Analysis of the Mechanical Behavior of Porcine Graft Fixation in a Polyurethane Block Using a 3D-printed PLA Interference Screw / Análise do comportamento mecânico da fixação do enxerto suíno em um bloco de poliuretano usando um parafuso de interferência PLA impresso em 3D

Abstract Objective The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

Resumo Objetivo O interesse em utilizar a impressão 3D na área da saúde tem crescido ao longo dos anos, dadas as suas vantagens e o seu potencial na rápida fabricação de dispositivos e implantes personalizados com geometrias complexas. Assim, o objetivo do presente estudo foi comparar o comportamento de fixação mecânica de um parafuso de interferência impresso em 3D, produzido pela modelagem fundida de deposição do filamento de ácido polilático (PLA), com o de um parafuso de interferência de titânio. Métodos Oito tendões suínos flexores profundos, de aproximadamente 8 mm de largura e 9 cm de comprimento, foram utilizados como enxerto e fixados em um bloco de poliuretano de 40 PCF em cada uma de suas extremidades. Um grupo foi fixado apenas com parafusos de interferência de titânio (grupo 1) e o outro apenas com parafusos PLA impressos em 3D (BR 20 2021 018283-6 U2) (grupo 2). Os testes foram realizados utilizando uma máquina de teste universal eletromecânica EMIC DL 10.000 no modo de tração axial. Resultados O grupo 1 (titânio) obteve força máxima de 200 ± 7 N com deformação média do enxerto de 8 ± 2 mm, e a força máxima do grupo 2 (PLA) foi de 300 ± 30 N e deformação média do enxerto de 7 ± 3 mm. Ambos os parafusos de titânio e PLA forneceram boa fixação de enxerto no bloco de poliuretano, sem deslizamento ou deformação aparente. Em todas as amostras o teste culminou na ruptura do enxerto, com cerca de 20 mm de deformação em relação ao comprimento inicial. Conclusão O parafuso PLA impresso em 3D proporcionou boa fixação, semelhante à de sua contraparte de titânio, produzindo resultados satisfatórios e promissores.

Outcomes of the Carlson Approach in the Treatment of Posterior Tibial Plateau Fractures.

Objectives To describe a series of cases of tibial fractures surgically treated using the posterior approach as described by Carlson, focusing on evaluating its functional results and complication rate. Methods Eleven patients with tibial plateau fractures, who underwent surgical treatment using the Carlson approach from July to December 2019, were followed-up. The minimum follow-up period was defined as 6 months. The American Knee Society Score (AKSS), American Knee Society Score/Function (AKSS/Function) and the Lysholm score were used to check treatment results at 6 months after the fracture. The patients underwent standard anteroposterior and lateral radiographs to assess fracture healing, and clinical healing was determined by the absence of pain during full weight-bearing. Results The mean follow-up period was 12 months (9-16 months). The primary mechanism of trauma was motorcycle accident, and the most prevalent side of fracture was the right side. Eight participants were male. The mean age of the patients was 28 years. All fractures healed, and none of the patients presented complications. The AKSS was excellent in 11 patients, with a mean AKSS/Function of 99.1 ± 3, and Lysholm scores with a median of 95.0 ± 5.6. Conclusions The Carlson approach for posterior fractures of the tibial plateau can be considered safe, presenting a low complication rate and satisfactory functional results.

Anatomy of the Medial Meniscotibial Ligament of the Knee: A Systematic Review.

Objectives To perform a systematic review of the literature on the anatomy of the medial meniscotibial ligaments (MTLs), and to present the most accepted findings, as well as the evolution of the anatomical knowledge on this structure. Materials and Methods An electronic search was conducted in the MEDLINE/PubMed, Google Scholar, EMBASE and Cochrane library databases with no date restrictions. The following index terms were used in the search: anatomy AND meniscotibial AND ligament AND medial . The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We included anatomical studies of the knee were included, such as cadaver dissections, histological and/or biological investigations, and/or imaging of the medial MTL anatomy. Results Eight articles that met the inclusion criteria were selected. The first article was published in 1984 and the last, in 2020. The total sample in the 8 articles was of 96 patients. Most studies are purely descriptive in terms of the macroscopic morphological and microscopic histological findings. Two studies evaluated the biomechanical aspects of the MTL, and one, the anatomical correlation with the magnetic resonance imaging examination. Conclusion The main function of the medial MTL, a ligament that originates in the tibia and is inserted in the lower meniscus, is to stabilize and maintain the meniscus in its position on the tibial plateau. However, there is a limited amount of information regarding medial MTLs, primarily in terms of anatomy, especially vascularization and innervation.

