3D printed metal augment or tibial prosthesis for reconstruction of large bone defects in total knee arthroplasty and revision surgery / 中华骨科杂志

Objective:To investigate the clinical efficacy of 3D printed metal augment or tibial prosthesis for reconstruction of large bone defects in total knee arthroplasty (TKA) and knee revision surgery.Methods:A total of 7 patients (7 knees) with TKA or knee revision who were admitted to the Department of Orthopaedics of the Second Affiliated Hospital of Zhejiang University School of Medicine with large bone defects from July 2018 to December 2023 were retrospectively analyzed, including 4 patients with TKA and 3 patients with knee revision. There were 3 males and 4 females, aged 58.7±7.6 years (range, 54-68 years), 3 patients with left knee and 4 patients with right knee. All the patients had bone defects in the knee joint (AORI type III), 2 cases had bone defects only in the femur, 4 cases had bone defects only in the tibia, and 1 case had bone defects in both the tibia and femur, which were treated with personalized reconstruction using 3D printing. Hip-knee-ankle angles, American Knee Society score (KSS) before and after surgery were compared, and postoperative complications were observed.Results:All patients successfully completed the operation, and the operation time was 189.3±35.5 min (range, 125-240 min). Complex TKA was performed in 4 cases with surgical times of 175, 195, 210, and 240 min, and revision surgery was performed in 3 cases with surgical times of 125, 180, and 200 min, respectively. Intraoperative blood loss was 114±24.4 ml (range, 100-150 ml). Five cases used 3D printed metal augment, and two used 3D printed one-piece tibial components. All patients were followed up for 2, 2, 5, 6, 7, 20, 57 months, respectively. The KSS of the five patients at 3 months postoperatively were 56, 61, 66, 56, and 56 points, respectively, greater than the preoperative scores of 35, 44, 36, 27, and 41 points. The KSS functional scores of the five patients at 3 months postoperatively were 45, 45, 45, 30, and 45 points, respectively, which were greater than the preoperative scores of 30, 30, 15, 20, and 20 points. The hip-knee-ankle angle was 181.8°±3.4° (range, 177.9° to 188.0°) at the final follow-up and 175.8°±12.4° (range, 153.3° to 192.1°) before surgery, with no significant difference ( t=-1.230, P=0.242). At the final follow-up, the 3D printed component was well integrated with the bone surface, the prosthesis was securely positioned, and the force lines of the lower limbs were normal. There were no postoperative complications such as poor wound healing, infection, fat liquefaction, nerve injury, deep vein thrombosis of lower limbs, knee joint stiffness, periprosthesis infection and loosening. Conclusion:Using 3D printed metal augment or tibial prosthesis to reconstruct the huge bone defect in TKA and revision has a satisfactory early clinical effect, satisfactory joint function and good surgical safety.

Short-term evaluation between polyethylene thickness in primary total knee arthroplasty / Avaliação a curto prazo entre a espessura do polietileno na artroplastia total primária do joelho

ABSTRACT Objective: The objective of the research was to carry out a comparative study between Smith & Nephew ® or Zimmer ® prostheses with thick versus thin polyethylene, in patients undergoing primary total knee arthroplasty, during a short-term follow-up. Thus, the objective was to analyze the survival of the implants in question under the clinical and radiographic aspect. Methods: The sample was divided into two groups: Group 1 with thick polyethylene and group 2 with thin polyethylene. A clinical analysis of the patients was carried out and the implants were checked for loosening. Results: The groups were similar when compared. According to the Ahlbäck classification, 83% of the patients were in groups IV and V. The median functional score in the postoperative period was similar between the two groups. Postoperatively, the tibiofemoral angle fluctuated between 5 and 6 0 valgus on average. Two complications were observed in each group. None of the evaluated patients presented implant loosening Conclusion: Patients treated with thick polyethylene had the same functional score as the control group, as well as the absence of radiographic changes in this short-term follow-up, with implant survival and a similar rate of complications between both groups. Level of evidence III, Retrospective study.

RESUMO Objetivo: O objetivo desta pesquisa foi realizar um estudo comparativo entre as próteses Smith & Nephew ® e Zimmer ®, com polietileno espesso versus o fino, em pacientes submetidos à artroplastia total primária do joelho, durante um seguimento de curto prazo. Dessa forma, foi analisada a sobrevida dos implantes em questão sob o aspecto clínico e radiográfico. Métodos: A amostra foi dividida em dois grupos: grupo 1 com polietileno espesso e grupo 2 com polietileno fino. Foi realizada análise clínica dos pacientes e verificado se ocorreu soltura dos implantes. Resultados: Os grupos tiveram resultados semelhantes quando comparados. Segundo a classificação de Ahlbäck, 83% dos pacientes eram dos grupos IV e V. A mediana do escore funcional no pós-operatório foi similar entre os grupos. No pós-operatório o ângulo tíbio-femoral oscilou na média entre 5 e 6 0 de valgo. Foram observadas duas complicações em cada grupo. Nenhum dos pacientes avaliados apresentou soltura do implante. Conclusão: Os pacientes tratados com o polietileno espesso apresentaram o mesmo escore funcional do grupo controle, assim como ausência de alterações radiográficas nesse seguimento de curto prazo, com sobrevida do implante e índice de complicações similar entre ambos os grupos. Nível de evidência III, Estudo retrospectivo.

