Variation in osteoid pattern with age in human vertebrae.

Abstract

The change in extent and pattern of new bone formation with age was studied by quantitative and qualitative observation of osteoid covering vertebral irabecular surfaces. The various types of trabecular structures, such as transverse and longitudinal trabeculae,. were separately studied by a technique of staining thin slabs of vertebrae. The percentage of osteoid is highest in infancy and then decreases to a minimal value in early adulthood. It remains at this basal level through age 40. During the 5th through 7th decade, formation increases three-fold above the basal level as progressive loss of bone mass occurs. In infancy and childhood, osteoid seams are evenly distributed throughout the vertebra, regardless of the type or location of the trabecular structures. However, in young adults, osteoid is small in amount and is seen only at the surfaces of the transverse trabeculae. In the 5th and 6th decades, osteoid is chiefly on the transverse trabeculae, indicating the high turnover of these structures which are being lost first in the involutional process. With decreasing mass of bone in aging, persisting longitudinal trabeculae are converted into plates by apposition of new bone, which is reflected by the presence of osteoid surfaces on longitudinal trabeculae in old age.