The effects of postooperative electrotherapy in the repair of full-thickness osteochondral defects in the troclear groove of 36 adult rabbits were evaluated histologically. In the control group, granulation tissue was present two weeks post-operatively (PO); hyaline cartilage was observed at four and at seven weeks PO; subchondral bone regeneration was limited to the deeper portions of the defects at seven weeks PO. In group I (stimulated daily), granulation tissue presented abundant vascularization at two weeks PO and the repair tissue remained undifferentiated superficially, with formation of new subchondral bone up to the level of the original osteochondral junction, at seven weeks PO. The animals in group II (stimulated every other day), responded in two ways: through repair with hyaline cartilage, with reduced osteogenesis, similar to control group; or undifferentiated tissue, with an intense osteogenesis, as in group I. The postoperative electrical stimulation inhibited the tissue differentiation into hialine cartilage. On the other hand, endochondral ossification was accelerated, with complete regeneration of subchondral bone, in treated animals. In view of the importance of the subchondral bone for the integrity of the repair tissue, electrical stimulation is benefic in the initial fase (four weeks) of osteochondral defects repair.
articular cartilage; physiotherapy; bone repair
