidas para diferentes energias. Tais imagens foram obtidas a partir da superposição das imagens de concentração de água e iodo, que foram ponderadas pelos seus respectivos coeficientes de atenuação mássicos. Verificou-se que para as imagens monoenergéticas simuladas e reais em altas energias a imagem de concentração da água é a componente dominante, produzindo imagens que apresentaram as cavidades de iodo como menos atenuantes do que a água. Por outro lado, para energias baixas, a componente dominante nas imagens monoenergéticas foi a imagem de concentração do iodo. O CNR foi analisado nas imagens monoenergéticas como função da energia. As curvas do CNR dos dispositivos simulado e real exibiram semelhanças em sua forma, mas com escala diferente devido à diferença no ruído. Foi possível concluir que o modelo DECT simulado apresenta resultados qualitativos semelhantes aos obtidos no dispositivo real. O sistema de TC simulado permite explorar as características das imagens com diferentes materiais e composições. Ele também pode ser usado como uma ferramenta didática para melhorar a compreensão da diferenciação de materiais em tomografia espectral e DECT. / Dual Energy (DE) Computed Tomography (CT) is one of the fields of tomographic images that has evolved rapidly during the last years. DECT uses two X-ray spectra to irradiate patients It is capable to differentiate materials based on its elementary composition. Despite being similar to standard CT devices, DECT devices require the development of specific tools that allow the study of their image properties. The objective of this work was to build a modelled CT system capable of producing images similar to those obtained in real DECT devices. The modelled CT would also allow exploring the image properties of test materials before their physical construction. This work presents the simulation of the acquisition process of a DECT device that works with rapid kV switching, the GE Discovery CT 750 HD. The simulated geometry was based on a device currently available at the InRad (Institute of Radiology of the Faculty of Medicine of the University of São Paulo). The simulations were carried out using the PENELOPE/penEasy Monte Carlo code, which simulates radiation transport through the materials and detectors. A comparison between the images obtained in the real device and from simulations is also presented. To do so, a real phantom was prepared to be imaged and an equivalent system was simulated. The phantom contained inserts with concentrations of iodine and calcium. The images were acquired and reconstructed according to the possibilities of the real CT device. Standard, material concentration and virtual monoenergetic images were acquired[L1] from both, the real CT device and simulations. The Projection-Based BMD method was implemented using the mass attenuation coefficients of water and iodine. Then, material concentration images of water and iodine were obtained. The iodine concentrations estimated from the images agreed with the expected values in both real device and simulated images. Beam hardening artefacts were observed in the simulated material concentration images. Monoenergetic images were obtained for different energies. Such images were obtained as a superposition of the concentration images of water and iodine, weighed by their respective mass attenuation coefficient. It was verified that in the simulated and real device images, at high energies, the water concentration image predominated in the monoenergetic images, producing images that presented the iodine cavities as less attenuating than water. In contrast, at low energies, the predominant component of the monoenergetic images was the iodine concentration image. Contrast Noise Ratio (CNR) was analysed in the monochromatic images as a function of energy. Simulated and real device CNR curves exhibited similarities in their shape but with a different scale due to their difference in noise. It was possible to conclude that the simulated DECT model presented qualitative results similar to the obtained in the real device. The modelled CT system permits exploring the image features with different materials and compositions. It could also be used as a didactic tool to improve the understanding of material differentiation in spectral or DECT.

