Predicting trabecular arrangement in the proximal femur: An artificial neural network approach for varied geometries and load cases.

Machine learning (ML) and deep learning (DL) approaches can solve the same problems as the finite element method (FEM) with a high degree of accuracy in a fraction of the required time, by learning from previously presented data. In this work, the bone remodelling phenomenon was modelled using feed-forward neural networks (NN), by gathering a dataset of density distribution comprising several geometries and load cases. The model should output for some point in the domain the its apparent density, taking into consideration the geometric and loading parameters of the model . After training. the trabecular distribution obtained with the NN was similar to the FEM while the analysis was performed in a fraction of the time, having shown a reduction from 1020 s to 0.064 s. It is expected that the results can be extended to different structures if a different dataset is acquired. In summary, the ML approach allows for significant savings in computational time while presenting accurate results.

Multiscale Homogenization Techniques for TPMS Foam Material for Biomedical Structural Applications.

Multiscale techniques, namely homogenization, result in significant computational time savings in the analysis of complex structures such as lattice structures, as in many cases it is inefficient to model a periodic structure in full detail in its entire domain. The elastic and plastic properties of two TPMS-based cellular structures, the gyroid, and the primitive surface are studied in this work through numerical homogenization. The study enabled the development of material laws for the homogenized Young's modulus and homogenized yield stress, which correlated well with experimental data from the literature. It is possible to use the developed material laws to run optimization analyses and develop optimized functionally graded structures for structural applications or reduced stress shielding in bio-applications. Thus, this work presents a study case of a functionally graded optimized femoral stem where it was shown that the porous femoral stem built with Ti-6Al-4V can minimize stress shielding while maintaining the necessary load-bearing capacity. It was shown that the stiffness of cementless femoral stem implant with a graded gyroid foam presents stiffness that is comparable to that of trabecular bone. Moreover, the maximum stress in the implant is lower than the maximum stress in trabecular bone.

Treatment of Acute Spinal Cord Injuries: A Survey Among Iberolatinoamerican Spine Surgeons - Part 1: Use of High-Dose Corticosteroids.

Objective The aim of the present study was to evaluate the current practice of using of methylprednisolone sodium succinate (MPSS) in acute spinal cord Injuries (ASCIs) among spine surgeons from Iberolatinoamerican countries. Methods A descriptive cross-sectional study design as a survey was conducted. A questionnaire composed of 2 sections, one on demographic data regarding the surgeons and MPSS administration, was sent by email to members of the Sociedad Ibero Latinoamericana de Columna (SILACO, in the Spanish acronym) and associated societies. Results A total of 182 surgeons participated in the study: 65.4% (119) orthopedic surgeons and 24.6% (63) neurosurgeons. Sixty-nine (37.9%) used MPSS in the initial management of ASCIs. There were no significant differences between countries ( p = 0.451), specialty ( p = 0.352), or surgeon seniority ( p = 0.652) for the use of corticosteroids in the initial management of ASCIs. Forty-five (65.2%) respondents reported using an initial high-dose bolus (30 mg/Kg) followed by a perfusion (5.4 mg/kg/h). Forty-six (66.7%) surgeons who used MPSS only prescribed it if the patients presented within 8 hours of the ASCI. Most of the surgeons (50.7% [35]) administered high-dose corticosteroids because of the conviction that it has clinal benefits and improves neurological recovery. Conclusion Results from the present survey show that MPSS use in ASCI is not widespread within spine surgeons and that the controversy regarding its use remains unresolved. This is probably due to the low level of evidence of the available data, to variations over the years, to inconsistencies in acute care protocols, and to health service pathways.

Treatment of Acute Spinal Cord Injuries: A Survey Among Iberolatinoamerican Spine Surgeons - Part 2 Timing to Surgery.

Objective The objective of the present study was to evaluate the current practice in terms of timing to surgery in acute spinal cord injury (ASCI) patients among spinal surgeons from Iberolatinoamerican countries. Methods A descriptive cross-sectional study design as a questionnaire was sent by an email for all members of the Sociedad Ibero Latinoamericana de Columna (SILACO, in the Spanish acronym) and associated societies. Results A total of 162 surgeons answered questions related to the timing for surgery. Sixty-eight (42.0%) considered that ASCI with complete neurology injury should be treated within 12 hours, 54 (33.3%) performed early decompression within 24 hours, and 40 (24,7%) until the first 48 hours. Regarding ASCI with incomplete neurological injury, 115 (71.0%) would operate in the first 12 hours. There was a significant difference in the proportion of surgeons that would operate ASCI within ≤ 24 hours, regarding the type of injury (complete injury:122 versus incomplete injury:155; p < 0.01). In the case of patients with central cord syndrome without radiological evidence of instability, 152 surgeons (93.8%) would perform surgical decompression: 1 (0.6%) in the first 12 hours, 63 (38.9%) in 24 hours, 4 (2.5%) in 48 hours, 66 (40.7%) in the initial hospital stay, and 18 (11.1%) after neurologic stabilization. Conclusion All inquired surgeons favour early decompression, with the majority performing surgery in the first 24 hours. Decompression is performed earlier in cases of incomplete than in complete injuries. In cases of central cord syndrome without radiological evidence of instability, there is a tendency towards early surgical decompression, but the timing is still extremely variable. Future studies are needed to identify the ideal timing for decompression of this subset of ASCI patients.

