Effects of time-dependent degradation and freezing on biomechanical properties of healthy bovine jejunum / Efeitos da degradação dependente do tempo e do congelamento sobre as propriedades biomecânicas do jejuno bovino saudável

Degradation of bovine small intestine and respective effects on biomechanics have not been described to date. Biomechanical testing of intestinal tissues is often carried out within a few hours of donor death and tissue deterioration is not accounted for. Freezing is efficient for the preservation of several tissues; however, it may cause cellular damage. This study investigated the morphologic and biomechanical changes of bovine jejunum at different postmortem moments. Effects of freezing and thawing on morphology and biomechanical behavior were also examined. Macroscopic changes were first noted within eight hours of death. At this time, histologic changes also started to set in, and biomechanical tests revealed lower bursting pressure (203.10±46.14mmHg). At 12 hours, tissue rearrangement was noted, and bursting pressure increased (238.43±31.04mmHg). A second drop in pressure was detected at 18 hours (235.20±38.21mmHg), followed by a progressive drop until the end of the experimental period. Histologic changes revealed progressive deterioration. Mechanical resistance did not differ between thawed and fresh specimens. It was concluded that bovine jejunal specimens retain biomechanical resistance up to 6 hours after death. Freezing and thawing did not affect the mechanical resistance of the intestinal wall in this experimental model.

A degradação do intestino delgado de bovinos e seu efeito biomecânico não são descritos na literatura. Trabalhos que envolvem a biomecânica intestinal realizam os ensaios em poucas horas após o óbito dos doadores, sem avaliação de seu estado de deterioração. O congelamento é eficiente na conservação de vários tecidos, porém pode provocar danos em nível celular. Este estudo teve por objetivo avaliar a degradação morfológica e biomecânica do jejuno de bovinos em diferentes tempos post mortem. O efeito do congelamento e do descongelamento sobre essas características também foi avaliado. As primeiras alterações macroscópicas foram observadas oito horas após o óbito. No mesmo momento, se iniciaram as alterações histológicas e a menor pressão suportada ao teste biomecânico (203,10±46,14mmHg). A partir de 12 horas, o tecido sofreu um rearranjo, suportando maior pressão (238,43±31,04mmHg). Uma segunda queda foi detectada após 18 horas (235,20±38,21mmHg), seguida de redução progressiva até o término do experimento. As lesões histológicas foram progressivas e graduais. As amostras testadas após descongelamento não apresentaram diferença estatística quanto à resistência mecânica em comparação com os espécimes frescos. Concluiu-se que as amostras mantêm sua resistência biomecânica até 6 horas após o óbito. Também se mostrou que o congelamento e o descongelamento, nas condições testadas, não alteraram a resistência mecânica da parede intestinal.

Effect of lunging exercise program with Pessoa training aid on cardiac physical conditioning predictors in adult horses / Efeito de um programa de exercício utilizando Rédea Pessoa sobre preditores de condicionamento físico em cavalos adultos

The aim of this study was to evaluate the effect the Pessoa training aid (PTA) exercise program exerts in some physical conditioning predictors. Eight detrained adult horses were evaluated in 12 sessions of work with PTA (3 sessions per week). All horses used a heart rate monitor and GPS (V800, Polar Electro) and data was used to calculate energy expenditure (EE), net cost of transport (COT), metabolic energy requirement (Pmet), oxygen pulse, oxygen utilization, heart rate and heart rate variability (HRV). The horses were weighted, and the thoracolumbar shape were measured at the level of the 18th (T18), 13th (T13) and 8th (T8) thoracic vertebrae with a flexible ruler before and after the experimental period. Data obtained weekly were submitted to ANOVA and Tukey test (p≤0.05). Data obtained just before and after the experimental period were submitted to paired t test. There was a decrease in left-right asymmetry. In the third week there was an increase in HR, EE, oxygen pulse and oxygen utilization followed by a decrease in the fourth week. The biomechanics related parameters, COT and Pmet decreased week by week. The HRV showed a sympathetic stimulus in the third week followed by a shift to parasympathetic in the fourth week. We conclude that 12 sessions of lunge exercise with PTA contributed to physical condition improvement.

O objetivo deste estudo foi avaliar o efeito que um programa de exercício com Rédea Pessoa exerce sobre algumas variáveis de condicionamento físico. Oito cavalos adultos destreinados foram avaliados em 12 sessões de exercício de chão com Rédea Pessoa. Todos os cavalos trabalharam com frequencímetro cardíaco e GPS para a obtenção das frequências cardíacas (HR) e variabilidade de frequência cardíaca (HRV) e cálculos de gasto energético (EE), custo de transporte metabólico (COT), requerimento de energia metabólica (Pmet), pulso de oxigênio e utilização de oxigênio. Também foram avaliadas medidas na altura das vértebras torácicas T18, T13 e T8 com régua flexível antes e depois do experimento quando os animais foram pesados. Os dados obtidos semanalmente foram analisados por ANOVA e Tukey teste (p≤0.05). Os dados obtidos somente antes e após o período experimental foram analisados pelo teste t pareado. Houve diminuição da assimetria entre os lados direito e esquerdo. Na terceira semana houve aumento da FC, EE, pulso de oxigênio e utilização de oxigênio seguido de diminuição na quarta semana. Os parâmetros relacionados à biomecânica, COT e Pmet diminuíram semana a semana. A VFC apresentou estímulo simpático na terceira semana seguido de desvio para parassimpático na quarta semana. Concluiu-se que 12 sessões de exercício com a Rédea Pessoa contribuíram para melhora do condicionamento físico.