A Tomografia Computadorizada de Energia Dupla (DECT em inglês) é um dos campos das imagens tomográficas que mais evoluiu nos últimos anos. O DECT usa dois espectros para irradiar pacientes e é capaz de diferenciar tecidos com base na sua composição elementar. Apesar de serem semelhantes aos dispositivos padrão de tomografia, para essa modalidade é necessário o desenvolvimento de ferramentas específicas que permitam o estudo de suas propriedades de imagem. O objetivo deste trabalho era construir um sistema simulado de Tomografia Computadorizada (TC) com a capacidade de produzir imagens semelhantes às obtidas em dispositivos DECT reais. O TC simulado também permitiria explorar as propriedades das imagens de materiais de teste antes de sua construção física. Este trabalho presenta a simulação do processo de aquisição de imagens de um dispositivo DECT que funciona a partir da troca rápida de kV, o GE Discovery CT 750 HD. A geometria simulada foi baseada num dispositivo atualmente disponível no InRad (Instituto de Radiologia da Faculdade de Medicina da Universidade de São Paulo). As simulações foram realizadas usando o código Monte Carlo PENELOPE/penEasy para simular o transporte de radiação através dos materiais e detectores. Também é apresentada uma comparação entre as imagens obtidas no dispositivo real e nas simulações. Para isso, foi preparado um objeto simulador cilíndrico contendo concentrações de materiais equivalentes a iodo e cálcio. As imagens de tal objeto simulador foram adquiridas no equipamento GE Discovery CT 750 HD. Um objeto simulador equivalente foi modelado e as suas imagens foram simuladas com o código PENELOPE/penEasy. As imagens foram adquiridas e reconstruídas de acordo com as possibilidades do equipamento clínico de tomografia. Imagens de concentração de material e imagens monoenergéticas foram obtidas a partir do dispositivo CT clínico e das simulações. O algoritmo BMD (Basis Material Decomposition em Inglês) baseado nas projeções foi implementado usando os coeficientes de atenuação mássicos da água e do iodo. Consequentemente, imagens de concentração dos materiais água e iodo foram obtidas. A concentração medida nos cilindros de iodo foi equivalente às esperadas tanto no dispositivo real quanto nas imagens simuladas. Foram observados artefatos de endurecimento de feixe nas imagens de concentração de material. Imagens monoenergéticas foram obtidas para diferentes energias. Tais imagens foram obtidas a partir da superposição das imagens de concentração de água e iodo, que foram ponderadas pelos seus respectivos coeficientes de atenuação mássicos. Verificou-se que para as imagens monoenergéticas simuladas e reais em altas energias a imagem de concentração da água é a componente dominante, produzindo imagens que apresentaram as cavidades de iodo como menos atenuantes do que a água. Por outro lado, para energias baixas, a componente dominante nas imagens monoenergéticas foi a imagem de concentração do iodo. O CNR foi analisado nas imagens monoenergéticas como função da energia. As curvas do CNR dos dispositivos simulado e real exibiram semelhanças em sua forma, mas com escala diferente devido à diferença no ruído. Foi possível concluir que o modelo DECT simulado apresenta resultados qualitativos semelhantes aos obtidos no dispositivo real. O sistema de TC simulado permite explorar as características das imagens com diferentes materiais e composições. Ele também pode ser usado como uma ferramenta didática para melhorar a compreensão da diferenciação de materiais em tomografia espectral e DECT. / Dual Energy (DE) Computed Tomography (CT) is one of the fields of tomographic images that has evolved rapidly during the last years. DECT uses two X-ray spectra to irradiate patients It is capable to differentiate materials based on its elementary composition. Despite being similar to standard CT devices, DECT devices require the development of specific tools that allow the study of their image properties. The objective of this work was to build a modelled CT system capable of producing images similar to those obtained in real DECT devices. The modelled CT would also allow exploring the image properties of test materials before their physical construction. This work presents the simulation of the acquisition process of a DECT device that works with rapid kV switching, the GE Discovery CT 750 HD. The simulated geometry was based on a device currently available at the InRad (Institute of Radiology of the Faculty of Medicine of the University of São Paulo). The simulations were carried out using the PENELOPE/penEasy Monte Carlo code, which simulates radiation transport through the materials and detectors. A comparison between the images obtained in the real device and from simulations is also presented. To do so, a real phantom was prepared to be imaged and an equivalent system was simulated. The phantom contained inserts with concentrations of iodine and calcium. The images were acquired and reconstructed according to the possibilities of the real