Computed Tomography Does Not Improve Intra- and Interobserver Agreement of Hertel Radiographic Prognostic Criteria.

Background and Objectives: Proximal humerus fractures are the second most frequent site of avascular necrosis (AVN), occurring in up to 16% of cases. The Hertel criteria have been used as a reference for the prediction of humerus head ischemia. However, these are based solely on the use of radiographs, which can make interpretation extremely difficult due to several reasons, such as the overlapping fragments, severity of the injury, and noncompliant acute pain patients. The objectives of the study were to evaluate the role of computed tomography (CT) in the interpretation of the Hertel criteria and to evaluate the intra- and interobserver agreement of orthopedic surgeons, comparing their area of expertise. Materials and Methods: The radiographs and CT scans of 20 skeletally mature patients who had fractures of the proximal humerus were converted to jpeg and mov, respectively. All images were evaluated by eight orthopedic surgeons (four trauma surgeons and four shoulder surgeons) in two different occasions. The intra- and interobserver agreement was assessed by using the Kappa coefficient. The level of significance was 5%. Results: There was a weak-to-moderate intraobserver agreement (κ < 0.59) for all examiners. Only the medial metaphyseal hinge greater than 2 mm was identified by 87.5% of evaluators both in the radiographic and CT examinations in the two rounds of the study (p < 0.05). There was no significant interobserver agreement (κ < 0.19), as it occurred only in some moments of the second round of evaluation. Conclusions: The prognostic criteria for humeral head ischemia evaluated in this study showed weak intra- and interobserver agreement in both the radiographic and tomographic evaluation. CT did not help surgeons in the primary interpretation of Hertel prognostic criteria used in this study when compared to the radiographic examination.

Plate-screw and screw-washer stability in a Schatzker type-I lateral tibial plateau fracture: a comparative biomechanical study.

The aim of this study was to evaluate the biomechanical role of both a non-locking two-hole small fragment dynamic compression plate with 3.5-mm screws and a 4.5-mm cortical screw with a washer applied to a Schatzker type-I tibial plateau fracture. Sixteen right synthetic tibiae were used to create an anterolateral shear tibial plateau fracture (Schatzker type-I fracture). Eight models were fixed with a small fragment non-locked straight dynamic compression plate with one 3.5-mm bicortical screw (plate-screw construction) and eight models were fixed with a 4.5-mm cortical screw and a washer (screw-washer construction), both inserted at 1.0 mm distal to the apex of the fracture. Specimens were tested up to the onset of yielding at a constant strain rate of 5.0-mm/min. Stiffness ranged from 311.83 N/mm to 199.54 N/mm, with a mean + SD of 260.32 + 33.8 N/mm in the plate-screw construction, and from 290.34 N/mm to 99.16 N/mm, with a mean + SD of 220.46 + 63.12 N/mm in screw-washer construction. There was no significant difference (p=0.172). Use of a two-hole small-fragment non-locked plate with one 3.5-mm cortical screw or a 4.5-mm cortical screw with a washer applied at 1.0 mm distal to the apex of the fracture as buttressing present similar stiffness in terms of preventing axial displacement in synthetic tibiae models tested up to the onset of yielding.

Intramedullary nailing of lateral malleolus in ankle fractures - surgical technique and literature review. / Haste intramedular de fíbula nas fraturas maleolares do tornozelo - técnica cirúrgica e revisão da literatura.

Our objective is to describe the technique of intramedullary (IM) nailing of lateral malleolus in the surgical management of ankle fractures. Fracture reduction is performed either percutaneously with a small pointed reduction clamp in simple oblique fractures or using longitudinal traction and rotation for comminuted fractures, thus reducing complications related to open reduction and internal fixation with a plate. The technique has been shown to be simple and reproducible. In addition, the technique allows early weight bearing, which accelerates rehabilitation and potentially fasten fracture healing. IM nailing is a viable option for the fixation of the of lateral malleolus in ankle fractures and should be considered in the surgeon's armamentarium.

Nosso objetivo é descrever a técnica de fixação intramedular (IM) da fíbula no tratamento cirúrgico das fraturas maleolares do tornozelo. A redução é realizada sempre de forma percutânea: quando o traço de fratura é oblíquo simples, utilizamos uma pinça de redução de pontas e quando a fratura apresenta padrão multifragmentar, usa-se tração longitudinal e rotação. Isso reduz as complicações relacionadas à redução aberta e fixação interna com placa. A técnica demonstrou ser simples e reprodutível. Além disso, essa forma de fixação permite apoio precoce do peso corporal, o que acelera o processo de reabilitação e potencialmente acelera a cicatrização da fratura. A fixação IM da fíbula mostrou-se uma opção viável para a fixação do maléolo lateral nas fraturas do tornozelo, devendo ser considerada no arsenal do cirurgião.

