Orthopaedic tissue engineering: from laboratory to the clinic.

Tissue engineering involves the use of cells (either adult, mesenchymal or embryonic stem cells) coupled with biological or artificial matrices or scaffolds which guide the cells during repair or regeneration of the tissue. Recently discovered and isolated growth factors can promote either adult or stem-cell growth and differentiation along selected pathways to re-form and repair skeletal tissues in adults. Bone repair enhancement and replacement is now possible with the use of tissue-engineering technologies. It is now possible to repair articular cartilage using the patient's own articular chondrocytes retrieved during arthroscopy, and expanded in vitro. Clinical results of this technique are very satisfactory.