Abstract
Aims: Tissue engineering is an increasingly popular method of addressing pathological disorders of cartilage. Recent studies have demonstrated the clinical efficacy of autologous chondrocytes implantation in cartilage defects, but there is little information on the use of a solid scaffold and on the composition of the repair tissue. The present study analysed the clinical outcome and the histological characteristics of membrane-seeded autologous chondrocyte implantation at 12–24 month after operation.
Materials and methods: Eleven patients (7 males and 4 females, mean age 37 years) suffering from cartilage lesions of the knee (10 cases) and the ankle (1 case), underwent autologous chondrocyte implantation procedure in which the expanded cells were seeded on type I/III collagen membrane before transplantation (MACI – Verigen, D). Clinical outcomes were assessed by ICRS evaluation package: revised IKDC form and Knee Osteoarthritis and Injury Outcome Score (KOOS). At least 12 months after implantation biopsy samples were arthroscopically obtained from 7 patients previous informed consent. The regenerated tissue were taken according to the ICRS standardized procedure. The specimens were stained with safranin-O and alcian blue, polyclonal antibodies anti S-100 protein and monoclonal antibodies anti chondroitin sulphate, anti-collagen type I and II. Moreover the number of cells/area was quantitatively assessed by histomorphometric method (Quantimet 500+). Ultrastructural analysis was also performed by transmission electron microscopy (TEM). The specimens were evaluated by the ICRS visual histological assessment scale.
Results: Improvement 12 months after operation was found subjectively (39.7 to 57.9) and in knee function levels. The International Knee Documentation Committee (IKDC) scores showed marked improvement at 12 months (87% A/B). 90% of biopsies showed: smooth articular surface (I:3), hyaline-like matrix cartilage (II:3), cell distribution (columnar-clusters III:2), predominantly viable cells (IV:3), normal subchondral bone (V:3), normal cartilage mineralization and tide-mark (VI:3). All sections were clearly stained with safranin-O and alcian blue. In all the specimens the cells revealed a strong immunoreaction for S-100 protein and showed a positive reaction for chondroitin-S and type II collagen. Type I collagen was immuno-detected in the more superficial layers of the biopsies. TEM analysis revealed a defined chondral cell phenotype within a chondroid matrix. Tissue heterogeneity and irregularities of the surface were observed in two cases.
Conclusions: Clinical improvement and hyaline-like appearance of the repair tissue indicate that membrane-seeded autologous chondrocyte implantation is an effective technique for the treatment of cartilage lesions.
The abstracts were prepared by Ms Grazia Gliozzi. Correspondence should be addressed to her at the Italian Orthopaedic Research Society, Laboratory for Pathophysiology, Instituti Ortopedici Rizzoli, University of Bologna, Bologna, Italy.
