Evaluation of cartilage reconstruction by means of autologous chondrocyte versus periosteal graft transplantation: an animal study.
Autologous chondrocyte transplantation (ACT) has been shown to heal cartilage defects under experimental and clinical conditions. However, the evaluation of successful transplantation still remains arbitrary and further research is required to establish objective criteria of treatment. The aim of the present study was to evaluate the criteria of successful ACT and to compare the results with those obtained following periosteal grafting (PG). Articular cartilage specimens were taken from the distal femur of 30 adolescent New Zealand rabbits and chondrocytes were obtained by collagenase digestion. The chondrocytes were identified by a functional assay, based on estimating procollagen type II mRNA by reverse-transcribed polymerase chain reaction. The cells cultured in vitro were transplanted under a periosteal flap into a full thickness defect (ICRS III(0)). The quality of the repaired tissue was evaluated macroscopically according to a modified scale of Brittberg et al, and microscopically according to O'Driscoll et al. For comparative purposes animals treated with PG were used. Cultured chondrocytes expressed procollagen type II and, upon transplantation into the defect, produced hyaline cartilage. To evaluate the results of transplantation, two categories of criteria were adopted-macroscopic analysis and microscopic examination. By all adopted criteria the results were significantly better in the ACT group (P < .05) than in the PG group. Prior to transplantation, assays for specialized functions of chondrocytes required semiquantitative evaluation of macroscopic and microscopic appearance of the repaired tissue, showing the benefit of autologous chondrocyte versus periosteal graft transplantation.