Outcomes of the Carlson Approach in the Treatment of Posterior Tibial Plateau Fractures / Resultados da abordagem de Carlson para o tratamento de fraturas no platô tibial posterior

Abstract Objectives To describe a series of cases of tibial fractures surgically treated using the posterior approach as described by Carlson, focusing on evaluating its functional results and complication rate. Methods Eleven patients with tibial plateau fractures, who underwent surgical treatment using the Carlson approach from July to December 2019, were followed-up. The minimum follow-up period was defined as 6 months. The American Knee Society Score (AKSS), American Knee Society Score/Function (AKSS/Function) and the Lysholm score were used to check treatment results at 6 months after the fracture. The patients underwent standard anteroposterior and lateral radiographs to assess fracture healing, and clinical healing was determined by the absence of pain during full weight-bearing. Results The mean follow-up period was 12 months (9-16 months). The primary mechanism of trauma was motorcycle accident, and the most prevalent side of fracture was the right side. Eight participants were male. The mean age of the patients was 28 years. All fractures healed, and none of the patients presented complications. The AKSS was excellent in 11 patients, with a mean AKSS/Function of 99.1±3, and Lysholm scores with a median of 95.0±5.6. Conclusions The Carlson approach for posterior fractures of the tibial plateau can be considered safe, presenting a low complication rate and satisfactory functional results.

Resumo Objetivos O objetivo deste trabalho é descrever uma série de casos de fraturas de tíbia submetidas ao tratamento cirúrgico pela via posterior de Carlson para avaliação de resultados funcionais e frequência de complicações. Métodos Onze pacientes com fraturas do platô tibial foram submetidos a tratamento cirúrgico pela via de Carlson de julho a dezembro de 2019 e acompanhados por um período mínimo de 6 meses. As pontuações American Knee Society Score (AKSS), American Knee Society Score/Function (AKSS/Função) e de Lysholm verificaram os resultados do tratamento 6 meses após a fratura. Os pacientes foram submetidos a radiografias comuns em incidência anteroposterior e de perfil para avaliação da consolidação da fratura e a cicatrização clínica foi determinada pela ausência de dor à descarga total de peso. Resultados O período médio de acompanhamento foi de 12 meses (9 a 16 meses). O principal mecanismo de trauma foi acidente motociclístico e a fratura foi mais prevalente no lado direito. Oito pacientes eram do sexo masculino. A média de idade dos pacientes foi de 28 anos. Todas as fraturas cicatrizaram e nenhum paciente apresentou complicações. A AKSS foi excelente em 11 pacientes, com AKSS/Função média de 99,1 ±3, e a mediana das pontuações de Lysholm foi de 95,0 ±5,6. Conclusões Nas fraturas posteriores do platô tibial, a abordagem de Carlson pode ser considerada segura, apresentando baixo índice de complicações e resultados funcionais satisfatórios.

Anatomy of the Medial Meniscotibial Ligament of the Knee: A Systematic Review / Anatomia do ligamento meniscotibial medial do joelho: Uma revisão sistemática

Abstract Objectives To perform a systematic review of the literature on the anatomy of the medial meniscotibial ligaments (MTLs), and to present the most accepted findings, as well as the evolution of the anatomical knowledge on this structure. Materials and Methods An electronic search was conducted in the MEDLINE/PubMed, Google Scholar, EMBASE and Cochrane library databases with no date restrictions. The following index terms were used in the search: anatomy AND meniscotibial AND ligament AND medial. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We included anatomical studies of the knee were included, such as cadaver dissections, histological and/or biological investigations, and/or imaging of the medial MTL anatomy. Results Eight articles that met the inclusion criteria were selected. The first article was published in 1984 and the last, in 2020. The total sample in the 8 articles was of 96 patients. Most studies are purely descriptive in terms of the macroscopic morphological and microscopic histological findings. Two studies evaluated the biomechanical aspects of the MTL, and one, the anatomical correlation with the magnetic resonance imaging examination. Conclusion The main function of the medial MTL, a ligament that originates in the tibia and is inserted in the lower meniscus, is to stabilize and maintain the meniscus in its position on the tibial plateau. However, there is a limited amount of information regarding medial MTLs, primarily in terms of anatomy, especially vascularization and innervation.

