Reconstrução cirúrgica da tíbia em fratura mal consolidada em um cão / Surgical reconstruction of tibia in poorly consolidated fracture in a dog

Objetiva-se com este trabalho relatar um caso de reconstrução cirúrgica tibial em uma fratura mal consolidada em um canino, salientando a versatilidade do fixador esquelético externo (FEE) e a importância do enxerto esponjoso como coadjuvante da cicatrização. Para a reconstrução cirúrgica da tíbia, esta foi refraturada, e em seguida, alinhada com o auxílio de pino intramedular de Steinmann temporário. Empregou-se fixação esquelética externa associada à enxertia óssea esponjosa autógena coletada da asa do ílio. No protocolo pós-cirúrgico, foi recomendado os mesmos cuidados e medicações de uma osteossíntese habitual. Decorridos 35 dias da cirurgia, observou-se perda da linha de fratura e formação de calo ósseo, permitindo a remoção do FEE. O animal voltou a apoiar o membro normalmente, apenas com um leve encurtamento do mesmo, mas sem prejuízo à deambulação.

The aim of this study is to report a case of tibial surgical reconstruction in a poorly consolidated canine fracture, emphasizing the versatility of the external skeletal fixator (ESF) and the importance of the cancellous graft as an adjunct to healing. For surgical reconstruction of the tibia, it was refracted and then aligned with support by temporary Steinmann intramedullary pin. External skeletal fixation was applied in association with bone grafting of spongy autogenous tissue collected by iliac wing. In the post-surgical protocol, the same care and medications as usual for osteosynthesis were recommended. Fracture line loss and bone callus formation were observed thirty-five days after the surgery, allowing the removal of the ESF. The animal returned to support the limb normally, only with a slight shortening of the limb, but without prejudice to the walking.

Reconstrução cirúrgica da tíbia em fratura mal consolidada em um cão / Surgical reconstruction of tibia in poorly consolidated fracture in a dog

Objetiva-se com este trabalho relatar um caso de reconstrução cirúrgica tibial em uma fratura mal consolidada em um canino, salientando a versatilidade do fixador esquelético externo (FEE) e a importância do enxerto esponjoso como coadjuvante da cicatrização. Para a reconstrução cirúrgica da tíbia, esta foi refraturada, e em seguida, alinhada com o auxílio de pino intramedular de Steinmann temporário. Empregou-se fixação esquelética externa associada à enxertia óssea esponjosa autógena coletada da asa do ílio. No protocolo pós-cirúrgico, foi recomendado os mesmos cuidados e medicações de uma osteossíntese habitual. Decorridos 35 dias da cirurgia, observou-se perda da linha de fratura e formação de calo ósseo, permitindo a remoção do FEE. O animal voltou a apoiar o membro normalmente, apenas com um leve encurtamento do mesmo, mas sem prejuízo à deambulação.(AU)

The aim of this study is to report a case of tibial surgical reconstruction in a poorly consolidated canine fracture, emphasizing the versatility of the external skeletal fixator (ESF) and the importance of the cancellous graft as an adjunct to healing. For surgical reconstruction of the tibia, it was refracted and then aligned with support by temporary Steinmann intramedullary pin. External skeletal fixation was applied in association with bone grafting of spongy autogenous tissue collected by iliac wing. In the post-surgical protocol, the same care and medications as usual for osteosynthesis were recommended. Fracture line loss and bone callus formation were observed thirty-five days after the surgery, allowing the removal of the ESF. The animal returned to support the limb normally, only with a slight shortening of the limb, but without prejudice to the walking.(AU)

The effect of graft application and allopurinol treatment on calvarial bone defect in rats

Purpose:To investigate the effects of allopurinol administration on osteoinductive reaction and bone development with graft material.Methods:Thirty-six Wistar albino rats were divided into 3 groups. In the control group, calvarial bone defect was only created without any treatment. In the Defect + Graft group, allograft treatment was performed by forming 8 mm calvarial bone defect. In the Defect + Graft + Allopurinol group, alloplastic bone graft was placed in the calvarial bone defect and then, allopurinol (50 mg/kg/day) treatment was intraperitoneally applied for 28 days.Results:Histopathological examination revealed inflammation, congestion in the vessels, and an increase in osteoclast cells in the defect area. We also observed that new osteocyte cells, increase in connective tissue fibers, and new bone trabeculae. Osteopontin expression was positive in osteoblast cells and lacunated osteocyte cells were located in the periphery of the new bone trabeculae. Osteopontin expression was also positive in osteoblasts and osteocytes cells of new bone trabeculae in the graft site.Conclusion:It has been shown that allopurinol treatment in rat calvaria defects may induce osteoblastic activity, matrix development, mature bone cell formation and new bone formation when used with autogenous grafts.(AU)

Enxerto osteocondral autógeno associado ao IGF-1 emlesão induzida na cartilagem articular de coelhos / Autogenous osteochondral graft associated with IGF-1 in induced articular cartilage lesion in rabbits

Background: Articular cartilage has a limited capacity for regeneration and of the various treatments proposed, none have reached appropriate therapeutic effectiveness. This study aimed to evaluate autogenous osteochondral grafts in intact or macerated format, in association with or without insulin-like growth factor type-1 (IGF-1) in the repair of osteochondral defects induced in the femoral trochlear groove of rabbits.Materials, Methods & Results: Seventeen healthy White New Zealand rabbits were selected for this study. The rabbits were female, six months old, and had an average body weight of 4.5 kg. All 34 stifle joints were subjected to autogenous osteochondral grafting in the femoral trochlear groove. The joints were divided into four groups designated as intact osteochondral graft with IGF-1 (INT + IGF), intact osteochondral graft with physiological solution (INT + FIS), macerated osteochondral graft with IGF-1 (MAC + IGF), and macerated osteochondral graft with physiological solution (MAC + FIS). Serial evaluations were performed by orthopedic and radiographic examination. After 6 and 12 weeks postoperatively, the grafted area was subjected to macroscopic, histological, and immunohistochemical analyses. Although no statistically significant differences were found between the groups in relation to clinical, macroscopic, histological, and immunohistochemical aspects, a tendency of IGF-1 to promote tissue repair was evident. In the radiographic evaluation, the articular surface and the recipient site in both groups with IGF-1 showed significantly more effective filling (P ≤ 0.05). Regardless of the group, collagen type 2 production, as assessed by immunohistochemistry, was found to be appropriate on the grafted articular surface.[...]