Swallowing, voice and quality of life of patients submitted to extended supratracheal laryngectomy.

Objective To describe functional and quality of life results after extended supratracheal laryngectomy. Methods In the period from September 2009 to January 2018, 11 male subjects were submitted to extended supratracheal laryngectomy. Swallowing abilities were assessed through videofluoroscopy and the clinical scale Functional Communication Measures of Swallowing. The voices were classified by means of the perceptual-auditory analysis Consensus Auditory-Perceptual Evaluation of Voice. All subjects completed a self-assessment questionnaire for voice and swallowing. Results Aspiration was found in four patients and all presented stasis in different structures. All subjects in this study were exclusively orally fed and hydrated. In the evaluation of quality of life in swallowing, patients had mean >80 in all areas (83.47 mean of scores). The general degree and the presence of roughness were the highest means present in Consensus Auditory-Perceptual Evaluation of Voice (37.81 and 49.36, respectively). The mean of 33.36 (±22.56) had little impact on quality of life under the perspective of vocal aspects. Conclusion After supratracheal laryngectomy, swallowing was sufficiently restored and the quality of life was satisfactory. The voice presents severely impaired quality and preserved oral communication, with low impact on the activities of daily living. All individuals who maintained two cricoarytenoid units presented better functional results in swallowing and voice.

Haste intramedular de fíbula nas fraturas maleolares do tornozelo - técnica cirúrgica e revisão da literatura / Intramedullary nailing of lateral malleolus in ankle fractures - surgical technique and literature review

RESUMO Nosso objetivo é descrever a técnica de fixação intramedular (IM) da fíbula no tratamento cirúrgico das fraturas maleolares do tornozelo. A redução é realizada sempre de forma percutânea: quando o traço de fratura é oblíquo simples, utilizamos uma pinça de redução de pontas e quando a fratura apresenta padrão multifragmentar, usa-se tração longitudinal e rotação. Isso reduz as complicações relacionadas à redução aberta e fixação interna com placa. A técnica demonstrou ser simples e reprodutível. Além disso, essa forma de fixação permite apoio precoce do peso corporal, o que acelera o processo de reabilitação e potencialmente acelera a cicatrização da fratura. A fixação IM da fíbula mostrou-se uma opção viável para a fixação do maléolo lateral nas fraturas do tornozelo, devendo ser considerada no arsenal do cirurgião.

ABSTRACT Our objective is to describe the technique of intramedullary (IM) nailing of lateral malleolus in the surgical management of ankle fractures. Fracture reduction is performed either percutaneously with a small pointed reduction clamp in simple oblique fractures or using longitudinal traction and rotation for comminuted fractures, thus reducing complications related to open reduction and internal fixation with a plate. The technique has been shown to be simple and reproducible. In addition, the technique allows early weight bearing, which accelerates rehabilitation and potentially fasten fracture healing. IM nailing is a viable option for the fixation of the of lateral malleolus in ankle fractures and should be considered in the surgeon's armamentarium.

Plate-screw and screw-washer stability in a Schatzker type-I lateral tibial plateau fracture: a comparative biomechanical study / Comportamento biomecânico de dois tipos de fixação usados como suporte na fratura do platô tibial lateral do tipo I de Schatzker

ABSTRACT The aim of this study was to evaluate the biomechanical role of both a non-locking two-hole small fragment dynamic compression plate with 3.5-mm screws and a 4.5-mm cortical screw with a washer applied to a Schatzker type-I tibial plateau fracture. Sixteen right synthetic tibiae were used to create an anterolateral shear tibial plateau fracture (Schatzker type-I fracture). Eight models were fixed with a small fragment non-locked straight dynamic compression plate with one 3.5-mm bicortical screw (plate-screw construction) and eight models were fixed with a 4.5-mm cortical screw and a washer (screw-washer construction), both inserted at 1.0 mm distal to the apex of the fracture. Specimens were tested up to the onset of yielding at a constant strain rate of 5.0-mm/min. Stiffness ranged from 311.83 N/mm to 199.54 N/mm, with a mean + SD of 260.32 + 33.8 N/mm in the plate-screw construction, and from 290.34 N/mm to 99.16 N/mm, with a mean + SD of 220.46 + 63.12 N/mm in screw-washer construction. There was no significant difference (p=0.172). Use of a two-hole small-fragment non-locked plate with one 3.5-mm cortical screw or a 4.5-mm cortical screw with a washer applied at 1.0 mm distal to the apex of the fracture as buttressing present similar stiffness in terms of preventing axial displacement in synthetic tibiae models tested up to the onset of yielding.

