Search

Introduction: The population around the world is aging. With this, there will be an increased incidence of fractures due to osteoporosis of the hip and this will be a serious global health problem. A World Health Organization (WHO) estimate suggests that the incidence of hip osteoporotic fractures worldwide will triple by 2050. Objective: To present, through a literature review, the main results of the femoral reinforcement, a technique described by scientific articles, with the potential to increase the proximal femoral load for the occurrence of fractures, whether using polymethylmethacrylate (PMMA), phosphate cement calcium (CPC), elastomers and metal implants. Methods: Through electronic search in databases PubMed, Latin American and Caribbean Center of Health Information Information (Bireme), Coordination for the Improvement of Higher Education Personnel (Capes), Scientific Electronic Library Online (SciELO), Google Scholar And Cochrane, using the terms cementoplasty and femororplasty, the studies were selected according to a specific inclusion criterion, describing the main findings of the biomechanical results, type of study and material used to perform the femoral reinforcement. Results: Of the 15 articles analyzed, 14 were experimental analyzes and one was a clinical trial, seven studies used PMMA, two used CPC, four elastomers and two metal implants, 13 of them showed favorable Newton load (N) results for the fracture hip. Conclusion: Most of the studies on femoral reinforcement is experimental, and mostly used the PMMA, presenting an increase in the load in N for fracture occurrence.

Abstract Objective To evaluate the biomechanical capacity of two forms of fixation for Pipkin type-II fractures, describing the vertical fracture deviation, the maximum and minimum principal stresses, and the Von Mises equivalent stress in the syntheses used. Materials and Methods Two internal fasteners were developed to treat Pipkin type-II fractures through finite elements: a 3.5-mm cortical screw and a Herbert screw. Under the same conditions, the vertical fracture deviation, the maximum and minimum principal stresses, and the Von Mises equivalent stress in the syntheses used were evaluated. Results The vertical displacements evaluated were of 1.5mm and 0.5mm. The maximum principal stress values obtained in the upper region of the femoral neck were of 9.7 KPa and 1.3 Kpa, and the minimum principal stress values obtained in the lower region of the femoral neck were of-8.7 KPa and -9.3 KPa. Finally, the peak values for Von Mises stress were of 7.2 GPa and 2.0 GPa for the fixation models with the use of the 3.5-mm cortical screw and the Herbert screw respectively. Conclusion The fixation system with the Herbert screw generated the best results in terms of reduction of vertical displacement, distribution of the maximum principal stress, and the peak Von Mises equivalent stress, demonstrating mechanical superiority compared to that of the 3.5-mm cortical screw in the treatment of Pipkin type-II fractures.

Abstract Objective The present study aims to identify the energy required for synthetic proximal femoral fracture after removal of three implant types: cannulated screws, dynamic hip screws (DHS), and proximal femoral nail (PFN). Methods Twenty-five synthetic proximal femur bones were used: 10 were kept intact as the control group (CG), 5 were submitted to the placement and removal of 3 cannulated screws in an inverted triangle configuration (CSG), 5 were submitted to the placement and removal of a dynamic compression screw (DHSG), and 5 were submitted to the placement and removal of a proximal femur nail (PFNG). All samples were biomechanically analyzed simulating a fall on the greater trochanter using a servo-hydraulic machine to determine the energy (in Joules [J]) required for fracture. Results All samples presented basicervical fractures. The energy required for fracture was 7.1 J, 6.6 J, 6 J, and 6.7 J for the CG, CSG, DHSG and PFNG, respectively. There was no statistically significant difference (considering a 95% confidence interval) in energy among the study groups (p = 0.34). Conclusion There was no statistically significant difference in the energy required to cause a synthetic proximal femoral fracture after removing all three implant types and simulating a fall over the greater trochanter.

ABSTRACT Objectives To analyze the results of biomechanical assays of the fixation of Pauwels type II femoral neck fractures in synthetic bones, using two parallel cannulated screws or three cannulated screws in an inverted pyramid formation. Methods Ten Brazilian-made synthetic bones were divided into 2 groups. Groups A and B utilized three and two cannulated screws, respectively, after osteotomy in the middle third of the femur, perpendicular to the axis of the femoral neck, simulating a Pauwels type II femoral neck fracture. The resistance of these fixations was analyzed by compression on the axis of the force resulting from hip compression, simulated with a manual hydraulic press. The T-test and post hoc analysis were used to compare the groups, and the significance criterion adopted was p < 0.05. Results In group A, which used fixation with three screws, synthesis failure was seen at a mean force of 526 N. In group B, which used two screws, the mean force was 466 N. The results presented a statistically significant difference (p = 0.02). Conclusion The osteosynthesis of femoral neck fractures in synthetic bone fixated with two screws presented inferior results to fixation with three screws. Level of Evidence III; Case-control study.