CT device. Standard, material concentration and virtual monoenergetic images were acquired[L1] from both, the real CT device and simulations. The Projection-Based BMD method was implemented using the mass attenuation coefficients of water and iodine. Then, material concentration images of water and iodine were obtained. The iodine concentrations estimated from the images agreed with the expected values in both real device and simulated images. Beam hardening artefacts were observed in the simulated material concentration images. Monoenergetic images were obtained for different energies. Such images were obtained as a superposition of the concentration images of water and iodine, weighed by their respective mass attenuation coefficient. It was verified that in the simulated and real device images, at high energies, the water concentration image predominated in the monoenergetic images, producing images that presented the iodine cavities as less attenuating than water. In contrast, at low energies, the predominant component of the monoenergetic images was the iodine concentration image. Contrast Noise Ratio (CNR) was analysed in the monochromatic images as a function of energy. Simulated and real device CNR curves exhibited similarities in their shape but with a different scale due to their difference in noise. It was possible to conclude that the simulated DECT model presented qualitative results similar to the obtained in the real device. The modelled CT system permits exploring the image features with different materials and compositions. It could also be used as a didactic tool to improve the understanding of material differentiation in spectral or DECT.

The diploma thesis "Strategic Defense Initiative" deals with the issue of the Strategic initiative on the basis of historical-political analysis. The SDI was a crucial topic during the 80s, which had political impacts on the development of the international events and the Cold war in general. This work presents brief history of the United States ABM systems and introduced historical context. Furthermore, the author analyzes possible reasons for the SDI announcement and reexamines Reagan's speech from March 1983. Persons and interest groups who were promoting strategic defense are also included in this analysis. Problems connected to the SDI and its brief description are also mentioned. The following chapter deals with Soviet reaction to the SDI. The seventh chapter dicusses the European reaction to the SDI. The topic is analyzed on the example of United Kingdom. Next chapter deals with the Anti Ballistic Missile treaty and its interpretations from the SDI prespective. Last chapter discusses US - Soviet summits which took place in the 80s with emphasis on the SDI.

Low trauma hip fractures, due to bone fragility, are a major healthcare burden with serious consequences for individuals in terms of long-term morbidity and mortality; and also for society due to the high medical and care costs associated with these injuries. Because of the association with low bone mass, these fractures are particularly prevalent in elderly populations and are likely to become more common as longevity increases globally. Avoidance of these fractures is therefore an extremely important goal. Low bone mass, manifested in the conditions of osteopenia and osteoporosis, is the primary cause of bone fragility, and reductions in bone mass are the inevitable corollary of aging and menopause. Bone loss may be exacerbated by immobilisation and reduced weight-bearing activity, giving rise to the condition of disuse osteopenia. Immobilisation may itself be the result of low trauma leg fragility fractures that potentially causes further bone density loss. If this loss occurs at the hip, there is an increased risk for hip fracture as a sequela to the original injury. Osteoarthritis is also a condition strongly associated with aging that may necessitate knee arthroplasty as a last stage treatment, potentially causing a period of reduced mobility and weight-bearing activity following surgery. Leg fracture and knee replacement both present additional risk factors for hip fracture due to changes in muscle mass, gait and postural stability that may increase the risk of falls. This study aims primarily to investigate the effects of immobilisation on leg fracture and knee replacement patients, immediately following injury or surgery, in order to quantify bone and muscle loss and to monitor recovery over a one year period. A postmenopausal population were studied as they are already losing bone density systemically and may be at greater risk of further bone loss following immobilisation. Factors of activity, function, weight-bearing, pain, treatments, therapies, health perceptions and mental wellbeing, that potentially contribute to bone loss and recovery, were also investigated. Results from the study may provide information relating to increased future hip fracture risk and lead to treatment options to alleviate bone loss in these groups.