Treatment of Acute Spinal Cord Injuries: A Survey Among Iberolatinoamerican Spine Surgeons - Part 1: Use of High-Dose Corticosteroids / Tratamento das lesões agudas da medula espinal: Uma pesquisa entre cirurgiões de coluna iberoamericanos - Parte 1: Uso de corticosteroides em altas doses

Abstract Objective The aim of the present study was to evaluate the current practice of using of methylprednisolone sodium succinate (MPSS) in acute spinal cord Injuries (ASCIs) among spine surgeons from Iberolatinoamerican countries. Methods A descriptive cross-sectional study design as a survey was conducted. A questionnaire composed of 2 sections, one on demographic data regarding the surgeons and MPSS administration, was sent by email to members of the Sociedad Ibero Latinoamericana de Columna (SILACO, in the Spanish acronym) and associated societies. Results A total of 182 surgeons participated in the study: 65.4% (119) orthopedic surgeons and 24.6% (63) neurosurgeons. Sixty-nine (37.9%) used MPSS in the initial management of ASCIs. There were no significant differences between countries (p = 0.451), specialty (p = 0.352), or surgeon seniority (p = 0.652) for the use of corticosteroids in the initial management of ASCIs. Forty-five (65.2%) respondents reported using an initial high-dose bolus (30 mg/Kg) followed by a perfusion (5.4 mg/ kg/h). Forty-six (66.7%) surgeons who used MPSS only prescribed it if the patients presented within 8 hours of the ASCI. Most of the surgeons (50.7% [35]) administered high-dose corticosteroids because of the conviction that it has clinal benefits and improves neurological recovery. Conclusion Results from the present survey show that MPSS use in ASCI is not widespread within spine surgeons and that the controversy regarding its use remains unresolved. This is probably due to the low level of evidence of the available data, to variations over the years, to inconsistencies in acute care protocols, and to health service pathways.

Resumo Objetivo O objetivo do presente estudo foi avaliar a prática atual de uso do succinato sódico de metilprednisolona (MPSS, na sigla em inglês) nas lesões agudas da medula espinal (LAMEs) entre cirurgiões de coluna de países ibero-americanos. Métodos Um estudo transversal descritivo foi realizado. O questionário continha duas seções, uma sobre os dados demográficos dos cirurgiões e acerca da administração de MPSS, e foi enviado por correio eletrônico aos membros da Sociedad Ibero Latinoamericana de Columna (SILACO, na sigla em espanhol) e sociedades associadas. Resultados No total, 182 cirurgiões participaram do estudo: 65,4% (119) eram cirurgiões ortopédicos e 24,6% (63), neurocirurgiões. Sessenta e nove (37,9%) usaram MPSS no tratamento inicial da LAME. Não houve diferenças significativas entre países (p = 0,451), especialidades (p = 0,352) ou senioridade do cirurgião (p =0,652) em relação ao uso de corticosteroides no tratamento inicial da LAME. Destes, 45 (65,2%) relataram a administração de um bolus de alta dose (30 mg/kg) seguido por perfusão (5,4 mg/kg/h). Quarenta e seis (66,7%) dos cirurgiões que usam MPSS apenas o prescrevem a pacientes tratados nas primeiras 8 horas após a LAME. A maioria dos cirurgiões (50,7% [35]) administrou corticosteroides em alta dose devido à convicção de seus benefícios clínicos e melhora da recuperação neurológica. Conclusão Os resultados do presente questionário mostram que o uso de MPSS na LAME não está disseminado entre os cirurgiões de coluna e que a controvérsia sobre sua administração ainda não foi resolvida. É provável que isto se deva ao baixo nível de evidência dos dados existentes, a variações ao longo dos anos, a inconsistências nos protocolos terapêuticos agudo e a diferentes sistemas de saúde.

Treatment of Acute Spinal Cord Injuries: A Survey Among Iberolatinoamerican Spine Surgeons - Part 2 Timing to Surgery / Tratamento de lesões agudas da medula espinal: Uma pesquisa entre cirurgiões de coluna iberoamericanos - Parte 2: Momento da cirurgia

Abstract Objective The objective of the present study was to evaluate the current practice in terms of timing to surgery in acute spinal cord injury (ASCI) patients among spinal surgeons from Iberolatinoamerican countries. Methods A descriptive cross-sectional study design as a questionnaire was sent by an email for all members of the Sociedad Ibero Latinoamericana de Columna (SILACO, in the Spanish acronym) and associated societies. Results A total of 162 surgeons answered questions related to the timing for surgery. Sixty-eight (42.0%) considered that ASCI with complete neurology injury should be treated within 12 hours, 54(33.3%) performed early decompression within 24 hours, and 40 (24,7%) until the first 48 hours. Regarding ASCI with incomplete neurological injury, 115 (71.0%) would operate in the first 12 hours. There was a significant difference in the proportion of surgeons that would operate ASCI within ≤ 24 hours, regarding the type of injury (complete injury:122 versus incomplete injury:155; p<0.01). In the case of patients with central cord syndrome without radiological evidence of instability, 152 surgeons (93.8%) would perform surgical decompression: 1 (0.6%) in the first 12 hours, 63 (38.9%) in 24 hours, 4 (2.5%) in 48 hours, 66 (40.7%) in the initial hospital stay, and 18 (11.1%) after neurologic stabilization. Conclusion All inquired surgeons favour early decompression, with the majority performing surgery in the first 24 hours. Decompression is performed earlier in cases of incomplete than in complete injuries. In cases of central cord syndrome without radiological evidence of instability, there is a tendency towards early surgical decompression, but the timing is still extremely variable. Future studies are needed to identify the ideal timing for decompression of this subset of ASCI patients.