Metallic artifact suppression with MAVRIC-SL in magnetic resonance imaging for assessing chronic pain after hip or knee arthroplasty / Supressão do artefato metálico na ressonância magnética com MAVRIC-SL na avaliação da dor crônica em artroplastia de quadril ou joelho

Abstract Objective: To analyze the association between osteolysis at the prosthesis interfaces, as determined by magnetic resonance imaging (MRI) with multiacquisition variable-resonance image combination selective (MAVRIC-SL) sequences, and clinical severity after knee or hip arthroplasty, as well as to assess interobserver and intraobserver agreement on periprosthetic bone resorption. Materials and Methods: This was a cross-sectional study of 47 patients (49 joints) under postoperative follow-up after knee or hip arthroplasty, with chronic pain, between March 2019 and August 2020. All of the patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The component interfaces were evaluated and ordered into two groups: osseointegrated and osteolytic. Nonparametric tests were used. Results: There were significant differences between the two groups in terms of the mean WOMAC scores: total (p = 0.010); stiffness domain (p = 0.047); and function (p = 0.011) domains. There was substantial interobserver and intraobserver agreement for most analyses of the components. Conclusion: Periprosthetic osteolysis appears to be associated with clinical complaints of pain in the post-arthroplasty scenario, and MAVRIC-SL provides reproducible assessments. It could prove to be an important tool for orthopedists to use in the evaluation of challenging cases of chronic pain after arthroplasty.

Resumo Objetivo: Analisar associação entre osteólise nas interfaces protéticas por ressonância magnética com sequências MAVRIC-SL e a gravidade clínica dos pacientes submetidos a artroplastias de joelho ou quadril. Determinar concordância intraobservador e interobservador na reabsorção óssea peri-implante. Materiais e Métodos: Foi realizado estudo transversal entre março de 2019 e agosto de 2020, com 47 pacientes (49 articulações) em seguimento pós-operatório de artroplastias de joelho ou quadril, com dor crônica, que responderam ao questionário WOMAC. As interfaces dos componentes foram avaliadas e definiram dois grupos: osteointegrado e osteólise. Testes não paramétricos foram usados. Resultados: Houve diferença significativa na média do escore WOMAC entre os grupos (p = 0,010), assim como nos domínios rigidez (p = 0,047) e função (p = 0,011). Houve concordância substancial interobservador e intraobservador para a maioria dos componentes analisados. Conclusão: Osteólise periprótese parece estar associada com a queixa clínica de dor pós-artroplastia, com avaliação reprodutível pela MAVRIC-SL. Isto pode ser uma importante ferramenta para o ortopedista na avaliação de casos desafiadores de dor crônica pós-artroplastia.

Evaluation of utilizing cement-in-cement technique for endoprosthetic revision surgeries around the knee / 中华骨科杂志

Objective:To investigate the clinical efficacy of cement-in-cement (CiC) technique for endoprosthetic revision surgeries of noninfectious causes around the knee.Methods:All of 128 patients who had received cement-in-cement technique for endoprosthetic revision from February 2002 to August 2020 including 71 males and 57 females, whose mean age was 33.5±15.4 years (range, 8-77 years). 128 patients included 73 cases of osteosarcoma, 38 cases of giant cell tumors, 8 cases of undifferentiated sarcoma, 4 cases of chondrosarcoma, 2 cases of Ewing sarcoma, 2 cases of fibrosarcoma and 1 case of synovial sarcoma, with 105 cases in distal femur and 23 cases in proximal tibia. The failure mode classification included 64 cases of aseptic loosening, 47 cases of structure failure and 17 cases of tumor progression. 16 out of the 19 endoprosthese failure after the first cement-in-cement procedure received a second cement-in-cement procedure. The survival of revised prostheses, duration of the operation, the amount of blood loss, epidemiological data, complications and limb function were enrolled and statistical analyzed.Results:The mean follow-up from CiC revision was 127±33 months (range, 6-326 months). There were 25 (19.5%) complications for the first CiC procedure and 19 (14.8%) of the 25 complications lead to the protheses failure including 5 (3.9%) structure failure, 6 (4.7%) aseptic loosening, 2 (1.6%) tumor recurrence and 6 (4.7%) infection. The other 6 cases included 5 poor superficial wound healing and 1 patellar ligament rupture. All were recovered after debridement and tendon repair. The cumulative survival rates of first CiC procedure were 85.0%, 76.6% and 70.7% at 5, 10 and 15 years, respectively. Limb salvage rate was 97.7%. Sixteen of the 19 cases received a second CiC revision. The mean operative time (206±51 min vs. 258±41 min, t=3.18, P=0.399), blood loss (596±217.99 ml vs. 621±245.84 ml, t=0.30, P=0.926) and the median MSTS 93 score (26.38±2.47 vs. 25.06±2.11, t=1.61, P=0.376) of the first and second CiC procedure for the 16 cases were similar. Conclusion:CiC technique is a repeatable, conservative and viable option for endoprosthetic revision surgeries of noninfectious causes around the knee, with acceptable prosthetic survival rate, complication rate and limb function.

Outra falha de bioprótese valvar cirúrgica: uma segunda solução transcateter valve-in-valve / Another failed surgical bioprosthetic valve: a second transcatheter valve-in-valve solution

A substituição transcateter valve-in-valve da valva mitral surgiu recentemente como uma alternativa cada vez mais utilizada nos pacientes de alto risco cirúrgico. O presente caso relata uma substituição de valva mitral transcateter valve-in-valve, por via transeptal, como tratamento da degeneração de uma bioprótese mitral cirúrgica e regurgitação grave, em paciente de 86 anos já submetido a uma substituição transcateter valve-in-valve aórtica, há 6 anos. Este caso enfatiza o papel crucial de uma avaliação pré-operatória cuidadosa, com uso de diferentes modalidades de exames de imagem, para planejamento do procedimento, em paciente com maior risco de obstrução da via de saída do ventrículo esquerdo, devido a um procedimento valve-in-valve aórtico prévio.

