Cell-based cartilage repair strategies in the horse

Damage to the articular cartilage surface is common in the equine athlete and, due to the poor intrinsic healing capabilities of cartilage, can lead to osteoarthritis (OA). Joint disease and OA are the leading cause of retirement in equine athletes and currently there are no effective treatments to stop the progression of OA. Several different cell-based strategies have been investigated to bolster the weak regenerative response of chondrocytes. Such techniques aim to restore the articular surface and prevent further joint degradation. Cell-based cartilage repair strategies include enhancement of endogenous repair mechanisms by recruitment of stem cells from the bone marrow following perforation of the subchondral bone plate; osteochondral implantation; implantation of chondrocytes that are maintained in defects by either a membrane cover or scaffold, and transplantation of mesenchymal stem cells into cartilage lesions. More recently, bioengineered cartilage and scaffoldless cartilage have been investigated for enhancing repair. This review article focuses on the multitude of cell-based repair techniques for cartilage repair across several species, with special attention paid to the horse.