ABSTRACTS The apophyseal fracture or avulsion of the greater trochanter occurs in skeletally immature patients. It has at etiological factors indirect mechanisms (avulsion) and direct mechanisms (trauma on the trochanter), the latter being the most common. The clinical presentation is easily identified and a simple X- ray can confirm the diagnosis. Regardless of the treatment chosen, this pathology has a high correlation with osteonecrosis of the femoral head, even as a rare fact, however with innocent appearance, on this pathology.

OBJETIVO: Apresentar os resultados obtidos em ensaios de aplicabilidade de uma placa do tipo sistema dinâmico do quadril modificado, que permite a manipulação ou troca do parafuso deslizante, sem que haja necessidade da retirada de todo o sistema. MÉTODO: Foram utilizadas cinco placas do tipo sistema dinâmico do quadril modificado (DHS- AFpat.req.), fabricadas por uma empresa nacional, produzidas em aço inoxidável austenítico ASTM F 138, com quatro furos e ângulo de 135o, as quais foram aplicadas a cinco segmentos de osso sintético de fêmur proximal da marca Synbone. Todos os implantes foram fixados ao osso sintético, seguindo as técnicas cirúrgicas descritas pela fundação AO (Arbeitsgemeinschaft für Osteosynthesefragen). RESULTADOS: Todas as placas do sistema dinâmico do quadril modificado (DHS-AF) permitiram facilidade na manipulação e a troca do pino deslizante sem a necessidade de retirada da placa. CONCLUSÃO: Os testes in vitro de aplicabilidade do DHS-AF nos forneceram resultados promissores e nos levaram a acreditar que, após avaliações biomecânicas, para confirmar a sua segurança, podem ser reproduzidos in vivo.OBJECTIVE: This report considers the results of the applicability test of a modified dynamic hip system developed by the authors, which allows either the manipulation or the exchange of the sliding screw, without the need to remove the plate and take all the system apart in order to change its size or position. METHODS: Five modified plates - DHS-AF - manufactured with austenitic stainless steel ASTM F 138, with 4 holes and a 135o angle were inserted in five segments of synthetic bone of proximal femur (Synbone). All implants were fixed to the femur following the surgical techniques described by AO foundation (Arbeitsgemeinschaft für Osteosynthesefragen). RESULTS: The modified dynamic hip system (DHS-AF) allowed ease in handling and exchange of sliding screw without the need for plate removal. CONCLUSION: In vitro test of the applicability of DHS-AF afforded promising results and led us to believe that after biomechanical evaluation to confirm its safety it may be reproduced in vivo.

OBJETIVO: Avaliar a relação entre lesões abdominais e a introdução de fios guia em ensaios cirúrgicos do quadril, propor um sistema de escorização e conduta médica em função da distância percorrida pelo fio guia a partir da placa quadrilátera e a estrutura anatômica lesionada. MATERIAL E MÉTODOS: Utilizou-se 18 quadris de cadáveres, um fio de Steimann de 3.2 x 300 mm, um perfurador elétrico e um paquímetro. Introduziu-se o fio no centro do colo femoral por via de acesso lateral no quadril sob visualização direta. Por via de acesso abdominal mediana longitudinal estendida à região pélvica, observou-se a placa quadrilátera até o fio a transfixar. A partir deste ponto, prolongou-se a inserção por mais 140 mm, a fim de observar seu trajeto abdominal e descrever as lesões apresentadas em função da distância percorrida. RESULTADOS: Houve cinco (27%) lesões de cólon sigmóide e uma (5%) lesão transfixante do nervo obturador. Artérias e veias ilíacas comuns contra laterais ao quadril fixado não foram lesionadas. CONCLUSÃO: O fio guia não deve ultrapassar a placa quadrilátera. Medidas de prevenção são importantes no pré e intra-operatório e o escore e a conduta médica propostos neste estudo devem ser criteriosamente observados nos casos de lesão comprovada.OBJECTIVES: Evaluate the relationship between abdominal injuries and the introduction of guide wire in experimental hip surgery, to propose a scoring system and a medical management based on the distance traveled by the guide wire from the quadrilateral plate until the damaged anatomical structure. MATERIAL AND METHODS: 18 cadaveric hips, a Steimann pin of 3.2 x 300mm, an electric drill and a caliper were used. The wire was inserted in the center of the femoral neck through a lateral approach in the hip under direct visualization. Via median abdominal extended approach to the pelvic region, the quadrilateral plate was observed until the wire crossed it. From this point the wire was further inserted 140 mm in order to observe its abdominal path and describe the lesions presented based on the distance traveled. RESULTS: There were five lesions (27%) in the sigmoid colon, and one transfixing injury (5%) of the obturator nerve. The common iliac arteries and veins from the contralateral hip were not injured. CONCLUSION: The guide wire must not exceed the quadrilateral plate. Preventive measures are important in the pre- and intra-operatory stages and the score and medical management proposed in this study should be carefully observed in cases of injury.