Resumo Objetivo O objetivo do presente estudo foi avaliar a prática atual em termos de momento de realização da cirurgia em pacientes com lesão medularaguda (LMA) entre cirurgiões de coluna de países ibero-americanos. Métodos Estudo transversal descritivo com base em um questionário enviado por correio eletrônico para todos os membros da Sociedad Ibero Latinoamericana de Columna (SILACO, na sigla em espanhol) e sociedades associadas. Resultados Um total de 162 cirurgiões responderam a perguntas relacionadas ao momento da cirurgia. Sessenta e oito (42,0%) consideraram que a LMA com lesão neurológica completa deve ser tratada em até 12 horas, 54 (33,3%) realizariam a descompressão precoce em até 24 horas e 40 (24,7%) fariam este procedimento nas primeiras 48 horas. Em relação à LMA com lesão neurológica incompleta, 115 (71,0%) operariam nas primeiras 12 horas. Houve diferença significativa na proporção de cirurgiões que fariam o tratamento cirúrgico da LMA em ≤ 24 horas quanto ao tipo de lesão (lesão completa [122] versus lesão incompleta [155]; p<0.01). Em pacientes com síndrome medular central sem evidência radiológica de instabilidade, 152 cirurgiões (93,8%) realizariam a descompressão cirúrgica: 1 (0,6%) nas primeiras 12 horas, 63 (38,9%) em 24 horas, 4 (2,5%) em 48 horas, 66 (40,7%) no internamento inicial e 18 (11,1%) após a estabilização neurológica. Conclusão Todos os cirurgiões participantes favoreceram a descompressão precoce; a grande maioria realizaria a cirurgia nas primeiras 24 horas. A descompressão é feita antes em casos de lesões incompletas do que em lesões completas. Nos casos de síndrome medular central sem evidência radiológica de instabilidade, há uma tendência à descompressão cirúrgica precoce, mas o momento de intervenção ainda é extremamente variável. Estudos futuros são necessários para identificar o momento ideal para descompressão neste subconjunto de pacientes com LMA.

Melt Electrospinning Writing of Mesh Implants for Pelvic Organ Prolapse Repair.

Over the past decade, melt electrospinning writing has attracted renewed attention. When combined with three-dimensional (3D) printing capabilities, complex 3D structures can be produced, from ultrafine fibers in the absence of toxic solvents, making it particularly attractive to fabricate customized scaffolds and implants for medical applications. This research aimed to develop novel less stiff vaginal mesh implants for pelvic organ prolapse (POP) repair, matching the physiological biomechanics of vaginal tissues. The main objectives, to attain that goal, were: development of a melt electrospinning writing prototype, with additive manufacturing capability, to produce complex structures from micrometer scale fibers, in a direct 3D printing mode; and design and validate new concepts of biodegradable meshes/scaffolds with new geometries, for POP repair. The melt electrospinning writing prototype was built based on different modules. Biodegradable polycaprolactone was used to produce novel implants: three geometries and two fiber configurations were employed. The commercially available Restorelle® (Coloplast) mesh was used as a benchmark. Printed implants were analyzed via scanning electron microscopy (SEM) and uniaxial tensile testing. The SEM images showed that the geometry is generally well produced; however, some minor deviations are visible due to charge interactions. The tensile test results indicated that, regardless of the geometry, the samples showed an elastic behavior for smaller displacements; aplastic behavior dominates later stages. In the physiological range of deformation, the novel meshes (80 µm fiber diameter) matched the tissue properties (p > 0.05). The Restorelle mesh was significantly stiffer than vaginal tissue (p < 0.05) and novel meshes. The precision of the various geometrical patterns and fiber diameters produced highlights the success of the designed and built prototype equipment. Results showed that the biodegradable meshes produced are biomechanically more compatible with native tissue than commercial implants.

Cross-cultural validation of a questionnaire to assess spinal pain in children / Validação transcultural de um questionário de avaliação da dor na coluna em crianças / Validación transcultural de un cuestionario para evaluar el dolor de espalda en niños

ABSTRACT Objective: To validate the cross-cultural adaptation of the English version of theYoung Spine Questionnaire (YSQ) to Portuguese. The questionnaire enables the evaluation, in children, of back pain prevalence and frequency, restrictions on activity, care-seeking behavior, and the influence that the parents' manifestations of back pain can have. Method: The research was conducted in a school setting, with a sample of 128 children aged 9 to 12 years (63 males and 65 females). The questionnaire was completed at two different moments. Test-retest reliability was used to evaluate the degree of reproducibility, and the intraclass correlation coefficient (ICC) between the two sets of observed values was estimated for p<0.05. Cronbach's alpha coefficient was used to assess the degree of reliability (internal consistency) of the questionnaire. Results: For most of questions, the ICC ranged between 0.527 and 0.870, with reasonable to excellent correlation to the reproducibility index. The exceptions were foritem c) in two of the first three questions, where the ICC values (0.149 and 0.277) were lower. The value of Cronbach's alpha calculation was 0.8, indicating high internal consistency. Conclusion: It was demonstrated that the cross-cultural adaptation of the YSQ had content validity, was well-understood, and suitable for use in studies with Portuguese children between 9 and 12 years of age. Level of evidence II; Development of diagnostic criteria.

