RESUMO
The development of bioactivity in bioinert metallic alloys is a field of interest aiming to improve some aspects of these materials for implant applications. New Co63 Cr28 W9-x Tax alloys with different Ta concentrations (x = 0, 2, 4, 6, and 9% w/w) were synthesized in the work reported here. The alloys were characterized by x-ray diffraction, volumetric density, Vickers microhardness, atomic force microscopy, scanning electron microscopy (SEM), and energy-dispersion x-ray spectroscopy (EDS). Bioactivity properties were evaluated by in vitro tests with simulated body fluid (SBF). In vivo assays were performed to assess biocompatibility. The influence of surface thermochemical treatment and Ta insertion on the bioactive properties of the alloys was investigated. The results showed that the alloy structure comprises εCo and αCo phases, with cobalt as a matrix with Cr, W, and Ta as a solid solution. TaCo2 phase is observed in the alloys with 4, 6, and 9% w/w of Ta, and its amount increase as Ta concentration increases. Volumetric density is reduced (from 8.78 ± 0.06 to 8.56 ± 0.09 g/cm3 ) as Ta concentration increases (from 0% to 9% w/w) mainly due to the lower density of the tantalum compared to the tungsten metal. On the other hand, the TaCo2 phase contributes to the increase of Vickers's hardness by ~17.6% for the alloy with 9% Ta (394.7 ± 8.1 HV) compared with Co63 Cr28 W9 (336 ± 5 HV). The topographic analysis showed increased roughness and adhesion due to the nucleation of Ta1.1 O1.05 and Ca2 Ta2 O7 crystals after surface thermochemical treatment. The roughness and adhesion increase from 16.9 ± 0.6 nm and 8.3 ± 1.8 nN (untreated surface) to 255.7 ± 17.7 nm and 24.1 ± 12.6 nN (treated surface), respectively, for the Co63 Cr28 Ta9 alloy. These results suggest that thermochemical treatment provides surface conditions favorable to hydroxyapatite (HA) nucleation. The SEM and EDS data showed the nucleation of spongy structures, consistent with HA, composed mainly of Ca and P, indicating that oxides tantalum promoted a bioactive response on the sample's surface. The biological assay corroborated the alloy's safety and applicability, highlighting its potential in biomedical application since no harmful effects were observed.
Assuntos
Ligas , Tantálio , Ligas/farmacologia , Tantálio/farmacologia , Durapatita/química , Metais , Próteses e Implantes , Propriedades de Superfície , Teste de MateriaisRESUMO
Abstract Objective The management of bone loss represents a challenge in revisions of total knee arthroplasty (rTKA) and in complex primary total knee arthroplasties (TKAs). The purpose of the present study was to evaluate the midterm outcomes (5-year minimum follow-up) of knee reconstructions with tantalum trabecular metal (TM) cones on bone defects Anderson Orthopaedics Research Institute (AORI) 2 and 3. Materials and MethodsA retrospective analysis of the medical records of patients operated on between July 2008 and November 2014 was performed, collecting the following data: age, gender, laterality, body mass index, etiology of arthrosis, comorbidities, AORI classification of bone defects, causes for revision, readmissions, reoperations, perioperative and postoperative complications, radiographic signs of osteointegration, and maintenance of the TM support. Results A total of 11 patients with a mean follow-up of 7.28 years (standard deviation [SD] = 1.88; range = 5.12-10 years) was evaluated, with 1 patient operated upon for a primary arthroplasty, 6 for revision arthroplasties, and 4 for a second revision arthroplasty (re-revision). There were complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component in three of the patients that led to the necessity of four procedures due to complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component. Radiological signs of osteointegration of the trabecular cones were observed in all patients. We did not observe migration of the TM cones or the prosthetic components in the sample. Conclusion The tantalum metaphyseal cones were able to provide efficient structural support to prosthetic implants with radiographic signs of osteointegration in the medium term.