Enxerto osteocondral autógeno associado ao IGF-1 emlesão induzida na cartilagem articular de coelhos / Autogenous osteochondral graft associated with IGF-1 in induced articular cartilage lesion in rabbits

Background: Articular cartilage has a limited capacity for regeneration and of the various treatments proposed, none have reached appropriate therapeutic effectiveness. This study aimed to evaluate autogenous osteochondral grafts in intact or macerated format, in association with or without insulin-like growth factor type-1 (IGF-1) in the repair of osteochondral defects induced in the femoral trochlear groove of rabbits.Materials, Methods & Results: Seventeen healthy White New Zealand rabbits were selected for this study. The rabbits were female, six months old, and had an average body weight of 4.5 kg. All 34 stifle joints were subjected to autogenous osteochondral grafting in the femoral trochlear groove. The joints were divided into four groups designated as intact osteochondral graft with IGF-1 (INT + IGF), intact osteochondral graft with physiological solution (INT + FIS), macerated osteochondral graft with IGF-1 (MAC + IGF), and macerated osteochondral graft with physiological solution (MAC + FIS). Serial evaluations were performed by orthopedic and radiographic examination. After 6 and 12 weeks postoperatively, the grafted area was subjected to macroscopic, histological, and immunohistochemical analyses. Although no statistically significant differences were found between the groups in relation to clinical, macroscopic, histological, and immunohistochemical aspects, a tendency of IGF-1 to promote tissue repair was evident. In the radiographic evaluation, the articular surface and the recipient site in both groups with IGF-1 showed significantly more effective filling (P ≤ 0.05). Regardless of the group, collagen type 2 production, as assessed by immunohistochemistry, was found to be appropriate on the grafted articular surface.[...](AU)

Uso de enxerto autógeno de fáscia lata no tratamento de defeito segmentar crônico do tendão calcâneo comum em felino doméstico / Use of autogenous fascia lata graft in the treatment of chronic segmental defect of the common calcaneus tendon in domestic feline

Background: The common calcaneus tendon is formed by the common tendon of the femoral biceps muscle, tendon of the superficial digital flexor muscle and gastrocnemius muscle tendon, and its rupture is related to acute traumas in small animals. Among some applications described, surgical repair can be adopted in the correction of tendon ruptures and the use of grafts may be indicated in some severe lesions, where it is not possible to perform tenorrhaphy. This study aims to report the case of a feline with rupture of the common calcaneus tendon in which the tenorrafia associated with the autogenous fascia lata graft was performed as adjuvant to the cicatrization of the same.Case: A 24-month-old, undefined male feline with approximately 3 kg was treated at the FCAV Veterinary Hospital, UNESP Jaboticabal, State of São Paulo, Brazil, with a history of falling, for approximately two weeks, and has since plantigrade posture. Upon physical examination, it was possible to identify a discontinuity of the common calcaneus tendon. The radiographs were performed, which did not show any bone changes. A hemogram and biochemical profile were performed, which were within normal limits. The patient underwent surgery, and a complete lesion of the common calcaneus tendon was identified, with a chronic aspect. Approximation of the stumps was impossible, so a flap of fascia lata, about two centimeters long and one centimeter wide, was removed, which was used as a bed and tendon support for tendon growth. After removal all of the present fibrosis, the tendon stumps were approximated by means of modified Kessler suture with mononylon thread, and fascia lata flap of the ipsilateral limb was sutured with separate single points in both tendon ends and in their lateral and medial portion. In the tibiotarsic joint, the external skeletal fixator type II was used for immobilization, during a period of 30 days.[...]

Uso de enxerto autógeno de fáscia lata no tratamento de defeito segmentar crônico do tendão calcâneo comum em felino doméstico / Use of autogenous fascia lata graft in the treatment of chronic segmental defect of the common calcaneus tendon in domestic feline

Background: The common calcaneus tendon is formed by the common tendon of the femoral biceps muscle, tendon of the superficial digital flexor muscle and gastrocnemius muscle tendon, and its rupture is related to acute traumas in small animals. Among some applications described, surgical repair can be adopted in the correction of tendon ruptures and the use of grafts may be indicated in some severe lesions, where it is not possible to perform tenorrhaphy. This study aims to report the case of a feline with rupture of the common calcaneus tendon in which the tenorrafia associated with the autogenous fascia lata graft was performed as adjuvant to the cicatrization of the same.Case: A 24-month-old, undefined male feline with approximately 3 kg was treated at the FCAV Veterinary Hospital, UNESP Jaboticabal, State of São Paulo, Brazil, with a history of falling, for approximately two weeks, and has since plantigrade posture. Upon physical examination, it was possible to identify a discontinuity of the common calcaneus tendon. The radiographs were performed, which did not show any bone changes. A hemogram and biochemical profile were performed, which were within normal limits. The patient underwent surgery, and a complete lesion of the common calcaneus tendon was identified, with a chronic aspect. Approximation of the stumps was impossible, so a flap of fascia lata, about two centimeters long and one centimeter wide, was removed, which was used as a bed and tendon support for tendon growth. After removal all of the present fibrosis, the tendon stumps were approximated by means of modified Kessler suture with mononylon thread, and fascia lata flap of the ipsilateral limb was sutured with separate single points in both tendon ends and in their lateral and medial portion. In the tibiotarsic joint, the external skeletal fixator type II was used for immobilization, during a period of 30 days.[...](AU)

Ressonância magnética na avaliação de enxerto osteocondral autógeno na cartilagem articular de coelhos / Magnetic resonance in the evaluation of autogenous osteochondral graft in articular cartilage of rabbits

Este trabalho teve o objetivo de determinar as características e a aplicabilidade do exame de ressonância magnética na avaliação de enxerto ostecondral autógeno, em formato íntegro ou macerado, associado ou não ao fator de crescimento semelhante à insulina tipo 1 (IGF-1), utilizado no reparo de lesões induzidas na cartilagem articular de coelhos. Foram utilizados 9 coelhos da linhagem Nova Zelândia, em que as 18 articulações fêmoro-tíbio-patelares foram submetidas à enxertia osteocondral autógena no sulco troclear femoral. Estas foram divididas em quatro grupos, denominados como enxerto osteocondral íntegro + IGF-1 (n=5), enxerto osteocondral íntegro + solução fisiológica (n=4), enxerto osteocondral macerado + IGF-1 (n=5) e enxerto osteocondral macerado + solução fisiológica (n=4). Os animais foram eutanasiados em 12 semanas após a cirurgia e as articulações foram submetidas ao exame de ressonância magnética utilizando um aparelho scanner de 1,5 Tesla de alto campo magnético. Além disso, amostras dos locais de enxertia foram submetidas aos exames anatomopatológicos. O exame de ressonância magnética mostrou-se eficaz como um método não invasivo para avaliação do tecido de reparação em enxertos osteocondrais na cartilagem articular do fêmur de coelhos, fornecendo dados complementares aos exames macroscópicos e histológicos. Por meio destas imagens e dos exames anatomopatológicos, foram observados resultados satisfatórios em relação ao processo de reparação dos enxertos osteocondrais autógenos na cartilagem de coelhos, independentemente de seu formato ou da adição de IGF-1.(AU)