RESUMO: Objetivo: Objetivo: Validar a adaptação transcultural da versão inglesa do "The Young Spine Questionnaire" (YSQ), para a língua portuguesa. O questionário permite avaliar, em crianças, a taxa de prevalência e a frequência de dor na coluna, as restrições de atividade, o comportamento de procura de cuidados e a influência que pode ter a dor de coluna manifestada pelos pais. Método: A pesquisa foi realizada em contexto escolar, com uma amostra de 128 crianças dos 9 aos 12 anos (63 do sexo masculino e 65 do sexo feminino). O questionário foi preenchido em dois momentos distintos. Para avaliar o seu grau de reprodutibilidade utilizou-se o Teste-Reteste, estimando-se o coeficiente de correlação intraclasse (ICC) entre os dois conjuntos de valores observados, para p<0,05. Também se recorreu ao coeficiente Alfa de Cronbach, para encontrar o grau de confiabilidade (consistência interna) do questionário. Resultados: Na maioria das questões o intervalo do ICC situou-se entre 0,527 e 0,870, correspondente a uma correlação situada entre razoável a excelente para índice de reprodutibilidade. A exceção foram dois dos itens c) das três primeiras questões, em que o ICC apresentou valores inferiores (0,149 e 0,277). O valor do cálculo do Alfa de Cronbach resultou em 0,8, apresentando elevada consistência interna. Conclusão: Ficou demonstrado que a adaptação transcultural do YSQ tem validade de conteúdo e é bem compreendida para ser utilizada em estudos com crianças portuguesas dos 9 aos 12 anos de idade. Nível de evidência II; Desenvolvimento de critérios de diagnóstico.

RESUMEN: Objetivo: Validar la adaptación transcultural de la versión inglesa del "The Young Spine Questionnaire" (YSQ) al portugués. El cuestionario permite evaluar, en los niños, la tasa de prevalencia y frecuencia del dolor de espalda , las restricciones de actividad, el comportamiento de búsqueda de atención y la influencia que puede tener el dolor de espalda manifestado por los padres. Método: La investigación se llevó a cabo en un entorno escolar, con una muestra de 128 niños de 9 a 12 años (63 niños y 65 niñas). El cuestionario se completó en dos momentos diferentes. Para evaluar su grado de reproducibilidad, se utilizó el "Test-Retest", estimando el coeficiente de correlación intraclase (CCI) entre los dos conjuntos de valores observados, para p <0,05. También se utilizó el coeficiente Alfa de Cronbach, para conocer el grado de confiabilidad (consistencia interna) del cuestionario. Resultados: En la mayoría de las preguntas, el CCI osciló entre 0,527 y 0,870, lo que corresponde a una correlación situada entre razonable y excelente para el índice de reproducibilidad. Las excepciones fueron dos de los ítems c) de las tres primeras preguntas, donde el ICC mostró valores más bajos (0,149 y 0,277). El valor del cálculo del Alfa de Cronbach dio como resultado 0,8, lo que demuestra una alta consistencia interna. Conclusión: Se demostró que la adaptación transcultural del YSQ tiene validez de contenido y es adecuada para ser utilizada en estudios con niños portugueses de entre 9 y 12 años. Nivel de evidencia II; Desarrollo de criterios diagnósticos.

[How to Resume Elective Orthopaedic Surgical Procedures during the COVID-19 Pandemic?] / Como Retomar a Atividade Cirúrgica Eletiva em Ortopedia durante a Pandemia COVID-19?

This document was prepared by the College of Orthopedics of the Portuguese Medical Association with the aim of developing the guidelines on the resumption of elective surgical activity in Orthopedics during the COVID-19 pandemic. It sets the criteria that allow the prioritization of surgeries according to the severity of the clinical situation, based on existing and published classifications. Moreover, it provides an organizational model for patient preparation and describes the patient pathways in the preoperative, intraoperative and postoperative periods. It also describes safety rules for elective surgery and a model for monitoring patients after discharge according to scientific evidence.

Este documento foi elaborado pelo Colégio de Ortopedia da Ordem dos Médicos com o objetivo de estabelecer as orientações sobre a retoma da atividade cirúrgica programada em Ortopedia durante a pandemia COVID-19. As presentes normas de orientação: a) definem os critérios que permitem a priorização das cirurgias de acordo com a gravidade da situação clínica, com base em classificações existentes e publicadas; b) fornecem um modelo de organização para a preparação dos doentes, descrevendo os circuitos do doente nos períodos pré-operatório, intraoperatório e pós-operatório; c) realçam as regras de segurança para a realização de cirurgias e desenham um modelo de acompanhamento após a alta de acordo com a evidência científica.

Screw-assisted 3D printing with granulated materials: a systematic review.

This paper presents a systematic review on extrusion additive manufacturing (EAM), with focus on the technological development of screw-assisted systems that can be fed directly with granulated materials. Screw-assisted EAM has gained importance as an enabling technology to expand the range of 3D printing materials, reduce costs associated with feedstock fabrication, and increase the material deposition rate compared to traditional fused filament fabrication (FFF). Many experimental printheads and commercial systems that use some screw-processing mechanism can be found in the literature, but the design diversity and lack of standard terminology make it difficult to determine the most suitable solutions for a given material or application field. Besides, the few previous reviews have offered only a glimpse into the topic, without an in-depth analysis about the design of the extruders and associated capabilities. A systematic procedure was devised to identify the screw-assisted EAM systems that can print directly from granulated materials, resulting in 61 articles describing different pieces of equipment that were categorized as experimental printheads and commercial systems, for small- and large-scale applications. After describing their main characteristics, the most significant extruder modifications were discussed with reference to the materials processed and performance requirements. In the end, a general workflow for the development of 3D printers based on screw extrusion was proposed. This review intends to provide information about the state-of-the-art screw-assisted EAM and help the academy to identify further research opportunities in the field.