Resumo Objetivo O manejo da perda óssea representa um grande desafio em cirurgias de revisão de artroplastia do joelho (rATJ) e em artroplastias totais do joelho (ATJ) primárias complexas. O objetivo do presente estudo foi avaliar os resultados em médio prazo (seguimento mínimo de 5 anos) das reconstruções de joelho nas quais cones de metal trabecular (MT) de tântalo foram utilizados para tratamento de defeitos ósseos tipos 2 e 3, de acordo com a classificação proposta pela Anderson Orthopaedic Research Institute (AORI). Métodos Feita análise retrospectiva dos prontuários dos pacientes operados entre julho de 2008 e novembro de 2014, coletando-se os seguintes dados: idade, gênero, lateralidade, índice de massa corporal, etiologia da artrose, comorbidade, classificação AORI da falha óssea, causa da revisão da artroplastia total do joelho, reinternações, reoperações, complicações peri- e pós-operatórias, ocorrência de osteointegração radiográfica e manutenção da função de suporte do MT. Resultados Foram avaliados 11 pacientes com tempo médio de seguimento de 7,28 anos (desvio padrão [DP] = 1,88; variação = 5,12-10 anos), sendo que 1 paciente foi submetido a artroplastia primária, 6 a artroplastia de revisão e 4 a segunda revisão de artroplastia (re-revisão). Três pacientes necessitaram de quatro reoperações devido a complicações com a ferida operatória, a lesão do mecanismo extensor e a soltura do componente femoral. Sinais de osteointegração dos cones trabeculados foram observados em todos os pacientes. Não observamos migração do cone de MT ou dos componentes protéticos. Conclusão Os cones metafisários de tântalo foram capazes de prover suporte estrutural eficiente aos implantes protéticos com sinais radiográficos de osteointegração em médio prazo.
Assuntos
Humanos , Complicações Pós-Operatórias , Tantálio , Estudos Retrospectivos , Osseointegração , Avaliação de Resultados em Cuidados de Saúde , Artroplastia do Joelho , Prótese do JoelhoRESUMO
Introducción: Las alternativas reconstructivas para defectos óseos severos en la cirugía de revisión de prótesis son las camisas metafisarias, los conos de metal trabecular y el injerto óseo impactado o estructural. El objetivo del estudio fue analizar la tasa de osteointegración de los conos de metal trabecular en pacientes con cirugía de revisión de prótesis total de rodilla. El objetivo secundario fue analizar los resultados funcionales, las tasas de complicaciones y reoperaciones. Materiales y Métodos: Cohorte retrospectiva de pacientes con conos de metal trabecular colocados en la cirugía de revisión de prótesis y un seguimiento mínimo de 2 años. Se evaluaron las causas de la revisión, cirugías previas, tipo de defecto óseo, cantidad y tipo de conos utilizados, y los diseños de las prótesis. Se realizó una evaluación clínico-radiográfica, se registraron las complicaciones y las revisiones ulteriores. Resultados: Se evaluó a 35 pacientes (49 conos de metal trabecular) en forma retrospectiva, con un seguimiento promedio de 32.1 meses. La mayoría de los defectos eran tibiales AORI 3, seguidos de los femorales tipo 3. La tasa de osteointegración de los conos fue del 94%; la de complicaciones, del 20% y la de reoperaciones, del 8,5%. El KSS objetivo promedio aumentó de 39 en el preoperatorio a 71 en el último control y el puntaje de la EAV promedio fue 8 y 2,5, respectivamente. Conclusión: La excelente tasa de osteointegración (94%) y los buenos resultados clínicos posicionan a los conos de metal trabecular como una alternativa para los defectos óseos severos. Nivel de Evidencia: IV
Introduction: Major bone defects represent a challenge during revision total knee arthroplasty (TKA) and there is still considerable debate about the best therapeutic option. The purpose of this study was to retrospectively assess the osseointegration rate of trabecular metal cones in revision TKA with severe bone defects. The secondary purpose was to evaluate the functional outcomes and complication and reoperation rates. Materials and Methods: A single-center, retrospective cohort including all consecutive cases of revision TKA using trabecular metal cones. All patients with a minimum 2-year follow-up were included in the study. Reasons for revision, number of previous surgeries, type of bone defect, and number and type of trabecular cones used were evaluated. Clinical and radiological outcomes were also analyzed as well as complications rates. Results: 35 patients (49 cones) were evaluated with a mean follow-up of 32.1 months (24-62). Most defects were localized in the tibia and were classified as AORI type 3. The rate of osseointegration of the cones was 94%; the complication rate, 20%; and the reoperation rate, 8.5%. The mean KSS increased from 39 preoperatively to 71 at the last follow-up, and the mean VAS from 8 to 2.5. Conclusion: The excellent osseointegration rate (94%), added to the good clinical outcomes, position the trabecular metal cones as an alternative to treat severe bone defects. Level of Evidence: IV
Assuntos
Reoperação , Tantálio , Reabsorção Óssea , Seguimentos , Osseointegração , Resultado do Tratamento , Artroplastia do JoelhoRESUMO
The polymer poly(ε-caprolactone) (PCL) has been used in the biomaterial field for its relatively inexpensive price and suitability for modification. Also, its chemical and biological properties are desirable for biomedical applications. The electrospinning process has been used for producing polymer fibers of PCL due in large part to an increased interest in nanoscale properties and technologies. Moreover, the use of biocompatible polymers for the viability of cell growth is a promising alternative to improve osseointegration. Characterization techniques such as scanning electron microscopy and contact angle were used for analyses of samples. Adult human dermal fibroblasts (neonatal) were utilized to evaluate the biocompatibility of the association of the electrospinning process of the biocompatible polymer (PCL) with TiO2 nanotubes on the Ti-30Ta alloy surface. The results of this study showed a favorable response for adhesion on the surface. This promising material is due to the modulation of the biological response.
