Estudo comparativo do uso de meloxicam por via intra-articular e sistêmica no controle da osteoartrite experimentalmente induzida em joelho de coelhos

Objective: This study aimed to evaluate morphologic changes, as well as chondroprotective and intra-articular effects of meloxicam on joint repair in rabbits induced by experimental trochleoplasty, minimizing possible adverse side effects. Methods: Thirty-five rabbits were divided into four groups: the control group, which did not undergo surgery, and operated groups, which used different ways of administering the anti-inflammatory agent: systemic, 0.2 mg/kg; intra-articular, 0.5 mg/kg; positive group control, without meloxicam. Each operated group was divided according to the periods of 7 or 30 days evaluation after surgery. Results: Regarding macroscopic and histological evaluation of cartilage, after 30 days, most animals showed almost complete joint repair, the presence of few or no inflammatory cells; whereas part of the animals treated with meloxicam presented necrosis in the trochlear ridge and absence of inflammatory cells after 7 days. In positive control group, it was observed moderate inflammation and connective tissue proliferation. None of the animals in the operated groups showed irregularities 30 days after surgery. Conclusion: Either intra-articular or systemic, meloxicam revealed to be favorable to be used for joint repair and control of inflammatory reaction. © 2013 Sociedade Brasileira de Ortopedia e Traumatologia.

Two Surgical Approaches to Fracture Malunion Repair

Two birds were presented with malunion fractures. The first was a young toco toucan (Ramphastos toco) with malunion of the tarsometatarsus that was treated by an opening-corrective osteotomy and an acrylic-pin external skeletal fixator (type II) to stabilize the osteotomy. The second bird was m adult southern caracara (Caracara plancus) with radial and ulnar malunion that was treated by closing-wedge osteotomies. Stabilization of the osteotomy sites was accomplished through 1 bone plate fixed cranially on the ulna with 6 cortical screws and an interfragmentary single wire in radius. In both cases, the malunion was corrected, but the manus of the southern caracara was amputated because of carpal joint luxation that induced malposition of the feathers.

Influence of surface treatments on the flexural strength of denture base repair

Objective: The purpose of this study was to evaluate the flexural strength of repairs made with autopolymerising acrylic resin after different treatments of joint surfaces.Material and Methods: Fifty rectangular specimens were made with heat-polymerised acrylic resin and 40 were repaired with autopolymerising acrylic resin following joint surface treatments: group 1 (intact specimens), group 2 (chemical treatment: wetting with methyl-methacrylate for 180 s), group 3 (abraded with silicon carbide paper), group 4 (abraded and wetting with methyl-methacrylate for 180 s) and group 5 (without surface treatment). The flexural strength was measured by a three-point bending test using a universal testing machine with a 100 Kgf load cell in the centre of repair at 5 mm/min cross-head speed. All data were analysed using one-way ANOVA and Tukey HSD test for multiple comparisons (p < 0.05).Results: Among repaired specimens, groups 2 and 4 had 66.53 +/- 3.4 and 69.38 +/- 1.8 MPa mean values and were similar. These groups had superior flexural strength than groups 3 and 5 that were similar and had 54.11 +/- 3.4 and 51.24 +/- 2.8 MPa mean values, respectively. Group 1 had a mean value of 108.30 +/- 2.8 MPa being the highest result.Conclusion: It can be concluded that the treatment of the joint surfaces with methyl-methacrylate increases the flexural strength of denture base repairs, although the strength is still lower than that observed for the intact denture base resin. Abrasion with sandpaper was not able to influence the flexural strength of repaired denture bases.

Repair of lamellar scleral lesions in dogs with preserved equine renal capsule: short report