"The goal of this thesis work has been to investigate improved diagnostic methods for both detecting osteoporosis and estimating fracture risk non-invasively, by assessing bone mass density (BMD) and bone microstructure. It evaluates new approaches for analyzing through-transmission ultrasound signals using coral samples as models for trabecular bone. The results of BUA, impulse response of coral samples and the angular decorrelation function of coral samples indicate that these ultrasound parameters may be useful in detecting changes in both bone mineral density (BMD) and the presence of dominant trabecular bone structure axis. "

Resumo: A osteoporose é uma doença metabólica, que se caracteriza por baixa massa e deterioração do tecido ósseo, conduzindo à fragilidade do osso com conseqüente aumento do risco de fraturas. O início da doença é influenciado por uma complexa interação entre fatores genéticos e ambientais, que pode afetar diferentemente os indivíduos. Por essa razão, faz-se necessário o estudo dos polimorfismos dos genes associados ao metabolismo ósseo, como os do Receptor para Vitamina D (VDR) e da Apolipoproteína E (APOE), além dos envolvidos no biometabolismo de agentes ambientais, como as Glutatião-S-Transferases (GSTs). Foram estudados 53 pacientes, homens e mulheres, com osteoporose e ou osteopenia, pareados por sexo e faixa etária com um grupo controle. O DNA foi extraído de leucócitos de sangue periférico e amplificado por Reação em Cadeia da Polimerase (PCR). Os polimorfismos GSTM1 e GSTT1 foram analisados em gel de agarose 2%, enquanto os da APOE e VDR foram submetidos à restrição enzimática com as enzimas Hha I e Fok I, respectivamente, seguido da análise em gel de poliacrilamida 6%, corados com brometo de etídeo e visualizados em luz UV. A análise estatística dos dados foi realizada, utilizando-se o teste t, teste de Fisher, a regressão multivariada e o teste de equilíbrio de Hardy-Weinberg. O genótipo nulo (0/0) de GSTM1 mostrou-se significantemente mais freqüente nos pacientes (64,1%) comparado ao dos controles (37,7%; P= 0,00112). Por outro lado, pacientes e controles não diferiram quanto à presença (+/+) e ausência (0/0) do gene GSTT1 (P=0,5328). A distribuição genotípica do polimorfismo VDR - Fok I revelou freqüência significantemente aumentada do genótipo ff nos pacientes (22,6%; P=0,0078). Para o gene da APOE, o alelo e3 foi significantemente mais freqüente nos controles (0,85; P=0,0431), enquanto...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Osteoporosis is a metabolic disease characterized by low body mass and bone deterioration, leading to bone fragility with the consequent increase of fractures risk. The disease onset is influenced by a complex interaction between genetic, and environment factors that can affect differently the individuals' response. Therefore, the study of polymorphisms regarding the genes involved in bone metabolism is of upgrade necessity, such as the Vitamin D Receptor gene (VDR), Apolipoprotein E (APOE), besides the genes involved in xenobiotic metabolism, it means, the Glutathion-S-Transferases (GSTs). We have studied 53 patients, men and women, with osteoporosis and/or osteopenia, matched by gender and age with a control group. The DNA was extracted from peripheral blood lymphocytes and amplified through Polimerase Chain Reaction (PCR). GSTM1, and GSTT1 polymorphisms were analyzed in 2% agarose gel, while APOE, and VDR had been submitted to enzymatic restriction with Hha I and Fok I enzymes, respectively, followed by the analysis in 6% polyacrilamide gel, stained with ethidium bromide and visualized under UV light. The statistic analysis was carried on using test t, test of Fisher, the multi-varied regression and the test of Hardy-Weinberg balance. The GSTM1 null genotype (0/0) was significantly more frequent in patients (64.1%) compared to the controls (37.7%; P= 0.00112). On the other hand, patients, and controls did not differ concerning the presence (++) and absence (0/0) of GSTT1 gene (P=0.5328). The genotypic distribution of VDR -Fok I polymorphism showed a significantly increased frequency of the genotype ff in patients (22.6%; P=0.0078). For the APOE, the allele e3 was significantly more frequent in controls (0.85; P=0.0431), while the allele e4 was in patients (0.20; P=0.0075). The genotype...