Relationships of static and kinetic histomorphometric features of bone

Morphologic features of non-decalcified histologic sections of bone assessed by conventional staining techniques were quantitatively compared with kinetic parameters of the same sections as evaluated by time-spaced, fluorescent tetracycline markers. Double tetracycline labels appeared in apposition to more than 90% of osteoid seams lined by histologically characteristic osteoblasts in a biopsy exhibiting accelerated skeletal metabolism. In contrast, less than half of such surfaces exhibited a double tetracycline label in slowly remodeling bone. Furthermore, in actively metabolizing bone, double labels were found juxtaposed to approximately one-third of osteoid surfaces not lined by typical osteoblasts, and to more than 9% of surfaces exhibiting no osteoid seam at all. Single tetracycline labels were also present in association with non-osteoid lined surfaces in both biopsies. These data underscore the necessity of time-spaced tetracycline markers in ascribing kinetic features to histologic parameters of bone.