Effect of ascorbic acid and epidermal growth factor in a rat tibia defect

Purpose: Bone repair aims to restore the anatomical, biomechanical, and functional integrity of the affected structure. Here we study the effects of ascorbic acid (AA) and epidermal growth factor (EGF) applied in a single dose and in combination on the repair of a noncritical bone defect model. Methods: Twenty-four rats were divided into four groups: an intact G-1 control group, and three groups that underwent a noncritical bone defect in the right tibia: G-2 treated with AA, G-3 treated with EGF, and G-4 treated with AA in combination with EGF. After 21 days of treatment, rats were sacrificed, the tibias were dissected and a destructive biomechanical analysis of three-point flexion test was performed in a universal testing machine; the values of stiffness, resistance, maximum energy, and energy at maximum load were statistically compared. Results: G-3 and G-4 recovered the biomechanical properties of strength and stiffness of an intact tibia 3 weeks after their application. Not so the energy and energy at maximum load. For G-2, only the stiffness of an intact tibia was recovered. Conclusion: EGF and AA-EGF applied to a noncritical bone defect in the rat tibia favors the recovery of bone resistance and stiffness.

Aspectos da locomoção e bases gerais dos andamentos básicos naturais dos equinos / Aspects of locomotion and general bases of basic natural gait of horses / Aspectos de locomoción y bases generales de la marcha natural básica en caballos

A locomoção é a função do organismo que permite executar os movimentos corporais e o deslocamento do centro de gravidade em qualquer direção. Os andamentos são considerados formas de locomoção, que podem ser habilidades inatas ou adquiridas, e se classificam em naturais ou artificiais e em básicos ou especiais. Os básicos naturais são o passo, a andadura, o trote e o galope de três e quatro tempos. Entre os andamentos naturais especiais estão as marchas, como a picada e a batida, presentes em algumas raças de equinos brasileiras, e as modalidades de "paso" ocorrentes nos cavalos passo fino Peruano, fino Colombiano e fino de Porto Rico. Nos andamentos os equinos movimentam os membros locomotores, deslocam o corpo com características como a velocidade, sequência dos momentos de apoio e elevação, além de mostrar as pegadas, as pistas e as batidas, que são características biomecânicas que definem os andamentos. O estudo dos andamentos é parte vinculante da biomecânica/cinesiologia e, portanto, deve ser compreendido além da anatomia funcional ou da fisiologia, da medicina esportiva e do estudo das claudicações. Esta revisão tem por objetivo revisar e descrever os conceitos gerais da locomoção e os diferentes andamentos naturais em equinos.(AU)

Locomotion is the function of the organism that allows the execution of body movements and displacement of the center of gravity in any direction. Gaitsare the forms of locomotion that can be innate or acquired skills, classified as natural or artificial and as basic or special. The natural basic gaits are the walk, pace, trot and three-and four-beat gallop. Among the special natural gaits are the gaits, such as the "marcha batida" and "marcha picada", observed in some Brazilian horse breeds, and the "paso" modalities that occur in Peruvian fine, Colombian fine and Puerto Rican fine horses. In the gaits, the horses move the limbs, move the body with characteristics such as speed, sequence of moments of bearing and elevation, and show the footprints, tracks and beats, which are biomechanical characteristics of the gaits. The study of gaits is a complementary part of biomechanics/kinesiology and must be understood beyond functional anatomy or physiology, sports medicine and the study of lameness. This literature review aims to describe the general concepts of locomotion and the different natural gaits in horses.(AU)

La locomoción es la función del organismo que permite la ejecución de movimientos corporales y el desplazamiento del centro de gravedad en cualquier direcciónde un entorno. Los modos de andar se consideran formas de locomoción que pueden ser habilidades innatas o adquiridas, clasificadas en naturales o artificiales y en básicas o especiales. Los fundamentos naturales son el paso, la ambladura, el trote, el galope de tres y cuatro tiempos. Entre los aires naturales especiales están los aires, como las "marchas batida" y "marcha picada", presentes en las razas de caballos brasileños, y las modalidades de "paso" que se dan en los caballos finos peruanos, finos colombianos y finos puertorriqueños. En las marchas, los caballos mueven las extremidades locomotoras, mueven el cuerpo con características como velocidad, secuencia de momentos de apoyo y elevación, además de mostrar las pisadas, huellas y golpes, que son características biomecánicas que definen las marchas. El estudio de revision de la marcha es una parte vinculante de la biomecánica/kinesiología y, por lo tanto, debe entenderse más allá de la anatomía o fisiología funcional, la medicina deportiva y el estudio de la cojera, siendo estos partes de la "ciencia equina". Este material tiene como objetivo revisar y describir los conceptos generales de locomoción y los diferentes aires naturales en los caballos.(AU)

Ex vivo biomechanical testing of Funkquist B dorsal laminectomy between the sixth and seventh cervical vertebrae in dogs / Análise biomecânica ex vivo dos efeitos da laminectomia dorsal Funkquist B entre a sexta e a sétima vertebras cervicais em cães

Dorsal laminectomy is routinely performed for spinal cord compressions or stenosis of the cervical vertebral canal. However, despite good results, relevant complications have been described in dogs. Considering the incomplete understanding of the necessity for complementary surgical stabilization after performing laminectomies in the cervical region, this study compared the resistance and range of motion (ROM) of the cervical spinal column subjected to Funkquist B laminectomy between the sixth and seventh vertebrae in dogs. Forty-four cervical vertebral columns (C2-T1) of dogs, with an average weight of 26.2±3.8 kg, were selected using radiography and computed tomography. Four experimental groups (n=11) were established according to the mechanical test: two control groups (flexion and extension control) and two laminectomy groups (flexion and extension laminectomies). Numerical results of the maximum load for measuring the resistance and ROM of the columns of the two control groups and the two laminectomy groups were compared. The laminectomy groups showed a lower maximum load, regardless of the mechanical test performed (P<0.001). The ROM was not influenced by laminectomy, the type of mechanical test (ventral flexion or extension), or its interaction (P<0.05). There was no interaction between the effect of the laminectomy factors (yes or no) and the effect of the mechanical tests for ventral flexion or extension (P<0.05). In conclusion, Funkquist B dorsal cervical laminectomy between C6 and C7 decreases mechanical resistance with a supraphysiological loading force but does not alter the ROM, suggesting that it can be used without additional mechanical stabilization in dogs.

