Transilial bone biopsies following in vivo fluorochrome labeling were obtained from 90 women with postmenopausal osteoporosis and 34 healthy post-menopausal women. Standard histomorphometric data were collected from undecalcified sections.

The distribution of values for both structural and remodelling indices was the same for each group. Bone volume was 35% lower (P < 0.001), wall thickness was 12% lower (P < 0.001), and trabecular thickness was 11% lower (P < 0.02) in osteoporotics. Trabecular separation was 34% greater (P < 0.001) and trabecular number was 36% lower (P < 0.001) in osteoporotics. Biopsy core width was 11% less (P < 0.02) and cortical width was 35–50% less (P < 0.001) in osteoporotics. Static indices of remodelling, mineralizing surfaces, and mineral apposition rate were similar in the two groups.

The absolute values for bone histomorphometric variables for both groups are similar to most published data. Osteoporotics had poorer bone structure, marked by decreased trabecular connectivity and thin cortices. There were no major differences in dynamic indices of remodelling. Since the histomorphometric data were distributed the same in both groups, special subsets of osteoporotic subjects not in the normal population did not exist.