Assuntos
Fibroblastos/efeitos dos fármacos , Nanofibras , Nanotubos , Tantálio , Titânio/farmacologia , Ligas , Materiais Biocompatíveis , Caproatos , Humanos , Lactonas , Teste de Materiais/métodos , Microscopia Eletrônica de Varredura , Polímeros , Pele/citologia , Pele/efeitos dos fármacos , Titânio/químicaRESUMO
Titanium alloys have been widely used as biomaterials, especially for orthopedic prostheses and dental implants, but these materials have Young's modulus almost three times greater than human cortical bones. Because of this, new alloys are being produced for the propose of decreasing Young's modulus to achieve a more balanced mechanical compatibility with the bone. In this paper, it is reported the development of Ti-25Ta alloys as a base material, in which was introduced zirconium, with concentration varying between 0 and 40 wt%, with the aim of biomedical applications. The alloys were prepared in an arc-melting furnace. The microstructural analysis was performed by x-ray diffraction as well as optical and scanning electron microscopy. Selected mechanical properties were analyzed by microhardness and Young's modulus measurements, and cytotoxicity analysis by indirect test. X-ray measurements revealed the presence of αâ³ phase in the alloy without zirconium; αâ³ + ß phases for alloys with 10, 20, and 30 wt% of zirconium, and ß phase only for the alloy with 40 wt% of zirconium. These results were corroborated by the microscopy results. The hardness of the alloy was higher than that of cp-Ti due to the actions of zirconium and tantalum as hardening agents. The Young's modulus decreases with high levels of zirconium due to the stabilization of the ß phase. The cytotoxicity test showed that the extracts of studied alloys are not cytotoxic for osteoblast cells in short periods of culture.
Assuntos
Ligas/química , Ligas/toxicidade , Osteoblastos/efeitos dos fármacos , Tantálio/química , Titânio/química , Zircônio/química , Animais , Sobrevivência Celular , Teste de Materiais , CamundongosRESUMO
AIM: To evaluate biological behavior of human peripheral mononuclear cells (PBMC) in contact with porous tantalum (PT) and Porphyromonas gingivalis (Pg). METHODS: Pg was incubated for 8 hours. The groups formed were: PBMC (control), PBMC + PT, PBMC + Pg and PBMC + PT + Pg. Cell viability was evaluated using MTT assay. The morphology and adhesion of PBMC to PT was evaluated using scanning electron microscopy. Expression of interleukin (IL)-10, transforming growth factor (TGF)-ß, matrix metallopeptidase (MMP)-9 and receptor activator of nuclear factor-κΒ ligand (RANKL) was determined by enzyme-linked immunosorbent assay. RESULTS: MTT assay revealed that PT did not interfere in the mitochondrial activity of PBMC (P > .05). Scanning electron microscopy showed the adherence of PBMC to PT. IL-10 levels in PBMC + PT were similar to PBMC and lower than PBMC + Pg. TGF-ß levels in PBMC + PT were higher than PBMC and PBMC + Pg. MMP-9 levels in PBMC + PT were similar to PBMC and lower than PBMC + Pg and PBMC + PT + Pg. RANKL levels in PBMC + PT were lower than in PBMC. CONCLUSION: PT did not affect PBMC viability, allowed cell adhesion, reduced expression of RANKL and enhanced TGF-ß in comparison with the control group.