Transcatheter mitral valve-in-valve replacement has recently emerged as an increasingly common alternative for high surgical risk patients. We report a case of a successful transseptal transcatheter mitral valve-in-valve replacement for the treatment of a bioprosthetic mitral valve degeneration and severe regurgitation, in an 86-year-old patient who had undergone transcatheter aortic valve-in-valve procedure 6 years ago. This case emphasizes the crucial role of a careful preoperative assessment using multimodality imaging to plan the procedure, in a patient with higher risk of left ventricular outflow obstruction due to the previous transcatheter aortic valve-in- valve procedure.

Evaluation of Removal Force in Prosthetic Components of Morse Taper Dental Implants

Abstract The longevity of prosthetic rehabilitation is determined by the stability of the implant and abutment interfaces. True morse taper connections on dental restorations have been effective, however activation force still empirical. This work compared the activation strength and internal contact of Morse taper system according to the removal force. Eighty sets, composed of implants and prosthetic abutments, were evaluated with different internal contact areas; 15.12mm2 (G3.3) and 21.25mm2 (G4.3). The specimens were activated at 0° and 30°, with loads of 10, 20, 40 and 60N. The specimens were submitted to tensile test and the data to ANOVA and Tukey's tests (α=0.05). Representative specimens were examined under SEM. Removal force of G3.3 (2.15±1.33MPa) did not differed to G4.3 (1.99±1.03MPa). The activation at 0º (2.95±0.98MPa) statistically differed to 30º (1.19±0.54MPa). The 60N load was statistically superior for G3.3 and there was no statistical difference between 20N to 60N in G4.3. The values of 10N at 30o and 20N at the long axis of the morse taper implant, independent of the frictional contact area showed the best settlement.

Resumo A longevidade da reabilitação protética é determinada pela estabilidade das interfaces implante e pilar. Conexões de cone Morse em restaurações dentárias têm se mostrado eficazes, porém a força de ativação ainda é empírica. Este trabalho comparou a força de ativação e contato interno do sistema cone Morse de acordo com a força de remoção. Oitenta conjuntos, compostos por implantes e pilares protéticos, foram avaliados com diferentes áreas de contato interno; 15,12mm2 (G3.3) e 21,25mm2 (G4.3). Os corpos-de-prova foram ativados a 0° e 30°, com cargas de 10, 20, 40 e 60N. Os corpos de prova foram submetidos ao ensaio de tração e os dados aos testes ANOVA e Tukey (α=0,05). Espécimes representativos foram examinados em MEV. A força de deslocamento do G3.3 (2,15±1,33MPa) não diferiu do G4.3 (1,99±1,03MPa). A ativação a 0º (2,95±0,98MPa) diferiu estatisticamente para 30º (1,19±0,54MPa). A carga de 60N foi estatisticamente superior para G3.3 e não houve diferença estatística entre 20N a 60N no G4.3. Os valores de 10N em 30o e 20N no longo eixo do implante cone morse, independente da área de contato friccional apresentaram o melhor assentamento.

Bone Integration and Prevalence of Radiolucent Lines around the Pegs of Minimally Cemented Glenoid Components in Total Shoulder Arthroplasty / Integração óssea e prevalência de linhas radiotransparentes ao redor dos pinos de componentes glenoidais minimamente cimentados na artroplastia total de ombro

Abstract Objectives Glenoid component failure is the main cause of total shoulder arthroplasty (TSA) revision, and component design seems to influence the failure rate. The aim of the present study was to clinically and radiographically (through X-rays and computed tomography scan) evaluate the results of TSA using a minimally cemented glenoid component. Methods Total should arthroplasties performed using the minimally cemented Anchor Peg (DuPuy Synthes, Warsaw, IN, USA) glenoid component between 2008 and 2013 were evaluated. University of California at Los Angeles (UCLA) scores were calculated, and standardized plain film and computed tomography images were obtained, at a minimum follow-up of 24 months. The presence of bone between the fins of the central component peg, which indicates its integration, was assessed on the images, as well the presence of radiolucent lines around the glenoid component. Results Nineteen shoulders in 17 patients were available for evaluation. According to the UCLA score, clinical results were satisfactory in 74% of cases and fair in 21% of cases. One patient had a poor result. Component integration was found in 58% of patients (total in 42% and partial in 16%). Radiolucent lines were observed in 52% of cases. No relationship was detected between component integration and clinical results. Conclusion Satisfactory clinical results were achieved in most patients undergoing TSA using a minimally cemented glenoid component. Radiolucent lines around the glenoid component are common, but do not interfere with the clinical results. Level of evidence IV; Case series; Treatment study.

Resumo Objetivos A falha do componente glenoidal é a principal causa de revisão da artroplastia total do ombro (ATO) e sua frequência parece ser influenciada pelo design do componente. O objetivo deste estudo foi a avaliação clínica e radiográfica (através de raios X e tomografia computadorizada) dos resultados da ATO com componente glenoidal minimamente cimentado. Métodos O presente trabalho analisou ATOs realizadas com componente glenoidal Anchor Peg (DuPuy Synthes, Warsaw, IN, EUA) minimamente cimentado entre 2008 e 2013. Por um período mínimo de acompanhamento de 24 meses, escores segundo critérios da University of California at Los Angeles (UCLA) e imagens padronizadas de radiografia simples e tomografia computadorizada foram analisadas. A presença de osso entre as aletas do pino do componente central, que é um indicador de sua integração, foi avaliada nas imagens, bem como a presença de linhas radiotransparentes ao redor do componente glenoidal. Resultados Dezenove ombros de 17 pacientes foram avaliados. De acordo com o escore da UCLA, os resultados clínicos foram satisfatórios em 74% dos casos e moderados em 21% dos casos. O resultado foi ruim em um paciente. A integração de componentes foi observada em 58% dos pacientes, sendo total em 42% e parcial em 16% dos casos. Linhas radiotransparentes foram observadas em 52% dos pacientes. Nenhuma relação entre a integração de componentes e os resultados clínicos foi detectada. Conclusão A maioria dos pacientes submetidos à ATO com componente glenoidal minimamente cimentado apresentou resultados clínicos satisfatórios. Linhas radiotransparentes ao redor do componente glenoidal são comuns, mas não interferem nos resultados clínicos Nível de evidência IV; Série de caso; Estudo terapêutico.