A laminectomia dorsal é realizada com frequência no tratamento de compressões medulares ou estenose do canal vertebral cervical. No entanto, complicações relevantes têm sido descritas em cães. Considerando que ainda não há entendimento completo da necessidade de estabilização cirúrgica complementar após a realização de uma ou múltiplas laminectomias na região cervical, o objetivo deste estudo foi comparar a resistência e amplitude de movimento (ADM) da coluna cervical submetida à laminectomia Funkquist B entre a sexta e a sétima vértebras em cães. Quarenta e quatro colunas vertebrais cervicais (C2-T1) de cães, com peso médio de 26,2 ± 3,8 kg, foram selecionadas por meio de radiografia e tomografia computadorizada. Quatro grupos experimentais (n = 11) foram estabelecidos de acordo com o teste mecânico realizado: dois grupos controle (flexão e extensão controle) e dois grupos laminectomia (flexão e extensão laminectomia). Os resultados numéricos da carga máxima para medir a resistência e ADM das colunas dos dois grupos de controle e dos dois grupos de laminectomia foram comparados. Os grupos de laminectomia apresentaram menores valores de carga máxima, independentemente do teste mecânico realizado (P < 0,001). A ADM não foi influenciada pela laminectomia, tipo de teste mecânico (flexão ou extensão ventral) ou sua interação (P < 0,05). Não houve interação entre o efeito do fator de laminectomia, sim ou não, ou o efeito do teste mecânico na flexão ou extensão ventral (P < 0,05). A laminectomia cervical dorsal Funkquist B entre C6 e C7 diminui a resistência mecânica com uma força de carga suprafisiológica, mas não altera a ADM, sugerindo que pode ser usada sem estabilização mecânica adicional em cães.

Objective lameness assessment in horses used for equine-assisted therapy in Rio Grande do Sul state, Brazil / Avaliação objetiva da claudicação em cavalos de equoterapia no Rio Grande do Sul, Brasil

Equine-assisted therapy is a method used since ancient times to rehabilitate individuals. The biomechanics provided by horses and the friction between their back and the riders' saddle generate impulses that are transmitted to riders' central nervous system; thus, these horses must be healthy enough to enable the desired therapeutic effect. The aim of the current study is to investigate lameness prevalence and intensity in equine-assisted therapy horses in Rio Grande do Sul State. The adopted methodology consisted of the objective evaluation of lameness based on Lameness Locator® wireless inertial sensors, which were placed in the 21 horses assessed in six equestrian centers in Rio Grande do Sul State. Results have shown that 90.1% of the assessed horses presented lameness in the hind (54.2%) and forelimbs (45.8%), as well as that 72% of them with presented mild lameness degree. This outcome has evidenced the need, and significance, of assessing these horses' locomotor system. To support effective therapy and protect equine welfare, it is essential that veterinarians should regularly monitor these animals in order to treat and prevent disease. Even subtle lameness can influence the generated stimuli; thus, it is an important factor to be taken into consideration when selecting equine-assisted therapy.

A equoterapia é um método de terapia, utilizada para reabilitação do praticante desde a antiguidade. A biomecânica proporcionada pelo cavalo e o atrito entre o dorso do cavalo e a sela do praticante geram impulsos que são transmitidos ao sistema nervoso central do mesmo, por isso a importância desse cavalo estar em condições aptas para promover o efeito terapêutico desejado. Nosso objetivo foi identificar a prevalência e intensidade da claudicação em equinos de equoterapia no estado do Rio Grande do Sul. A metodologia utilizada foi a avaliação objetiva da claudicação com base na utilização de sensores inerciais sem fio Lameness Locator® em seis centros equestres do Rio Grande do Sul, totalizando 21 equinos avaliados. Foi constatado que 90,1% dos equinos avaliados apresentavam claudicação, 54,2% do membro pélvico e 45,8% do membro torácico, quanto a intensidade 72% foram leves. A partir desse resultado, verifica-se a necessidade e a importância da avaliação no sistema locomotor destes animais. Para uma terapia eficaz e proteger o bem-estar dos equinos, é essencial o acompanhamento periódico por um médico veterinário para tratamento e prevenção de afecções. Claudicações, mesmo sutis, podem interferir nos estímulos gerados, sendo um importante fator de escolha do cavalo apto para a equoterapia.

Effect of glycerol addition time on the cryopreserved Korean native brindle cattle (Chikso) sperm quality

Although cryopreservation is an efficient method for maintaining the biological and genetic resources of sperm, the sperm damage during the cryopreservation process cannot be ignored. It should be possible to obtain the most effective cryopreservation performance by accurately grasping the effects of various factors on the cryopreservation of sperm. The previous study demonstrated that a suitable standard protocol for cryopreservation of Korean native brindled cattle (Chikso) does not exist, based on the methods for semen cryopreservation of Chikso differ in each research center. The most obvious difference between most of protocols is the addition of glycerol before and after cooling during the Chikso cryopreserved semen process. Therefore we focused on the effects of glycerol addition time on the quality of cryopreserved Chikso sperm. In the present study, 27 individual Chikso samples were collected by transrectal massage and divided into two parts: the "cryopreservation method A" group (adding glycerol before cooling) and the "cryopreservation method B" group (adding glycerol after cooling). Meanwhile, the values of various sperm parameters were derived from each group, including sperm motility, kinematics, capacitation status, cell viability, and intracellular ATP levels, which we used to compare and evaluate sperm function. The results of this study indicated that during the semen cryopreservation process of the Chikso, the addition of glycerol after cooling yielded superior results in a variety of sperm parameters, such as sperm motility, progressive motility, rapid motility, VCL, VSL, VAP, ALH, capacitation status, viability, and intracellular ATP level after freezing and thawing. Our study is suggested that the glycerol addition time during the cryopreservation process for Chikso should be considered. In addition, our results may be provided reference to develop suitable the cryopreservation procedure of the Chikso sperm.(AU)

