The mineralized ring, a single structure peculiar to long bone growth.

Mineralized ring, an elongated tubular structure ensheathing bone metaphysis, is described at successive stages of long bone growth. It is shown that the mineralized ring is characterized by different morphological aspects during its development, corresponding to successive growth stages of one and the same anatomical formation. Its origin is different from periosteal bone and its development is parallel to that of the metaphysis.