Official websites use. Share sensitive information only on official, secure websites. Articular cartilage of higher animals does not regenerate, but under some circumstances mesenchymal cells can be inducted to behave phenotypically as chondrocytes. Tissue engineering has produced only partial cartilage repair and inconsistent outcomes.
This study reports full thickness articular cartilage regeneration induced by freeze-dried particulate cartilage. Full thickness cartilage defects in the femoral condyles of 22 baboons were filled with freeze-dried cartilage particles. Defects in two animals were filled with frozen cartilage particles. Four animals served as controls. Experimental animals were sacrificed at 2 weeks 2 , 6 weeks 6 , 9 weeks 1 12 weeks 3 , 14β16 weeks 4 and at 7 and 14 months.
The knees were photographed and x-rayed. The condyles were frozen, sectioned, photographed again, fixed, decalcified and processed for histology. To determine if cartilage preparations were osteogenic samples were implanted intramusculary in 16 athymic rats. Cartilage particles were also implanted intraosseously into 2 baboons. Regenerating cartilage was graded in accordance with a modified Mankin's method. Cartilage regeneration proceeded from the edges of the defect.
The 12 week and older defects were covered with smooth and glistening new cartilage. Control defects remained open or contained uneven patches of cartilage. Animals with frozen cartilage implants appeared identical to controls. Cartilage particles implanted into athymic rats remained inert and elicited neither osteogenesis nor chondrogenesis, as did cartilage placed intramedullary in baboons.
The data demonstrates induction of articular cartilage regeneration by freeze-dried hyaline cartilage particles implanted orthotopically. Long-term maintenance of cartilage allograft tissue is challenging. This study examines if dexamethasone, a synthetic adrenal corticosteroid, can play a role in maintaining the mechanical properties of cartilage explants in serum-free tissue culture.