Biomechanical comparison of a modified TPLO plate, a locking compression plate, and plate-rod constructs applied medially in a proximal gap model in canine synthetic tibias / [Comparação biomecânica entre placa de TPLO modificada, placa bloqueada e construção placa-pino intramedular aplicadas medialmente em modelo de fratura proximal em tíbias sintéticas caninas]

The aim of this study was to develop a modified tibial plateau leveling osteotomy (TPLO) plate and to compare its biomechanical properties with a locking compression plate (LCP) and plate-rod constructs for the stabilization of experimentally induced gap fractures in canine synthetic tibias. The tibial models were assigned to either repair with a modified TPLO plate (Group 1), locking compression plate construct (Group 2), or plate-rod construct (Group 3). The specimens were loaded to failure in axial compression, three-point mediolateral and craniocaudal bending. There was no statistical difference between the three groups regarding stiffness (N/mm) and deformation (mm) in axial compression. The modified TPLO plate achieved load to failure similar to the plate-rod construct in craniocaudal bending. There was no significant difference between groups on mediolateral bending tests regarding load to failure and deformation. Furthermore, there was no significant difference in stiffness between groups 1 and 2. In conclusion, the modified TPLO plate had similar mechanical properties to LCP and plate-rod construct in the axial compression and bending tests. Nonetheless, clinical studies with a large population of dogs are required to determine the value of this new implant in proximal tibial fracture repair.

Objetivou-se desenvolver uma placa de osteotomia niveladora do platô tibial (TPLO) modificada e compará-la biomecanicamente à placa de compressão bloqueada (LCP) e à construção placa-pino intramedular na estabilização da fratura cominutiva proximal em tíbias sintéticas caninas. Para tal, tíbias caninas sintéticas foram divididas em três grupos, sendo o grupo 1 formado pela placa de TPLO modificada, o grupo 2 por placas LCP e o grupo 3 pela construção placa-pino intramedular. Os espécimes foram submetidos à carga até a falha em compressão axial, flexão mediolateral e craniocaudal em três pontos. Não houve diferença estatística entre os três grupos quanto à rigidez (N/mm) e à deformação (mm) nos testes de compressão axial. A placa de TPLO modificada obteve carga até a falha semelhante à construção placa-pino intramedular em flexão craniocaudal. Não houve diferença significativa entre os grupos nos testes de flexão mediolateral em relação à carga até a falha e a deformação, e a variável rigidez não apresentou diferenças significativas entre os grupos 1 e 2. Em conclusão, a placa de TPLO modificada apresentou similaridade mecânica em comparação com a LCP e a construção placa-pino. No entanto, estudos clínicos são necessários para determinar o valor desse novo implante na fixação de fraturas tibiais proximais.

Two-dimensional and three-dimensional techniques for determining the kinematic patterns for hindlimb obstacle avoidance during sheep locomotion / Técnicas bidimensionais e tridimensionais para determinar os padrões cinemáticos durante a ultrapassagem de obstáculos pelos membros pélvicosdurante a locomoção de ovinos

Analysis of locomotion is often used as a measure for impairment and recovery following experimental peripheral nerve injury. Compared to rodents, sheep offer several advantages for studying peripheral nerve regeneration. In the present study, we compared for the first time, two-dimensional (2D) and three-dimensional (3D) hindlimb kinematics during obstacle avoidance in the ovine model. This study obtained kinematic data to serve as a template for an objective assessment of the ankle joint motion in future studies of common peroneal nerve (CP) injury and repair in the ovine model. The strategy used by the sheep to bring the hindlimb over a moderately high obstacle, set to 10% of its hindlimb length, was pronounced knee, ankle and metatarsophalangeal flexion when approaching and clearing the obstacle. Despite the overall time course kinematic patterns about the hip, knee, ankle, and metatarsophalangeal were identical, we found significant differences between values of the 2D and 3D joint angular motion. Our results showed that the most apparent changes that occurred during the gait cycle were for the ankle (2D-measured STANCEmax: 157±2.4 degrees vs. 3D-measured STANCEmax: 151±1.2 degrees; P .05) and metatarsophalangeal joints (2D-measured STANCEmin: 151±2.2 degrees vs. 3D-measured STANCEmin: 162 ± 2.2 degrees; P .01 and 2D-measured TO: 163±4.9 degrees vs. 3D-measured TO: 177±1.4 degrees; P .05), whereas the hip and knee joints were much less affected. Data and techniques described here are useful for an objective assessment of altered gait after CP injury and repairin an ovine model.(AU)

