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Magnesium alloys have been extensively studied as degradable biomaterials for clinical applications due to their biocompatibility and mechanical properties. However, their poor corrosion resistance can lead to issues such as osteolysis and the release of gaseous hydrogen. This study investigated the influence of the activation time of magnesium surfaces in a sodium hydroxide (NaOH) solution on the concentration of active hydroxyl groups and corrosion resistance. The results indicated that immersion time significantly influences the formation of a corrosion-resistant film and the distribution of surface hydroxyl groups. Specifically, specimens treated for 7.5 h exhibited the highest concentration of hydroxyl groups and the most uniform oxide film distribution. Electrochemical tests demonstrated capacitive behavior and passive surface formation for all evaluated times, with the 7.5-h immersion in NaOH yielding superior corrosion resistance, lower current density, and a more efficient and thicker protective film. SEM and EDS analyses confirmed increased formation of Mg(OH)2 for samples treated for 5 and 7.5 h, while a 10-h treatment resulted in a brittle, porous layer prone to degradation. Statistical analysis using ANOVA and Fisher's LSD test corroborated these findings. The optimal 7.5-h alkali treatment enhanced magnesium's corrosion resistance and surface properties, making it a promising candidate for orthopedic implants. However, further studies are necessary to assess biocompatibility and physiological responses before clinical implementation.

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Background: Orthopedic implants are commonly used for different types of surgical procedures to gain optimal functionand to provide stability to both bones and tendon structures. When inserting these implants, the characteristics of the material are important for surgical success, and the ideal implant must be biocompatible and nonallergenic. However, whenmolding an implant to the bone structure, its resistance can change significantly. Implants can be temporary or permanentin the body, and metal possesses properties that make it acceptable for bone repair. In biomedical implants, 2 types aremost common, commercially pure (CP)-Ti and Ti-6A1-4V. They both provide stable fixation and low risk of loosening.Implants made with the same material and composition can perform differently if the material has been altered by processing techniques for different scenarios. Stress, strain and elastic modulus are the primary metrics used in the description ofimplant materials. They can be calculated based on mechanical tests of specimens with defined geometry, most commonlytensile, bending and torsional tests. In order to better evaluate those changes, we compared the mechanical characteristicsof titanium bone plates, before and after they were molded to the bone, to verify and quantify the loss of stiffness andresistance after molding the plate.Materials, Methods & Results: The study was prospective. Orthopedic implant made of commercially pure titanium (CPTi) were divided into 2 groups, one group without plate molding and the other with plate molding to a dog femora bone.Thirty-six plates of different sizes (5.0, 6.5, 8.0, 9.0, 10.0- and 11.0-mm diameter) were divided into 6 groups containing6 plates of each size and submitted to the 4-point flexion test of resistance, using a piece of dog femur (weights of 5, 10,15, 20 and 25 kg) as the bone in which the...(AU)

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Background: Orthopedic implants are commonly used for different types of surgical procedures to gain optimal functionand to provide stability to both bones and tendon structures. When inserting these implants, the characteristics of the material are important for surgical success, and the ideal implant must be biocompatible and nonallergenic. However, whenmolding an implant to the bone structure, its resistance can change significantly. Implants can be temporary or permanentin the body, and metal possesses properties that make it acceptable for bone repair. In biomedical implants, 2 types aremost common, commercially pure (CP)-Ti and Ti-6A1-4V. They both provide stable fixation and low risk of loosening.Implants made with the same material and composition can perform differently if the material has been altered by processing techniques for different scenarios. Stress, strain and elastic modulus are the primary metrics used in the description ofimplant materials. They can be calculated based on mechanical tests of specimens with defined geometry, most commonlytensile, bending and torsional tests. In order to better evaluate those changes, we compared the mechanical characteristicsof titanium bone plates, before and after they were molded to the bone, to verify and quantify the loss of stiffness andresistance after molding the plate.Materials, Methods & Results: The study was prospective. Orthopedic implant made of commercially pure titanium (CPTi) were divided into 2 groups, one group without plate molding and the other with plate molding to a dog femora bone.Thirty-six plates of different sizes (5.0, 6.5, 8.0, 9.0, 10.0- and 11.0-mm diameter) were divided into 6 groups containing6 plates of each size and submitted to the 4-point flexion test of resistance, using a piece of dog femur (weights of 5, 10,15, 20 and 25 kg) as the bone in which the...