Troca valvar transcateter valve-in-valve mitral por via transeptal em paciente com prótese mitral biológica degenerada / Transeptal valve-in-valve transcatheter mitral valve replacement in patient with deteriorated mitral bioprosthesis

A troca valvar mitral transcateter apresenta-se como uma nova opção terapêutica para o tratamento de próteses cirúrgicas degeneradas em pacientes com alto risco cirúrgico. É crescente o número de procedimentos valve-in-valve mitral ao longo dos últimos anos. O presente caso relata uma experiência inicial com esse tipo de procedimento, sendo efetivado de forma segura e eficaz em uma paciente idosa de alto risco cirúrgico para retroca valvar.

Transcatheter mitral valve replacement is a new option to treat deteriorated surgical prosthesis in high surgical risk patients. The number of valve-in-valve mitral procedures has been growing in the last few years. This case reports an initial experience with this type of procedure, safely and effectively performed in an elderly female patient with high-risk for valve replacement.

Surgical complications related to artificial lumbar disc prosthesis / 中华创伤骨科杂志

As a result of medical advancement and increasing requirements for the physiological reconstruction of the spine, various kinds of artificial lumbar prostheses have flourished.The first-generation Charité prosthesis, the second-generation ProDisc-L prosthesis and the third-generation Activ-L Systems prosthesis have all been applied widely in clinic.In addition, Acroflex, Maverick, XL TDR, M6-L and other products have also been approved for clinical application.This article reviews the literature on application of artificial lumbar intervertebral disc prostheses to conduct a comprehensive analysis of the surgical complications related to the different design features of the prostheses like unconstrained, semiconstrained, constrained, one elastomeric piece, constrained plus elastic core and integral lateral implantation, hoping to provide references for subsequent improvement in design and application of the prosthesis.

Avaliação do tipo de retenção e o uso de diferentes intermediários na adaptação de próteses unitárias sobre implantes / Evaluation of the type of retention and the use of different abutments in the adaptation of single prostheses on implants

Atualmente, devido a perda do elemento dentário e a procura por um tratamento estético e principalmente funcional, a reabilitação com próteses sobre implante tem sido amplamente empregada, com elevada previsibilidade a longo prazo. Com isso, muito tem sido relatado na literatura acerca das possíveis complicações dessa modalidade de tratamento, principalmente relacionado às possibilidades de falhas mecânicas das próteses implantossuportadas. Por isso, o objetivo do presente projeto foi avaliar a influência na adaptação marginal e interna, da utilização do intermediário protético e do tipo de retenção das próteses (parafusada e cimentada) em implantes cone morse submetidos à ciclagem mecânica. Foram confeccionados 40 corpos de prova, no qual cada um tinha a presença de um implante, com as dimensões de 4mm de diâmetro e 11,5mm de comprimento cone morse (n = 40). Dessa forma, foi avaliado a influência da utilização do intermediário e dos sistemas de retenção em cada conexão de maneira específica. Metade dos corpos de prova de cada sistema de conexão foram confeccionados em UCLA (n=20, sendo 10 parafusadas e 10 cimentadas), enquanto que a outra metade foi utilizado um intermediário pré-fabricado (Pilar Universal (n=20, sendo 10 parafusadas e 10 cimentadas). Os corpos de prova foram submetidos à ciclagem mecânica submersos em água destilada simulando um tempo clínico de cinco anos. Além disso, foram avaliados quanto ao torque e destorque (N) e adaptação marginal e interna (µm) antes e após a ciclagem mecânica. Os dados provenientes das mensurações foram organizados em tabela em formato Excel (Microsoft Office Excel, Redmond, WA, Estados Unidos) e submetidos ao software SigmaPlot (SigmaPlot, San Jose, CA, EUA) versão 12.0. Todos os dados foram analisados inicialmente com a utilização da estatística descritiva. Em seguida, os dados para intrusão (valores positivos), extrusão (valores negativos), destorque inicial, destorque final, e descimentação foram analisados em relação a distribuição de normalidade (teste Shapiro-Wilk e igualdade de variância) e, posteriormente, foi adotada a Análise de Variância (ANOVA) a um fator (Grupos diferentes materiais: G1 a G4), quando houve normalidade dos dados, o pós teste de Tukey foi adotado para as comparações múltiplas, quando não foi identificado uma distribuição normal, empregou-se o teste de Kruskall-Wallis e pós-teste de Dunn's ou Tukey, semelhantemente foi realizada a análise específica das variáveis pilares (UCLA e Pilar Universal) e sistemas de retenção (Parafusado e Cimentado). Para todos os testes aplicou-se nível de significância de 5% (α=0,05). A análise gráfica foi considerada através de um gráfico de barras para os dados que apresentaram normalidade com valores de média e desvio padrão, e as demais análises que não apresentaram normalidade foi considerado a confecção de um boxplot para cada grupo comparativo. As próteses sobre implante utilizando pilares em zircônia tem ganhado cada vez mais espaço, além do estudo in vitro, foi realizada uma revisão sistemática para comparar a perda óssea marginal e as complicações próteticas de reabilitações utilizando pilares de zircônia cimentado e parafusado. Em relação as próteses cimentadas e parafusadas, devido as evidências conflitantes e a presença de muitas revisões sistemáticas sobre o tema, foi realizada uma overview de revisões sistemáticas, com o objetivo de compilar as informações disponiveis e avaliar a qualidade metodologica desses estudos a respeito das complicações presentes nas próteses sobre implante cimentadas ou parafusadas(AU)