This study aimed to determine the characteristics and applicability of magnetic resonance imaging (MRI) in the evaluation of autogenous osteochondral graft in intact or macerated format, with or without insulin-like growth factor type 1 (IGF-1) used in repair of cartilage lesions induced in rabbits. Nine New Zealand rabbits were used, in which 18 stifle joints underwent grafting procedure in the femoral trochlear groove. These were divided into four groups, referred as intact osteochondral graft + IGF-1 (n=5), intact osteochondral graft + saline solution (n=4), macerated osteochondral graft + IGF-1 (n=5) and macerated osteochondral graft + saline solution (n=4). Animals were euthanized 12 weeks after surgery and the joints were subjected to MRI using a high magnetic field scanner of 1.5 Tesla. In addition, samples of grafting sites were subjected to anatomopathological examination. The MRI was effective as a noninvasive method to evaluate the repair tissue in osteochondral grafts in articular cartilage of the femur of rabbits by providing complementary data to macroscopic and histological examinations. Through these images and anatomopathological examinations satisfactory results were observed in relation to the repair process of autogenous osteochondral grafts in cartilage of rabbits, regardless of its format or the addition of IGF-1.(AU)

Effects of local alendronate administration on bone defect healing. Histomorphometric and radiological evaluation in a rabbit model

Purpose: To performed a histomorphometric and radiological study to evaluate the effects of alendronate sodium administered locally in mandibular bone defects created in rabbits. Methods: Two circular defects 5 mm in diameter were created bilaterally in the mandibular corpus of 20 New Zealand rabbits (i.e., four defects per animal). Each defect received one of four treatments: no treatment (EC group), alendronate irrigation (AL group), autogenous bone grafting (AG group), or alendronate irrigation with autogenous bone grafting (AL+AG group). Histomorphometric and radiological assessments were conducted at 4 and 8 weeks after surgery. Results: Between-group comparisons of the new bone area, the value of the AL+AG group was significantly lower thanthe remaining three groups at 4 weeks postoperatively. In all groups, the new bone area was significantly larger at 8 weeks than at 4 weeks. The residual graft area at 4 and 8 weeks was significantly higher in the AL+AG group than in the AG group, although it was significantly smaller at 8 weeks than at 4 weeks in both these groups. Conclusion: The use of alendronate sodium in conjunction with autogenous bone grafting improves the osteoconductive properties of the graft, enhances graft retention in the defect, and improves ossification.(AU)

Successful use of autogenous bone graft for the treatment of a radius-ulna nonunion in an amputee dog / Uso de enxerto ósseo autógeno no tratamento de uma não união óssea em um radioulna de um canino amputado

Fracture nonunions represent important complications in orthopedic surgeries. Nonunion repairs or bone defects are surgically challenging. Our aim was to describe a nonunion case, which was repaired with rapid bone recovery. An 8-month-old male mixed breed dog that has been previously operated was presented to the Veterinary Medical Teaching Hospital of São Paulo State University, with a right radius-ulna nonunion and an amputated contralateral forelimb. A cancellous bone graft was collected from a partially amputated limb, in order to correct the nonunion, and used in association with a locking plate. After four weeks, the bone graft had been incorporated into the original bone. Clinical union with good weight bearing was achieved after eight weeks.(AU)

As não uniões ósseas representam uma importante complicação nas cirurgias ortopédicas. Não uniões ósseas ou defeitos ósseos são um desafio na cirurgia. O objetivo do presente trabalho foi descrever um caso de não união óssea, que foi reparada de forma rápida. Um cão SRD de oito meses, macho, que havia sido operado previamente, deu entrada no Hospital Veterinário da Unesp - Jaboticabal com uma não união óssea em radioulna e o membro contralateral amputado. Um enxerto ósseo autógeno foi coletado do coto do membro contralateral amputado e utilizado junto a uma placa óssea bloqueada para o tratamento. Após quatro semanas, o enxerto ósseo estava incorporado ao osso original. A união clínica e o retorno normal à função foram alcançados após oito semanas.(AU)

FRAÇÃO ESTROMAL DO TECIDO ADIPOSO NO TRATAMENTO DE DEFEITOS OSTEOCONDRAIS EM COELHOS

Um grande desafio encontrado por profissionais da ortopedia tanto da medicina veterinária quanto humana, é o tratamento de forma eficaz das lesões articulares, que podem, posteriormente, evoluir para doença articular degenerativa (DAD). A utilização de células tronco (CT) traz consigo esperança para o tratamento de diversas patologias, podendo ser extraídos de diferentes tecidos, mas principalmente, medula óssea e o tecido adiposo. O presente trabalho teve como objetivo a avaliação da eficiência da fração estromal derivada do tecido adiposo no tratamento de defeitos osteocondrais em coelhos. Foram utilizados 24 coelhos da raça Nova Zelândia de coloração branca, onde realizamos um defeito osteocondral no sulco troclear nas articulações desses animais e outros 12 animais onde foram coletados o tecido adiposo na região panículo adiposo para a realização da digestão do tecido e obter a fração estromal do tecido adiposo, posteriormente, divididas em três tempo de digestão 30, 40 e 50 minutos. Os grupos que realizaram o defeito nas articulações, foram divididos em controle negativo (C-), fração estromal do tecido adiposo (FETA) e controle positivo (C+) com enxerto autógeno osteocondral. Os resultados dos tempos de digestão do tecido adiposo não mostraram diferença significativa entre os tempos. As avaliações clínicas, radiográficas, macroscópicas e histopatológica mostraram que os efeitos terapêuticos da fração estromal do tecido adiposo, mostrou minimizar os sinais degenerativos da cartilagem articular no tratamento defeitos osteocondrais em coelhos.

A major challenge encountered by orthopedic professionals in both veterinary and human medicine is the effective treatment of joint injuries, which may later develop into degenerative joint disease (DAD). The use of stem cells (TC) brings hope for the treatment of various pathologies, which can be extracted from different tissues, but especially bone marrow and adipose tissue. The present work aimed to evaluate the efficiency of adipose-derived stromal fraction in the treatment of osteochondral defects in rabbits. Twenty-four white New Zealand rabbits were used, where we performed an osteochondral defect in the trochlear groove in the joints of these animals and 12 other animals where adipose tissue was collected in the adipose panicle region to perform tissue digestion and to obtain the stromal fraction. of the adipose tissue, subsequently divided into three digestion times 30, 40 and 50 minutes. The groups that performed the joint defect were divided into negative control (C-), stromal adipose tissue fraction (FETA) and positive control (C +) with osteochondral autogenous graft. Results of adipose tissue digestion times showed no significant difference between times. Clinical, radiographic, macroscopic and histopathological evaluations showed that the therapeutic effects of adipose tissue stromal fraction showed to minimize the degenerative signs of articular cartilage in the treatment of osteochondral defects in rabbits.