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Cobalt-base alloys (Co-Cr-Mo) are widely employed in dentistry and orthopedic implants due to their biocompatibility, high mechanical strength and wear resistance. The osseointegration of implants can be improved by surface modification techniques. However, complex geometries obtained by additive manufacturing (AM) limits the efficiency of mechanical-based surface modification techniques. Therefore, plasma immersion ion implantation (PIII) is the best alternative, creating nanotopography even in complex structures. In the present study, we report the osseointegration results in three conditions of the additively manufactured Co-Cr-Mo alloy: (i) as-built, (ii) after PIII, and (iii) coated with titanium (Ti) followed by PIII. The metallic samples were designed with a solid half and a porous half to observe the bone ingrowth in different surfaces. Our results revealed that all conditions presented cortical bone formation. The titanium-coated sample exhibited the best biomechanical results, which was attributed to the higher bone ingrowth percentage with almost all medullary canals filled with neoformed bone and the pores of the implant filled and surrounded by bone ingrowth. It was concluded that the metal alloys produced for AM are biocompatible and stimulate bone neoformation, especially when the Co-28Cr-6Mo alloy with a Ti-coated surface, nanostructured and anodized by PIII is used, whose technology has been shown to increase the osseointegration capacity of this implant.

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Background: In domestic rabbits, fractures are usually the result of household accidents. Fractures of the distal femoral physis are frequently observed in animals with immature skeletons and may cause future orthopedic problems. With this type of fracture, early reduction and stabilization are necessary to prevent additional damage to the physis and to preserve the growth potential of the bone. This report aims to describe the clinical and radiographic findings, as well as the surgical method used that combined Rush pins with an intramedullary pin, associated with a Salter Harris type I fracture of the right distal femur in a rabbit.Case: A 4-month male domestic rabbit (Oryctolagus cuniculus) weighing 1.2 kg, was referred to the Veterinary Hospital with a right pelvic limb lameness after an episode of trauma. Orthopedic examination revealed swelling, instability, crepitation, and increased pain sensitivity in the distal aspect of the right femur. Following physical and radiographic examination, a Salter Harris type I fracture of the right distal femur was diagnosed. The patient was premedicated with a combination of xylazine (2 mg/kg IM) and ketamine (10 mg/kg IM), which allowed placement of an IV catheter for the administration of fluids and intubation using an endotracheal tube with an internal diameter of 2 mm. Anesthesia was maintained with isoflurane, and an epidural was performed with a combination of lidocaine (2 mg/kg) and bupivacaine (0.75 mg/kg). Osteosynthesis was performed with two Rush pins and an intramedullary pin. Radiographic examination 110 and 330 days after the surgical procedure showed good alignment of the bone and adequate healing of the fracture. The combination of techniques used in this case report proved to be effective, resulting in functional recovery of the limb and rapid bone healing.[...](AU)