Currently, due to the loss of the dental element and the search for an aesthetic and mainly functional treatment, rehabilitation with implant prostheses has been widely used, with high long-term predictability. Thus, much has been reported in the literature about the possible complications of this treatment modality, mainly related to the possibility of mechanical failure of implant-supported prostheses. Therefore, the objective of the present project was to evaluate the influence on the marginal and internal adaptation, the use of the prosthetic intermediate and the type of retention of the prostheses (screwed and cemented) in morse taper implants submitted to mechanical cycling. 40 specimens were made, in which each one had an implant, with dimensions of 4 mm in diameter and 11.5 mm in length (n = 40). In this way, the influence of the use of intermediaries and retention systems in each connection was evaluated in a specific way. Half of the specimens of each connection system were made in UCLA (n=20, being 10 screwed and 10 cemented), while the other half was used a prefabricated intermediate (Universal Abutment (n=20, being 10 screwed) and 10 cemented). The specimens were submitted to mechanical cycling submerged in distilled water simulating a clinical time of five years. In addition, they were evaluated for torque and detorque (N) and marginal and internal adaptation (µm) before and after mechanical cycling. Data from measurements were organized in a table in Excel format (Microsoft Office Excel, Redmond, WA, USA) and submitted to SigmaPlot software (SigmaPlot, San Jose, CA, USA) version 12.0. All data were initially analyzed using descriptive statistics. Then, data for intrusion (positive values), extrusion (negative values), initial detorque, final detorque, and debonding were analyzed in relation to dist determination of normality (Shapiro-Wilk test and equality of variance) and, later, the one-way Analysis of Variance (ANOVA) was adopted (Different material groups: G1 to G4), when there was normality of the data, the Tukey post test was adopted for multiple comparisons, when a normal distribution was not identified, the Kruskall-Wallis test and Dunn's or Tukey post-test were used, similarly the specific analysis of the pillar variables (UCLA and Universal Pillar) and systems retainer (Screwed and Cemented). For all tests, a significance level of 5% (α=0.05) was applied. The graphical analysis was considered through a bar graph for the data that presented normality with mean and standard deviation values, and the other analyzes that did not present normality was considered the creation of a boxplot for each comparative group. Implant prostheses using zirconia abutments have gained more and more space, in addition to the in vitro study, a systematic review was performed to compare marginal bone loss and prosthetic complications of rehabilitations using cemented and screwed zirconia abutments. Regarding cemented and screw-retained prostheses, due to conflicting evidence and the presence of many systematic reviews on the subject, an overview of systematic reviews was performed, with the objective of compiling the available information and evaluating the methodological quality of these studies regarding complications present in cemented or screw-retained implant prostheses(AU)

Tasa de supervivencia de prótesis fija unitaria de cerámica feldespática y feldespática reforzada / Survival rate of feldspathic and reinforced feldspathic ceramic single-unit fixed prostheses

Introducción: Gracias a su eficiencia y al uso exclusivo de cerámicas libres de metal, en rehabilitación oral se ha logrado alcanzar los estándares estéticos y mecánicos, manteniendo o, incluso, superando, la calidad de los tratamientos en comparación con las restauraciones metal cerámicas tradicionales. Actualmente los mecanismos de confeccion de cerámica libre están evolucionando cada vez mas hacia las tecnologías maquinadas CAD-CAM y disminuyendo su producción mediante la técnica de Inyeccion PRESS. Objetivo: Comparar la tasa de supervivencia de prótesis fija unitaria realizadas con cerámicas feldespáticas convencionales y reforzadas con disilicato de litio, confeccionadas con sistema CAD/CAM de CEREC® chair-side, en comparación con el método de inyección de laboratorio PRESS convencional de prensión. Métodos: Revisión sistemática realizada a través de búsqueda de evidencia científica en PubMed, PubMed Clinical Queries, Epistemónikos, Tripdatabase, Cochrane Library, recursos electrónicos de la Universidad de los Andes y bibliografía retrógrada, de artículos publicados hasta el año 2019. Se incluyeron todos aquellos estudios referentes a prótesis fija unitaria de cerámicas feldespática convencional y feldespática reforzada con disilicato de litio, confeccionadas mediante CAD/CAM y/o método convencional. Resultados: Un total de 28 artículos cumplieron los criterios de inclusión: 21 estudios observacionales de cohorte, 4 ensayos clínicos aleatorizados y 3 no aleatorizados. A corto y mediano plazo, CAD/CAM de CEREC® registró tasas de supervivencia de 98 por ciento y 91,9 por ciento, respectivamente. El sistema convencional registró tasas de supervivencia de 97,5 por ciento a corto plazo y 93 por ciento a mediano. Conclusiones: A corto plazo se describe en la literatura que CAD/CAM de CEREC® tuvo una tasa de supervivencia ligeramente superior al sistema convencional. Por otro lado, a mediano plazo CAD/CAM de CEREC® presentó una leve disminución respecto al sistema convencional. Aún no hay estudios disponibles para determinar la supervivencia clínica de los tratamientos a largo plazo(AU)