RESUMO O objetivo do estudo foi avaliar o comportamento biomecânico de dois tipos de fixação: placa de compressão dinâmica de pequenos fragmentos, não bloqueada com parafuso de 3,5mm e parafuso cortical de 4,5mm com arruela, ambos posicionados no vértice de fratura do platô tibial do tipo I de Schatzker. Dezesseis tíbias sintéticas foram utilizadas para criar uma fratura por cisalhamento na face ântero-lateral do platô tibial (tipo I de Schatzker). Oito modelos foram fixados com placa de compressão dinâmica de pequenos fragmentos não bloqueada com parafuso de 3,5mm, inserido 1,0mm distal ao vértice da fratura (construção placa-parafuso), e oito modelos foram fixados com parafuso cortical de 4,5mm com arruela, inserido 1,0mm distal ao vértice da fratura (construção parafuso-arruela). Os modelos foram testados em compressão axial até o início da falha mecânica na interface construção-osso, com taxa de deformação constante de 5,0mm/min. A rigidez variou de 311,83 N/mm a 199,54 N/mm, com média + DP de 260,32 + 33,8 N/mm nos modelos da construção placa-parafuso, e de 290,34 N/mm a 99,16 N/mm, com média + DP de 220,46 + 63,12 N/mm nos modelos da construção parafuso-arruela. Não houve diferença estatisticamente significativa (p=0,172). A utilização de placa de compressão dinâmica de pequenos fragmentos não bloqueada com parafuso de 3,5mm ou de parafuso cortical de 4,5mm com arruela, posicionados no vértice da fratura do platô tibial do tipo I de Schatzker, apresenta rigidez similar na prevenção do desvio axial da fratura.

Swallowing, voice and quality of life of patients submitted to extended supratracheal laryngectomy / Deglutição, voz e qualidade de vida de pacientes submetidos à laringectomia supratraqueal alargada

ABSTRACT Objective To describe functional and quality of life results after extended supratracheal laryngectomy. Methods In the period from September 2009 to January 2018, 11 male subjects were submitted to extended supratracheal laryngectomy. Swallowing abilities were assessed through videofluoroscopy and the clinical scale Functional Communication Measures of Swallowing. The voices were classified by means of the perceptual-auditory analysis Consensus Auditory-Perceptual Evaluation of Voice. All subjects completed a self-assessment questionnaire for voice and swallowing. Results Aspiration was found in four patients and all presented stasis in different structures. All subjects in this study were exclusively orally fed and hydrated. In the evaluation of quality of life in swallowing, patients had mean >80 in all areas (83.47 mean of scores). The general degree and the presence of roughness were the highest means present in Consensus Auditory-Perceptual Evaluation of Voice (37.81 and 49.36, respectively). The mean of 33.36 (±22.56) had little impact on quality of life under the perspective of vocal aspects. Conclusion After supratracheal laryngectomy, swallowing was sufficiently restored and the quality of life was satisfactory. The voice presents severely impaired quality and preserved oral communication, with low impact on the activities of daily living. All individuals who maintained two cricoarytenoid units presented better functional results in swallowing and voice.

RESUMO Objetivo Descrever os resultados funcionais e de qualidade de vida após a laringectomia supratraqueal alargada. Métodos No período de setembro de 2009 a janeiro de 2018, 11 indivíduos do sexo masculino foram submetidos à laringectomia supratraqueal alargada. As habilidades de deglutição foram avaliadas por meio da videofluoroscopia e da escala clínica Functional Communication Measures . As vozes foram classificadas por análise perceptivo-auditiva da Consensus Auditory-Perceptual Evaluation of Voice . Todos os voluntários preencheram um questionário de autoavaliação para voz e deglutição. Resultados A aspiração foi encontrada em quatro pacientes, e todos apresentaram estase em diferentes estruturas. Todos os sujeitos deste estudo apresentavam alimentação e hidratação exclusivas por via oral. Na avaliação da qualidade de vida na deglutição, os pacientes demonstraram médias >80 em todas as áreas (83,47 média dos escores). O grau geral e a presença de rugosidade foram os maiores escores médios na avaliação perceptivo-auditiva da voz (37,81 e 49,36 consecutivamente). A média de 33,36 (±22,56) demonstrou pouco impacto na qualidade de vida sob a perspectiva dos aspectos vocais. Conclusão Após a laringectomia supratraqueal, a deglutição foi suficientemente restaurada, e a qualidade de vida foi satisfatória. A voz apresenta qualidade gravemente comprometida com comunicação oral preservada, demonstrando baixo impacto nas atividades da vida diária. Todos os indivíduos que mantiveram duas unidades cricoaritenóideas apresentaram melhores resultados funcionais na deglutição e na voz.