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Background: In domestic rabbits, fractures are usually the result of household accidents. Fractures of the distal femoral physis are frequently observed in animals with immature skeletons and may cause future orthopedic problems. With this type of fracture, early reduction and stabilization are necessary to prevent additional damage to the physis and to preserve the growth potential of the bone. This report aims to describe the clinical and radiographic findings, as well as the surgical method used that combined Rush pins with an intramedullary pin, associated with a Salter Harris type I fracture of the right distal femur in a rabbit.Case: A 4-month male domestic rabbit (Oryctolagus cuniculus) weighing 1.2 kg, was referred to the Veterinary Hospital with a right pelvic limb lameness after an episode of trauma. Orthopedic examination revealed swelling, instability, crepitation, and increased pain sensitivity in the distal aspect of the right femur. Following physical and radiographic examination, a Salter Harris type I fracture of the right distal femur was diagnosed. The patient was premedicated with a combination of xylazine (2 mg/kg IM) and ketamine (10 mg/kg IM), which allowed placement of an IV catheter for the administration of fluids and intubation using an endotracheal tube with an internal diameter of 2 mm. Anesthesia was maintained with isoflurane, and an epidural was performed with a combination of lidocaine (2 mg/kg) and bupivacaine (0.75 mg/kg). Osteosynthesis was performed with two Rush pins and an intramedullary pin. Radiographic examination 110 and 330 days after the surgical procedure showed good alignment of the bone and adequate healing of the fracture. The combination of techniques used in this case report proved to be effective, resulting in functional recovery of the limb and rapid bone healing.[...]

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Avanços na compreensão da biologia óssea e das complicações das fraturas têm levado a modificações na abordagem da fixação interna, sendo a osteossíntese minimamente invasiva com placa (Mipo) uma das recentes evoluções para o manejo biológico das fraturas. O objetivo do presente estudo foi avaliar o uso de placas bloqueadas aplicadas de forma minimante invasivas em fraturas da tíbia de cães, sem a utilização de intensificadores de imagem intraoperatória. Foram utilizados 10 cães que apresentavam fraturas da tíbia, de idades e raças variadas. Os animais foram avaliados quanto à deambulação, à intensidade do edema, e exames radiográficos foram realizados nos períodos zero, 15, 30, 60, 90 e 120 dias de pós-operatório. Após 15 dias de pós-operatório, 80% dos cães já utilizavam o membro ao caminhar e apresentavam formação de edema discreto a ausente no membro operado. Após 30 dias de pós-operatório, todos os cães já apoiavam o membro ao caminhar e não apresentavam formação de edema. Todos os pacientes apresentaram sinais radiográficos de início de consolidação óssea após 15 dias de pós-operatório e pôde-se observar que a união clínica ocorreu em média aos 42,5 dias. O tratamento de fraturas de tíbia por meio da Mipo é alternativa eficaz, resultando em utilização precoce do membro e união clínica efetiva, e pode ser realizado sem uso de intensificadores de imagem.(AU)

Advances in the comprehension of bone healing and complications of treatment of fractures have occurred. Less invasive procedures have been advocated. A minimally invasive plate osteosynthesis (MIPO) is one of the ways to avoid tissue damage. The aim of this study was to evaluate the use of MIPO in tibial fractures in dogs, with no intraoperative imaging. Ten dogs presenting tibial fracture were used. Deambulation, swelling and radiographic changes were evaluated preoperatively, just after the procedure and at 15, 30, 60, 90 e 120 days postoperatively. After 15 days of surgery 80% dogs were able to walk with slight swelling or without swelling. After 30 days all dogs have supported the member to walk and had no swelling. All dogs presented initial radiographic signs of bone healing after 15 postoperative days and it can be seen that the average clinical union occurred at 42.5 days. The treatment of tibial fractures by MIPO is an effective alternative resulting in early and effective clinical union and can be performed without the use of image intensifiers.(AU)