Introduction: Thanks to its efficiency and the exclusive use of metal-free ceramics, in oral rehabilitation it has been possible to achieve aesthetic and mechanical standards, maintaining or even exceeding the quality of the treatments compared to traditional metal-ceramic restorations. Currently, free ceramic manufacturing mechanisms are increasingly evolving towards CAD-CAM machined technologies and decreasing their conventional production through the PRESS Injection technique. Objective: Compare the survival rate of single-unit fixed prostheses made with conventional feldspathic ceramics and reinforced with lithium disilicate by the CEREC® CAD/CAM chairside system, with the conventional PRESS laboratory injection method. Methods: A systematic review was conducted of scientific evidence included in papers published until the year 2019 in PubMed, PubMed Clinical Queries, Epistemonikos, Tripdatabase, Cochrane Library, electronic resources of Los Andes Peruvian University, and retrograde bibliography. The papers selected dealt with conventional and lithium-disilicate reinforced feldspathic ceramic single-unit prostheses made by CAD/CAM and/or the conventional method. Results: A total 28 papers met the inclusion criteria. Of these, 21 were observational cohort studies, four were randomized clinical assays and three were non-randomized assays. Short- and mid-term, CEREC® CAD/CAM achieved survival rates of 98 percent and 91.9 percent, respectively. The conventional system achieved survival rates of 97.5 percent short-term and 93 percent mid-term. Conclusions: As described in the literature, CEREC® CAD/CAM had a slightly higher survival rate than the conventional system in the short term. In the medium term, however, CEREC® CAD/CAM displayed a slight reduction in comparison with the conventional system. No studies are available to determine the clinical survival of the treatments in the long term(AU)

Evaluation of Polyethylene Wear in a Brazilian Ultracongruent Knee Prosthesis with a Rotating Platform / Avaliação do desgaste do polietileno de uma prótese de joelho nacional ultracongruente de base rotatória

Abstract Objective To evaluate the wear of polyethylene in a Brazilian ultracongruent knee prosthesis with a rotating platform (Rotaflex, Víncula, Rio Claro, SP, Brasil). Methods We used the test method with the loading and preparation parameters mentioned in the standards regulation ISO 14243-1:2009, and the measurement methods mentioned in the standards regulation ISO 14243-2:2009, for the evaluation of the wear behavior of a Brazilian prosthesis with a rotating platform. The equipment used for the wear test was the ISO 14243-1 gait simulator (EndoLab, Riedering, Germany). Results After 10 million cycles, the evaluation of the polyethylene wear showed a regular appearance of surface wear at a mean rate of 2.56 mg per million cycles. Conclusion The wear of the polyethylene of the evaluated prosthesis was minimal after the tests performed and with safety limits higher than those recommended by biomechanical engineering.

Resumo Objetivo Avaliar o desgaste do polietileno de uma prótese de joelho brasileira ultracongruente de base rotatória (Rotaflex, Víncula, Rio Claro, SP, Brasil). Métodos Utilizou-se o método de ensaio com os parâmetros de carregamento e preparação citados na norma ISO 14243-1:2009, e os métodos de medição citados na norma ISO 14243-2:2009, para a avaliação do comportamento de desgaste de uma prótese nacional com base rotatória. O equipamento utilizado para o teste de desgaste foi o simulador de marcha ISO 14243-1 (EndoLab, Riedering, Alemanha). Resultados Após 10 milhões de ciclos, a avaliação do desgaste do polietileno mostrou uma aparência regular do desgaste da superfície com taxa média de 2,56 mg por milhão de ciclos. Conclusão O desgaste do polietileno da prótese avaliada foi mínimo após os ensaios realizados e com os limites de segurança superiores aos preconizados pela engenharia biomecânica.

Finite element analysis of biomechanical properties of bionic surface hip prosthesis / 中华骨科杂志

Objective:To compare the biomechanical properties of traditional surface hip prosthesis and bionic surface hip prosthesis.Methods:The Sawbone digital model (#3908, Left, Medium) was selected as the research object. Mimics 21.0 software was used to reconstruct the physical model of femur. Solidworks 16.0 software was used to build the model of prostheses, including the traditional and bionic (type 1-4) protheses and their assembly. The distances from the screw cross position to the top of pressure screw of type 1 to type 4 protheses were 20.22 mm, 30.12 mm, 32.17 mm and 37.76 mm, respectively. The mechanical distribution characteristics of the whole model were measured and the stress distribution cloud map was obtained.Results:The peak stresses at bone-stem junction of traditional prosthesis and type 1-4 hip prostheses were 32.18 MPa, 13.80 MPa, 15.01 MPa, 23.46 MPa and 34.51 MPa, respectively. With the fulcrums away from the top of the femur, the peak stresses at the fulcrums of type 1-4 hip protheses were 37.98 MPa, 48.60 MPa, 54.80 MPa, and 53.87 MPa, respectively. The maximum stress above femoral neck of traditional prosthesis and type 1-4 hip prostheses were 8.00 MPa, 7.80 MPa, 7.04 MPa, 7.03 MPa and 7.51 MPa, respectively. The maximum stresses under femoral neck was 15.38 MPa, 14.20 MPa, 11.11 MPa, 13.10 MPa and 12.18 MPa, respectively. The maximum stresses in the greater trochanter region of femur were 13.08 MPa, 11.61 MPa, 13.09 MPa, 11.02 MPa and 39.51 MPa, respectively.Conclusion:Compared with the traditional surface hip prosthesis, the type I bionic surface hip prosthesis is designed based on the lever balance reconstruction theory. With the bionic reconstruction of the tension trabeculae and compression trabeculae through reasonable screw placement angles and the inward movement of the fulcrum closer to the center of the femoral head, the new type prothesis make up for the design defects of the traditional surface hip prosthesis, optimize the stress distribution in the proximal femur, and improve the stability of the prosthesis after replacement, which help reduce the risk of femoral neck fracture and prosthesis loosening, and extend the service life of the prosthesis.

