Radioautographic findings in osteoarthritic femoral head.

During total hip replacement for 8 patients with hip joint osteoarthritis specimens of femoral articular cartilages of 3 types of involvement were taken, i.e. the "normal" articular cartilage, the fissured and wrinkled articular cartilage, and the yellow or dusky red, markedly thickened, and roughened articular cartilage. Radioautographical studies with 3H-Thymidine labelling showed the clusters of articular chondrocyte, degeneration, death and vanishing of the chondrocytes with empty lacunae left; and mitosis and proliferation of the chondrocytes, as evidenced by silver granules in the nuclear area. In the articular cartilages of three types of involvement, the percentages of degenerated, dead and vanished chondrocytes represented by empty lacunae, of non-mitotic chondrocytes without silver granule and of chondrocytes undergoing mitosis with silver granules, were 19.9, 38.3 and 41.8; 9.1, 48.9 and 42; 5.3, 35.0 and 59.7 respectively. A large number of empty lacunae appeared in the "normal" articular cartilage, signifying aging of the cartilage. Chondrocytes bearing silver granules appeared not only in the "normal" articular cartilage but also largely in the severe osteoarthritic cartilage and served as a compensatory manifestation of both aging and osteoarthritis.