Assuntos
Porphyromonas gingivalis , Tantálio , Humanos , Leucócitos , Leucócitos Mononucleares , PorosidadeRESUMO
Abstract Objective The objective of the present study is to evaluate the restoration capacity of the hip anatomic rotation center with the use of acetabular tantalum cups, associated or not with addition wedges. Methods Retrospective analysis of patients undergoing hip arthroplasty revision using tantalum between June 2013 and April 2017. The abduction angle of the acetabular component and the horizontal and vertical distances of the component to the center of anatomical rotation of the hipwere evaluated. The measurements were made through baseline radiographs performed in the preoperative period and at the last follow-up visit. Results A sample of 21 patients was obtained, 11 (52%) men and 10 (48%) women, with amean age of 62 ± 13 years old. The mean abduction angle of the acetabular cup decreased from 48.76° ± 13.88 ° in the preoperative period to 38.52° ± 10.08 ° in the postoperative period, and this difference was statistically significant (p = 0.001). The distances from the center of rotation of the prosthesis relative to the center of anatomical rotation of the hip were also lower after revision surgery with tantalum. The mean horizontal distance of 12.74 ± 10.59 mm was reduced to 7.11 ± 4.84 mm, and the mean vertical distance was reduced from 14.79 ± 10.05 mm to 4.89 ± 6.21 mm, and these reductions were statistically significant (p < 0.001). Conclusion Hip arthroplasty revision with tantalum cups, associated or not with addition wedges, significantly recovered the anatomical rotation center of the hip.
Resumo Objetivo O objetivo do presente estudo é avaliar a capacidade de restauração do centro de rotação anatômico do quadril com uso de copas acetabulares de tântalo associado ou não a cunhas de adição. Métodos Análise retrospectiva dos pacientes submetidos a revisão de artroplastia do quadril comuso de tântalo entre o período de junho de 2013 e abril de 2017. Foramavaliados o ângulo de abdução do componente acetabular e as distâncias horizontal e vertical do componenteao centro de rotação anatômicodoquadril.Asmedidas foramrealizadas através de radiografias da bacia realizadas no pré-operatório e na última visita de seguimento. Resultados Obteve-se uma amostra de 21 pacientes, 11 (52%) homens e 10 (48%) mulheres, com média de idade de 62 ± 13 anos. O ângulo médio de abdução da copa acetabular reduziu de 48,76° ± 13,88° no pré-operatório para 38,52° ± 10,08° no pósoperatório, sendo esta diferença estatisticamente significativa (p = 0,001). As distâncias do centro de rotação da prótese em relação ao centro de rotação anatômico do quadril também foram menores após a cirurgia de revisão com o tântalo. A distância média horizontal de 12,74 ± 10,59 mm foi reduzida para 7,11 ± 4,84 mm, e a distância média vertical foi reduzida de 14,79 ± 10,05 mm para 4,89 ± 6,21 mm, sendo essas reduções estatisticamente significativas (p < 0,001). Conclusão As revisões de artroplastia do quadril comcopas de tântalo, associadas ou não a cunhas de adição, recuperaram de forma significativa o centro de rotação anatômico do quadril.
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Tantálio , Artroplastia de Quadril , AcetábuloRESUMO
The aim of this study was to tailor the deposition parameters of magnetron sputtering to synthetize tantalum oxide (TaxOy) films onto commercially pure titanium (cpTi) surface. The structural and optical properties, morphology, roughness, elemental chemical composition and surface energy were assessed. The impact of TaxOy films on initial Streptococcus sanguinis adhesion was investigated. The morphology and spreading of pre-osteoblastic (MC3T3-E1) cells on a crystalline tantalum oxide film were evaluated. TaxOy films with estimated thickness of 600â¯nm and different structures (amorphous or crystalline) were produced depending on the various oxygen flow rates and parameters used. X-ray diffraction analysis revealed that the 8 O2 sccm (600⯰C/400â¯W) group showed crystallization corresponding to the ß-Ta2O5 phase. Optical analysis showed that the 4 O2 sccm (200⯰C 300â¯W) to 8 O2 sccm (600⯰C 300â¯W) groups and 10 O2 sccm (200⯰C 300â¯W) group presented regular and large-amplitude interference oscillations, suggesting high optical homogeneity of the films. The crystalline ß-Ta2O5 coating showed higher roughness and surface energy values than the other groups (Pâ¯<â¯.05) and was biocompatible. Compared with cpTi, the amorphous and crystalline tantalum oxide films did not increase bacterial adhesion (Pâ¯>â¯.05). By tailoring the deposition parameters, we synthetized a crystalline ß-Ta2O5 coating that improved titanium surface properties and positively affected cell spreading and morphology, making it a promising surface treatment for titanium-based implants.