Added value of three-phase bone scintigraphy combined with SPECT/CT for differential diagnosis of periprosthetic infection and prosthesis loosening / 中华核医学与分子影像杂志

Objective:To explore the advantage of three-phase bone scintigraphy combined with SPECT/CT over three-phase bone scintigraphy in the differential diagnosis of periprosthetic infection from prosthesis loosening in patients after prosthesis replacement.Methods:Seventy patients (27 males, 43 females, age (69.5±10.5) years) who were suspected with prosthesis loosening or periprosthetic infection underwent 99Tc m-methylene diphosphonate (MDP) three-phase bone scintigraphy and SPECT/CT from October 2008 to November 2019 in Zhongshan Hospital, Fudan University were retrospectively reviewed. All patients had pathological diagnoses based on surgical resection or lesion biopsy. The diagnostic efficiency of three-phase bone scintigraphy images and three-phase bone scintigraphy combined with SPECT/CT were evaluated. χ2 test was used for data analysis. Results:Among 70 patients, 34(48.6%, 34/70) were diagnosed as periprosthetic infection and 36(51.4%, 36/70) were diagnosed as prosthesis loosening. Using three-phase bone scintigraphy for the differential diagnosis of bone lesions, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 94.1%(32/34), 77.8%(28/36), 85.7%(60/70), 80.0%(32/40) and 93.3%(28/30), when combined with SPECT/CT, the corresponding results were 94.1%(32/34), 94.4%(34/36), 94.3%(66/70), 94.1%(32/34), 94.4%(34/36), respectively. The specificity and accuracy were increased ( χ2 values: 4.167, 4.167, both P=0.031). Conclusion:Combination of three-phase bone scintigraphy with SPECT/CT can provide added value over three-phase bone scintigraphy for differential diagnosis in patients with periprosthetic loosening or periprosthetic infection.

Fracasos de las restauraciones cerámicas en base de circonio / Failure of zirconia-based ceramic restorations

RESUMEN Introducción: Existen numerosos tipos de fracaso en las restauraciones cerámicas en base de circonio, cerámicas sobre base o núcleo de circonio siendo el agrietamiento uno de los más frecuentes. Objetivo: Describir las asociaciones de los fracasos en las prótesis con núcleo de circonio y laminadas con cerámicas de recubrimiento. Métodos: Se realizó una revisión bibliográfica sobre los fracasos de la cerámica de restauraciones de circonio y sus mecanismos en MEDLINE, PubMed y SciELO. La búsqueda se orientó a artículos publicados fundamentalmente en los últimos 5 años sin hacer distinciones de idioma. Los tópicos consultados en la revisión estuvieron referidos a estudios experimentales en humanos, animales e in vitro que incluyeran los tópicos de fracaso, longevidad de restauraciones, mecanismos de fracaso, fracturas y tipos de ellas. Análisis e integración de la información: Se profundiza en el tema de los fracasos de la cerámica de restauraciones de circonio. La causa de fracaso más prevalente es el agrietamiento, en sus distintos grados que alcanzan hasta tasas de 16 por ciento a los 5 años, lo que representa una causa de fracaso relevante. No existe evidencia de unión química entre el núcleo de circonio y la cerámica de revestimiento, esto explicaría la génesis de las fracturas. Conclusiones: Las complicaciones más comunes encontradas en restauraciones de núcleo de circonio recubiertas con porcelana están asociadas con el agrietamiento de la porcelana de recubrimiento, a las fracturas del núcleo de circonio que se asocian fundamentalmente a traumas y hábitos parfuncionales; la pérdida de retención y problemas endodónticos(AU)

ABSTRACT Introduction: There are numerous types of failure in zirconia-based ceramic restorations, i.e. ceramic restorations on a zirconia base or core, cracking being one of the most common. Objective: Describe the association between failure in zirconia-core and ceramic-veneered prostheses. Methods: A bibliographic review was conducted about failure in zirconia-based ceramic restorations and its mechanisms in the databases MEDLINE, PubMed and SciELO. The search was aimed at papers published in any language mainly in the last five years. Papers were searched for which referred to experimental studies in humans, animals and in vitro, and dealt with the topics of failure, longevity of restorations, failure mechanisms, fractures and their types. Data analysis and integration: The topic of failure in zirconia-based ceramic restorations was studied in depth. The leading cause of failure is cracking in its various degrees, which reaches rates of up to 16 percent at five years, a relevant failure level. No evidence was found of chemical bonding between the zirconia core and the veneering ceramic, which would otherwise explain the genesis of fractures. Conclusions: The most common complications found in zirconia-core restorations covered with porcelain are associated to cracking of the veneering porcelain, fractures in the zirconia core mainly caused by traumas and parafunctional habits, retention loss and endodontic problems(AU)

Risk Factors of Allogenous Bone Graft Collapse in Two-Level Anterior Cervical Discectomy and Fusion

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse.METHODS: We retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height.RESULTS: The subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ≥37.3% was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, 5.8±5.7 months; subsidence, 0.99±0.50 months; and instrument failure, 9.13±0.50 months.CONCLUSION: We experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various pre-operative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.