A análise da locomoção é frequentemente usada como uma medida para avaliar a disfunção e sua recuperação após lesão nervosa periférica experimental. Quando comparadas com os roedores, as ovelhas oferecem várias características atrativas como modelo experimental para o estudo da regeneração nervosa periférica. Não existem estudos acerca dos resultados da locomoção após lesão e reparação do nervo periférico no modelo ovino. No presente estudo, realizámos e comparámos a cinemática bidimensional (2D) e, pela primeira vez, tridimensional (3D) do membro pélvico durante a ultrapassagem de obstáculos no modelo ovino. Este estudo teve como objetivo obter dados cinemáticos para servir de modelo para uma avaliação objetiva do movimento articular do tornozelo em estudos futuros de lesão e reparação do nervo fibular comum (FC) no modelo ovino. A estratégia usada pelas ovelhas para elevar o membro pélvico sobre um obstáculo com uma altura moderada, fixado em 10% do seu comprimento, caracteriza-se por uma flexão pronunciada do joelho, tornozelo e metatarso-falangeana ao se aproximar e ultrapassar o obstáculo. Apesar dos padrões cinemáticos do quadril, joelho, tornozelo e metatarso-falangeano terem sido idênticos, foram encontradas diferenças significativas entre os valores do movimento angular das articulações em 2D e 3D. Os nossos resultados mostram que as mudanças mais aparentes que ocorreram durante o ciclo da marcha foram nas articulações do tornozelo (em 2DSTANCEmax: 157±2.4 graus vs. em 3D STANCEmax: 151±1.2 graus; P .05) e metatarso-falangeana (em 2D STANCEmin: 151±2.2 graus vs. em 3D STANCEmin: 162 ± 2.2 graus; P .01 e em 2D TO: 163±4.9 graus vs. em 3D TO: 177±1.4 graus; P .05), enquanto as articulações do quadril e do joelho foram muito menos afetadas. É provável que os dados e técnicas descritas aqui sejam úteis para uma avaliação objetiva das alterações na marcha após lesão e reparação do PC no modelo ovino.(AU)

Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model

ABSTRACT Purpose To evaluate the biomechanical properties of a novel total hip replacement femoral stem. Methods Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed. Results Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy. Conclusions The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.

A castor oil plant (Ricinus communis)-derived implant improves the biomechanical properties of noncritical bone defects

Purpose The biomechanical properties of the polyurethanes implant material derived from castor oil plant (Ricinus communis) were evaluated in a noncritical bone defect model in rat tibia. Methods After three weeks of the implant application, the tibias were tested by means of the biomechanical three-point flexion test and resistance, rigidity, energy at maximum load and maximum energy were evaluated. Nonparametric statistical analysis was performed. Results It was found that the group that received the implant behaved the same as the intact control group and also showed a significant increase in maximum load compared to the spontaneous repair group. Conclusions Our results indicate that the tibias with the implant material in a noncritical bone defect recover normal biomechanical parameters in less time than spontaneously.(AU)

Tensiometric evaluation of the effect of low frequency electric stimulation on healing Achilles tendons in rats

Purpose: To evaluate the effects of low-frequency electric stimulation on biomechanics following surgical treatment of the Achilles tendon in rats. Methods: Forty-two rats were divided into two groups. One was given electric stimulation and the other was not. All were submitted to Achilles tenotomy and tenorrhaphy performed with a modified Kessler stitch. The experiment group underwent electric stimulation with 2 Hz, a nonpolarized current of 1 mA intensity for 14 days. The animals were euthanized at 2, 4 and 6 weeks for the biomechanical study. Results: The work performed, that is, the tendons capacity to absorb energy until rupture, was greater in the electrically stimulated group in the 2nd (p = 0.032) and in the 6th week (p = 0.010). The maximum tension, which is the capacity to support a load, was higher in the treated group in the 2nd (p = 0.030) and the 6th week (p = 024). These results indicate greater resistance of the electrically stimulated tendons. An analysis of the elastic module showed no differences. Conclusion: Low-frequency electric stimulation increased the resistance of the tendons at 2 and 6 weeks of evolution in rats.(AU)

Comparison of Some Biomechanical Properties of Tibiotarsus in Four Different Feather Color Lines of 60-Day Old Female Quails

This study aimed to compare some morphological and mechanical measurements of four different color female quails to contribute to the formation of the morphological database. Quails are the smallest farmed avian species which are becoming more important for the poultry industry. They are also used as experimental animals and are valuable birds for researches. Genetic factors are important determinants of bone strength. Thus, skeletal disorders may be reduced by breeding selection in quails. Forty female quails with four different feather colors, including wild, white, yellow, and black, were compared at 60 days of age. Each quail group contained ten individuals. A three-point bending test was performed with a custom-made testing machine designed for low strength materials. No significant difference was found between the groups in terms of body weight. The tibiotarsus weight in wild and black (0,665±0,055g and 0,687±0,025g, respectively) was significantly lower than in the others but, the significant highest value was in white quails (0,758±0,063g) (p=0.001). Significantly shorter tibiotarsus was observed in the black quails (51,286±1,374mm), while the tibiotarsi of the white and yellow quails were the tallest (53,216±1,796mm and 53,083±1,092mm, respectively) (p=0.005). There were no significant differences among the groups in the biomechanical properties of tibiotarsus, except stiffness. Stiffness was the highest in the white quails (109,500±3,807 N/mm) and the lowest in the black quails (99,000±9,498 N/mm) (p=0.042). In conclusion, white quails have been observed to have relatively better bone biomechanical properties compared to the other color groups at 60 days of age.(AU)

Comparison of Some Biomechanical Properties of Tibiotarsus in Four Different Feather Color Lines of 60-Day Old Female Quails

This study aimed to compare some morphological and mechanical measurements of four different color female quails to contribute to the formation of the morphological database. Quails are the smallest farmed avian species which are becoming more important for the poultry industry. They are also used as experimental animals and are valuable birds for researches. Genetic factors are important determinants of bone strength. Thus, skeletal disorders may be reduced by breeding selection in quails. Forty female quails with four different feather colors, including wild, white, yellow, and black, were compared at 60 days of age. Each quail group contained ten individuals. A three-point bending test was performed with a custom-made testing machine designed for low strength materials. No significant difference was found between the groups in terms of body weight. The tibiotarsus weight in wild and black (0,665±0,055g and 0,687±0,025g, respectively) was significantly lower than in the others but, the significant highest value was in white quails (0,758±0,063g) (p=0.001). Significantly shorter tibiotarsus was observed in the black quails (51,286±1,374mm), while the tibiotarsi of the white and yellow quails were the tallest (53,216±1,796mm and 53,083±1,092mm, respectively) (p=0.005). There were no significant differences among the groups in the biomechanical properties of tibiotarsus, except stiffness. Stiffness was the highest in the white quails (109,500±3,807 N/mm) and the lowest in the black quails (99,000±9,498 N/mm) (p=0.042). In conclusion, white quails have been observed to have relatively better bone biomechanical properties compared to the other color groups at 60 days of age.

