Repair of defects in articular joints. Prospects for material-based solutions in tissue engineering.

©2004 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.86B8. 15609 $2.00 J Bone Joint Surg [Br] 2004;86-B:1093-9. Each year, more than one million procedures to treat defects of articular cartilage are performed in the knee alone.1 While removal of loose bodies and the chondroplastic procedures of debridement and shaving account for approximately half of these, the remainder involve treatment of defects which are sufficiently severe to require the replacement or assisted regeneration of damaged hyaline cartilage. Over the past decade, methods based on the principles of tissue engineering and regenerative medicine have emerged as the most promising approaches for the repair of defects in articular joints.2,3 These make use of combinations of cells, signalling molecules and scaffolds to augment the natural regenerative capacity of the body, with the aim of restoring healthy structure and function to damage or diseased tissue.4 Tissue engineering has produced success in a number of soft-tissue applications,5,6 but the regeneration of articular surfaces poses a unique challenge, in that articular cartilage has a limited capacity for self-repair and mechanical stimuli play a large role in the structure and function of cartilage and subchondral bone. While these factors place special demands on all aspects of tissue engineering, scaffold design takes on a role of particular importance. This review addresses the design requirements for scaffolds used in the treatment of chondral and osteochondral defects. Particular emphasis is placed on recent trends in scaffold design and their potential for clinical application.