How do Orthopedic Surgeons Manage Displaced Femoral Neck Fracture in the Middle-Aged Patient? Brazilian Survey of 78 Orthopaedic Surgeons.

Objective The aim of the present study was to evaluate the practices and preferences of Brazilian orthopedic surgeons for the treatment of femoral neck fractures in middle-aged patients. Methods A survey containing 10 images of femoral neck fractures was sent to a group of 100 orthopedic surgeons, all of them members of the Brazilian Society of Orthopedics and Traumatology. The questionnaire asked the treatment option for cases of nondisplaced and displaced fractures of the femoral neck in middle-aged patients, that is, those between 50 and 69 years old. Descriptive and inferential statistical analyzes were performed using the chi-squared (χ2) and the Fisher exact tests. The level of significance was 5%. Results The survey was answered by 78% of the orthopedic surgeons invited to participate in the study. There was no significant difference in the treatment method distribution between generalists and specialists ( p = 0.16) in the sample of nondisplaced femoral neck fractures. There was a highly significant difference in the treatment method distribution between generalists and specialists ( p < 0.0001) in the sample of displaced fractures of the femoral neck. Conclusion Preservation of the femoral head through multiple cannulated screws fixation is the treatment of choice for nondisplaced femoral neck fractures for both generalists and specialists. Low chronological and/or physiological age are the main factors for this decision-making. In displaced femoral neck fractures, femoral head replacement is preferred for both groups of orthopedists (generalists and specialists). In this situation, specialists prefer total hip arthroplasty (THA), whereas generalists favor partial hip arthroplasty (PHA).

How do Orthopedic Surgeons Manage Displaced Femoral Neck Fracture in the Middle-Aged Patient? Brazilian Survey of 78 Orthopaedic Surgeons / Como os cirurgiões ortopédicos tratam a fratura desviada do colo do fêmur no paciente de meia idade? Pesquisa brasileira com 78 cirurgiões ortopédicos

Abstract Objective The aim of the present study was to evaluate the practices and preferences of Brazilian orthopedic surgeons for the treatment of femoral neck fractures in middleaged patients. Methods A survey containing 10 images of femoral neck fractures was sent to a group of 100 orthopedic surgeons, all of them members of the Brazilian Society of Orthopedics and Traumatology. The questionnaire asked the treatment option for cases of nondisplaced and displaced fractures of the femoral neck in middle-aged patients, that is, those between 50 and 69 years old. Descriptive and inferential statistical analyzes were performed using the chi-squared (χ2) and the Fisher exact tests. The level of significance was 5%. Results The survey was answered by 78% of the orthopedic surgeons invited to participate in the study. There was no significant difference in the treatment method distribution between generalists and specialists (p = 0.16) in the sample of nondisplaced femoral neck fractures. There was a highly significant difference in the treatmentmethod distribution between generalists and specialists (p < 0.0001) in the sample of displaced fractures of the femoral neck. Conclusion Preservation of the femoral head through multiple cannulated screws fixation is the treatment of choice for nondisplaced femoral neck fractures for both

Resumo Objetivo O objetivo do presente estudo foi avaliar as práticas e preferências dos cirurgiões ortopédicos brasileiros para o tratamento da fratura do colo do fêmur no paciente de meia idade. Métodos Foi elaborado um questionário contendo 10 imagens de fraturas do colo do fêmur enviado a um grupo de 100 ortopedistas, todos membros titulares da Sociedade Brasileira de Ortopedia e Traumatologia. No questionário, foi perguntada a opção de tratamento para casos de fratura não desviada e desviada do colo do fêmurempacientes de meia idade, caracterizados como aqueles comidades entre 50 e 69 anos. Foramrealizadas análises estatísticas descritiva e inferencial, pelos testes de qui-quadrado (χ2) e exato de Fisher. O critério de determinação de significância adotado foi o nível de 5%. Resultados O questionário foi respondido por 78% dos ortopedistas convidados a participar do presente estudo. Observou-se que não existe diferença significativa na distribuição do método de tratamento entre as avaliações de generalistas e especialistas (p = 0,16) na amostra de fraturas não desviadas do colo do fêmur. Observou-se que existe diferença altamente significativa na distribuição do método de tratamento entre as avaliações de generalistas e especialistas (p < 0,0001) na amostra de fraturas desviadas do colo do fêmur. Conclusão A preservação da cabeça femoral por meio da fixação com múltiplos parafusos canulados é o tratamento de escolha para as fraturas não desviadas do colo do fêmur, tanto para os generalistas quanto para os especialistas. Idade cronológica e/ ou fisiológica baixas são os principais fatores para esta tomada de decisão. Nos casos em que a fratura do colo do fêmur encontra-se desviada, a substituição da cabeça femoral é a preferência para os dois grupos de ortopedistas (generalistas e especialistas). Nesta situação, os especialistas preferem a artroplastia total do quadril (ATQ) e os generalistas a artroplastia parcial do quadril (APQ).

