Objective The main purpose of this study was to evaluate the characteristics of a vegetal polymeric biomaterial intended for bone substitution in horses and to investigate the responses of the equine third metacarpal bone to biomaterial implantation. Materials and Methods Six horses were submitted to osteotomy on the dorsal aspect of the left and right third metacarpal bones; one bone defect was randomly selected for treatment with biopolymer, while the other was left untreated and served as a control. Bone density was monitored radiographically after surgery and bone biopsy fragments were collected at the end of the 120-day follow-up period. Biopsy fragments were analysed using light and scanning electron microscopy. Results Mean bone density values (mmAL) were greater in control defects (16.33 ± 1.6) than in polymer-treated defects (14.17 ± 1.7) at 120 days (p = 0.027). Light microscopy revealed greater percentages of new bone formation in control defects (50.15 ± 14.8) than in polymer treated defects (26.94 ± 12.1) at 120 days (p < 0.0001). Scanning electron microscopy analysis suggested a similar quality of pre-existing bone and new bone formed in the presence of biomaterial. Clinical Significance The absence of adverse reactions supports biomaterial biocompatibility and osteoconducting capacity and suggests the castor oil polymer is a suitable bone substitute for the treatment of bone defects in horses.
OBJECTIVE To evaluate the efficacy of castor oil polyurethane polymer with calcium carbonate for use in a unicortical ostectomy on the dorsal surface of the third metacarpal bone of horses. ANIMALS 6 adult horses. PROCEDURES A unicortical ostectomy was created on the dorsal surface of both third metacarpal bones of each horse. Castor bean (Ricinus communis) oil polyurethane polymer with calcium carbonate was implanted into the ostectomy on 1 limb, and the ostectomy of the contralateral limb was left unfilled and served as a control sample. Ostectomy sites were evaluated histologically 120 days later. Biopsy specimens were obtained from the interface of bone and polymer or the interface of bone and newly formed tissue; specimens were processed for histomorphometric evaluation by use of light microscopy, immunohistochemical analysis, histochemical analysis, and transmission electron microscopy. RESULTS Osteoconductive activity of the biomaterial was confirmed by the presence of osteoblasts in the biopsy specimens. Absence of a chronic inflammatory response or foreign body reaction indicated biocompatibility. Expression of osteoblast markers was detected in the newly formed tissue. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that castor oil polyurethane polymer with calcium carbonate could be an acceptable compound for use as a bone substitute in horses with fractures in which bone filling is necessary.
AGRADECIMENTOSAgradeço a Deus pela vida e por todas as oportunidades de evoluir.Sou muito grata à minha família, principalmente aos meus pais, Carlos e Eunice, que sempre se esforçaram para dar a melhor educação aos seus três filhos.Muito obrigada por nos proporcionar uma vida confortável, repleta de amor e carinho. Aos meus irmãos, Camila e André, por sempre "pegarem no meu pé". Hoje enxergo o quanto isso foi importante para o meu amadurecimento. Aos meus cunhados, Fernando e Cristina, pelo carinho e amizade. Aos meus queridos avós, Eurico e Nancy, segundos pais, que até hoje não compreendem bem o meu trabalho na área de pesquisa, mas sempre me apoiaram e me admiraram pelas minhas realizações. À minha tia Luiza, pelos meus lanchinhos e confecções para os cavalos e para mim.Agradeço ao meu namorado Lucas, que acompanhou de perto a minha jornada durante o mestrado, e que, devido a isso, passou do pavor à grande afinidade pelos cavalos. Sou muito grata pela compreensão nos momentos de ausência, nervosismo, cansaço e por toda atenção, amor, carinho e, acima de tudo, companheirismo nas dificuldades. Muito obrigada pelos momentos de descontração e alegria, eles tornaram os obstáculos quase imperceptíveis. Também agradeço à nova família que ganhei: Ivaldo, Deise, Denise, Benito, Neide e Vô Ciro. Obrigada por me tratarem com tanto amor e carinho, sempre me recebendo bem em seu lar! E aos amigos... Agradeço a todos do grupo C da 71ª turma da FMVZ USP, em especial à Carol (Bá), Carla (Gá), Ana (Baranguinha), Joyce (Muflinha) e Taís (Bruxinha). Obrigada pelo apoio e amizade desde os primeiros anos de curso, seja com dúvidas técnicas, ouvindo reclamações, choradeiras, reuniões, telefonemas, desentendimentos e sempre muitas risadas! Aos amigos de longa data: Taci, Luciana, Lucy e André Assi, sempre presentes, torcendo e vibrando comigo. E aos amigos mais recentes, como os da Casa de Goytacaz, com os quais aprendo um pouco a cada dia. The light microscopy showed a higher percentage of new bone formation in the control group ( 50.15% ± 14.83 ) than in the polymer group ( 26.94 % ± 12.06 ) , with p ˂ 0.0001. However, scanning electron microscopy allowed to observe that the quality of bone formation tissue in the presence of biomaterial was maintained.Furthermore, there were no adverse reactions to biomaterial, such as scar formation or as a foreign body reaction, allowing to conclude that the polymer of castor oil can be considered suitable to fill bone defects in horses, since it demonstrated compatibility and osteoconductivity.
