Techniques for repairing focal articular cartilage defects are evolving from methods that induce a local stimulation of fibrocartilaginous repair to methods that will lead to a hyaline articular cartilage repair. Mosaicplasty and autologous chondrocyte implantation are examples of the latter. A tissue engineered hyaline cartilage implant that could be used off the self would minimize the morbidity of these techniques. However, there are significant questions that still need to be resolved before such tissue-engineered implants will be practical. Principally among these is the question of what is the ideal matrix for such an implant, particularly from the standpoint of the best material and architecture. Second, what is the ideal cell source to use with these implants. A third major unknown is what is the most ideal way to use growth factors to enhance the repair. As these issues are resolved, the prospects of a tissue engineered cartilage replacement will advance from theory to practice.
From the Department of Orthopaedics, University of California, San Diego, Malcolm and Dorothy Coutts Institute for Joint Reconstruction and Research, San Diego, CA.
Work from the authors' laboratory was supported by funding from NIH Grant R01 AR28467.
Reprint requests to Richard Coutts, MD, Department of Orthopaedics, University of California, San Diego, Malcolm and Dorothy Coutts Institute for Joint Reconstruction and Research, 8825 Aero Drive, Suite 103, San Diego, CA 92123.