INFLUÊNCIA DO ENXERTO OMENTAL LIVRE AUTÓGENO NO TRATAMENTO DE LESÃO ÓSSEA INDUZIDA EXPERIMENTALMENTE NO OSSO RÁDIO DE COELHO (Oryctolagus cuniculus familiaris)

O tecido ósseo é fundamental na locomoção, proteção dos órgãos internos e na produção de células do sistema hematopoiético e imunológico dos animais. As lesões neste tecido, principalmente nos animais de companhia, normalmente ocorrem devido a traumas. As fraturas têm sido bastante discutidas na ortopedia veterinária, principalmente quanto aos métodos de tratamento, tempo de recuperação e complicações. Uma opção no tratamento das lesões ósseas são os enxertos. Com o objetivo de se estudar a influência do enxerto omental livre autógeno na reparação de falha óssea utilizou-se 32 coelhos adultos, machos, não castrados da raça Nova Zelândia, com idade entre 6 e 7 meses, divididos em dois grupos (GI controle e GII tratados com enxerto omental) com 16 animais cada. Falhas ósseas segmentares de 1cm foram criadas cirurgicamente no terço médio da diáfise radio direito. No mesmo momento cirúrgico realizou-se também a celiotomia para obtenção do enxerto a partir do omento, inclusive nos animais do GI. Os animais do GII tiveram as falhas ósseas cobertas com o enxerto omental livre autógeno. Imediatamente após as cirurgias, aos 45 e 90 dias, os animais tiveram os respectivos antebraços radiografados para posterior avaliação do processo de regeneração óssea. Também foi realizada coleta de sangue para a dosagem da fosfatase alcalina óssea nos dias 0 (antes das cirurgias), 45 e 90 (após as cirurgias). Metade dos animais de cada grupo foram eutanásiados aos 45dias e aos 90 dias respectivamente para realização da coleta de amostra da área anteriormente lesionada visando a confecção de laminas histológicas. Não houve diferença nos níveis séricos da FAO entre GI e GII aos 45 e nem aos 90 dias (p=0,42), nem na avaliação radiográfica comparando os grupos (p=0,99). Histologicamente também não foi notada diferença no processo de regeneração óssea entre GI e GII, exceto pela presença de resíduos do enxerto omental em absorção, sugerindo uma reação tipo corpo estranho. O enxerto omental autógeno livre, no tratamento de falhas ósseas com 1cm de extensão no osso Rádio de coelhos Nova Zelândia, não influenciou o processo de regeneração óssea.

Bone tissue is essential in locomotion, internal organs protection and in the hematopoietic and immunological systems cells production of animals. Lesions in this tissue, especially in pet animals, usually occur due to trauma. Fractures have been widely discussed in veterinary orthopedics, mainly regarding treatment methods, recovery time and complications. An option in the treatment of bone lesions are the grafts. with aim to study the influence of the autogenous free omental graft on the repair of bone defect, 32 male, uncastrated New Zealand rabbits aged between 6 and 7 months were divided into two groups (GI control and GII treated with free omental graft) with 16 animals each. 1 cm Segmental bone defects were surgically criated in the middle third of the right Radio. At the same surgical procedure, the celiotomy was also performed to obtain the graft from the omentum, including the GI animals. The GII animals had bony defects covered with autogenous free omental graft. Immediately after the surgeries and at 45 and 90 days, the animals had their respective forearms radiographed for later images evaluation. Blood samples were also collected for the measurement of bone alkaline phosphatase on days 0 (before surgery), 45 and 90 (after surgery). Half of the animals in each group were euthanized at 45 days and 90 days, respectively, to collect samples from the previously injured area, aiming the preparation of histological laminae. There was no difference in bone alkaline phosphatase serum levels between GI and GII at 45 and 90 days (p = 0.42), nor at the radiographic evaluation comparing the groups (p = 0.99). Histologically, no difference was also observed in the regeneration process of bone defects between GI and GII, except for the presence of residues from the omental graft under absorption, suggesting a foreign body reaction. The autogenous free omental graft, on treatment of 1 cm extension bone defects in New Zealand rabbit Radio, did not influence the bone regeneration process.

AVALIAÇÃO DA REVASCULARIZAÇÃO DE FRAGMENTOS ÓSSEOS BOVINOS AUTOCLAVADOS E IMPLANTADOS COM E SEM A PRESENÇA DO OMENTO EM SÍTIOS INTRACORPÓREOS DE COELHOS (Oryctolaguscuniculus) COMO MODELO DE BIORREATOR IN-VIVO

As falhas ósseas, principalmente as críticas, representam entidade à parte. Para que se possa gerar reconstituição de falhas ósseas críticas é necessário o auxílio de métodos de enxertia que promovam osteoindução e osteocondução. É frequente a busca de substitutos ósseos de forma a aprimorar técnicas já existentes que promovam osteogênese visando o rápido restabelecimento de suas funções. O enxerto autógeno isolado pode ser insuficiente nas falhas ósseas críticas apesar de ser a melhor opção, causa maior morbidade na recuperação do paciente. O omento tem sido frequentemente estudado na cirurgia devido suas diversas propriedades vasculares vantajosas em locais pouco vascularizados, melhorando a cicatrização e controle de infecção. Este estudo teve como objetivo avaliar a capacidade angiogênica e osteoindutora de fragmentos ósseos xenógenos autoclavados implantados, com ou sem a presença de omento no espaço subcutâneo (S1), espaço subcutâneo juntamente com o omento (S2) e região intraóssea (S3) em coelhos. Utilizou-se 30 animais em um único grupo onde cada animal recebeu os fragmentos ósseos em três sítios corpóreos diferentes (S1, S2 e S3) e foram avaliados por métodos histológicos sua atividade angiogênica e osteogênica. Diante dos resultados obtidos foi possível observar que, o material implantado foi rejeitado devido à reação de corpo estranho ter sido intensa e persistente por todos os tempos (7, 15, 30, 45, 60 dias) de avaliação em todos os locais de implantação. Não houve osteogênese em nenhum dos locais de implantação. Foi possível comparar a angiogênese entre locais de implantação avaliando a infiltração vascular no interior dos fragmentos ósseos, onde S2 apresentou melhores resultados, com início de infiltração vascular aos 7 dias, enquanto que os demais grupos se iniciaram aos 30 dias. Conclui-se com este estudo que diante desta metodologia de preparo de implante ósseo xenógeno, provavelmente não houve remoção completa da antigenicidade, nem mesmo a preservação das BMPs, mas foi possível afirmar que o contato com o omento foi capaz de aumentar a angiogênese nos fragmentos implantados em comparação com os demais locais.