(Complete abstract click electronic access below) / Orientador: Nívea D T Conforti Froes / Coorientador: Dorotéia Rossi Silva / Banca: Adriana Madeira Alvares da Silva / Banca: Eny Maria Goloni Bertollo / Mestre

Se evaluó la toxicidad individual y binaria de los plaguicidas metomilo y rotenona en la macrofita Lemna minor (Linnaeus, 1753) para determinar la acción sinérgica o antagónica de una mezcla equitóxica. Los ensayos se realizaron bajo condiciones de laboratorio (T 29 ± 2°C; H 48,6 ± 9,4 %) y los resultados fueron analizados con los programas estadísticos BMDS® y Probit para calcular la concentración efectiva media (CE50) a través de los parámetros Área de la Fronda (AF) y Nuevas Frondas (NF). Los resultados sugieren una mayor precisión al utilizar el Método del Punto de Referencia del programa BMDS® para el cálculo de la concentración efectiva. Adicionalmente, se calculó la concentración total de clorofila (CTC) y peso húmedo (PH) para determinar la inhibición del crecimiento (Ir). Del mismo modo, se realizó una comparación entre los valores NOAEL (nivel de efecto no observado) y LOAEL (nivel bajo de efecto observado) versus los valores de BMDL (límite inferior del punto de referencia) y BMD (nivel de variación en el punto de referencia), respectivamente. El análisis muestra que existe una mayor precisión al emplear los valores BMD y BMDL. La acción fitotóxica varió según el parámetro analizado. La CE50 mostró mayores valores en el parámetro NF (1079,22 mg·L-1 para rotenona; 7147,42 mg·L-1 para metomilo; 597,904 mg·L-1 mezcla binaria: metomilo y 298,93 mg·L-1 mezcla binaria: rotenona) que en el parámetro AF (782,173 mg·L-1 para rotenona; 6919,79 mg·L-1 para metomilo; 629,513 mg·L-1 mezcla binaria: metomilo y 314,754 mg·L-1 mezcla binaria: rotenona). Finalmente, el modelo de concentración-adición mostró que la acción fitotóxica de la mezcla de ambos plaguicidas en Lemna minor tiene un efecto sinérgico. Macrophyte Lemna minor (Linnaeus, 1753) was used to evaluate the phytotoxicity of the individual and mix action of methomyl and rotenone pesticides under laboratory conditions (Temperature 29 ± 2°C; Humidity 48,6 9,4 %). The taken measures to establish half effective concentration (EC50) were the frond area (AF) and production of new fronds (NF). In this study, BMDS® and Probit stadistical data analyses were used to compare the results about effective concentration. Results suggest Benchmark dose method of BMDS® program was more effective than Probit program when EC50 were determined. Additionally, total chlorophyll concentration (CTC) and humidity weight (PH) parameters were calculated to determinate the growth inhibition (Ir). Likewise, NOAEL (no observed adverse effect level) and LOAEL (low observer adverse effect level) were compared with BMDL (lower bench mark dose) and BMD (Bench mark dose), respectively. BMD and BMDL values were more accurate than NOAEL and LOAEL values. Phytotoxic action varied according the parameter. EC50 values of Lemna minor showed poor sensibility to methomyl pesticide with an elevated concentration in both parameters (6919,79 mg•L-1 and 7147,42 mg•L-1 for AF and NF, respectively). Results of rotenone pesticide were lower than methomyl, with 1079,22 mg•L-1 (NF) and 782,173 mg•L-1 (AF). Finally, the mix toxicity was 597,904 mg•L-1 (methomyl: NF), 298,93 mg•L-1 (rotenone: NF), 629,513 mg•L-1 (methomyl: AF) and 314,754 mg•L-1 (rotenone: AF). For synergy calculation, Concentration-Adition value was used, concluding a higher synergism.

