Second generation issues in cartilage repair.

In recent years, regenerative techniques, such as autologous chondrocyte implantation (ACI), have emerged as a potential therapeutic option for the treatment of chondral lesions. However, the good results reported have to be weighed against the number of problems that can be observed with traditional ACI methods. To address these problems, the so-called second generation ACI techniques have been developed. Autologous chondrocyte transplantation on a 3-dimensional matrix was introduced in clinical practice from 1998 to 1999 and results at short to medium-term follow-up are well documented for different types of scaffolds. These techniques may be used for the treatment of large chondral lesions in the young, active population and highly competitive athletes, but long-term and randomized controlled studies will be needed to confirm reliability of these procedures.