Histomorphometric study of trabecular channels in normal iliac bone.

Cancellous bone channels in the normal iliac crest have been studied histologically and by histomorphometry, and their biological role has been considered. Eighty percent of trabecular channels were typical osteons with the same structural and remodeling features as cortical osteons. The similarity of osteons in these two locations was corroborated by the comparability of morphometric features. The points of difference between osteons in the two types of bone were irregular configurations of trabecular osteons and marrow cells in the central canal in some. Since the number of trabecular osteons decreases with age, and since active trabecular resorption cavities were few in number, it is unlikely that additional osteons are formed in normal bone after the active modeling phase of bone growth. It is improbable that they make a significant contribution to bone remodeling since their number decreases with age, and since the available surface of trabecular channels for remodeling is extremely small. However, it is probable that they aid the intraosseous microcirculation and mineral exchange in thick trabecula and bifurcations, where they are mainly located. The demarcation curves at the 95% confidence interval, which suggest the normal range for numbers of channels, was calculated from the scatter diagram against bone area.