The role of cartilage canals: experimental study using rabbits' femoral heads.

The role of the cartilage canals of the epiphysis was investigated by studying the process of initial enchondral osteogenesis of the secondary ossification center using decapitated femoral heads of one day old Japanese rabbits. Specimens of decapitated femoral heads returned to the original acetabulum demonstrated granulation tissue invasion at ten days after birth, followed by the normal process of enchondral osteogenesis of the secondary ossification centers. In contrast, specimens of heads inserted in the peritoneal cavity to prevent invasion of granulation tissue showed no enchondral osteogenesis of the secondary ossification center, and the major portion of the decapitated femoral head was replaced by necrotic chondrocytes and empty lacunae. The results of this study confirm that the cartilage canal is important not only in the nutrition of the chondroepiphysis but also in the initial enchondral osteogenesis of the secondary ossification center.