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A maioria dos casos de fraturas ósseas é utilizada nas cirurgias, implantes ortopédicos de osteossíntese (placa-parafuso e parafusos) e a infecção associada ao implante está relacionada com crescimento de microrganismos em biofilme. O objetivo deste estudo foi identificar os microrganismos recuperados de implantes de osteossíntese usados para fixação de fratura óssea, avaliar a viabilidade celular, a capacidade de aderência dos estafilococos e, determinar o perfil de sensibilidade/resistência aos antimicrobianos. Após a remoção cirúrgica, os conjuntos metálicos de aço inoxidável austenítico ASTM F138/F139 ou ISO NBR 5832-1/9 foram enviados ao Laboratório de Microbiologia Clínica, lavados em solução tampão e submetidos ao banho ultrassônico em 40±2 kHz por 5 minutos. O fluido sonicado foi semeado em meios de cultura e a viabilidade celular foi avaliada por meio de marcador fluorescente. A produção de polissacarídeo extracelular por Staphylococcus spp. foi averiguada por meio do teste de aderência em placa de poliestireno. O perfil de sensibilidade/resistência foi determinado por meio de técnica do disco difusão. As bactérias mais isoladas incluíram Staphylococcus coagulase-negativa resistente à eritromicina, oxacilina e clindamicina. Em menor freqüência, Pseudomonas aeruginosa resistente à sulfametoxazol/trimetoprim e ampicilina; Acinetobacter baumannii resistente à ceftazidima; Enterobacter cloacae resistente à cefalotina, cefoxitina, cefazolina, levofloxacina, ciprofloxacina; Bacillus spp. e Candida tropicalis. A observação ao microscópio de fluorescência demonstrou agrupamentos celulares vivos envoltos em substância transparente. O teste de aderência dos Staphylococcus coagulase-negativa à placa de poliestireno mostrou que estes microrganismos são produtores de polissacarídeo extracelular. Em conclusão, os conjuntos metálicos foram colonizados por bactérias relacionadas à infecção de implantes ortopédicos, os quais apresentaram resistência múltipla aos antimicrobianos.

In the majority of cases of bone fracture requiring surgery, orthopedic implants (screw-plate and screw) are used for osteosynthesis and the infections associated with such implants are due to the growth of microorganisms in biofilms. The objective of this study was to identify microorganisms recovered from osteosynthesis implants used to fix bone fractures, to assess the viability of the cells and the ability of staphylococci to adhere to a substrate and to determine their sensitivity/resistance to antimicrobials. After surgical removal, the metal parts of austenitic stainless steel (ASTM F138/F139 or ISO NBR 5832-1/9) were transported to the Laboratory of Clinical Microbiology, washed in buffer and subjected to ultrasonic bath at 40±2 kHz for 5 minutes. The sonicated fluid was used to seed solid culture media and cell viability was assessed under the microscope by with the aid of a fluorescent marker. The production of extracellular polysaccharide by Staphylococcus spp. was investigated by means of adhesion to a polystyrene plate. The profile of susceptibility to antimicrobials was determined by the disk diffusion assay. The most frequently isolated bacteria included coagulase-negative Staphylococcus resistant to erythromycin, clindamycin and oxacillin. Less frequent were Pseudomonas aeruginosa resistant to trimethoprim/sulfamethoxazole and ampicillin, Acinetobacter baumannii resistant to ceftazidime, Enterobacter cloacae resistant to cephalothin, cefoxitin, cefazolin, levofloxacin and ciprofloxacin, Bacillus spp. and Candida tropicalis. The observation of slides by fluorescence microscope showed clusters of living cells embedded in a transparent matrix. The test for adherence of coagulase-negative Staphylococcus to a polystyrene plate showed that these microorganisms produce extracellular polysaccharide. In conclusion, the metal parts were colonized by bacteria related to orthopedic implant infection, which were resistant to multiple antibiotics.

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La colocación de implantes en diferentes partes del cuerpo ha sido realizada desde hace muchotiempo atrás. Se ha identificado diferentes factores de riesgo y complicaciones que pueden alterarlos tejidos perimplantares posterior a la colocación de estos. No existe evidencia científica que realice la comparación entre diferentes implantes colocados en diferentes partes del cuerpo.

The placement of implants on different body parts has been practiced since long ago. Variousrisk factors and complications that can alter perimplant tissue after placement of these have beenidentified. There is no scientific evidence to make the comparison among different implants placed indifferent parts of the body.

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