Cell Carriers as the Next Generation of Cell Therapy for Cartilage Repair

BACKGROUND: Since the first patient was implanted with autologous cultured chondrocytes more than 20 years ago, new variations of cell therapies for cartilage repair have appeared. Autologous chondrocyte implantation, a first-generation cell therapy, uses suspended autologous cultured chondrocytes in combination with a periosteal patch. Collagen-covered autologous cultured chondrocyte implantation, a second-generation cell therapy, uses suspended cultured chondrocytes with a collagen type I/III membrane. Today's demand for transarthroscopic procedures has resulted in the development of third-generation cell therapies that deliver autologous cultured chondrocytes using cell carriers or cell-seeded scaffolds. PURPOSE: To review the current evidence of the matrix-induced autologous chondrocyte implantation procedure, the most widely used carrier system to date. Also discussed are the characteristics of type I/III collagen membranes, behavior of cells associated with the membrane, surgical technique, rehabilitation, clinical outcomes, and quality of repair tissue. STUDY DESIGN: Systematic review. METHODS: Relevant publications were identified by searching Medline from its inception (1949) to December 2007; peer-reviewed publications of preclinical and clinical cell behavior, manufacturing process, surgical technique, and rehabilitation protocols were identified. Preclinical and clinical studies were included if they contained primary data and used a type I/III collagen membrane. RESULTS: Data from these studies demonstrate that patients treated with matrix-induced autologous chondrocyte implantation have an overall improvement in clinical outcomes. Reduced visual analog scale pain levels (range, 1.7-5.32 points) and improvements in the modified Cincinnati (range, 3.8-34.2 points), Lysholm-Gillquist (range, 23.09-47.6 points), Tegner-Lysholm (range, 1.39-3.9 points), and International Knee Documentation Classification scale (P <.05) were observed. Patients had good-quality (hyaline-like) repair tissue as assessed by arthroscopic evaluation (including International Cartilage Repair Society score), magnetic resonance imaging, and histology, as well as a low incidence of postoperative complications. CONCLUSION: The findings suggest that matrix-induced autologous chondrocyte implantation is a promising third-generation cell therapy for the repair of symptomatic, full-thickness articular cartilage defects.