[Electron microscopic studies of the healing of preserved and non preserved allogenic articular cartilage transplants].
Preserved and fresh homologeous osteochondral grafts were implanted in the knee joints of 150 animals. The animals were sacrificed at various intervals, up to two years. Examination of the tissue was carried out by light microscopy, transmission and scanning electron microscopy. The preserved homologeous grafts become necrotic. Later a substitute tissue is seen. The ultrastructure of this tissue is not the same as that of fibrocartilage nor that of normal articular cartilage. The fresh homologeous transplants with postoperative protecting the joint from stress survive. Immediate postoperative stress leads to biomechanically caused disintegrations in the fresh homologeous grafts. Immunological factors are not important in homologeous osteochondral grafts with defined osseous portion. The most important factor for the survival of the homologeous grafts is the vitality of the transplanted tissue.