ABSTRACT: Nowadays, alternative methods that do not use formaldehyde to preserve cadavers must be used due to this substance’s toxicity. Synthetic models are a training option for teaching, but cost makes their use unviable in most underdeveloped countries. The present study’s main objective was to develop a model for education and researching thorax radiology in cadavers of chemically prepared dogs. Megaesophagus, pleural effusion, pneumothorax, and bronchography, as well as pulmonary insufflation, were simulated in 32 dogs cadavers, which received 150 mL/kg of pure ethyl alcohol solution with 5% glycerin followed by injection of 120 mL/kg of a solution containing 20% sodium chloride, 1% sodium nitrite and 1% sodium nitrate; they were kept refrigerated between 2 to 6 °C, for 30, 60, 90 or 120 days (G30, G60, G90, G120). There was no contamination, putrid odor, or subcutaneous emphysema. The pulmonary insufflation was kept, and the color and the consistency were similar to a fresh corpse after 120 days of conservation. It was possible to perform radiographic procedures, and almost all affections could be greatly mimicked. Megaesophagus and bronchography were easily simulated. Pneumothorax was the most challenging condition to be reproduced, especially in cadavers with some liquid in the thorax. The alcoholic and curing salt solutions are an embalming alternative with low financial and environmental costs and proved to preserve corpses.

RESUMO: Nos dias atuais, métodos alternativos e que não utilizem o formaldeído para conservação de cadáveres devem ser empregados, devido à toxicidade desse agente. Modelos sintéticos são opção de treinamento para o ensino, mas geralmente o preço inviabiliza seu uso na maioria dos países subdesenvolvidos. O objetivo do presente trabalho foi desenvolver um modelo visando ao ensino e pesquisa da radiologia torácica em cadáveres de cães quimicamente preparados. Foram simulados megaesôfago, efusão pleural, pneumotórax e broncografia, além de insuflação pulmonar, em 32 cadáveres de cães, que receberam 150 mL/kg de solução de álcool etílico puro com 5% de glicerina seguido de injeção de 120 mL/kg de solução contendo 20% de cloreto de sódio, 1% de nitrito de sódio e 1% de nitrato de sódio, mantidos sob refrigeração entre 2 e 6 graus, por 30, 60, 90 ou 120 dias (G30, G60, G90, G120). Não houve contaminação, odor pútrido ou enfisema subcutâneo. A insuflação pulmonar foi mantida, e a cor e a consistência foram semelhantes a um cadáver fresco após 120 dias de conservação. Em todos os grupos foi possível realizar os procedimentos radiográficos e quase todas afecções puderam ser grandemente mimetizadas. O megaesôfago e a broncografia foram facilmente simuladas. O pneumotórax foi a afecção mais difícil de ser simulada principalmente nos cadáveres com um pouco de líquido na cavidade torácica. A solução alcoólica e de sal de cura são uma alternativa de embalsamamento com baixo custo financeiro e ambiental e comprovadamente conservam cadáveres.

ABSTRACT: Cervical arthroplasty with disc prosthesis has been proposed as a treatment option for dogs with Cervical Spondylomyelopathy. The present study developed a novel vertebral disc prosthesis for dogs. Sixteen Functional Spinal Units (C5-C6) were collected from dog cadavers with body weights ranging between 25 and 35 kg, and their vertebral measurements were used to design a prosthetic disc. The sizing of the prosthesis was performed based on the averages of the measurements of width, height, and length of the vertebral bodies from C5-C6 of all specimens. The prosthesis was developed using the Rhinoceros 3D® and SolidWorks® programs, and 3D prototyping was carried out to define the best design. The developed prosthesis consisted of two independent parts that are fixed to the cranial and caudal vertebral bodies, in the intervertebral space, and fitted together by metal-to-metal surfaces capable of moving in the lateral, ventral, and dorsal directions. Each part of the prosthesis is angled in two portions: vertically, in the intervertebral space, and horizontally, in contact with the ventral surface of the vertebral bodies, both of which are fixed by means of monocortical locking screws. The design of the developed prototype allowed a good fit in the intervertebral space between C4-C5, C5-C6, and C6-C7.