Individuals with intellectual and developmental disabilities (IDD) are prone to certain diseases in their lifetime, such as osteoporosis. Absorption of calcium is essential to maintaining good bone health and preventing osteoporosis. This study examined primary care providers’ (PCPs) choice of calcium supplementation, as well as type of calcium supplementation, and the relationship between variables in the IDD population. Ten PCPs were asked to complete a 14-question web-based survey, with five surveys completed. Calcium citrate was the preferred supplement among respondents at 50%. Retrospective data was collected from patient records and included type of calcium supplement prescribed, bone density test results, and other variable factors. The type of calcium supplement prescribed did not affect bone density results in subjects with IDD. There was a weak significance between calcium supplement type and gender and vitamin D. It is of modest benefit to include vitamin D with calcium supplementation to enhance calcium absorption.

In Sweden approximately 25000 distal radius fractures occur annually, which is 37 % of all fractures related to osteoporosis. In this thesis, risk factors for osteoporosis, bone mineral density (BMD) and health-related quality of life (the SF-36) were compared in patients who suffered a distal radius fracture after low energy trauma with a control group matched on the basis of age, gender, and municipality of residence. The aim was also to analyse, among these patients, whether a risk factor questionnaire, tests on dynamic and static balance and a one-leg rise test could identify those, who have osteopenia or osteoporosis, and run a risk of new falls. Moreover, in a three-year follow-up, mortality, the need for in- and outpatient care, and health-related quality of life after radius fracture were investigated and compared between the patients and matched controls. Finally, the effect of a preventive intervention program including patient education and self-training was evaluated. Falls were reported in a risk factor questionnaire and in a fall diary. The patients aged 45-64 years showed lower, although not statistically significant, BMD, compared with the controls of the same age, but there was no difference concerning their history of falls. In contrast, the patients aged 64 years or older had a history of falling more often than the corresponding controls, but no difference in BMD was found. For all other risk factors, except falls, no differences were found between the patients and the controls. The results of the one-leg rise test were associated with those of dynamic and static balance, but none of the functional tests were associated with the number of falls. Decreased height and cigarette smoking were the only risk factors, which predicted osteopenia and osteoporosis. Five patients, although none of the controls, died during the study time. The patients needed statistically significantly more episodes as inpatients than the controls. The patients also had lower SF-36, Role Physical scores, than the controls at three months. This difference disappeared by the time of the follow-up. Both the patients, who participated in a four-week intervention program, “the osteoporosis school” followed by a one-year home-based exercise program, and the controls showed statistically significantly improved dynamic and static balance, ability to walk backwards and to stand on one leg with eyes open and closed at the end of the study. However, no significant differences were found between the patients and the controls in any of the tests, in BMD or in the number of the falls. The thesis shows that, except for the falls in patients aged over 64 years, there were no significant differences between patients and controls with respect to BMD and other risk factors related to osteoporosis. Consequently, in patients aged 45-64 years and older, the underlying cause of a distal radius fracture is more related to falls than to osteoporosis. Furthermore, the thesis shows that the functional tests and the risk factor questionnaire seem to be of limited value for identifying 8 people with a radius fracture, who are at risk of falling or have osteopenia or osteoporosis. If, in spite of this, functional tests on musculoskeletal function are considered for testing of functional ability in patients with a recent radius fracture, the one leg-rise test may be sufficient. There seems to be an increased mortality and morbidity necessitating inpatient care among patients with a recent radius fracture. The osteoporosis school had no significant effect on BMD, balance, muscle strength or falls in this thesis. Therefore, the lack of proven efficacy of the osteoporosis school for the secondary prevention of distal radius fractures highlights the need for more and long-term randomised controlled follow-up studies in this specific population.