Bone failures, especially criticism, represent a separate entity. In order to generate reconstitution of critical bone defects it is necessary to use grafting methods that promote osteoinduction and osteoconduction. The search for bone substitutes is frequent in order to improve existing grafting techniques for the rapid restoration of their functions. The isolated autogenous graft may be insufficient in the critical bone faults although it is the best option, it causes greater morbidity in the recovery of the patient. The omentumhas frequently been studied in the surgery due to its several advantageous vascular properties in places little vascularized, improving the cicatrization and control of infection. The purpose of this study was to evaluate the angiogenic and osteoinductive capacity of implanted autogenous xenogene bone fragments, with or without the presence of omentum in the subcutaneous space (S1), subcutaneous space together with the omentum (S2) and intraosseous region (S3). Thirty animals were used in a single group where each animal received the bone fragments at three different body sites (S1, S2 and S3) and their angiogenic and osteogenic activity were assessed by histological methods. In view of the results obtained, it was possible to observe that the implanted material was rejected because the foreign body reaction was intense and persistent at all times (7, 15, 30, 45, 60 days) of evaluation at all implantation sites. There was no osteogenesis at any of the implantation sites. It was possible to compare the angiogenesis between implantation sites by evaluating the vascular infiltration within the bone fragments, where S2 presented better results, with vascular infiltration beginning at 7 days, while the other groups started at 30 days. It was concluded from this study that in view of this xenogen graft preparation methodology, there was probably no complete removal of the antigenicity, not even the preservation of the BMPs, but it was possible to affirm that the contact with the omentum was able to increase the angiogenesis in the fragments in comparison with the other sites.

Virtual planning and construction of prototyped surgical guide in implant surgery with maxillary sinus bone graft

PURPOSE: To evaluate the efficacy of associating techniques of bone grafting in the maxillary sinus with the use of a prototyped surgical guide for planning and positioning dental implants in total edentulous maxillae, rehabilitated after six months. METHODS: Eight patients consecutives with totally edentulous maxilla presenting few remaining bone in the posterior alveolar ridge, associated with pneumatization of the maxillary sinus were selected. Twenty eight Brånemark RP 10mm implants were installed in 14 maxillary sinuses. The surgical planning for the implant installation was performed with the DentalSlice software by means of a computerized tomography. The obtained images were used for building a surgical guide that, placed over the maxilla, showed the exact position for the implants installation (prototyped surgical guide). The portion of the implants that went into the maxillary sinus was covered by an autogenous bone graft. RESULTS: The patients were re-evaluated six months after the surgery and a 100% success rate was achieved. All of the implants presented no mobility or symptoms, permitting an oral rehabilitation with total fixed screw-retained prosthesis over the implants. CONCLUSION: The technique of associating implants and bone graft in the maxillary sinus aided by a prototyped guide planned on DentalSlice has showed itself efficient for positioning implants and for quantifying and locating the bone graft.(AU)

Remoção da cartilagem articular associada ou não a implante homógeno ou enxerto autógeno de osso esponjoso em cães submetidos à artrodese atlantoaxial

The aim of this study was to evaluate the degree of joint fusion and bone formation in dogs undergoing atlantoaxial arthrodesis after removal of articular cartilage associated or not to implant homogenous or autogenous cancellous bone. Twelve dogs, weighing between 8 and 12kg were randomly divided into three groups. Group I (GI) performed only the removal of joint cartilage and joint immobilization with acrylic resin and pins. Group II (GII): after removel of joint cartilage and articular immobilization was performed modeling and placement of homogenous cancellous bone at the given location. The volume of homograft placed in the joint was measured using a precision balance and all animals received the same amount. Group III (GIII): this was the same procedure as GI, however, was used autogenous cancellous bone graft at the given location. Radiographic examinations were performed on all animals at 30, 60 and 90 days postoperatively. At 90 days of PO was carried out euthanasia of animals for testing of manual palpation and CT evaluation and histological. Samples were kept in solution in 10% buffered formaldehyde for fixation for a minimum of 72 hours and after, decalcified in formic acid and sodium citrate for subsequent processing and included in paraffin. Sections were stained with hematoxylin-eosin for light microscopy evaluation. Statistical analysis of the association between the degree of joint fusion assessed by manual palpation, the digitized radiographic images and CT scans and treatment groups, we applied the Chi-square test of independence. The test results were evaluated by the exact significance and considered statistically significant at 5% significance (P 0.05). By manual palpation test and by the CT images can be seen that there was no statistically significant difference between groups at 90 days postoperatively. Radiographic analysis of the atlantoaxial joint showed that the degree of fusion was similar among treatments, no statistical difference at 30, 60 and 90 days postoperatively. Regarding the histopathological study of atlantoaxial joint of dogs after 90 days postoperatively was found that bone formation in group I had 25% of each intensity (absent, mild, moderate, severe) in group II, 75% lighter and 25% sharp and in group III, 25% moderate and 75% severe. It can be concluded that the use of graft homogenous preserved in 98% glycerin in dogs undergoing atlantoaxial fusion method is a viable alternative for treatment of atlantoaxial instability. There is no difference in the degree of joint fusion and bone formation when the technique of atlantoaxial arthrodesis in dogs is associated with autogenous cancellous bone graft or implant homogenous. The removal of articular cartilage alone is an effective and shows similar results to the use of autograft or homogenous implant.

O objetivo deste estudo foi avaliar o grau de fusão articular e formação óssea na articulação atlantoaxial de cães submetidos à artrodese após a remoção da cartilagem articular associada ou não ao implante homógeno ou enxerto autógeno de osso esponjoso. Foram utilizados 12 cães, adultos, distribuídos aleatoriamente em três grupos iguais. Grupo I (GI): realizada apenas a remoção da cartilagem articular e imobilização articular com pinos e resina acrílica. Grupo II (GII): feita a remoção da cartilagem articular e imobilização da articulação, seguida da colocação e modelagem do implante ósseo esponjoso homógeno entre as superfícies articulares. Grupo III (GIII): foi realizado o mesmo procedimento do GII, mais o enxerto ósseo esponjoso autógeno no local determinado. Realizaram-se exames radiográficos em todos os animais aos 30, 60 e 90 dias de pós-operatório (PO). Aos 90 dias de PO foi feita a eutanásia para o emprego do teste de palpação manual, avaliação tomográfica e histopatológica. Para análise estatística da associação entre o grau de fusão articular, aplicou-se o Teste Qui-quadrado de independência. Os resultados dos testes foram avaliados pela significância exata e considerados significantes a 5% (P 0,05). Pelo teste de palpação manual e pelas imagens tomográficas, não houve diferença entre os grupos aos 90 dias de PO. A análise radiográfica da articulação atlantoaxial mostrou que o grau de fusão era semelhante entre os tratamentos entre os tempos de evolução. Com relação ao estudo histopatológico da articulação atlantoaxial dos cães, decorridos 90 dias de PO, foi verificado que a proliferação óssea no grupo I apresentou grau de intensidade proporcional, no grupo II, 75% leve e 25% acentuada e, no grupo III, 25% moderada e 75% acentuada. Não existe diferença quanto ao grau de fusão articular e formação óssea quando a técnica de artrodese atlantoaxial em cães for associada ao enxerto de osso esponjoso autógeno ou implante homógeno. A remoção da cartilagem articular isoladamente é uma alternativa eficiente e apresenta resultados semelhantes, quando associada ao enxerto autógeno ou implante homógeno.

