Viability of periosteal tissue obtained postmortem.

Abstract

Periosteal autografts have the potential to regenerate articular cartilage defects, but this potential is limited by the patient's age. Allograft transplantation from a young donor to an older recipient might bypass this limitation. The effect of the time delay, between death and harvesting of a periosteal graft, on the chondrogenic potential of periosteum is important not only for transplantation but also for studies dealing with tissues retrieved postmortem (i.e., including the periosteal explant model). The purpose of this study was to investigate the chondrogenic potential of periosteum obtained postmortem and a possible beneficial effect of hypothermia. Thirty NZ white rabbits (2 months old) were sacrificed and stored at room temperature or 4 degrees C for 0, 4, 6, 8, 12, 16, 18, or 24 h. Periosteal explants were then obtained and a standard cartilage yield assay performed by culturing them for 6 weeks using the periosteal organ culture model as previous published. TGF-beta1 (10 ng/ml) was added for the first 14 days of culture. Histochemical analysis and quantitative collagen typing were performed. In the explants from the animals kept for 4 h at room temperature growth and chondrogenesis were dramatically reduced. Little or no chondrogenesis was seen in explants from rabbits maintained at room temperature after 4-8 h (or more) postmortem. Cooling the rabbits to 4 degrees C partially prevented this loss of viability and continued to do so for 24 h. Even storage at 4 degrees C did not eliminate the decrease in chondrogenic potential, though it did permit partial preservation of chondrogenic potential. If periosteum is to be used for allograft transplantation, or if it is used for experimental study, its viability must be assured. This is best accomplished by harvesting it immediately postmortem. Preservation techniques, cryopreservation, or hypothermia might be useful in preserving periosteal chondrogenic potential.