OBJETIVO: Avaliar o uso da cápsula renal de eqüino preservada em glicerina 98% no reparo de lesões lamelares esclerais em cães. MÉTODOS: Foram utilizados 12 cães, machos e fêmeas, com peso médio de 12kg. Foram realizadas avaliações clínica e morfológica aos 1, 3, 7, 15, 30 e 60 dias de pós-operatório. Após anestesia geral e procedimentos padrões de preparo do campo operatório, foi realizada cantotomia temporal, seguida de incisão conjutival e escleral com área de 0,5x0,5 cm na posição de 1hora, próxima ao limbo. em seguida, um fragmento de mesma dimensão de cápsula renal de eqüino preservada em glicerina, previamente hidratado em solução salina, foi aplicado ao defeito escleral criado sendo fixado com pontos simples isolados com vicryl 7-0®. RESULTADOS: A avaliação clínica revelou blefaroespasmo/fotofobia até o sétimo dia de pós-operatório. Foi observado edema conjuntival até o quinto dia, acompanhado de secreção ocular mucóide, que persistiu até o décimo dia de pós-operatório. Não foram observados sinais clínicos de rejeição do enxerto em todos os animais, em todos os períodos avaliados. Os segmentos anterior e posterior do bulbo ocular não apresentaram sinais de inflamação. A análise morfológica revelou exsudação inflamatória aguda nos períodos precoces e intermediários da avaliação e inflamação crônica nos períodos tardios da observação. Houve incorporação do enxerto ao leito receptor. CONCLUSÃO: Os resultados sugerem que a cápsula renal de eqüino preservada pode ser mais uma alternativa de membrana biológica para o reparo de lesões esclerais lamelares em cães e no homem.

Role of the oblique ligament in the integrity of the medial collateral ligament of the canine elbow joint

Foram estudados o arranjo e o diâmetro médio das fibrilas colágenas do ligamento colateral medial da articulação do cotovelo do cão, isolado ou associado ao ligamento oblíquo e tracionado até a ruptura. Dezoito articulações foram divididas em três grupos. O primeiro grupo teve o ligamento colateral medial coletado, mas não tracionado; o segundo grupo teve o ligamento colateral medial tracionado isoladamente; o terceiro grupo teve os ligamentos colateral medial e oblíquo tracionados associadamente. O ligamento colateral medial não submetido ao ensaio de tração apresentou um padrão ondulado das fibras colágenas, o qual não foi totalmente destruído quando foi tracionado, associado ao ligamento oblíquo, e perdeu totalmente o padrão reticular das fibras colágenas quando testado isoladamente. Quando o ligamento colateral medial foi submetido à tensão isoladamente, o diâmetro médio das fibrilas colágenas aumentou em relação ao grupo não submetido à tensão. Associado ao ligamento oblíquo, o diâmetro médio das fibrilas colágenas foi o maior na região de inserção e o menor na região média, em relação aos outros grupos. Concluiu-se que o ligamento oblíquo pode favorecer a integridade da região de inserção do ligamento colateral medial, aumentando a eficácia de sua reconstrução após a lesão.

Study on the bone mineral density of broiler suffering femoral joint degenerative lesions

An experiment was carried out with male and females broilers of two different commercial breeds to evaluate bone mineral density of the right femur head. A number of 600 one-day-old broilers were raised in an experimental poultry house up to 42 days of age at the School of Veterinary Medicine and Animal Science of UNESP, Botucatu, Brazil. After slaughter, three males and three females in each breed in each of the established gross scores were selected. Their femora heads were submitted to gross examination, and subsequently the thighs were submitted to the Veterinary Hospital for radiographic analysis. Femora were also submitted to bone resistance, Seedor index, and dry matter content analyses. All these bone quality characteristics were different between males and females, independent of breed. Breeds presented similar behavior. It was possible to establish correlations between bone quality parameters, and confidence intervals for bone mineral density values, correlating them to femoral degeneration score, which allows characterizing femoral head lesions by radiographic optical densitometry.

Mechanism of anticlastogenicity of Agaricus blazei Murill mushroom organic extracts in wild type CHO (K-1) and repair deficient (xrs5) cells by chromosome aberration and sister chromatid exchange assays

Agaricus blazei Murill is a medicinal mushroom native to Brazil. The present work assessed the clastogenic and anticlastogenic potential of organic extracts (ethanol and chloroform/methanol) from the lineage AB97/11 in chinese hamster CHO-K-1 (wild type) and CHO-xrs5 (repair deficient) cells using the chromosome aberration (CA) and sister chromatid exchange (SCE) assays. In these experimental conditions were observed: (a) anticlastogenic effect at concentrations of 0.06 and 0.09% of the EtOH extract and at the 0.03 and 0.06% concentrations of the C/MetOH extract in CHO-K-1; (b) absence of protector effect on CHO-xrs5 cells; and (c) absence of protector effect in the SCE assay. These results indicate that organic extracts of A. blazei lineage AB97/11 present bio-antimutagenic type protective activity. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Considerations on corrosion and weld repair effects on the fatigue strength of a steel structure critical to the flight-safety

The aim of this study is to analyze the effects of corrosion and successive tungsten inert gas (TIC) welding repairs on the reverse bending fatigue strength of AISI 4130 steel used in components critical to the flight-safety. The tests were performed on hot-rolled steel plate specimens, 1.10 mm and 1.60 mm thick, by means of a SCHENK PWS equipment, with load ratio R = -1, constant amplitude, 30 Hz frequency and room temperature. It was observed that the reverse bending fatigue strength of AISI 4130 steel decreases due to the corrosion and the TIC welding and re-welding processes. (C) 2010 Elsevier Ltd. All rights reserved.

