Macroscopic and histological evaluations of equine joint cartilage repair treated with microperforation of the subchondral bone associated or not with intra-articular kartogenin

The aim of this study was to evaluate the joint cartilage repair by macroscopic (via arthroscopy) and histological (biopsy fragments) analyses in chondral defects induced into equine femoral trochlea treated by microperforation associated with or without intra-articular administration of kartogenin. Six horses weighing 342 +/- 1.58 kg (mean +/- SD), aged approximately 7.2 +/- 1.30 years and with a body condition score of 7.1 +/- 0.75, were used. The horses underwent arthroscopy for induction of 1-cm(2) chondral lesions in lateral femoral trochlea immediately treated by microperforation of the subchondral bone of both knees. Four weekly intra-articular injections of kartogenin (20 mu M) in one knee (treated group) and Ringer lactate solution in the contralateral joint (control group) were performed during the postoperative period. After 60 days, macroscopic evaluations were performed by video-arthroscopy, and biopsy samples of the repair tissue were taken for histopathological healing evaluation. No significant change was observed in macroscopic and histological scores for chondral healing between treated and untreated groups (P>0.05). The overall mean percentage of hyaline cartilage in both groups (17.5%) was consistent with other international studies using other types of chondral microperforation; however, no statistical differences were observed between groups (P>0.05). In conclusion, the therapy with kartogenin, according to the used protocol, did not produce any macroscopic and histological healing improvement in induced chondral lesions treated with microperforations in equine femoral trochlea.