Fração total de células mononucleares intra-articular em cães submetidos à reconstrução do ligamento cruzado Total fraction of mononuclear intra-articular cells in dogs undergoing cruciate ligament reconstruction

Avaliou-sea ação da fração total de células mononucleares autógenas da medula óssea (FCMO) por aplicação intra-articular, após a correção cirúrgica do ligamento cruzado rompido. Foram utilizados 20 cães, os quais sofreram desmotomia do ligamento cruzado cranial e caudal unilaterais, 21 dias antes do reparo cirúrgico. Dez animais receberam as células autógenas no momento da correção. As avaliações se deram por estudo radiográfico, exames clínicos e biópsias aos 50 e 90 dias pós-operatórios. O grupo que recebeu a FCMO apresentou crescimento ósseo intra-articular ao estudo radiográfico, contudo os 20 animais apresentaram célulasCD34 positivas em suas amostras biopsiadas, indicando haver presença de células-tronco em ambos os grupos. Conclui-se que,para o modelo experimental proposto, não se recomenda o uso da fração total de células mononucleares e que trabalhos experimentais com o uso de células-tronco nas articulações devem evitar modelos cujo foco de lesão mantenha contato direto com a medula óssea.<br>This study was performed to evaluate the action of the fraction of total mononuclear cells from the bone marrow (FCMO) applied intra-articularly after the surgical repair of an experimentally ruptured cruciate ligament. Twenty dogs which suffered one-sided cruciate desmotomy of the cranial and caudal cruciate ligament 21 days before the correction were used. Ten animals received the FCMO at the time of correction. The assessments were done through X-ray and clinical examinations, and biopsies at 50 and 90 days postoperatively. It was concluded that there was no clinical difference between the two groups until 90 days of evaluation. The group that received FCMO grew intra-articular bone shown on the X-ray study. All twenty animals, however, presented cells marked with CD34 antibodies on their biopsy samples, indicating the presence of stem cells in both groups. It is concluded thatfor theexperimental model, it is not recommended to use the mononuclear cell fraction,andin experimental studies with the use of stem cells in the joints models whose focus of injury keep direct contact with the bone marrow should be avoided.