Levantamento de pododermatite em vacas de aptidão leiteira na região do Alto Paranaíba, MG, Brasil / Pododermatitis survey in dairy cows fitness in Alto Paranaíba region, MG, Brazil

Este estudo objetivou determinar a prevalência de pododermatite, o escore de claudicação e o perfil dos membros acometidos em vacas leiteiras na região do Alto Paranaíba, MG. Foram analisados o escore de claudicação e a presença ou não de lesões em 920 vacas leiteiras. Para realização do exame físico dos cascos os animais foram contidos em brete. Os dados obtidos foram descritos em uma ficha individual contendo também faixa etária, raça, se lactante ou não, bem como membro e dígito afetados. Do total de 920 vacas examinadas 15,11% apresentaram lesões nos cascos sendo o escore 3 o mais frequente (43,20%). Relatou-se que 86,3% das lesões podais foram encontradas nos membros pélvicos e 17,30% nos torácicos. O membro torácico esquerdo foi o mais afetado (12,90%), já os membros pélvicos contralaterais foram igualmente comprometidos (47,5%). O dedo IV foi o mais acometido (61,10%). Os animais mais afetados tinham menos de quatro anos (51,80%). A raça holandesa mostrou-se a mais afetada (87,80%). As vacas lactantes mostraram-se positivas em 93,5% dos casos. Conclui-se que a ocorrência de vacas com doenças podais na região do Alto Paranaíba foi de 15,11%, sendo o escore de claudicação 3 o mais frequente, o que reflete falhas no manejo nas fazendas comprometendo a integridade dos cascos. Os membros pélvicos mostraram-se mais frequentemente acometidos, relacionados provavelmente a má distribuição de pesos, a biomecânica entre o torácico e o pélvico e alterações circulatórias do membro quando em decúbito lateral.

This study aimed to determine the prevalence of pododermatitis, claudication score and the profile of affected limbs in dairy cows in the Alto Paranaíba-MG region. The claudication score and presence or absence of lesions in 920 dairy cows were analyzed. For the physical examination of the hooves the animals were contained in cattle crush. The data obtained were described in individual sheet also containing age group, race, if lactating or not, as well as affected limb and digit. Of the total of 920 cows examined, 15.11% presented hoof lesions, with score 3 being the most frequent (43.20%). It was reported that 86.3% of foot injuries were found in the pelvic limbs and 17.30% in the thoracic limbs. The left thoracic limb was the most affected (12.90%), while the contralateral pelvic limbs were also affected (47.5%). The IV finger was the most affected (61.10%). The most affected animals were less than four years old (51.80%). The Dutch breed was the most affected (87.80%). The lactating cows were positive in 93.5% of the cases. It was concluded that the occurrence of foot diseases in cows in the region of Alto Paranaíba-MG was 15.11%, with the claudication score 3 being the most frequent, which reflects failures in farm management compromising the integrity of the hooves. Pelvic limbs were more frequently affected, probably related to poor weight distribution, biomechanics between the thoracic and pelvic and limb circulatory changes when in the lateral decubitus position.

Levantamento de pododermatite em vacas de aptidão leiteira na região do Alto Paranaíba, MG, Brasil / Pododermatitis survey in dairy cows fitness in Alto Paranaíba region, MG, Brazil

Este estudo objetivou determinar a prevalência de pododermatite, o escore de claudicação e o perfil dos membros acometidos em vacas leiteiras na região do Alto Paranaíba, MG. Foram analisados o escore de claudicação e a presença ou não de lesões em 920 vacas leiteiras. Para realização do exame físico dos cascos os animais foram contidos em brete. Os dados obtidos foram descritos em uma ficha individual contendo também faixa etária, raça, se lactante ou não, bem como membro e dígito afetados. Do total de 920 vacas examinadas 15,11% apresentaram lesões nos cascos sendo o escore 3 o mais frequente (43,20%). Relatou-se que 86,3% das lesões podais foram encontradas nos membros pélvicos e 17,30% nos torácicos. O membro torácico esquerdo foi o mais afetado (12,90%), já os membros pélvicos contralaterais foram igualmente comprometidos (47,5%). O dedo IV foi o mais acometido (61,10%). Os animais mais afetados tinham menos de quatro anos (51,80%). A raça holandesa mostrou-se a mais afetada (87,80%). As vacas lactantes mostraram-se positivas em 93,5% dos casos. Conclui-se que a ocorrência de vacas com doenças podais na região do Alto Paranaíba foi de 15,11%, sendo o escore de claudicação 3 o mais frequente, o que reflete falhas no manejo nas fazendas comprometendo a integridade dos cascos. Os membros pélvicos mostraram-se mais frequentemente acometidos, relacionados provavelmente a má distribuição de pesos, a biomecânica entre o torácico e o pélvico e alterações circulatórias do membro quando em decúbito lateral.(AU)