Asymptomatic Dysplasia Epiphysealis Hemimelica of the Shoulder in a Skeletally Mature Patient with Normal Function.

Dysplasia epiphysealis hemimelica is a rare osteocartilaginous overgrowth syndrome of bone epiphysis, mostly encountered in the lower limbs of immature skeleton patients. We report a case of proximal humerus presentation in an adult male, with neither articular involvement nor clinical dysfunction. This case highlights the importance of stratification into intra- and extra-articular lesions, as this distinction ultimately influences both symptoms and treatment outcome. In addition, the case highlights the importance of specific imaging modalities, such as CT and MR images, which provide excellent anatomic location of the lesion, adequate extension of cartilaginous components, exact status of articular cartilage, and accurate assessment of neighboring structures, such as vessels, nerves, ligaments, tendons, and muscles. The imaging features are described, the relevant literature is reviewed, and salient features are discussed.

Metastatic tumor of the hand of unknown primary origin.

Acral metastases in the hand are exceedingly rare. We present the unusual case of a metastatic tumor of the hand of unknown primary site in a 77-year-old man with no known cancer history. The patient presented with pain and swelling in the tip of the left ring finger, which had previously been diagnosed as gout at another clinic. Laboratory tests, including white blood cell count, erythrocyte sedimentation rate/C-reactive protein, and uric acid were all within normal limits. Excisional biopsy was taken by amputation of the distal phalanx of the left ring finger through the distal third of the middle phalanx. Pathology confirmed the presence of a moderately differentiated adenocarcinoma of unknown primary site. Roentgenographic examination of the chest revealed no pathologic findings. The patient refused further investigation and adequate treatment. He died 4 months later. The current description confirms the rarity of metastatic malignancy of the hand and its poor prognosis.

General principles for treatment of femoral head fractures.

Femoral head fractures occur almost exclusively as a result of a traumatic hip dislocation. Treatment is typically an emergency and includes the reduction of the dislocated hip under anesthesia. As a rule, the earlier the reduction, the better the outcome. Open reduction and internal fixation of the fracture of the femoral head is the treatment of choice for most young patients. In some selected cases when there is a very small fragment located in the region below the fovea, removal should be indicated. In elderly patients and those who experience severe femoral head impaction, it is preferable to perform a total hip replacement. Despite optimal management, the rate of complications after femoral head fractures may reach as high as 50%. In the present study, the authors review the general principles of management of patients with femoral head fractures.

Combined Lag Screw and Cerclage Wire Fixation for Calcaneal Tuberosity Avulsion Fractures.

Avulsion fractures of the calcaneal tuberosity represent a rare injury pattern that is caused by a powerful tension force from the Achilles tendon and is usually seen following minor trauma, especially in elderly patients. The objective of this study is to describe a surgical technique using cerclage wiring through cannulated screws in the treatment of extra- and intra-articular avulsion fractures of the calcaneal tuberosity and to present our results in a small patient's cohort. Through a 5.0 cm longitudinal skin incision over the posterolateral aspect of the calcaneus, after adequate debridement of the fracture fragments and while keeping the ankle in plantarflexion, the calcaneal tuberosity is anatomically reduced with the help of a periarticular reduction clamp and an accessory plantar longitudinal approach. Provisionally fixation is performed with K-wires. Definitive fixation is achieved with two parallel partially threaded 7.0 cannulated screws, which are positioned from the superior and posterior aspect of the tuberosity to the inferior and anterior aspect of the plantar surface of the calcaneus, and 1.5 mm cerclage wires that are pulled epiperiosteally to the plantar aspect of the calcaneus to avoid damage to local soft tissues. Alternatively, for smaller fracture fragments, two 3.5 mm partially threaded cannulated screws and 1.25 mm cerclage wires can be used. We also report the results of the procedure in a small cohort of four patients. All fractures healed in an anatomic position. There was no failure of fixation, loss of reduction, or need for secondary surgery, including hardware removal. At final follow-up, all patients had regained full plantar flexion range of motion and strength, with no gait or weight-bearing restrictions. In conclusion, the combination of cerclage wire and large diameter cannulated screws represents a promising option in the treatment of avulsion fractures of the calcaneal tuberosity, demonstrating good functional and radiographic results in our cohort of patients.