Double Optimization of Rivastigmine-Loaded Nanostructured Lipid Carriers (NLC) for Nose-to-Brain Delivery Using the Quality by Design (QbD) Approach: Formulation Variables and Instrumental Parameters.

Rivastigmine is a drug commonly used in the management of Alzheimer's disease that shows bioavailability problems. To overcome this, the use of nanosystems, such as nanostructured lipid carriers (NLC), administered through alternative routes seems promising. In this work, we performed a double optimization of a rivastigmine-loaded NLC formulation for direct drug delivery from the nose to the brain using the quality by design (QbD) approach, whereby the quality target product profile (QTPP) was the requisite for nose to brain delivery. The experiments started with the optimization of the formulation variables (or critical material attributes-CMAs) using a central composite design. The rivastigmine-loaded NLC formulations with the best critical quality attributes (CQAs) of particle size, polydispersity index (PDI), zeta potential (ZP), and encapsulation efficiency (EE) were selected for the second optimization, which was related to the production methods (ultrasound technique and high-pressure homogenization). The most suitable instrumental parameters for the production of NLC were analyzed through a Box-Behnken design, with the same CQAs being evaluated for the first optimization. For the second part of the optimization studies, were selected two rivastigmine-loaded NLC formulations: one produced by ultrasound technique and the other by the high-pressure homogenization (HPH) method. Afterwards, the pH and osmolarity of these formulations were adjusted to the physiological nasal mucosa values and in vitro drug release studies were performed. The results of the first part of the optimization showed that the most adequate ratios of lipids and surfactants were 7.49:1.94 and 4.5:0.5 (%, w/w), respectively. From the second part of the optimization, the results for the particle size, PDI, ZP, and EE of the rivastigmine-loaded NLC formulations produced by ultrasound technique and HPH method were, respectively, 114.0 ± 1.9 nm and 109.0 ± 0.9 nm; 0.221 ± 0.003 and 0.196 ± 0.007; -30.6 ± 0.3 mV and -30.5 ± 0.3 mV; 97.0 ± 0.5% and 97.2 ± 0.3%. Herein, the HPH was selected as the most suitable production method, although the ultrasound technique has also shown effectiveness. In addition, no significant changes in CQAs were observed after 90 days of storage of the formulations at different temperatures. In vitro studies showed that the release of rivastigmine followed a non-Fickian mechanism, with an initial fast drug release followed by a prolonged release over 48 h. This study has optimized a rivastigmine-loaded NLC formulation produced by the HPH method for nose-to-brain delivery of rivastigmine. The next step is for in vitro and in vivo experiments to demonstrate preclinical efficacy and safety. QbD was demonstrated to be a useful approach for the optimization of NLC formulations for which specific physicochemical requisites can be identified.

Effect of Scan Strategies and Use of Support Structures on Surface Quality and Hardness of L-PBF AlSi10Mg Parts.

Additive manufacturing allows for a great degree of design freedom and is rapidly becoming a mainstream manufacturing process. However, as in all manufacturing processes, it has its limitations and specificities. Equipping engineers with this knowledge allows for a higher degree of optimization, extracting the most out of this technology. Therefore, a specific part design was devised and created via L-PBF (Laser Powder Bed Fusion) using AlSi10Mg powder. Certain parameters were varied to identify the influence on material density, hardness, roughness, residual stress and microstructures. It was found that on heat treated parts laser pattern strategy is one of the most influential aspects, showing that chessboard and stripes 67° improved outcome; average Ra roughness varied between 8-12 µm, residual stress was higher on vertical surfaces than horizontal surfaces, with the combination of support structures and stripes 67° strategies generating the lowest residual stress (205 MPa on a lateral/vertical face), hardness was non-orientation dependent and larger on samples with chessboard fabrication strategies, while microstructures were composed of α-Al dendrites surrounded by Si particles. The distribution and grain size of the microstructure is dependent on location regarding melt pool and HAZ area. Furthermore, Al-Mg oxides were encountered on the surface, along with pores generating from lack of fusion.

A Visual Scan Analysis Protocol for Postural Assessment at School in Young Students.

The aim of this study was to compare the X-ray diagnosis with a non-invasive method for spine alignment assessment adopting a visual scan analysis with a plumb line and simetograph in middle-school students. The sample of this study was composed of 31 males and 50 females with an average age of 14.23 (± 3.11) years. The visual scan analysis was assessed at a school; whereas, the X-ray was performed in a hospital. The Wilcoxon signed-rank test was used to assess the differences between methods and scoliosis classifications (non-accentuated <10º and scoliosis >10º), and the Kappa was used to assess the agreement between methods. The comparisons between the methods revealed non-significant differences (z = -0.577; p = 0.564), with almost perfect agreement between tests (K = 0.821; p < 0.001). Moreover, no statistical significance was observed between methods by the scoliosis classification (z = -1.000; p = 0.317), with almost perfect agreement between tests (K = 0.888; p < 0.001). This research supports the conclusion that there are no significant differences between the two methods. Therefore, it should be highlighted that this field test should be used by physical education teachers in their classes, or in a school context, in order to determine misalignments or scoliosis prevalence among middle-school students.

Major factors influencing the quantification of Nile Red stained microplastics and improved automatic quantification (MP-VAT 2.0).