Purpose: To compare biomechanical characteristics at different regions of the equine third metacarpal bone using standardized test specimens. Methods: Standardized test specimens were made from samples collected from each third metacarpal bone. Cortical bone samples were collected from the lateral (ts4L) and medial (ts4M) cortices of the mid-diaphysis and trabecular bone samples were collected from the distal (ts3) and proximal (ts2) epiphyses. A sample corresponding to the mid third of the third metacarpal bone was also collected (ts1). Test specimens were submitted to compressive testing for determination and comparison of biomechanical properties. Results: Stress and modulus of elasticity of ts4L and ts4M did not differ at the time of fracture. However, the modulus of elasticity of ts4L and ts4M differed from ts1. Maximum tension and modulus of elasticity differed between ts2 and ts3. A medium to high positive correlation between test specimen density and bone biomechanical properties was observed. Conclusion: The lateral and medial cortices of the equine third metacarpal bone have similar biomechanical characteristics. The proximal and distal epiphyses of the equine third metacarpal bone have different biomechanical properties that are correlated with bone density in these regions.
O terceiro osso metacarpiano equino é uma região de particular interesse devido ao grande número de lesões a que está sujeito. Assim, justifica-se o estudo detalhado da sua estrutura anatômica, dimensões e composição elementar para o aprimoramento de técnicas de diagnóstico, tratamento e prevenção de lesões. Neste trabalho,foi estudada a composição macroelementar óssea de 30 pares de osso terceiro metacarpiano equino e sua relação com a idade, sexo, peso, raça, alimentação e atividade dos animais. As concentrações médias de cálcio e fósforo das amostras foram 205 ± 62 mg/g e 97 ± 32 mg/g, respectivamente. A relação [Ca]/[P] encontrada foi de 2,12 ± 0,13, indicando que a proporção entre o cálcio e fósforo no tecido ósseo é constante e aproximadamente igual à razão 2:1. A análise estatística dos dados mostrou normalidade para todo o conjunto de medidas. A avaliação entre os animais com atividade física intensa e os animais com atividade física leve, em que a quantidade de material mineralizado para o primeiro e segundo conjuntos são, respectivamente, [Ca] = 222 ± 57 mg/g e [Ca] = 179 ± 47 mg/g, evidenciou a existência de correlação estatística entre o depósito de material mineral e a função exercida pelos animais. Para as demais características, não foram verificadas evidências estatísticas de inter-relações. Tais achados serão subsídios para estudos posteriores acerca de possíveis correlações com enfermidades de origem fisiológica ou nutricional frente à casuística de fraturas e outras afecções comuns ao aparelho locomotor equino.
Knowledge about non-invasive methods for early diagnostics in equine orthopedic disorders is economically important and has been widely studied. In this study, bone mineral density determined by radiographic absorptiometry was correlated to bone resistance of the equine third metacarpal bone submitted to biomechanical testing. Thirty pairs of third metacarpal bone of adult horses were collected, dissected, radiographed, analyzed by the radiographic absorptiometry technique, and submitted to tomographic study and biomechanical testing. No significant linear correlation between radiographic bone density values and measured biomechanical properties was observed. Therefore, bone mineral density of the third metacarpal bone determined by radiographic absorptiometry does not predict bone capacity to resist compression and flexion loads. Further studies should be developed to establish which techniques are reliably capable of giving such predictive information.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.