Mind the gap between the fracture line and the length of the working area: a 2-D finite element analysis using an extramedullary fixation model / Observe a distância entre a linha de fratura e o comprimento da área de trabalho: análise bidimensional de elementos finitos em modelo de fixação extramedular

ABSTRACT Objective: To determine the ideal working area for a simple transverse fracture line treated with a bridge plate. Methods: A 2-D finite element analysis of a hypothetical femur was performed for the quantitative evaluation of a large-fragment titanium alloy locking plate based on the precept of relative stability in a case of a simple transverse diaphyseal fracture. Two simulations (one case of strain and another case of stress distribution) were analyzed in three unique situations according to the von Mises stress theory. Load distributions were observed when the bone was subjected to a single vertical load of 1000 N. Results: The longer the length of the implant flexion, which coincided with the working area of the plate, the greater the flexion of the implant. The highest concentrations of stress on the plate occurred in the region around the screws closest to the bone gap. The closer the screws to the fracture site, the greater the demands on the plate. Conclusion: When using a large-fragment titanium alloy locking plate to stabilize a simple transverse fracture based on the precept of relative stability (bridge plate), there must be considerable distance between the proximal and distal screws closest to the fracture line. The farther away this fixation is, the lower the stress on the plate and the greater the dissipation of force in the form of deflection.

RESUMO Objetivo: Determinar qual é a área de trabalho ideal em uma fratura de traço simples transverso tratada com placa em ponte. Métodos: Foi feita uma análise bidimensional de elementos finitos em um fêmur hipotético para avaliação quantitativa de uma placa bloqueada para grandes fragmentos feita de liga de titânio, usada com o princípio de estabilidade relativa em uma fratura diafisária de traço simples e transverso. Foram analisadas duas simulações, uma de deformação e outra de distribuição de tensão, de acordo com a teoria de von Mises, em três situações distintas. Foram observadas as distribuições de carga quando o osso foi submetido a uma carga monotônica vertical de 1.000 N. Resultados: Quanto maior o comprimento de flexão do implante, o que coincidiu com a área de trabalho da placa, maior a flexão dele. A maior concentração de tensão na placa foi observada na região dos parafusos mais próximos do defeito ósseo. Quanto mais próximos os parafusos do foco de fratura, maior a demanda sobre a placa. Conclusão: Ao usar uma placa bloqueada para grandes fragmentos feita de liga de titânio para estabilizar uma fratura de traço simples e transverso pelo princípio de estabilidade relativa (placa em ponte), a distância entre os parafusos mais próximos do traço de fratura proximal e distalmente deve ser longa. Quanto mais distante essa fixação, menor a concentração de tensão na placa e maior a dissipação de esforços na forma de deflexão.

Mind the gap between the fracture line and the length of the working area: a 2-D finite element analysis using an extramedullary fixation model.

OBJECTIVE: To determine the ideal working area for a simple transverse fracture line treated with a bridge plate. METHODS: A 2-D finite element analysis of a hypothetical femur was performed for the quantitative evaluation of a large-fragment titanium alloy locking plate based on the precept of relative stability in a case of a simple transverse diaphyseal fracture. Two simulations (one case of strain and another case of stress distribution) were analyzed in three unique situations according to the von Mises stress theory. Load distributions were observed when the bone was subjected to a single vertical load of 1000 N. RESULTS: The longer the length of the implant flexion, which coincided with the working area of the plate, the greater the flexion of the implant. The highest concentrations of stress on the plate occurred in the region around the screws closest to the bone gap. The closer the screws to the fracture site, the greater the demands on the plate. CONCLUSION: When using a large-fragment titanium alloy locking plate to stabilize a simple transverse fracture based on the precept of relative stability (bridge plate), there must be considerable distance between the proximal and distal screws closest to the fracture line. The farther away this fixation is, the lower the stress on the plate and the greater the dissipation of force in the form of deflection.

OBJETIVO: Determinar qual é a área de trabalho ideal em uma fratura de traço simples transverso tratada com placa em ponte. MÉTODOS: Foi feita uma análise bidimensional de elementos finitos em um fêmur hipotético para avaliação quantitativa de uma placa bloqueada para grandes fragmentos feita de liga de titânio, usada com o princípio de estabilidade relativa em uma fratura diafisária de traço simples e transverso. Foram analisadas duas simulações, uma de deformação e outra de distribuição de tensão, de acordo com a teoria de von Mises, em três situações distintas. Foram observadas as distribuições de carga quando o osso foi submetido a uma carga monotônica vertical de 1.000 N. RESULTADOS: Quanto maior o comprimento de flexão do implante, o que coincidiu com a área de trabalho da placa, maior a flexão dele. A maior concentração de tensão na placa foi observada na região dos parafusos mais próximos do defeito ósseo. Quanto mais próximos os parafusos do foco de fratura, maior a demanda sobre a placa. CONCLUSÃO: Ao usar uma placa bloqueada para grandes fragmentos feita de liga de titânio para estabilizar uma fratura de traço simples e transverso pelo princípio de estabilidade relativa (placa em ponte), a distância entre os parafusos mais próximos do traço de fratura proximal e distalmente deve ser longa. Quanto mais distante essa fixação, menor a concentração de tensão na placa e maior a dissipação de esforços na forma de deflexão.