Automated count of Nile Red fluorescent microplastics allows fast and reliable quantification. However, factors involving staining, digital camera conditions and settings introduce variability to the results. The objective of this paper is to identify and propose solutions to these factors and improve on the previous MP-VAT script. While removal of digital sensor defects had little influence on results and staining can be reduced to 5 min, Nile Red concentrations cannot be reduced <0.01 mg mL-1, the 470 nm LED lantern emission must be >1600 lx, and photographic conditions should be maintained as stable as possible ideally improving the filter membrane area and using the recommended settings of 2 s, ISO100, F5.6. It was also found that Nile Red can be removed from microplastics using acetone or hydrogen peroxide with iron. More importantly, both particles and fluorescent are lost with time and thus quantification should be conducted within a week. Finally, MP-VAT 2.0 was developed to remove unselected areas and to identify only red particles, excluding white reflections from quantification. This updated version of MP-VAT produced improved recovery rates of 98.2 ± 6.9 for spiked samples and 95.9 ± 10.3 on actual environmental samples, presenting a cheap and reliable complementary method for microplastic identification.

High thoracic kyphosis: impact on total thoracic kyphosis and cervical alignment in patients with adolescent idiopathic scoliosis.

PURPOSE: To evaluate the impact of proximal thoracic segment (T1-T5) on global thoracic kyphosis, as well as its influence on cervical alignment (lordotic, kyphotic or straight) in patients with adolescent idiopathic scoliosis (AIS). METHODS: We conducted a retrospective study of 80 patients with AIS. The inclusion criteria were patients between 10 and 18 years of age with a posteroanterior (PA) and lateral full-length radiographs, excluding those subjected to surgery, orthotic treatment, with other spinal disease or with poor X-ray quality. The parameters evaluated were age, sex, pelvic incidence (PI), sacral slop (SS), pelvic tilt (PT), global sagittal balance (GSB), scoliotic curvatures (differentiated according to primary curve, lumbar modifier and sagittal modifier), cervical spine alignment, thoracic sagittal Cobb angle between T1 and T5, T5 and T12 and between T1 and T12. RESULTS: In patients with AIS, the proximal sagittal thoracic Cobb segment, contrary to the distal, demonstrated a significant positive correlation with cervical spine alignment (p < 0.05). As there is an increase in proximal thoracic angle, there is an increase in cervical lordosis. We also demonstrated that the correlation between an increase in scoliotic curvature and a decrease in kyphosis only occurred in the distal thoracic segment (T5-T12). Relative to the spinopelvic parameters, the PI was not related with the dorsal kyphosis or shape of the cervical spine. CONCLUSIONS: In AIS, proximal (T1-T5) and distal (T5-T12) thoracic kyphosis have different contributions on the global thoracic sagittal curvature and in the phenomenon of hypokyphosis. On the other hand, only the proximal segment is significantly related to the shape of the cervical spine. LEVEL OF EVIDENCE: IV.

Leg length discrepancy in adolescent idiopathic scoliosis / Dismetria dos membros inferiores na escoliose idiopática do adolescente / Discrepancia de la longitud de las piernas en la escoliosis idiopática del adolescente

ABSTRACT Objective The objective of this study is to evaluate leg length discrepancy in adolescent idiopathic scoliosis. Methods A retrospective study of 80 subjects with adolescent idiopathic scoliosis (AIS) was conducted. The inclusion criteria were patients aged 10 to 18 years old with posteroanterior (PA) and lateral full-length radiographs. The exclusion criteria were patients subjected to surgery or orthotic treatment, those with other spinal disease, and those with poor quality x-rays. The parameters evaluated were: age, sex, Risser stage (RS), triradiate cartilage (TC), scoliotic curvatures, differentiated according to Lenke classification, sagittal (SB) and coronal balance (CB), and leg length discrepancy, which was assessed through the difference between the femoral heads (LLD) and through the assessment of pelvic obliquity (PO). Results The majority of patients with AIS demonstrated a mild LLD (<1 cm). The mean LLD was significantly different (p<0.01) between the scoliotic population with a main thoracolumbar curvature and those with a main lumbar curvature. When there was an LLD, it was the left limb that was shortened in most cases. The side of the longer lower limb had a direct influence on the CB (p=0.052). Conclusions This study demonstrates that in an AIS population with small LLD values, the extent of the shortening has a stronger impact on coronal balance and location than on the dimension of the main scoliotic curvature. These results demonstrate the importance of a more in-depth study on the effects of LLD <1 cm in the development of AIS and coronal imbalance. Level of evidence IV; Case Series.