Resumo Objetivos Fazer uma revisão sistemática da literatura sobre a anatomia dos ligamentos meniscotibiais (LMTs) mediais, e apresentar os achados mais aceitos e a evolução das informações anatômicas sobre essa estrutura. Materiais e Métodos A busca eletrônica foi realizada nos bancos de dados MEDLINE/PubMed, Google Scholar, EMBASE e Cochrane, sem restrições de data. Os seguintes termos de indexação foram utilizados: anatomy AND meniscotibial AND ligament AND medial. A revisão seguiu as recomendações da declaração de Principais Itens para Relatar Revisões Sistemáticas e Metanálises (Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA, em inglês). Foram incluídos estudos anatômicos do joelho, como dissecções de cadáveres, investigações histológicas e/ou biológicas, e/ou imagens da anatomia do LMT medial. Resultados Oito artigos atenderam aos critérios de inclusão e foram selecionados. O primeiro foi publicado em 1984, e o último, em 2020. A amostra total nos 8 artigos foi de 96 pacientes. A maioria dos estudos é puramente descritiva em relação aos achados morfológicos macroscópicos e histológicos microscópicos. Dois estudos avaliaram os aspectos biomecânicos do LMT, e um analisou a correlação anatômica com o exame de ressonância magnética. Conclusão A principal função do LMT medial, ligamento que se origina na tíbia e se insere no menisco inferior, é estabilizar e manter a posição do menisco no platô tibial.

Study of the nerve endings and mechanoreceptors of the medial meniscotibial ligament of the knee: A structural and distribution analysis.

BACKGROUND: The aim of the present study is to describe the morphology and distribution of the nerve endings of the meniscotibial ligament (MTL) of the knee, in order to understand the interaction between the proprioceptive system and knee mechanics. METHODS: Twenty medial MTLs were obtained from deceased organ donors. The ligaments were measured, weighed and cut. Sections (10 mm) were prepared on hematoxylin and eosin-stained slides for analysis of tissue integrity, and 50 mm sections were submitted to immunofluorescence with the protein gene product (PGP) 9.5 as primary antibody and Alexa Fluor 488 as secondary antibody, followed by microscopic analysis. RESULTS: The medial MTL was identified in 100% of the dissections, with average length, width, thickness and weight of 7.07 ± 1.34 mm, 32.25 ± 3.09 mm, 3.53 ± 0.27 mm and 0.67 ± 0.13 g, respectively. The hematoxylin and eosin-stained histological sections exhibited typical ligament structure, with dense well-organized collagen fibers and vascular tissue. All the specimens analyzed contained type I (Ruffini) mechanoreceptors and free (type IV) nerve endings, varying from parallel to intertwined fibers. Nerve endings not classified with different irregular shapes were also found. Most type I mechanoreceptors were found close to the MTL insertions on the tibial plateau, while the free nerve endings were found adjacent to the capsule. CONCLUSION: The medial MTL showed a peripheral nerve structure, primarily type I and IV mechanoreceptors. These findings suggest that the medial MTL is important for proprioception and medial knee stabilization.

How to perform a meta-analysis: a practical step-by-step guide using r software and rstudio / Como realizar uma metanálise: um guia prático passo a passo utilizando o software r e o rstudio

ABSTRACT Meta-analysis is an adequate statistical technique to combine results from different studies, and its use has been growing in the medical field. Thus, not only knowing how to interpret meta-analysis, but also knowing how to perform one, is fundamental today. Therefore, the objective of this article is to present the basic concepts and serve as a guide for conducting a meta-analysis using R and RStudio software. For this, the reader has access to the basic commands in the R and RStudio software, necessary for conducting a meta-analysis. The advantage of R is that it is a free software. For a better understanding of the commands, two examples were presented in a practical way, in addition to revising some basic concepts of this statistical technique. It is assumed that the data necessary for the meta-analysis has already been collected, that is, the description of methodologies for systematic review is not a discussed subject. Finally, it is worth remembering that there are many other techniques used in meta-analyses that were not addressed in this work. However, with the two examples used, the article already enables the reader to proceed with good and robust meta-analyses. Level of Evidence V, Expert Opinion.

