RESUMO
Spontaneous proper healing of articular cartilage trauma in adults is rare and osteoarthritis might develop as a result. Cultured bone marrow mesenchymal stem cells [BM-MSCs] could differentiate into chondrocytes, and might thus be a good choice for treating such trauma. To assess the efficacy of an intraarticular injection of BM-MSCs derived from young albino rats in the repair of an induced chondral defect in the knee joints of adult albino rats. Six young male albino rats were used as a source of BM-MSCs. In addition, 30 adult male albino rats were divided into four groups. Group I served as a control. Group II served as a model of a chondral defect. Group III was subdivided into subgroups IIIa and IIIb, in which a cartilage defect was induced and sacrificed after 4 and 8 weeks, respectively. Group IV was subdivided into subgroups IVa and IVb, in which a cartilage defect was induced and injected intraarticularly by BM-MSCs suspended in hyaluronic acid [HA] in the right knees and HA alone into their left knees and then sacrificed after 4 and 8 weeks, respectively. Histological, immunohistochemical, and statistical studies were performed. Group III showed healing of the defect by fibrous tissue. However, BM-MSCs- injected knees healed by hyaline-like cartilage, whereas the HA injection induced healing by fibrocartilage. Intraarticular injections of BM-MSCs suspended in HA promoted healing of an articular cartilage defect by hyaline cartilage. Thus, it is recommended to treat a traumatic articular cartilage injury by BM-MSCs