Remoção da cartilagem articular associada ou não a implante homógeno ou enxerto autógeno de osso esponjoso em cães submetidos à artrodese atlantoaxial

The aim of this study was to evaluate the degree of joint fusion and bone formation in dogs undergoing atlantoaxial arthrodesis after removal of articular cartilage associated or not to implant homogenous or autogenous cancellous bone. Twelve dogs, weighing between 8 and 12kg were randomly divided into three groups. Group I (GI) performed only the removal of joint cartilage and joint immobilization with acrylic resin and pins. Group II (GII): after removel of joint cartilage and articular immobilization was performed modeling and placement of homogenous cancellous bone at the given location. The volume of homograft placed in the joint was measured using a precision balance and all animals received the same amount. Group III (GIII): this was the same procedure as GI, however, was used autogenous cancellous bone graft at the given location. Radiographic examinations were performed on all animals at 30, 60 and 90 days postoperatively. At 90 days of PO was carried out euthanasia of animals for testing of manual palpation and CT evaluation and histological. Samples were kept in solution in 10% buffered formaldehyde for fixation for a minimum of 72 hours and after, decalcified in formic acid and sodium citrate for subsequent processing and included in paraffin. Sections were stained with hematoxylin-eosin for light microscopy evaluation. Statistical analysis of the association between the degree of joint fusion assessed by manual palpation, the digitized radiographic images and CT scans and treatment groups, we applied the Chi-square test of independence. The test results were evaluated by the exact significance and considered statistically significant at 5% significance (P 0.05). By manual palpation test and by the CT images can be seen that there was no statistically significant difference between groups at 90 days postoperatively. Radiographic analysis of the atlantoaxial joint showed that the degree of fusion was similar among treatments, no statistical difference at 30, 60 and 90 days postoperatively. Regarding the histopathological study of atlantoaxial joint of dogs after 90 days postoperatively was found that bone formation in group I had 25% of each intensity (absent, mild, moderate, severe) in group II, 75% lighter and 25% sharp and in group III, 25% moderate and 75% severe. It can be concluded that the use of graft homogenous preserved in 98% glycerin in dogs undergoing atlantoaxial fusion method is a viable alternative for treatment of atlantoaxial instability. There is no difference in the degree of joint fusion and bone formation when the technique of atlantoaxial arthrodesis in dogs is associated with autogenous cancellous bone graft or implant homogenous. The removal of articular cartilage alone is an effective and shows similar results to the use of autograft or homogenous implant.

O objetivo deste estudo foi avaliar o grau de fusão articular e formação óssea na articulação atlantoaxial de cães submetidos à artrodese após a remoção da cartilagem articular associada ou não ao implante homógeno ou enxerto autógeno de osso esponjoso. Foram utilizados 12 cães, adultos, distribuídos aleatoriamente em três grupos iguais. Grupo I (GI): realizada apenas a remoção da cartilagem articular e imobilização articular com pinos e resina acrílica. Grupo II (GII): feita a remoção da cartilagem articular e imobilização da articulação, seguida da colocação e modelagem do implante ósseo esponjoso homógeno entre as superfícies articulares. Grupo III (GIII): foi realizado o mesmo procedimento do GII, mais o enxerto ósseo esponjoso autógeno no local determinado. Realizaram-se exames radiográficos em todos os animais aos 30, 60 e 90 dias de pós-operatório (PO). Aos 90 dias de PO foi feita a eutanásia para o emprego do teste de palpação manual, avaliação tomográfica e histopatológica. Para análise estatística da associação entre o grau de fusão articular, aplicou-se o Teste Qui-quadrado de independência. Os resultados dos testes foram avaliados pela significância exata e considerados significantes a 5% (P 0,05). Pelo teste de palpação manual e pelas imagens tomográficas, não houve diferença entre os grupos aos 90 dias de PO. A análise radiográfica da articulação atlantoaxial mostrou que o grau de fusão era semelhante entre os tratamentos entre os tempos de evolução. Com relação ao estudo histopatológico da articulação atlantoaxial dos cães, decorridos 90 dias de PO, foi verificado que a proliferação óssea no grupo I apresentou grau de intensidade proporcional, no grupo II, 75% leve e 25% acentuada e, no grupo III, 25% moderada e 75% acentuada. Não existe diferença quanto ao grau de fusão articular e formação óssea quando a técnica de artrodese atlantoaxial em cães for associada ao enxerto de osso esponjoso autógeno ou implante homógeno. A remoção da cartilagem articular isoladamente é uma alternativa eficiente e apresenta resultados semelhantes, quando associada ao enxerto autógeno ou implante homógeno.

Comparison of lyophilization, and freezing in honey as techniques to preserve cortical bone allografts used to repair experimental femoral defects in domestic adult cats / Comparação de enxerto ósseo cortical autógeno e implante ósseo cortical alógeno conservados no mel, congelados ou liofilizados na substituição de segmento diafisário do fêmur de gatos domésticos

Cats with orthopedic conditions are a prominent part of the clinical work of veterinary. Conditions such as comminuted fractures, bone tumors and non-unions are often difficult to repair and may require the use of bone grafts for treatment. This study evaluated cortical bone allografts preserved in honey, frozen or lyophilized for correcting long bone defects created in the diaphysis of the right femur of domestic cats (n=24). In the control group (n=6), the defect was repaired using autogenous cortical bone graft. In the remaining animals (n=6/group), the defect was repaired with cortical bone allografts preserved in honey, frozen or lyophilized. Success of graft incorporation and length of time for consolidation were assessed through clinical, radiographic and histological evaluations performed up to 180 days. In the control, frozen, honey and lyophylized groups, respectively, success of graft incorporation was 91.6%, 83.3%, 75%, and 25%, with corresponding mean length of time for consolidation of 83.1, 78, 105 and 120 days. Incorporation percentage in the lyophilized group was significantly lower than in the frozen and control groups. In conclusion, bone grafts preserved in honey or frozen were effective for repairing cortical defects in the femurs of cats as compared to autogenous cortical bone grafts.(AU)

