[Current status of autologous chondrocyte transplantation]

Autogenous chondrocyte transplantation (ACT) is a promising but disputable new method for the treatment of full thickness hyaline cartilage defects. Neither long-term follow-up studies nor prospective randomised comparative clinical trials exist to measure the outcome.

Several bioengeneering companies have emerged (Genzyme, Verigen, Co.don, etc.) and commercialised this new method of ACT which has generated enormous interest. Each company uses its own (secret) protocol for culturing human cartilage cells. These protocols vary considerably from each other with regard to culture media, enzymes and other additives (e.g. antibiotics) used. However, no quality control requirements for the culturing process of cartilage cells have been proposed which the companies have to fulfill. At the time of surgery the treating surgeon has to assume (and hope) that the cultured cells are viable, sterile, active and potent but a control mechanism does not exist.

Considering the enormous price for ACT which the patients and the insurance companies are asked to pay quality control standards should be developed with the following informations given: cell viability, grade of differentiation, cell morphology, secretion levels of essential matrix components (collagen type II, IX, X and XI, Aggrecan) and the total cell number. None of the above information is currently provided by any of the companies involved.

The widespread clinical use of this technique cannot be recommended at this stage as the scientific proof for reproducibility of ACT has not been given so far. The operative technique of ACT is demanding and should only be used by surgeons having attended special practical training courses and workshops to minimise technical failure rates. Clinical results should be documented in a uniform standardised way using established outcome scores and modern diagnostic measures (e.g. intraoperative biomechanical testing of repair tissue). Further controlled clinical trials, experimental research and the establishment of quality control standards are required.