AUTO-ENXERTO PERCUTÂNEO DE MEDULA ÓSSEA. II. REPARAÇÃO DE FALHAS SEGMENTARES PRODUZIDAS NO RÁDIO DE COELHOS 1 PERCUTANEOUS BONE MARROW AUTOGRAFT. II. REPAIR OF SEGMENTAR DEFECTS PRODUCED IN THE RADII RABBIT

Medico Veterinario, UFV.RESUMOPara determinar de que forma a medula ossea, inte-gral e concentrada, enxertada percutaneamente comporta-se noprocesso de reparacao ossea, foram utilizados 16 coelhos, daraca Nova Zelândia Branca, machos, com idade entre cinco e seismeses e peso corporeo medio de 3,5kg, distribuidos em doisgrupos experimentais iguais (grupos I e II). Nos dois grupos,foram realizadas falhas osseas em ambos os radios, pela remocaode um segmento osteoperiosteal, de 1cm de comprimento, locali-zado a 3cm da articulacao radio-carpo-ulnar. A enxertia percu-tânea foi feita cinco dias apos a realizacao das falhas, sendo queno grupo I, cada animal recebeu 1,0ml de medula ossea integral,em um dos radios (tratamento), imediatamente apos a aspiracaona crista iliaca. No grupo II, apos aspiracao e centrifugacao de2,0ml de medula ossea, foi injetado 1,0ml do sedimento em umdos radios (tratamento). Em ambos os grupos, foi injetado 1,0mlde solucao salina fisiologica no radio contralateral (controle). Aavaliacao radiografica, realizada a cada sete dias durante cincosemanas, mostrou que a enxertia percutânea de medula ossearesultou em radiopacidade precoce na regiao da falha ossea nosdois grupos, quando comparada com o controle. Na fase inicial,foi caracterizada por areas circunscritas e bem definidas, con-firmando a competencia osteogenica do enxerto de medula ossea,principalmente a partir da primeira e segunda semanas apos aenxertia. Ja nos radios que receberam solucao salina, a formacaoossea se deu a partir das extremidades em direcao ao centro.Histologicamente, os radios enxertados estavam em um estagiodiferente de reparacao em relacao ao controle, apesar de que ascinco semanas as semelhancas histologicas foram maiores que asdiferencas.Palavras-chave: cirurgia ossea, enxerto osseo, reparacao ossea.SUMMARYIn order to study the whole and concentrated bonemarrow grafted percutaneously in order to repair producedosseous defects, it was used 16 male White New Zealand rabbits,aged between 5 and 6 months, average body weight of 3.5kg, setapart in groups I and II. In both groups it was produced a radialbilateral defects by the removal of an 1-cm osteal-periostealsegment. Percutaneous grafting was performed 5 days aftersurgery. In group I, each animal received 1.0ml of whole bonemarrow in one radius (treatment) immediately after iliac crestaspiration and in group II, after aspiration and centrifuging of2.0ml of bone marrow, it was administrated 1.0ml of the sedimentin one radius (treatment). In both groups it was administered1.0ml of physiological saline solution in the contralateral radius(control). Radiographic evaluation, performed every 7 days for 5weeks, showed that percutaneous bone marrow grafting resultedin precocious radiopacity of the region of the osseous defect inboth groups when comparing to the control, being characterizedby circumscribed and well defined areas in the middle of thedefect. Bone formation of the control radii initiated from theextremities in direction to the middle of the defect. Concentrationof medullary cells by centrifuging does not negatively interfere inthe osteogenic potential of the sample. This osteogenic potentialof the bone marrow graft occurs mostly after the first and secondweeks post-grafting, which was evidenced by the difference ofradiographic images in this period and tendency to uniformity.Microscopically, the grafted radii were in a different repair stagein relation to the control, but at 5 weeks there were morehistological similarities t han differences.Key words: bone surgery, bone graft, bone repair