Abstract
During the last decade there has been an increasing interest in the management of cartilage lesions, owing to the introduction of new therapeutic options. Beside the improvement of the classical vascular techniques (mosaicplasty, microfractures, etc.), cell therapy and tissue engineering have opened new perspectives in this field. One of the most recent tissue engineering techniques is represented by the MACI‚ (Matrix-induced Autologous Chondrocyte Implantation). This method requires seeding of autologous chondrocytes on a type I-III collagene membrane, after their arthroscopy harvesting from the knee and subsequent in vitro expansion of the cellular population using autologous serum. The seeded membrane is implanted in the chondral defect using exclusively fibrin glue, through a limited exposure joint approach.
Membrane structure and its cellular population were investigated by light microscopy, SEM and electrophoresis (SDS PAGE 7%) before implantation. There was evidence of chondroblasts and type II collagen inside the seeded membrane.
Clinical series. At the Institute of Orthopaedics and Traumatology of the University of Insubria in Varese (Italy), the MACI‚ technique was used for the treatment of 13 patients, affected by chondral defects, between December 1999 and January 2001. There were 9 males and 4 females with an average age of 35 years (range, 18 to 49 years). The sites of the defects were the following: 8 medial femoral condyle, 2 lateral femoral condyle, 1 femoral trochlea, 2 talar dome. The average size of the defects was 3.5 cm2 (range, 2 to 4.5 cm2).
The clinical and functional evaluation was performed using the ICRS (International Cartilage Repair Society) rating scale, the modified Cincinnati rating system, Lysholm II and Tegner scores for the knee, while the AOFAS (American Orthopaedic Foot and Ankle Society) score was used for the ankle. MRIs were taken before the operation as well as at 6 and 12 months postoperatively.
The average follow-up was 6.5 months (range, 2 to 15 months). No complications were observed in the postoperative period. The six patients with a minimum follow-up of 6 months showed an improvement in the clinical and functional status after the operation, as testified by the scores reached with the different rating systems used. MRIs showed the presence of hyaline-like cartilage at the site of implantation.
Conclusions. According to our preliminary experience, the MACI‚ technique offers several advantages (technical simplicity, short operating times, minimal invasivity and easier access to difficult sites) and appears a reliable method for the repair of deep cartilage defects.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