Assuntos
Materiais Biocompatíveis/química , Tecnologia Biomédica/métodos , Tantálio/química , Animais , Linhagem Celular , Materiais Revestidos Biocompatíveis/química , Camundongos , Osteoblastos/citologia , Osteoblastos/ultraestrutura , Refratometria , Termodinâmica , Difração de Raios XRESUMO
Introducción: El objetivo de este estudio es analizar nuestros resultados clinico-radiologicos con el uso de copas de tantalio trabecular para la reconstruccion de acetabulos complejos, tanto en cirugias primarias como en revisiones, y compararlos con series similares de otros autores. Materiales y Métodos: Se llevo a cabo una revision retrospectiva de una serie de 42 cirugias (29 revisiones y 13 artroplastias primarias) en 40 pacientes, entre marzo de 2010 y marzo de 2016. La serie incluyo a 20 mujeres y 20 hombres, con una edad promedio de 60 anos (rango 27-93). El seguimiento promedio fue de 37 meses (rango 12-84). Todos los pacientes fueron tratados con el mismo tipo de metal trabecular. Resultados: Al promedio de seguimiento mencionado la supervivencia del componente acetabular fue del 97,6%. Un paciente fue tratado con artroplastia de reseccion debido a una infeccion persistente. La tasa de complicaciones totales fue del 12% y el promedio del Harris Hip Score posoperatorio fue de 81,54 (rango 63,25-92,75). Conclusiones: Aunque se necesita un seguimiento mas prolongado, el uso de copas de metal trabecular logra resultados prometedores para el tratamiento de acetabulos complejos. Nivel de Evidencia: IV
Introduction: The purpose of this paper is to review of our clinical and radiological results with the use of trabecular metal cups for complex acetabular reconstruction, both in primary and revision total hip arthroplasties, and to compare our results with those in similar series from other authors. Methods: A series of 42 surgeries (29 hip revisions and 13 primary total hip arthroplasties) in 40 patients, between March 2010 and March 2016 was retrospectively reviewed. The series included 20 women and 20 men, with a mean age of 60 years (range 27-93). The mean follow-up was 37 months (range 12-84). All patients were treated with the same type of trabecular metal. Results: At the average follow-up, the survival of the acetabular component was 97.6%. One patient required resection arthroplasty due to persistent infection. Overall complication rate was 12% and the average postoperative Harris Hip Score was 81.54 (range 63.25-92.75). Conclusions: Despite further follow-up is needed, trabecular metal cup use for complex acetabular reconstruction shows promising results. Level of Evidence: IV
Assuntos
Adulto , Pessoa de Meia-Idade , Idoso , Tantálio , Artroplastia de Quadril/métodos , Procedimentos de Cirurgia Plástica/métodos , Articulação do Quadril/cirurgia , Acetábulo/cirurgia , Seguimentos , Resultado do TratamentoRESUMO
PURPOSE: To analyze the angiographic and clinical results of transarterial embolization with Onyx (Medtronic-Covidien, Irvine, CA) in dural arteriovenous fistulas (DAVFs) partially fed by arteries arising from the carotid siphon or the vertebral arteries. METHODS: We isolated 40 DAVFs supplied by either the tentorial artery of the internal carotid artery (ICA) or the posterior meningeal artery of the vertebral artery. These DAVFs were embolized with Onyx through the middle meningeal artery or the occipital artery. We reviewed the occurrence of reflux into the arteries of carotid or vertebral origin. RESULTS: In all the cases, reflux occurred into the first millimeters of the DAVF arterial feeders arising from carotid or vertebral arteries but slowly enough to be controlled by interruption of Onyx injection. Reflux was always minimal and Onyx never reached the ostium of the arteries. No cerebral ischemic complications occurred in our series. CONCLUSION: The behavior of Onyx is clearly different from that of cyanoacrylate glue, resulting in superior control during injection. Reflux into arteries arising from the ICA or vertebral artery during DAVF treatment always carries a risk of unintentional non-target embolization of normal cerebral vasculature but Onyx appears to be safe in this situation.