This study aimed to determine the prevalence of pododermatitis, claudication score and the profile of affected limbs in dairy cows in the Alto Paranaíba-MG region. The claudication score and presence or absence of lesions in 920 dairy cows were analyzed. For the physical examination of the hooves the animals were contained in cattle crush. The data obtained were described in individual sheet also containing age group, race, if lactating or not, as well as affected limb and digit. Of the total of 920 cows examined, 15.11% presented hoof lesions, with score 3 being the most frequent (43.20%). It was reported that 86.3% of foot injuries were found in the pelvic limbs and 17.30% in the thoracic limbs. The left thoracic limb was the most affected (12.90%), while the contralateral pelvic limbs were also affected (47.5%). The IV finger was the most affected (61.10%). The most affected animals were less than four years old (51.80%). The Dutch breed was the most affected (87.80%). The lactating cows were positive in 93.5% of the cases. It was concluded that the occurrence of foot diseases in cows in the region of Alto Paranaíba-MG was 15.11%, with the claudication score 3 being the most frequent, which reflects failures in farm management compromising the integrity of the hooves. Pelvic limbs were more frequently affected, probably related to poor weight distribution, biomechanics between the thoracic and pelvic and limb circulatory changes when in the lateral decubitus position.(AU)

Cicatrização da musculatura reto-abdominal em coelhos submetidos à laparorrafia com fios de sutura à base de quitosana, categute cromado e poliglactina 910 / [Healing of the rectus abdominis muscle in rabbits submitted to laparorrhaphy with suture-based chitosan, chromic catgut and polyglactin 910]

Objetivou-se, com este estudo, avaliar o processo de cicatrização da musculatura reto-abdominal em coelhos submetidos à laparorrafia, utilizando-se o fio de sutura à base de quitosana, comparando-o aos fios de categute cromado e poliglactina 910. Foram utilizados 24 coelhos adultos, divididos aleatoriamente em quatro grupos: quitosana e categute 15 dias (QC-15dias), quitosana e categute 30 dias (QC-30 dias), quitosana e poliglactina 910 15 dias (QP-15 dias) e quitosana e poliglactina 910 30 dias (QP-30 dias). Cada grupo foi composto por seis coelhos, nos quais foram realizadas duas incisões, uma do lado direito e outra do lado esquerdo e, posteriormente, a laparorrafia, com o fio de quitosana de um lado e o categute cromado ou poliglactina 910 do outro. Realizou-se análise clínico-cirúrgica, histológica e avaliação de achados de necropsia, além de testes de citotoxicidade e de mecânica no fio de quitosana. Ele apresentou baixa resistência mecânica e citotóxica. O fio de quitosana não proporcionou uma cicatrização satisfatória em coelhos, pois desencadeou uma resposta inflamatória acentuada.(AU)

The objective of this study was to evaluate the healing process of the recto-abdominal muscles in rabbits submitted to laparorrhaphy using chitosan-based suture yarn, comparing it to chrome catgut and polyglactin 910 yarns. Twenty-four adult rabbits were divided in to four random groups: chitosan and polyglactin 910 15 days (QP-15 days) and chitosan and polyglactin 910 30 days (QC-30 days), chitosan and polyglactin 910 15 days (QP-15 days) QP-30 days). Each group consisted of six rabbits, in which two incisions were made, one on the right side and one on the left side, and later the laparorraphy with the chitosan yarn on one side and chromed catgut or polyglactin 910 on the other. Clinical-surgical, histological and necropsy findings were evaluated, as well as cytotoxicity and mechanical tests on the chitosan wire. It presented low mechanical and cytotoxic resistance. Chitosan thread did not provide satisfactory healing in rabbits, as it triggered a marked inflammatory response.(AU)

Ex-vivo evaluation of the three-column concept in canine thoracolumbar fractures / [Avaliação em ex-vivo do conceito dos três compartimentos em fraturas toracolombares da coluna]

Traumatic events such as a motor vehicle accident or falling from heights are very common in veterinary medicine and often lead to vertebral fracture-luxation with concomitant spinal cord injuries, mostly in the thoracolumbar spine. The purpose of this cadaveric biomechanical study was to determine the feasibility of the three-column concept in canine thoracolumbar segments with induced fractures. Eighteen Functional Spinal Units (FSU) of the thoracolumbar segments (T12-L2) were collected from 18 medium-sized adult dog cadavers and were subjected to flexion-extension and lateral bending tests so that range of motion (ROM) was recorded with a goniometer. Fractures were induced by compressive loads applied by a universal testing machine (EMIC®). After this, specimens were screened using computed tomography (CT) and the fractures were graded as affecting one, two or three columns, and divided into groups A, B, and C, respectively. Post-fracture range of motion (ROM) was compared with the previous results. Groups B and C (with fractures in two or three columns) had instability in the two axes evaluated (P<0.05). The outcomes of this study support the applicability of the three-column theory to thoracolumbar spines of dogs, as the FSUs that suffered fractures in two or more columns showed axial instability.(AU)

Eventos traumáticos, como acidentes automobilísticos ou quedas, são muito comuns na medicina veterinária e, frequentemente, levam a fraturas ou luxações vertebrais, associadas a lesões medulares concomitantes, mais frequentemente na coluna toracolombar. O propósito deste estudo biomecânico em cadáveres foi determinar a viabilidade da teoria dos três compartimentos em fraturas induzidas em segmentos toracolombares de cães. Dezoito unidades espinhais funcionais (UEF) de segmentos toracolombares (T12-L2) foram coletadas de 18 cadáveres de cães adultos de médio porte e submetidas a testes de flexão-extensão e curvamento lateral, de modo que a amplitude de movimento (ADM) foi registrada com um goniômetro. Fraturas foram induzidas por meio de cargas compressivas aplicadas por uma máquina universal de ensaios (EMIC®). As amostras foram submetidas à tomografia computadorizada (TC), e as fraturas foram classificadas como afetando um, dois ou três compartimentos e divididas nos grupos A, B e C, respectivamente. A ADM pós-fratura foi comparada com os resultados prévios. Os grupos B e C (com fraturas em dois ou três compartimentos) apresentaram instabilidade nos dois eixos avaliados (P<0,05). Os resultados deste estudo corroboram a aplicabilidade da teoria dos três compartimentos para segmentos de coluna toracolombar em cães, uma vez que as UEF que sofreram as fraturas em dois ou mais compartimentos apresentaram instabilidade axial.(AU)