RESUMO Objetivo O objetivo deste estudo é avaliar a discrepância no comprimento dos membros inferiores numa população com escoliose idiopática do adolescente. Métodos Foi realizado um estudo retrospetivo de 80 indivíduos com escoliose idiopática do adolescente (AIS). Os critérios de inclusão foram pacientes de 10 a 18 anos com radiografias coronais e sagitais extralongas, excluindo-se aqueles submetidos à cirurgia ou tratamento com coletes Milwaukee ou Boston, com outras doenças da coluna vertebral ou com exames que não cumpriam a qualidade radiográfica protocolada pelo Centro Hospitalar. Os parâmetros avaliados foram: idade, sexo, estadio de Risser (RS), cartilagem trirradiada (TC), curvaturas escolióticas diferenciadas segundo a classificação de Lenke, balanço sagital (SB), coronal (CB) e discrepância no comprimento dos membros inferiores, avaliado pelo desnível entre as cabeças femorais (LLD) e através da avaliação da obliquidade pélvica (PO). Resultados A maioria dos pacientes com AIS demonstrou LLD ligeira (<1 cm). A média de discrepância no comprimento dos membros inferiores foi significativamente diferente (p<0,01) entre a população escoliótica com uma curvatura toracolombar principal em relação àquela com uma curvatura lombar principal. Quando existe LLD, o membro esquerdo encontra-se encurtado na maioria dos casos e a discrepância dos membros inferiores influencia diretamente no balanço coronal (p=0,052). Conclusão A partir deste estudo, verificamos que, na população com AIS com pequenos valores de LLD, a magnitude do encurtamento tem um impacto de maior relevo no equilíbrio coronal e na localização do que na dimensão da curvatura escoliótica principal. Estes resultados levantam a importância de um estudo mais aprofundado sobre a importância da LLD <1 cm no desenvolvimento de AIS e no desequilíbrio coronal. Nível de evidência IV; Série de Casos.

RESUMEN Objetivos El objetivo de este estudio es evaluar la diferencia de la longitud de los miembros inferiores en la escoliosis idiopática del adolescente. Métodos Se realizó un estudio retrospectivo de 80 pacientes con escoliosis idiopática de adolescente (EIA). Los criterios de inclusión fueron los pacientes de 10 a 18 años con radiografías posteroanteriores (PA) y laterales de longitud completa. Los criterios de exclusión fueron los pacientes sometidos a cirugía o tratamiento ortopédico, aquellos con otra enfermedad de la columna y aquellos con radiografías de mala calidad. Los parámetros evaluados fueron: edad, sexo, estadio Risser (RS), cartílago trirradiado (CT), curvaturas escolióticas, diferenciadas según la clasificación de Lenke, balance sagital (BS) y coronal (BC) y discrepancia en la longitud de la pierna (DLP), que se evaluó a través de la diferencia entre las cabezas femorales y mediante la evaluación de la oblicuidad pélvica (OP). Resultados La mayoría de los pacientes con EIA demostró DLP leve (< 1 cm). La media de la DLP fue significativamente distinta (p < 0,01) entre la población escoliótica con una curvatura toracolumbar principal y los pacientes con curvatura lumbar principal. Cuando había DLP, la extremidad izquierda se acortaba en la mayoría de los casos. El lado de la extremidad más larga tuvo influencia directa en el BC (p = 0,052). Conclusiones Este estudio demuestra que en una población con EIA y bajos valores de DLP, la extensión del acortamiento tiene impacto mayor en el balance y la ubicación coronal que en la dimensión de la curvatura escoliótica principal. Estos resultados muestran la importancia de un estudio más profundo sobre los efectos de DLP < 1 cm en el desarrollo de EIA y el desequilibrio coronal. Nivel de evidencia - IV; Serie de Casos.

Sagittal balance in adolescent idiopathic scoliosis / Balanço sagital na escoliose idiopática do adolescente / Balance sagital en la escoliosis idiopática adolescente

ABSTRACT Objective The objective of this study is to achieve a better understanding of the parameters that influence sagittal balance in a population with adolescent idiopathic scoliosis (AIS). Methods A retrospective study of 80 patients with adolescent idiopathic scoliosis (AIS) was conducted. The parameters evaluated were: age, sex, pelvic incidence (PI), sacral slop (SS), pelvic tilt (PT), sagittal balance (SB), coronal balance (CB), lumbar lordosis (LL), thoracic kyphosis (TK) divided into upper (between T1 and T5) and lower (between T5 and T12), cervical spine alignment (CSA), and Cobb's coronal angle (CCA) of primary scoliotic curvature. Results Regarding the sagittal balance, this study demonstrated a significant statistical positive correlation with cervical shape (p<0.01) and upper thoracic kyphosis (from T1 to T5) (p<0.05), but not with the other variables. LL had a strong influence on lower thoracic curvature (from T5 to T12) and was strongly influenced by the PI and SS. Conclusions Sagittal balance is a parameter that is influenced by multiple factors. In fact, it is closely related to cervical shape and the upper thoracic curvature (from T1 to T5), which in turn, is closely linked to the severity of the scoliotic kyphosis. The Cobb angle of the lower thoracic spine (from T5 to T12) is more closely correlated with the angle of lumbar lordosis than with the upper thoracic kyphosis (from T1 to T5). Level of evidence IV; Case Series.

RESUMO Objetivo O objetivo deste estudo é obter uma melhor compreensão dos parâmetros que influenciam o equilíbrio sagital em uma população com escoliose idiopática do adolescente (AIS). Métodos Foi realizado um estudo retrospectivo de 80 pacientes com escoliose idiopática do adolescente (AIS). Os parâmetros avaliados foram: idade, sexo, incidência pélvica (PI), sacral slope (SS), pelvic tilt (PT), equilíbrio sagital (SB), balanço coronal (CB), lordose lombar (LL), cifose torácica (TK) dividida em alta (entre T1 e T5) e baixa (entre T5 e T12), alinhamento da coluna cervical (CSA) e ângulo de Cobb coronal de curvatura escoliótica principal (CCA). Resultados Em relação ao equilíbrio sagital, demonstrou-se uma correlação positiva significativamente estatística com o formato da coluna cervical (p <0,01) e com o ângulo de cifose da porção superior da coluna torácica (de T1 para T5) (p <0,05), mas não com as demais variáveis. A LL exerce uma forte influência sobre a porção inferior da curvatura torácica (de T5 a T12) e é fortemente influenciada pela PI e SS. Conclusões O equilíbrio sagital é um parâmetro influenciado por múltiplos fatores. De fato, está extremamente relacionado com o formato da coluna cervical e com a coluna torácica superior (de T1 a T5) que, por sua vez, apresenta uma simbiose com a gravidade da curvatura escoliótica. O ângulo de Cobb da porção inferior da coluna torácica (de T5 a T12) apresenta uma relação maior com o ângulo da lordose lombar do que com a curvatura torácica superior (de T1 a T5). Nível de evidência IV; Série de Casos.