Repair Welding Effects on the Bending Fatigue Strength of AISI 4130 Aeronautical Steel used in a Critical to the Flight-Safety Structure

The aim of this study was to analyze the effect of successive TIG (tungsten inert gas) welding repairs on the reverse bending fatigue strength of AISI 4130 steel, which is widely used in components critical to the flight-safety. In order to simulate the abrupt maneuvers, wind bursts, motor vibration and helixes efforts, which generate cyclic bending loadings at the welded joints of a specific aircraft component called motor cradle, experimental reverse bending fatigue tests were carried out on specimens made from hot-rolled steel plate, 1.10 mm (0.043 in) thick, by mean of a SCHENK PWS equipment, with load ratio R = -1, under constant amplitude, at 30 Hz frequency and room temperature. It was observed that the bending fatigue strength decreases after the TIG (Tungsten Inert Gas) welding process application on AISI 4130 steel, with subsequent decrease due to re-welding sequence as well. Microstructural analyses and microhardness measurements on the base material, heat-affected zone (HAZ) and weld metal, as well as the effects of the weld bead geometry on the obtained results, have complemented this study.

Considerations about the welding repair effects on the structural integrity of an airframe critical to the flight-safety

Structures critical to the flight-safety are commonly submitted to several maintenance repairs at the welded joints in order to prolong the in-service life of aircrafts. The aim of this study is to analyze the effects of Tungsten Inert Gas (TIG) welding repair on the structural integrity of the AISI 4130 aeronautical steel by means of experimental fatigue crack growth tests in base-material, heat-affected zone (HAZ) and weld metal. The tests were performed on hot-rolled steel plate specimens, 0.89 mm thick, with load ratio R = 0.1, constant amplitude, at 10 Hz frequency and room temperature. Increase of the fracture resistance was observed in the weld metal but decreasing in the HAZ after repair. The results were associated to microhardness and microstructural changes with the welding sequence. (C) 2010 Published by Elsevier Ltd.

Fatigue strength of tungsten inert gas-repaired weld joints in airplane critical structures

In this work the effect of Gas Tungsten Arc Welding (GTAW) repairs on the axial fatigue strength of an AISI 4130 steel welded joint used in airframe critical to the flight-safety was investigated. Fatigue tests were performed at room temperature on 0.89 mm thick hot-rolled plates with constant amplitude and load ratio of R = 0.1, at 20 Hz frequency. Monotonic tensile tests, optical metallography and microhardness, residual stress and weld geometric factors measurements were also performed. The fatigue strength decreased with the number of GTAW repairs, and was related to microstructural and microhardness changes, as well as residual stress field and weld profile geometry factors, which gave origin to high stress concentration at the weld toe. (C) 2011 Elsevier B.V. All rights reserved.

Modeling and Experimental Aspects of Self-healing Bolted Joint through Shape Memory Alloy Actuators

Bolted joints are a form of mechanical coupling largely used in machinery due to their reliability and low cost. Failure of bolted joints can lead to catastrophic events, such as leaking, train derailments, aircraft crashes, etc. Most of these failures occur due to the reduction of the pre-load, induced by mechanical vibration or human errors in the assembly or maintenance process. This article investigates the application of shape memory alloy (SMA) washers as an actuator to increase the pre-load on loosened bolted joints. The application of SMA washer follows a structural health monitoring procedure to identify a damage (reduction in pre-load) occurrence. In this article, a thermo-mechanical model is presented to predict the final pre-load achieved using this kind of actuator, based on the heat input and SMA washer dimension. This model extends and improves on the previous model of Ghorashi and Inman [2004, "Shape Memory Alloy in Tension and Compression and its Application as Clamping Force Actuator in a Bolted Joint: Part 2 - Modeling," J. Intell. Mater. Syst. Struct., 15:589-600], by eliminating the pre-load term related to nut turning making the system more practical. This complete model is a powerful but complex tool to be used by designers. A novel modeling approach for self-healing bolted joints based on curve fitting of experimental data is presented. The article concludes with an experimental application that leads to a change in joint assembly to increase the system reliability, by removing the ceramic washer component. Further research topics are also suggested.