Short-term clinical efficacy of three dimension printed titanium augments for the reconstruction of acetabular bone defects in revision total hip arthroplasty / 国际外科学杂志

Objective To evaluate the short-term clinical efficacy of three dimension printed titanium augments for the reconstruction of acetabular bone defects in revision total hip arthroplasty.Methods The retrospective study was conducted.To retrospectively analyze clinical data of 21 patients who were underwent revision total hip arthroplasty with severe acetabular bone defects reconstructed by three dimension printed titanium augment from March 2016 to September 2017 from Department of Orthopaedics,Beijing Friendship Hospital,Capital Medical University.There were 9 males and 12 females,age (58.9 ± 6.3) years,51-67 years,body mass index (23.8 ± 2.9) kg/m2.According preoperative CT scan of hip joints,three dimension printed titanium augments were designed for acetabular defects personality.The data including the vertical distance from centre of rotation to the interteardrop line in X-ray examination,preoperative Harris score,final follow-up Harris score of hip postoperatively,and complications were recorded.Outpatient visits ranged from 11.8 to 19.6 months.Measurement data were expressed as (Mean ± SD),and t test was used before and after surgery.Results For X-ray examination,the average vertical distance from centre of rotation to the interteardrop line was (6.1 ± 1.2) cm preoperatively and (2.8 ± 0.7) cm postoperatively,and the difference was statistically significant (P ＜ 0.01).The hip Harris score increased from preoperative (47.5 ± 6.4) scores to the last follow-up (84.6 ± 5.9) scores,and the difference was statistically significant (P ＜ 0.01).The final follow-up data showed the acetabular prosthesis and augments were stable,while there were no hip joint dislocation,periprosthetic joint infection,loosening of acetabular components and other complications.Conclusion Three dimension printed augments can reconstruct severe acetabular bone defects and restore the hip rotation centre.

Risk Factors of Allogenous Bone Graft Collapse in Two-Level Anterior Cervical Discectomy and Fusion

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse. METHODS: We retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height. RESULTS: The subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ≥37.3% was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, 5.8±5.7 months; subsidence, 0.99±0.50 months; and instrument failure, 9.13±0.50 months. CONCLUSION: We experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various pre-operative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.

Clinical and radiographic outcomes of hip resurfacing arthroplasty after eight years - a retrospective study / Avaliação do resultado clínico e radiográfico das próteses de recapeamento de quadril após oito anos - estudo retrospectivo

ABSTRACT Objective: To assess the clinical and radiographic outcomes of hip resurfacing arthroplasty for the treatment of hip osteoarthritis. Methods: This study retrospectively assessed 30 patients with hip osteoarthritis who underwent hip resurfacing arthroplasty between 2005 and 2014. Patients of both genders suffering from advanced primary and secondary hip osteoarthritis were included in the study. Data were collected about postoperative complications and the need for revision of the arthroplasty. Antero-posterior pelvis and lateral hip x-rays were performed in order to classify osteolysis according to the Amstutz criteria; the Lequèsne index of severity for osteoarthritis of the hip and the UCLA activity level questionnaires were answered pre- and postoperatively. Results: After a mean follow-up of eight years, a statistically significant improvement was observed between the mean of the outcomes of both scores, when compared pre- and postoperatively (p < 0.001). Nevertheless, there was a high incidence of arthroplasty revision (20%), related to the size of the femoral stem and errors in surgical technique. Conclusion: Using the appropriate technique, hip resurfacing arthroplasty can present good results in well-selected patients.

RESUMO Objetivo: Avaliar o resultado clínico e radiográfico dos pacientes submetidos à prótese de recapeamento de quadril para o tratamento da osteoartrose de quadril. Métodos: Foram avaliados retrospectivamente 30 pacientes com coxartrose tratados com prótese de recapeamento de quadril entre 2005 e 2014. Foram incluídos no estudo pacientes de ambos os sexos portadores de osteoartrose de quadril avançada, primária ou secundária. Foram coletados dados sobre complicações pós-operatórias e necessidade de revisão da prótese. Foram feitas radiografias AP de bacia e perfil de quadril para classificação da osteólise segundo os critérios de Amstutz; os questionários do escore funcional de Lequèsne e do nível de atividade física do escore UCLA foram aplicados nos períodos pré e pós-operatórios. Resultados: Após um seguimento médio de oito anos, observou-se melhoria estatisticamente significativa entre as médias dos resultados pré e pós-operatórios de ambos os escores (p < 0,001). Entretanto, foi observada uma elevada taxa de revisão das próteses (20%), correlacionada ao tamanho do componente femoral usado e à falha na técnica cirúrgica. Conclusão: A prótese de resurfacing de quadril pode proporcionar bons resultados, com a técnica adequada, em pacientes selecionados.

Disfunción de prótesis mitral mecánica: ¿Intervención quirúrgica o tratamiento inmediato con fibrinolíticos? / Mechanical mitral prosthesis dysfunction: Surgical intervention or immediate treatment with fibrinolytics?

Resumen: Existe en la actualidad controversia acerca del mejor tratamiento para los pacientes portadores de trombosis valvular protésica. Muchos factores deben ser tenidos en cuenta al momento de decidir entre la resolución quirúrgica o el tratamiento con fibrinolíticos sistémicos. Las guías americanas recomiendan en plano de igualdad ambas terapéuticas, poniendo énfasis en el análisis de cada caso en particular. Las guías europeas, en cambio, le dan mayor nivel de recomendación a la cirugía, dejando la fibrinólisis para aquellos pacientes con alto riesgo quirúrgico. Se presenta el caso de una paciente de 54 años, portadora de prótesis mitral mecánica implantada hace 15 años, disfuncionante, en clase funcional II de la New York Heart Association, y se discuten las opciones diagnósticas y terapéuticas.

Summary: There is ongoing debate regarding the optimal treatment for patients with prosthetic valve thrombosis. Several issues must be taken into consideration before defining either surgical or fibrinolytic treatment. North American guidelines place both therapeutic modalities under the same recommendation grade with special emphasis on the analysis of each individual case. European guidelines place surgical treatment as the preferred option except in patients with high surgical risk. Thereby, we present the clinical case of a 54 year old female with dysfunctional mechanical mitral prosthesis implanted 15 years ago and functional class II of the New York Heart Association. Diagnostic and therapeutic approaches are discussed.