Mecanismos do tromboembolismo venoso no câncer: uma revisão da literatura / Mechanisms of venous thromboembolism in cancer: aliterature review

Existe uma estreita relação entre o tromboembolismo venoso e o câncer. Pacientes com neoplasias apresentam maior incidência de eventos tromboembólicos em sua evolução clínica. A ocorrência desses eventos é considerada um marcador preditivo negativo nesse grupo de pacientes. Revisamos, então, a ativação dos mecanismos de coagulação neste grupo de pacientes. Trata-se de um processo complexo e multifatorial, relacionado tanto a características tumorais, estadiamento clínico, agressividade da doença e sítios tumorais, dentre outros. Novos biomarcadores vêm sendo pesquisados ao longo dos anos na tentativa de correlacioná-los ao risco trombótico, visando uma intervenção que melhore a evolução clínica desses pacientes oncológicos

There is a strong relationship between venous thromboembolism and cancer. Patients with tumors have a higher incidence of thromboembolic events in their clinical evolution. The occurrence of such events is considered a negative predictive marker in this group of patients. Thus, we aim to review activation of coagulation mechanisms in this group of patients. Activation of coagulation mechanisms in cancer patients is a complex and multifactorial process, related to tumor characteristics, clinical staging, the disease's aggressiveness, tumor sites, and additional factors caused by disease progression. New biomarkers have been under investigation over the years in the attempt to correlate them to the risk of thrombosis, aiming to develop interventions that improve the clinical evolution of these cancer patients

Finite element analysis of the equivalent stress distribution in Schanz screws during the use of a femoral fracture distractor.

To evaluate the mechanical stress and elastic deformation exercised in the thread/shaft transition of Schanz screws in assemblies with different screw anchorage distances in the entrance to the bone cortex, through the distribution and location of tension in the samples. An analysis of 3D finite elements was performed to evaluate the distribution of the equivalent stress (triple stress state) in a Schanz screw fixed bicortically and orthogonally to a tubular bone, using two mounting patterns: (1) thread/shaft transition located 20 mm from the anchorage of the Schanz screws in the entrance to the bone cortex and (2) thread/shaft transition located 3 mm from the anchorage of the Schanz screws in entrance to the bone cortex. The simulations were performed maintaining the same direction of loading and the same distance from the force vector in relation to the center of the hypothetical bone. The load applied, its direction, and the distance to the center of the bone were constant during the simulations in order to maintain the moment of flexion equally constant. The present calculations demonstrated linear behavior during the experiment. It was found that the model with a distance of 20 mm between the Schanz screws anchorage in the entrance to the bone cortex and the thread/shaft transition reduces the risk of breakage or fatigue of the material during the application of constant static loads; in this model, the maximum forces observed were higher (350 MPa). The distance between the Schanz screws anchorage at the entrance to the bone cortex and the smooth thread/shaft transition of the screws used in a femoral distractor during acute distraction of a fracture must be farther from the entrance to the bone cortex, allowing greater degree of elastic deformation of the material, lower mechanical stress in the thread/shaft transition, and minimized breakage or fatigue. The suggested distance is 20 mm.