Afecções ortopédicas em gatos são frequentes, podendo-se encontrar fraturas cominutivas, neoplasias ósseas ou não-uniões de fraturas. Uma opção para o tratamento dessas afecções é a utilização de enxerto ou implante ósseo. O objetivo deste trabalho foi avaliar implantes ósseos corticais alógenos conservados em mel, congelados ou liofilizados na substituição de segmento diafisário do fêmur de felinos. Foi confeccionada uma falha óssea na diáfise do fêmur de 24 felinos. Em seis felinos a falha foi preenchida com o próprio osso removido e nos outros 18 animais, com implantes ósseos corticais alógenos conservados em mel, congelados ou liofilizados. Os animais foram avaliados clínica, radiográfica e histologicamente durante 180 dias. A incorporação foi de 91,6% no grupo controle, com tempo médio para consolidação de 83,1 dias; no mel foi de 75%, com tempo médio de 105 dias; no congelado foi de 83,3% com tempo médio de 78 dias e no liofilizado foi de 25%, com tempo médio de 120 dias. A porcentagem de consolidação foi significativamente menor no grupo liofilizado em relação aos grupos congelado e controle. É possível concluir que os implantes ósseos autógenos e os conservados no mel e congelados são eficazes no preenchimento de defeito cortical em fêmur de felinos.(AU)

Mechanical properties of radial bone defects treated with autogenous graft covered with hydroxyapatite in rabbit / Propriedades mecânicas de defeito de osso radial tratado com enxerto autógeno coberto com nano-hydroxyapatite em coelho

PURPOSE: To determine biomechanical property of autogenous bone graft covered with hydroxyapatite in the defect of radial bone in rabbit. METHODS: Eighteen adult male New Zealand white rabbits were used which were divided into three groups (I, II, III) of six rabbits each. A segmental bone defect of 10 mm in length was created in the middle of the right radial shaft under general effective anesthesia in all rabbits and were stabilized using mini-plate with four screws. The defects In group I were left as such without filler, whereas in group II the defect were filled up with harvested 10 mm rib bone and in group III the defect were packed with rib bone covered with nano-hydroxyapatite. All rabbits in three groups were divided into two subgroups (one month and three months duration with three rabbits in each one). RESULTS: The mechanical property and the mean load for fracturing normal radial bone was recorded 388.2±6 N whereas it was 72.4±12.8 N for group I in 1 month duration which was recorded 182.4±14.2 N for group II and 211.6±10.4 N for group III at the end of 1 month. These values were 97.6±10.2 N for group I and 324.6±8.2 N for group II and 372.6±17.4 N for group III at the end of three months after implantation. CONCLUSION: Implantation of autologous graft covered with hydroxyapatite indicated to have positive effect in integral formation of qualitative callus at the site of fracture and early re-organization of callus to regain mechanical strength too.(AU)

OBJETIVO: Determinar as propriedades biomecânicas de enxerto ósseo autógeno coberto com hidroxiapatita em defeito do osso radial em coelhos. MÉTODOS: Foram utilizados 18 coelhos adultos, machos, brancos, Nova Zelândia, distribuídos em três grupos (I, II, III) de seis coelhos cada. Um defeito segmentar de 10 mm de comprimento foi criado no meio do eixo radial direito sob anestesia geral efetiva em todos os coelhos e foram fixados usando mini-placa com quatro parafusos. Os defeitos no grupo I foram deixados sem preenchimento, enquanto no grupo II o defeito foi preenchido com 10 mm de costela recoberta com nano-hidroxiapatita. Os coelhos nos três grupos foram distribuídos em dois subgrupos (Um e três meses, com três coelhos cada um). RESULTADOS: A propriedade mecânica e a média do peso para fraturar o osso radial normal foi 388,2±6 N, enquanto para o Grupo I, com um mês foi 72,4±12,8 N, para o grupo II 182,4±14,2 N e para o Grupo III 211,6±10,4 N. Após três meses de implantação, os valores foram 97,6±10,2 N para o Grupo I, 324,6±8,2 N para o Grupo II e 372,6±17,4 N para o Grupo III. CONCLUSÃO: A implantação de enxerto autólogo recoberto com hidroxiapatita indicou ter um efeito positivo na formação integral qualitativa do calo ósseo no local da fratura e precoce reorganização do calo com recuperação da força mecânica.(AU)

NEOFORMAÇÃO ÓSSEA COMPARATIVA DE BIOMATERIAIS MICRONANOESTRUTURADOS APLICADOS ATRAVÉS DE UM SISTEMA GUIADO EM CALVÁRIA DE COELHOS Oryctolagus cuniculus

KUCI, Cristiana Corrêa. Neoformação óssea comparativa de biomateriais micronanoestruturados aplicados através de um sistema guiado em calvária de coelhos Oryctolagus cuniculus. 2017. 73f. Dissertação (Mestrado em Ciência Animal) Universidade do Estado de Santa Catarina. Programa de Pós-Graduação em Ciência Animal, Lages, 2017. Diversas pesquisas relacionadas a substitutos ósseos têm sido realizadas na busca de um material ideal, que tenha qualidades próximas ao osso autógeno quanto à sua aplicação para reparação de um defeito ósseo, seja ele decorrente de fratura, degeneração ou neoplasias. Com esta finalidade, foram realizados experimentos cirúrgicos guiados em calvárias de coelhos onde se teve por objetivo analisar e comparar diferentes biomateriais micronanoestruturados em relação à sua capacidade de osteoindução e osteocondução. Foram utilizados 14 coelhos da raça Nova Zelândia, machos, com oito meses de idade e com peso médio de 3,43 ± 0,53kg. Os animais foram comprovadamente hígidos através de exame clínico e análise hematológica. Os animais foram submetidos à anestesia inalatória com isoflurano para realização do procedimento cirúrgico. A partir da exposição óssea da região da calvária, foram fixadas quatro guias cilíndricas de poliamida com parafuso de aço inoxidável. Cada guia foi preenchida por biomaterial pré-determinado, compostos por: Hidroxiapatita com Sílica a 5% (HA/SiO2 5%), Hidroxiapatita com Fosfato tricálcico- (HA/TCP-: 73,53/26,27%), Fosfato tricálcico (TCP-) e Bio-ss® (controle). Os animais foram distribuídos aleatoriamente em dois grupos: G60 (n=7) e G90 (n=7), que foram submetidos à eutanásia com 60 e 90 dias de pós-operatório, respectivamente, sendo cada calvária removida e acondicionada em formaldeído tamponado por 15 dias. Após, as calvárias foram seccionadas em quatro quadrantes, cada qual contendo o biomaterial, sendo mantidos em formaldeído tamponado 10% por mais 15 dias e então encaminhados para análises histológica e de microscopia eletrônica por varredura (MEV). A partir dos resultados obtidos pela metodologia deste estudo, pode ser concluído que todos os biomateriais aplicados, apresentam capacidade de osteoindução e osteocondução, mesmo que em graus variados. Observou-se que o Bio-Oss® apresentou menor neoformação de tecido ósseo. A composição bifásica HA/SiO2 5% não apresentou incorporação na interface entre o leito receptor e o enxerto ósseo na maior parte dos animais, induzindo à formação de tecido fibroso em sua maior parte. O TCP- e o bifásico HA/TCP- 73,53/26,27%, foram os biomateriais mais promissores deste estudo, induzindo a uma maior neoformação óssea. O TCP- demonstrou ser o biomaterial com velocidade mais rápida de formação e maturação do tecido ósseo. O bifásico HA/TCP- apresentou resultados bem próximos ao TCP- isolado. No entanto, apresentou maior quantidade de células fagocitárias, o que num período maior de avaliação, poderia apresentar maior velocidade de absorção do biomaterial.

