[Problems and complications of surgical techniques for treatment of full-thickness cartilage defects]

There has been great progress concerning the surgical treatment of full-thickness cartilage defects within recent years. Surgical techniques such as arthroscopic microfracturing (MF), autologous osteochondral transplantation (OCT) and autologous chondrocyte implantation (ACI) have been introduced and, by using these techniques, reliable and satisfying clinical results can be achieved. Nevertheless, there are also technique-related problems and characteristic complications of all surgical techniques in the field of cartilage repair. Knowledge of these complications is essential for every surgeon using these techniques. The aim of the present article is to give an overview concerning technique-associated and characteristic complications of the most common cartilage repair techniques including arthroscopic microfracturing, autologous osteochondral transplantation and autologous chondrocyte implantation (ACI).

In order to identify relevant literature concerning complications following cartilage repair, medical databases including "medline", "ovid" and "web of science" were searched for the terms "autologous chondrocyte implantation", "autologous chondrocyte transplantation", "microfracture", "osteochondral transplantation", "cartilage repair", "cartilage defect" and "complications" in October 2009. The present publication represents a non-systematic review including publications which were considered relevant for describing charateristic complications and adverse events in surgical techniques used for cartilage repair.

Although the number of studies describing complications and adverse events following surgical cartilage repair studies is limited, for all techniques included in the present review (arthroscopic microfracturing, autologous osteochondral transplantation and autologous chondrocyte implantation) technique-associated and characteristic complications could be identified. While regenerative tissue following microfracturing seems to be limited in terms of durability, intralesional bone formation and elevation of the subchondral bone plate seem to be characteristic problems of this technique. Harvest morbidity, degeneration of the surrounding cartilage, necrosis of the transplanted cylinders and a lack of integration of the cartilage into the surrounding cartilage seem to be related to the transplantation of osteochondral cylinders (OATS/OCT), while hypertrophic regenerative cartilage, disturbed fusion into the adjacent cartilage, delamination and insufficient cartilage regeneration are associated with the autologous chondrocyte implantation (ACI).

The present paper identifies technique-associated complications for the most common surgical techniques used for cartilage repair. Even if the clinical relevance of the complications described in the current article has not been investigated to its fullest extent, the awareness of these characteristic complications is essential in order to avoid them whenever possible or to develop standardised treatment regimes for these problems. This needs to be addressed in further investigations.