Comparative study between two techniques of incisional hernia repair with polypropylene mesh in rabbits

OBJETIVO: Comparar duas técnicas de tratamento da hérnia incisional em coelhos utilizando a tela de polipropileno apoiando um reforço peritônio - aponeurótico ou suturada nas bordas do anel herniário 'em ponte . MÉTODOS: Foram operados 60 coelhos para a produção de hérnia incisional, em uma incisão mediana de 4 centímetros. Após 30 dias, metade dos animais foram operados com o fechamento primário da parede, com colocação de uma tela de polipropileno apoiando o reforço e a outra metade dos animais com a colocação da tela suturada nas bordas do anel herniárioem ponte . Os animais foram avaliados com 30 (M1), 60 (M2)e 90 (M3) dias de pós-operatório. Os parâmetros analisados foram a evolução clínica, análise da força de ruptura da cicatriz, estudo macroscópico, análise microscópica e morfométrica. RESULTADOS: Não foram observadas diferenças significantes com relação a força de ruptura e estudos histológicos nos dois grupos e vários momentos estudados. Não houve diferença estatística com relação às complicações, embora os animais que receberam a telaem ponte tiveram aderências mais firmes e intensas à parede abdominal. CONCLUSÕES: As duas técnicas utilizadas para correção da hérnia incisional em coelhos não mostraram diferenças significantes quanto a força de ruptura, análise histológica e morfométrica. O número de complicações foi semelhante, porém a aderência de órgãos da cavidade abdominal à área de cicatriz foi muito mais intensa no grupo em que a tela foi colocadaem ponte .

Repair of the anophthalmic cavity of rats with synthetic hydroxyapatite

We placed spheres of synthetic hydroxyapatite (calcium chloride combined with sodium phosphate) in the eviscerated or enucleated orbital cavity of rats in order to evaluate the biocompatibility of this material with the orbital cavity. The study was conducted on 50 albino rats, 25 of which were submitted to enucleation and 25 to evisceration of one eye. The animals were sacrificed 7, 15, 21, 30 and 60 days after surgery and the orbital content was submitted to histopathological examination. A reaction of the young granulation tissue type was observed first. The hydroxyapatite was gradually surrounded by a granulomatous macrophage inflammatory response and covered with dense connective tissue that formed a sort of mesh septating and supporting progressively smaller blocks of the substance. The same type of reaction was observed in the enucleated and eviscerated cavities. We conclude that synthetic hydroxyapatite is an inert nonallergenic material which is appropriate for volume replacement in the anophthalmic cavity

Vegetal polymer in repair of defects of the orbital floor: an experimental study in rabbits

Background: An experimental study was done to assess the ability of the vegetal polymer miniplates and screws to repair defects of the orbital floor.Methods: An artificial standard-sized defect was created in the bony floor of right orbit of 45 albino rabbits. The animals were divided into three experimental groups: control group (G1) involving animals with orbital floor defect and no treatment; titanium group (G2) containing animals with orbital floor defect repaired by titanium miniplates and screws; vegetal polymer group (G3) composed of animals with similar orbital floor defects repaired by vegetal polymer miniplates and screws. Throughout the course of the experiment, the animals were clinically evaluated. At 15, 30 and 60 days after surgery, the animals were killed. They were X-rayed immediately after the floor defect and at the moment of sacrifice. Histological and morphometric evaluation of inflammatory reaction and bone healing was done. Data were statistically evaluated.Results: No implants were extruded. Bone consolidation was similar in G2 and G3 and better than in G1 group animals. Inflammatory reaction was most pronounced in animals of G3 15 days after surgery, and it subsided over time.Conclusion: Vegetal polymer miniplates and screws induces small inflammatory reaction and had the ability to stimulate bone growth with good integration in the orbital floor defect allowing to consider the vegetal polymer adequate option to treat orbital floor defects. Future studies involving long-term follow-up and biomechanical tests to evaluate material resistance to traction are needed.