RESUMO Metanálise é uma técnica estatística adequada para combinar resultados provenientes de diferentes estudos, seu uso vem crescendo e ganhando cada vez mais importância no meio médico. Assim, não apenas saber interpretar metanálise, como também saber realizar uma, mesmo que simples, é fundamental na atualidade. Portanto, o objetivo principal deste artigo é apresentar os conceitos básicos que a norteiam e servir de guia para a condução de uma metanálise utilizando os softwares R e RStudio. Para isso, através do presente artigo o leitor tem acesso aos comandos básicos existentes nos softwares R e RStudio, necessários para a condução de uma metanálise. A grande vantagem do R é o fato de ser um software livre. Para um melhor entendimento dos comandos, dois exemplos foram apresentados de forma prática, além de revisados alguns conceitos básicos dessa técnica estatística. É suposto que os dados necessários para a metanálise já foram coletados, ou seja, descrição de metodologias para revisão sistemática não é assunto discutido. Por fim, vale relembrar que existem muitas outras técnicas utilizadas em metanálises que não foram abordadas neste trabalho. Todavia, com os dois exemplos utilizados, o artigo já habilita o leitor a proceder boas e robustas metanálises. Nível de Evidência V, Opinião do Especialista.

Tratamento de fraturas ipsilaterais da diáfise e do colo do fêmur com implante único / Treatment of ipsilateral fractures of the shaft and femoral neck with single implant

Objetivo: apresentar um caso de coxa vara após tratamento de fraturas ipsilaterais da diáfise e do colo do fêmur com implante único e revisar sistematicamente a literatura sobre o assunto. Metodologia: foi realizada pesquisa em maio de 2019 nas bases de dados do PubMed, Clinicalkey e Google Scholar, com limite de data nos últimos cinco anos. Os seguintes termos de indexação foram usados para a busca: "intertrochanteric and ipsilateral shaft fractures" e " femoral neck and ipsilateral shaft fractures". Apenas estudos clínicos que apresentassem sugestões de manejo no tratamento de fratura do fêmur proximal e diafisário ipsilateral foram selecionados. Foram excluídos os estudos nos quais não apresentavam indicação da técnica de tratamento, assim como artigos de revisão e capítulos de livros ou periódicos não indexados. Resultados: finalizou-se a busca com número total de 21 artigos encontrados. Nenhum dos métodos de fixação disponíveis (implante único ou múltiplo) mostrou clara superioridade para abordar a associação de fraturas do fêmur proximal e diáfise do fêmur ipsilateral. No relato de caso, mesmo com a consolidação em varo do colo femoral, o quadro do paciente evoluiu bem. A fratura do colo era basocervical e, possivelmente, teve um comportamento mais próximo à fratura transtrocantérica, o que explica a evolução favorável, mesmo com desvio. Conclusão: nenhum método mostrou evidente superioridade ao outro. Deve-se atentar para a redução estável e a fixação rígida da fratura proximal, sobretudo do colo, embora a fixação da fratura diafisária não deva dificultar as ações sobre a fratura proximal.

Objective: to present a case of coxa vara after treatment of ipsilateral fractures of the shaft and femoral neck with a single implant and systematically review the literature on the subject. Methods: research was conducted in May 2019 in the databases of PubMed, Clinicalkey and Google Scholar, with date limit in the last five years. The following indexing terms were used for the search: "intertrochanteric and ipsilateral shaft fractures" and "femoral neck and ipsilateral shaft fractures". Only clinical studies that presented management suggestions for the treatment of proximal and ipsilateral femoral shaft fractures were selected. Studies in which they did not have an indication of treatment technique were excluded, as well as review articles and chapters of non-indexed books or journals. Results: the search was completed with a total number of 21 articles found. None of the available fixation methods (single or multiple implants) showed clear superiority to address the association of fractures of the proximal femur and diaphysis of the ipsilateral femur. In the case report, even with varus consolidation of the femoral neck, the patient evolved well. The neck fracture was basocervical and possibly had a behavior closer to the transtrochanteric fracture, which explains the favorable evolution, even with deviation. Conclusion: no method showed an evident superiority to the other. Attention should be paid to ensure stable reduction and rigid fixation of the proximal fracture, especially the neck, and fixation of the shaft fracture should not hamper the actions on the proximal fracture.