OBJETIVO: Avaliar isolada e comparativamente placas do tipo sistema dinâmico do quadril (DHS) de dois fabricantes nacionais, analisar estatisticamente seus resultados e demonstrar a falta de determinantes para sua fabricação. MÉTODOS: Foram realizados ensaios estáticos de flexão em cinco placas DHS do fabricante I (grupo I) e em igual quantidade do mesmo modelo do fabricante II (grupo II), sendo todas fabricadas em aço inoxidável austenítico ASTM F 138, com quatro furos e angulação de 135º. Utilizou-se máquina servohidráulica MTS, modelo Test Star II®, com capacidade de carga de 10 toneladas e controle de deslocamento. Foram obtidos dados da carga aplicada (P) em função do deslocamento vertical do pistão (L), cuja velocidade foi 5 mm/min. Os ensaios foram interrompidos após atingir a deflexão vertical máxima especificada pelas normas dos ensaios. RESULTADOS: Grupo I: resistência de flexão, 161,4 ± 17,2 kgf rigidez, 64,5 ± 1,8 kgf/mm, ductilidade, > 25,4 mm. Grupo II: resistência de flexão, 124,7 ± 4,4, rigidez 59,6 ± 2,3, ductilidade > 25,4 mm. Para análise estatística foi adotado o teste de Mann-Whitney e a determinação de significância foi de 5% (pOBJECTIVE: To evaluate, both individually and comparatively, dynamic hip system-type plates marketed by two local manufacturers, to statistically analyze its results and show the lack of parameters for its manufacturing. METHODS: Static tests of flexion were carried out in five DHS plates of the manufacturer I (I group I) and in equal quantity of the same model of the manufacturer II (I group II), being all made in stainless austenitic ASTM F 138 steel, with four holes and a 135º angle. A servo-hydraulic MTS machine, Test Star II model, was used with a load capacity of 10 tons and dislocation control. The data were obtained from the applied load (P) as a function of the vertical dislocation of the piston (L), whose speed was 5mm/min. The tests were shutdown after reaching the maximum vertical flexion specified by the tests' standards. RESULTS: GroupI: flexion resistance, 161,4 ± 17,2 kgf rigidity, 64,5 ± 1,8 kgf/mm, flexibility, > 25,4 mm. Group II: flexion resistance, 124,7 ± 4,4,rigidity 59,6 ± 2,3, flexibility > 25,4 mm. For statistical analysis, the Mann-Whitney test was adopted and the determination of significance was 5 % (p

Abstract Objective This study aims to evaluate, through biomechanical tests, the resistance and energy required for proximal femoral fracture in synthetic bones after removing cannulated screws shaped as an inverted triangle, comparing the obtained results to those of a reinforcement technique with polymethylmethacrylate (PMMA) as bone cement. Methods Twenty synthetic bones were used: 10 units for the control group (CG), 5 units for the test group without reinforcement (TGW/O), and 5 units for the test group using a reinforcement technique with PMMA (TGW). The biomechanical analysis simulated a fall on the large trochanter using a servo-hydraulic machine. Results All TGW/O and CG specimens had a basicervical fracture. Three TGW specimens presented a basicervical fracture, and two suffered a fracture near the fixation point of the device (femoral diaphyseal region), with one of thembeing associated with a femoral neck fracture. A mean PMMA volume of 8.2 mL was used to fill the 3 screw holes in the TGWgroup. According to the one-way analysis of variance (ANOVA) and the Tukey multiple comparisons tests at a 5% level, the TGW presented a statistically significant difference when compared with the other groups in all parameters: maximal load (p = 0.001) and energy until fracture (p = 0.0001). Conclusion The simple removal of the cannulated screws did not reduce significantly the maximum load and energy for fracture occurrence, but the proximal femoral reinforcement with PMMA significantly increased these parameters, modifying the fracture pattern.