RESUMEN Objetivo El objetivo de este estudio es lograr una mejor comprensión de los parámetros que influyen en el equilibrio sagital en una población con escoliosis idiopática del adolescente (EIA). Métodos Se realizó un estudio retrospectivo de 80 pacientes con escoliosis idiopática del adolescente (EIA). Los parámetros evaluados fueron: edad, sexo, incidencia pélvica (IP), inclinación sacra (IS), inclinación pélvica (InP), balance sagital (BS), balance coronal (BC), lordosis lumbar (LL), cifosis torácica (CT) divididos en alta (entre T1 y T5) y baja (entre T5 y T12), alineación de la columna cervical (AC) y ángulo coronal de Cobb (ACC) de curvatura escoliótica primaria. Resultados Con respecto al balance sagital, este estudio demostró una correlación positiva estadísticamente significativa con la forma cervical (p < 0,01) y cifosis de la porción superior de la columna (de T1 a T5) (p < 0,05), pero no con las otras variables. LL tuvo una fuerte influencia en la parte inferior de la curvatura torácica (de T5 a T12) y fue fuertemente influenciada por la IP y la IS. Conclusiones El balance sagital es un parámetro influenciado por múltiples factores. De hecho, está estrechamente relacionado con la forma cervical y la curvatura torácica superior (de T1 a T5), que a su vez, está estrechamente relacionada con la gravedad de la cifosis escoliótica. El ángulo de Cobb de la porción inferior de la columna torácica (de T5 a T12) presenta mayor relación con el ángulo de lordosis lumbar que con la cifosis torácica superior (de T1 a T5). Nivel de evidencia IV; Serie de Casos.

The Lateral Approach in the Surgical Treatment of a Complex Dorsal Metacarpophalangeal Joint Dislocation of the Index Finger.

Complex dorsal metacarpophalangeal (MCP) joint dislocations as a result of hyperextension injuries are uncommon in the pediatric population and irreducible to closed maneuvers. Treatment of these complex lesions is invariably surgical, and dorsal or volar approaches are traditionally used. The authors describe a case of a 16-year-old male who suffered a fall onto his outstretched right hand in a soccer game. The patient presented to the ER with pain and deformity of the index finger MCP joint. Radiographs confirmed a complex MCP dislocation with a small osteochondral fragment. A lateral surgical approach was made, and interposition of the volar plate and an osteochondral fragment blocking the reduction were found. This versatile approach allowed access to volar and dorsal structures, minimizing the risk of surgical scarring and mobility arch limitation. To our knowledge, there are no reported cases regarding a lateral surgical approach.

Pyogenic Sacroiliitis in a Pediatric Patient: A Rare Case of Infection by Streptococcus intermedius.

This is a case report of pyogenic sacroiliitis in a pediatric patient caused by Streptococcus intermedius. The patient is a 16-year-old boy who presented to an emergency department with sudden onset of back pain radiating to the left lower extremity. The diagnosis was confounded by the presence of isthmic spondylolisthesis. Plain radiography demonstrated mild isthmic spondylolisthesis but no radiographic signs of tumor, trauma, infection, arthritis, or other developmental problems. The C-reactive protein level was 23 mg/L. Over the next 24 hours, the patient developed fever, and the C-reactive protein level increased to 233 mg/L. Sacroiliitis and an iliopsoas abscess were identified on MRI. Blood cultures grew S intermedius. The patient responded to antibiotic treatment and needle aspiration under CT guidance. Sacroiliitis is an uncommon condition and, to our knowledge, there is only one other case report of its being caused by S intermedius. The previous report was in an adult.

Caenorhabditis elegans Tolerates Hyperaccelerations up to 400,000 x g.

One of the most important laboratory animal species is the nematode Caenorhabditis elegans, which has been used in a range of research fields such as neurobiology, body development, and molecular biology. The scientific progress obtained by employing C. elegans as a model in these areas has encouraged its use in new fields. One of the new potential applications concerns the biological responses to hyperacceleration stress (g-force), but only a few studies have evaluated the response of multicellular organisms to extreme hypergravity conditions at the order of magnitude 105 x g, which is the theorized force experienced by rocks ejected from Mars (or similar planets). Therefore, we subjected the nematode C. elegans to 400,000 x g (equivalent to that force) and evaluated viability, general morphology, and behavior of C. elegans after exposure to this stress. The metabolic activity of this nematode in response to the gravitational spectrum of 50-400,000 x g was also evaluated by means of the MTT assay. Surprisingly, we found that this organism showed no decrease in viability, no changes in behavior and development, and no drastic metabolic depression after hyperacceleration. Thus, we demonstrated for the first time that this multicellular research model can withstand extremely high g-forces, which prompts the use of C. elegans as a new model for extreme hypergravity. Key Words: Caenorhabditis elegans-Hypergravity-Ultracentrifugation-Acceleration-Panspermia-Astrobiology. Astrobiology 18, 825-833.