Fig. 5.

Case no. 1: The arthroscopic view shows the former defect filled completely by a smooth, well integrated but softer regenerative tissue (arrow heads) (a). A full core biopsy detects regenerative tissue tightly bonded with native hyaline cartilage on the right (arrow heads). Partly uneven surface. Numerous, viable cells with chondrocytic phenotype in the superficial zone. The junctional zone shows an increased bone remodelling after cancellous bone grafting. No tide mark is detectable (hematoxylin-eosin, magnification ×5) (b). High content of glycosaminoglycans (GAG) in native cartilage, lower GAG content in regenerative tissue (safranin-O, magnification ×5) (c)