ARE BIODEGRADABLE MATRICES SEEDED WITH MATURE HUMAN CHONDROCYTES THE FUTURE TREATMENT FOR ARTICULAR CARTILAGE DEFECTS?

Background: Tissue-engineered cartilage can be produced by human articular chondrocytes in vitro. The same set-up could be a valuable alternative for autologous chondrocyte implantation (ACI). The use of this matrix with human allogenic chondrocytes in in vivo manipulations for the treatment of (osteo-)chondral lesions is described.Methods: Allogenic human chondrocytes, retrieved from young organ donors, were cultured in 1.0% alginate beads for 2 weeks before implantation into cartilage defects of the knee joint. Prior to the surgical intervention a small part of the alginate beads was dissolved and the chondrocytes were tested for their phenotypical stability (percentage of aggrecan, type II and type I collagen synthesizing cells). The (osteo-)chondral lesion was debrided by an open technique, and covered by an autologous periosteal flap. Subsequently the defect was filled with the alginate beads. The cartilage lesion was finally injected with 0.5% fibrin gel before the defect was hermetically closed. The patients were followed clinically and by DTPA-Gadolinium-MRI (DTPA-Gd-MRI).Results: Immediate or short-term major adverse reactions to the alginate/fibrin matrix seeded with the allogenic cartilage cells were not observed. The results of the short-term clinical examination of the involved joint, the Visual Analogous Score, the WOMAC score and the Lequesne index were promising in the same follow-up period. Early period after surgery, a quick refill of the treated cartilage defect was seen on DTPA-Gd-MRI, but this slowed down in the later follow-up period. The same MRI findings, reflecting the synthesis of hyaline extracellular matrix by the chondrocytes, were also observed after an already accepted treatment for articular surface lesionc (ACI).Conclusion: We have already shown that human chondrocytes in vitro proliferate in this culture system, show an outgrowth from the alginate into the surrounding fibrin, and synthesize a cartilage-like matrix for up to 8 weeks. The surgical procedure is performed in one step. Biodegradable, biocompatible scaffolds could be used in the treatment of cartilage defects, with the advantage that the artificial matrix provides an initial support to the chondrocytes, making the implant biomechanically superior compared to the model in which cells are injected as a suspension under a periosteal flap.Citation: , volume , supplement , year 2003, page Session: Orthopedic surgery