RESUMO: A artroplastia cervical com prótese de disco tem sido proposta como uma opção de tratamento para cães com Espondilomielopatia Cervical. O presente estudo teve como objetivo desenvolver uma nova prótese de disco intervertebral para cães. Dezesseis Unidades Funcionais de Coluna Vertebral (C5-C6) foram coletadas de cadáveres de cães com peso corporal variando entre 25 e 35 kg, e suas medidas vertebrais foram usadas para projetar um disco intervertebral protético. O dimensionamento da prótese foi realizado com base nas médias das mensurações da largura, altura e comprimento dos corpos vertebrais de C5-C6 de todos os espécimes. A prótese foi desenvolvida nos programas Rhinoceros 3D® e SolidWorks® e utilizou-se prototipagem em 3D para a definição do melhor design. A prótese desenvolvida é formada por duas partes independentes que se fixam às espífises dos corpos vertebrais cranial e caudalmente ao espaço intervertebral, e se encaixam entre si por superfícies de metal-metal com capacidade de movimentação nas direções lateral, ventral e dorsal. Cada parte da prótese é angulada em duas porções: a vertical, que fica no espaço intervertebral, e a horizontal, que fica em contato com a superfície ventral dos corpos vertebrais, ambas as quais são fixadas por meio de parafusos bloqueados monocorticais. O design do protótipo desenvolvido permitiu bom encaixe no espaço intervertebral entre C4-C5, C5-C6 e C6-C7.

ABSTRACT Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate–PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

ABSTRACT Purpose To use a 3D printed poly (L-lactide) acid (PLLA) and hydroxyapatite (HA) composite as a bone substitute for reconstruction of a critical bone defect in the radius of rabbits. Methods A 1.5 cm ostectomy was performed in the radial diaphysis of 60 New Zealand white rabbits. The rabbits were divided into three groups according to surgical treatment of the bone defect (group I – control, group II – bone graft, group III – 3D PLLA). Each group was divided into four subgroups with different radiographic and histopathologic evaluation times (T1 – 15 days, T2 – 30 days, T3 – 60 days, T4 – 90 days). Results The implant group had greater clinically lameness (p = 0.02), edema (p = 0.007), pain (p = 0.04) and more complications at the surgical site (p = 0.03). Histologically, this group showed greater congestion (p = 0.04), hemorrhage (p = 0.04) and inflammation. Osteogenesis was microscopically similar between days (p = 0.54) and treatments (p = 0.17), even though radiographically, more effective bone healing occurred in the graft group (II), with more callus and bone bridge formation. Conclusions The customization of a 3D PLLA/HA scaffold was successful. However, in animals receiving the polymer-ceramic composite less bone callus and bone bridge was formed compared to the graft group.

ABSTRACT The aim of this study was to evaluate the feasibility of using ethanol (AE) and an aqueous sodium chloride solution 30% (ASCS) in various time periods for the preparation of carcasses of cats for the teaching of surgical techniques. The corpses of 60 cats were used. The specimens were fixed in AE, according to group, for 30 days (G1), 30 and 60 days (G2) and 30, 60 and 90 days (G3), and ASCS was applied to all of them at 30, 60, 90 and 120 days of conservation and the result was measured by means of the biomechanical study in the tissues to determine the best moment to interrupt the fixation in AE using as control the greatest similarity in tissue resistance found in fresh cadavers. The use of the anatomicaltechniqueusingAE andASCSwas efficientthroughout theexperiment.There was no significant difference between the mean value of the maximum breaking force (N) or between the storage groups in the ASCS and the control group in any of the groups for the skin samples. Neither was there a significant difference in maximum force between fixation and preservation groups, compared to the control group in the groups for jejunum samples. However, G2 presented less variation in the breaking force (-0.21 mm), being, therefore, the group most similar to fresh animals. The anatomical technique used was found to be efficient for both fixation and preservation of cat carcasses for up to seven months.

RESUMEN El objetivo del estudio fue evaluar la factibilidad de utilizar alcohol etílico (AE) y una solución acuosa de cloruro de sodio al 30% (SACS) en varios periodos de tiempo para la preparación de cadáveres de gatos para la enseñanza de técnicas quirúrgicas. Se utilizaron los cadáveres de 60 gatos. Los especímenes fueron fijados en AE, según grupo, por 30 días (G1), 30 y 60 días (G2) y 30, 60 y 90 días (G3), y a todos se les aplicó SACS a los 30, 60, 90 y120 días de conservación y el resultado fue medido mediante el estudio biomecánico en los tejidos para determinar el mejor momento para interrumpir la fijación en AE, utilizando como control la mayor similitud en la resistencia tisular encontrada en cadáveres frescos. El uso de la técnica anatómica utilizando AE y SACS fue eficiente durante todo el experimento. No hubo diferencia significativa entre las medias de la fuerza máxima de ruptura (N) ni entre los grupos de almacenamiento en el SACS y el tiempo de control en ninguno de los grupos para las muestras de piel. Tampoco se observó diferencia significativa en la fuerza máxima entre los grupos de fijación y preservación, comparado al grupo control en los grupos para las muestras de yeyuno. No obstante, G2 presentó menor variación en la fuerza de ruptura (-0.21 mm), siendo, por lo tanto, el grupo más parecido a los animales frescos. Se encontró que la técnica anatómica utilizada es eficiente tanto para la fijación y para la conservación de cadáveres de gatos por hasta siete meses.