KUCI, Cristiana Corrêa. Comparative bone formation of micronanostructured biomaterials applied through a calvary-guided system of rabbits Oryctolagus cuniculus. 2017. 73f. Dissertation (Masters in Animal Science) - Santa Catarina State University. Graduate Program in Animal Science, Lages, 2017. Several research studies related to bone substitutes have been conducted in order to find the ideal material for this purpose, with similar qualities to the autogenous bone regarding its application of repairing bone defects, whether it results from fracture, degeneration or neoplasias. Accordingly, surgical experiments were carried out in rabbit calvaries, aiming to analyse and compare different micro-nanostructured biomaterials in relation to their capacity of osteoinduction and osteoconduction. Fourteen male New Zealand rabbits, eight months old and with a mean weight of 3.43 ± 0.53kg, were used. The animals were proven to be healthy through clinical examination and haematological analysis. The animals were submitted to inhalation anesthesia with isoflurane for the surgical procedure. From the bone exposure of the calvary region, four cylindrical polyamide guides were fixed with stainless steel screw. Each guide was filled with a pre-determined biomaterial composed of: hydroxyapatite with 5% silica (HA/SiO2 5%), hydroxyapatite with -tricalcium phosphate (-TCP/HA - 26.27%/73.53%), -tricalcium phosphate (-TCP) and Bio-Oss® (control). The animals were randomly assigned into two groups: G60 (n=7) and G90 (n=7), which were submitted to euthanasia at 60 and 90 days postoperatively, respectively, each calvary being removed and conditioned in buffered formaldehyde for 15 days. Afterwards, the calvaries were sectioned in four quadrants, each containing the biomaterial, being kept in buffered formaldehyde for another 15 days and then sent to histological analysis and scanning electron microscopy (SEM). From the results obtained by the methodology of this study, it can be concluded that all applied biomaterials show osteoinduction and osteoconduction capacity, despite different degrees. Through the analysis performed, it was observed that the Bio-Oss® presented smaller neoformation of bone tissue. The biphasic HA/SiO2 5% composition did not show incorporation on the interface between the recipient bed and the bone graft in most animals, inducing the formation of fibrous tissue for the most part. The -TCP and the biphasic -TCP/HA 73,53/26,27%, were the most promising biomaterials of this study, inducing a greater bone neoformation. -TCP has been shown to be the biomaterial with the fastest rate of formation and maturation of bone tissue. The biphasic -TCP/HA presented results very close to the -TCP alone. However, it presented a greater amount of phagocytic cells, which in a longer period of evaluation could present a higher rate of absorption of the biomaterial.

Miniplate fixation for the repair of segmental mandibular defects filled with autogenous bone in cats / Uso de miniplacas na fixação de mandíbulas de gatos com defeitos segmentares preenchidos com osso autógeno

PURPOSE: To evaluate the use of maxillofacial miniplate 1.5 in the repair of segmental mandibular defects filled with autogenous bone in cats. METHODS: Twelve adult cats were divided into two groups. A segmental defect of 4mm was created in one of the hemimandibles and filled with autogenous iliac crest bone graft. The operated hemimandible was fixed with a 1.5mm titanium miniplate. In group 1 (n=6), the defect was performed in the body of the mandible, behind the 1st molar. In group 2 (n=6), the defect was performed between the 4nd premolar and 1st molar, with extraction of the 1st molar. Oral alimentation was reinitiated 24 hours after surgery. Cats were euthanized at 20 weeks postoperative. RESULTS: Incorporation of the graft was suggested by the radiographs taken 20 weeks after surgery. Macroscopic examination confirmed alignment and bone union of operated hemimandibles. Histological examination showed formation of woven bone in rostral and caudal mandible/graft interfaces. The percentage of bone tissue at these areas was measured by the histometry. There was no statistically significant difference between the values of group 1(64.48 ± 4.51) and group 2 (71.69 ± 14.47) (Mann-Whitney's test p= 0.294). CONCLUSION: The use of miniplate 1.5 for the fixation of mandibular defects filled with autogenous bone in cats provided the main goals in the treatment of mandibular fractures: bone union, normal dental occlusion and immediate return to oral alimentation.(AU)

OBJETIVO: Avaliar o uso de miniplacas na fixação de mandíbulas de gatos com defeitos segmentares preenchidos com osso autógeno. MÉTODOS: Foram utilizados 12 gatos adultos divididos em dois grupos de seis animais cada. Em uma das hemimandíbulas foi criado um defeito segmentar de 4mm, preenchido com enxerto autógeno do osso ilíaco. A hemimandíbula operada foi fixada com uma miniplaca 1.5 de titânio. No grupo 1, o defeito foi realizado caudalmente ao 1º molar e no grupo 2, entre o 4º pré-molar e 1º molar, com extração do 1º molar. A alimentação oral foi reiniciada 24 horas após a cirurgia. Os animais foram submetidos à eutanásia 20 semanas após a cirurgia. RESULTADOS: As radiografias realizadas 20 semanas após a cirurgia sugeriram a incorporação do enxerto. O exame macroscópico confirmou redução cirúrgica satisfatória e união óssea das hemimandibulas operadas. Os exames histológicos demonstraram a presença de tecido ósseo esponjoso nos locais de transição do enxerto com o osso da mandíbula. Os exames histométricos demonstraram que não houve diferença estatisticamente significante nos valores observados de porcentagem de tecido ósseo nas áreas de incorporação do enxerto das hemimandíbulas operadas dos gatos do grupo 1 (64,48 ± 4,51) e grupo 2 (71,69 ± 14,47) (Teste de Mann-Whitney p=0,294). CONCLUSÃO: Os resultados deste experimento permitiram concluir que o uso de miniplacas na fixação de mandíbulas de gatos com defeitos segmentares preenchidos com osso autógeno garante os principais objetivos no tratamento de fraturas da mandíbula: união óssea, oclusão dentária normal e alimentação oral imediata.(AU)