Ex-vivo evaluation of the three-column concept in canine thoracolumbar fractures / [Avaliação em ex-vivo do conceito dos três compartimentos em fraturas toracolombares da coluna]

Traumatic events such as a motor vehicle accident or falling from heights are very common in veterinary medicine and often lead to vertebral fracture-luxation with concomitant spinal cord injuries, mostly in the thoracolumbar spine. The purpose of this cadaveric biomechanical study was to determine the feasibility of the three-column concept in canine thoracolumbar segments with induced fractures. Eighteen Functional Spinal Units (FSU) of the thoracolumbar segments (T12-L2) were collected from 18 medium-sized adult dog cadavers and were subjected to flexion-extension and lateral bending tests so that range of motion (ROM) was recorded with a goniometer. Fractures were induced by compressive loads applied by a universal testing machine (EMIC®). After this, specimens were screened using computed tomography (CT) and the fractures were graded as affecting one, two or three columns, and divided into groups A, B, and C, respectively. Post-fracture range of motion (ROM) was compared with the previous results. Groups B and C (with fractures in two or three columns) had instability in the two axes evaluated (P<0.05). The outcomes of this study support the applicability of the three-column theory to thoracolumbar spines of dogs, as the FSUs that suffered fractures in two or more columns showed axial instability.(AU)

Eventos traumáticos, como acidentes automobilísticos ou quedas, são muito comuns na medicina veterinária e, frequentemente, levam a fraturas ou luxações vertebrais, associadas a lesões medulares concomitantes, mais frequentemente na coluna toracolombar. O propósito deste estudo biomecânico em cadáveres foi determinar a viabilidade da teoria dos três compartimentos em fraturas induzidas em segmentos toracolombares de cães. Dezoito unidades espinhais funcionais (UEF) de segmentos toracolombares (T12-L2) foram coletadas de 18 cadáveres de cães adultos de médio porte e submetidas a testes de flexão-extensão e curvamento lateral, de modo que a amplitude de movimento (ADM) foi registrada com um goniômetro. Fraturas foram induzidas por meio de cargas compressivas aplicadas por uma máquina universal de ensaios (EMIC®). As amostras foram submetidas à tomografia computadorizada (TC), e as fraturas foram classificadas como afetando um, dois ou três compartimentos e divididas nos grupos A, B e C, respectivamente. A ADM pós-fratura foi comparada com os resultados prévios. Os grupos B e C (com fraturas em dois ou três compartimentos) apresentaram instabilidade nos dois eixos avaliados (P<0,05). Os resultados deste estudo corroboram a aplicabilidade da teoria dos três compartimentos para segmentos de coluna toracolombar em cães, uma vez que as UEF que sofreram as fraturas em dois ou mais compartimentos apresentaram instabilidade axial.(AU)

Análise da resistência de placas ósseas de acrílico fabricadas a laser quando submetidas a diferentes forças que agem sobre o foco de fratura / Analysis of the resistance of laser-made acrylic bone plates when subjected to different forces acting on the fracture focus

Objetivou-se com este trabalho analisar a resistência de placas ósseas de acrílico, confeccionadas com cortadora a laser CO2, quando submetidas às forças que agem sobre o foco de fratura. Foram utilizados 40 fêmures de ovinos (Ovis aries) e confeccionadas 40 placas de acrílico, os quais foram avaliados em grupos: grupo OP - foram avaliados 20 ossos fraturados reduzidos com 20 placas de acrílico; grupo PS - foram avaliadas 20 placas de acrílico; e grupo OS - foram avaliados 20 ossos íntegros e frescos. Todos foram submetidos a ensaios mecânicos de compressão, flexão, torção e tração, em máquina de ensaios universal EMIC® 10000. Os testes eram interrompidos quando havia fratura do corpo de prova. O grupo PS suportou carga de compressão significativamente superior aos demais grupos OP e OS (13.255±290N, 4.932±827N e 8.681±303N, respectivamente). Já em relação à prova de flexão, o grupo OS foi significativamente mais resistente, com média de 2.698±305N, em relação aos grupos OP e PS, que obtiveram 1.315±92N e 1.537±37N, respectivamente. Conclui-se que as placas de acrílico usinadas a laser apresentam resistência mecânica inferior ao fêmur de ovinos, entretanto, devido à resistência exibida nos testes, demonstraram potencial para serem implantadas em ossos com menor demanda de carga.(AU)

The objective of this work was to analyze the resistance of acrylic bone plates, made with CO 2 laser cutter, when subjected to the forces acting on the fracture focus. Forty ovine femurs (Ovis aries) were used and 40 acrylic plates were prepared and evaluated in groups: In the OP Group, 20 fractured bones reduced with 20 acrylic plates were evaluated; in the PS Group, 20 acrylic plates were evaluated; and in the OS Group 20 intact and fresh bones were evaluated. All were submitted to mechanical tests of compression, bending, twisting and traction in an EMIC® 10000 universal testing machine. The tests were interrupted when the body of proof was fractured. The PS group supported a significantly higher compression load than the other OP and OS groups (13,255±290 N, 4,932±827 N and 8,681±303 N, respectively). Regarding the flexural test, the OS group was significantly more resistant, with a mean of 2,698±305 N, compared to the groups OP and PS that obtained 1,315±92 N and 1,537±37 N respectively. It is concluded that the laser-machined acrylic plates have inferior mechanical resistance to the femur of the ovine, however, due to the presented resistance, it shows potential to be implanted in bones with lower load demand.(AU)