Avaliar o comportamento do estresse mecânico e da deformação elástica exercida na transição rosca-talo liso dos pinos de Schanz do distrator femoral de fraturas em montagens com diferentes distâncias de ancoragem dos pinos na cortical óssea de entrada através de estudo da distribuição e da localização de tensões no corpo de prova.Feita análise de elementos finitos 3D para a avaliação da distribuição das tensões equivalentes em um pino de Schanz fixado de modo bicortical e ortogonal a um osso tubular, em dois padrões de montagem: (1) transição rosca-talo liso distante 20 mm da ancoragem dos pinos de Schanz na cortical de entrada e (2) transição rosca-talo liso distante 3 mm da ancoragem dos pinos de Schanz na cortical de entrada. Foram feitas simulações e manteve-se a mesma direção da carga e a mesma distância do vetor força em relação ao centro do osso hipotético. A carga aplicada, sua direção e a distância ao centro do osso foram constantes durante as simulações para manter o momento fletor igualmente constante. Os cálculos apresentados demonstraram comportamento linear durante todo o experimento. Verificou-se que o modelo com uma distância de 20 mm entre a ancoragem dos pinos de Schanz na cortical óssea de entrada e a transição rosca-talo liso reduziu o risco de ruptura ou fadiga do material durante a aplicação de cargas estáticas constantes. Nesse modelo, as forças máximas observadas foram superiores (350 MPa). A análise do comportamento do estresse mecânico e da deformação elástica exercida na transição rosca-talo liso dos pinos de Schanz do distrator femoral de fraturas mostrou que distâncias maiores entre a ancoragem dos pinos na cortical óssea de entrada e a transição rosca-talo liso dos pinos de Schanz permitem menor estresse mecânico na transição rosca-talo liso e maior grau de deformação elástica do material e minimizam quebra ou fadiga. A distância sugerida é de 20 mm.

Finite element analysis of the equivalent stress distribution in Schanz screws during the use of a femoral fracture distractor / Análise de elementos finitos da distribuição de tensões equivalentes nos pinos de Schanz durante o uso do distrator femoral de fraturas

ABSTRACT To evaluate the mechanical stress and elastic deformation exercised in the thread/shaft transition of Schanz screws in assemblies with different screw anchorage distances in the entrance to the bone cortex, through the distribution and location of tension in the samples. An analysis of 3D finite elements was performed to evaluate the distribution of the equivalent stress (triple stress state) in a Schanz screw fixed bicortically and orthogonally to a tubular bone, using two mounting patterns: (1) thread/shaft transition located 20 mm from the anchorage of the Schanz screws in the entrance to the bone cortex and (2) thread/shaft transition located 3 mm from the anchorage of the Schanz screws in entrance to the bone cortex. The simulations were performed maintaining the same direction of loading and the same distance from the force vector in relation to the center of the hypothetical bone. The load applied, its direction, and the distance to the center of the bone were constant during the simulations in order to maintain the moment of flexion equally constant. The present calculations demonstrated linear behavior during the experiment. It was found that the model with a distance of 20 mm between the Schanz screws anchorage in the entrance to the bone cortex and the thread/shaft transition reduces the risk of breakage or fatigue of the material during the application of constant static loads; in this model, the maximum forces observed were higher (350 MPa). The distance between the Schanz screws anchorage at the entrance to the bone cortex and the smooth thread/shaft transition of the screws used in a femoral distractor during acute distraction of a fracture must be farther from the entrance to the bone cortex, allowing greater degree of elastic deformation of the material, lower mechanical stress in the thread/shaft transition, and minimized breakage or fatigue. The suggested distance is 20 mm.

RESUMO Avaliar o comportamento do estresse mecânico e da deformação elástica exercida na transição rosca-talo liso dos pinos de Schanz do distrator femoral de fraturas em montagens com diferentes distâncias de ancoragem dos pinos na cortical óssea de entrada através de estudo da distribuição e da localização de tensões no corpo de prova. Feita análise de elementos finitos 3 D para a avaliação da distribuição das tensões equivalentes em um pino de Schanz fixado de modo bicortical e ortogonal a um osso tubular, em dois padrões de montagem: (1) transição rosca-talo liso distante 20 mm da ancoragem dos pinos de Schanz na cortical de entrada e (2) transição rosca-talo liso distante 3 mm da ancoragem dos pinos de Schanz na cortical de entrada. Foram feitas simulações e manteve-se a mesma direção da carga e a mesma distância do vetor força em relação ao centro do osso hipotético. A carga aplicada, sua direção e a distância ao centro do osso foram constantes durante as simulações para manter o momento fletor igualmente constante. Os cálculos apresentados demonstraram comportamento linear durante todo o experimento. Verificou-se que o modelo com uma distância de 20 mm entre a ancoragem dos pinos de Schanz na cortical óssea de entrada e a transição rosca-talo liso reduziu o risco de ruptura ou fadiga do material durante a aplicação de cargas estáticas constantes. Nesse modelo, as forças máximas observadas foram superiores (350 Mpa). A análise do comportamento do estresse mecânico e da deformação elástica exercida na transição rosca-talo liso dos pinos de Schanz do distrator femoral de fraturas mostrou que distâncias maiores entre a ancoragem dos pinos na cortical óssea de entrada e a transição rosca-talo liso dos pinos de Schanz permitem menor estresse mecânico na transição rosca-talo liso e maior grau de deformação elástica do material e minimizam quebra ou fadiga. A distância sugerida é de 20 mm.