Bone histological heterogeneity in postmenopausal osteoporosis: a sequential histomorphometric study.

We studied sequential bone biopsies performed at 6 to 24 month intervals from 14 untreated osteoporotic women (64 +/- 7). Subgroups were defined, respectively, by increased osteoclastic resorption surfaces and decreased osteoblastic surfaces +/- 2 S.D. Normal values were obtained from bone biopsy of 23 normal women (61 +/- 8). When patients were divided into subgroups according to the above criteria the first biopsy showed that 3 out of the 14 patients had high resorption surfaces and 6 had low osteoblastic surfaces. Eight patients spontaneously changed during the study. In 2 patients there was a change in resorption surfaces, in 3 in osteoblastic surfaces and in 3 a change in both osteoblastic and resorption surfaces was observed. Considering the first or second bone biopsy results the patient variance was higher than the control subject's variance; however the variance between the first and second bone biopsy of one patient was not different from the variance inside the group of patients. The average intraindividual variation of the parameters on sequential biopsies was of the same order as the one we previously observed on simultaneous bone biopsies of normal and hemodialyzed patients. We concluded that if osteoporosis is a heterogeneous disorder, subgroups cannot be definitively defined on the basis of cellular parameters of bone remodelling assessed on bone biopsies.