Growth-plate chondrocyte cultures for reimplantation into growth-plate defects in sheep. Characterization of cultures.

Damage to epiphyseal growth plates due to fracture, trauma, or infection can lead to invasion of bone across the cartilage and localized arrest of long-bone growth. The implantation of a viable de novo cartilage plug into such defects may provide the appropriate cartilage presence necessary to inhibit the initial formation of bony bridges across the epiphysis and so maintain the growth potential. De novo cartilage plugs were prepared from ovine growth plates by culturing isolated epiphyseal chondrocytes from fetal lambs. After 14 days of culture, these de novo cartilage discs were composed of chondroitin sulfate, a small amount (5%) of dermatan sulfate, and cartilage-specific collagen. The cellular morphology and the histochemistry resembled resting zones of normal growth-plate cartilage. Those de novo cartilage discs, which had been embedded in gelled Type I collagen, retained their morphology and could be easily manipulated. On the other hand, Type II collagen and a polyuronic acid gauze (Surgicel) were not satisfactory substrates to facilitate subsequent transplantation into growth-plate defects. The use of 5-carboxyfluorescein diacetate succinimidyl ester (CSFE) throughout the cultures of epiphyseal chondrocytes or prolonged incorporation of [3H]-thymidine appeared to label the cells with useful markers for following their fate subsequent to implantation in vivo.