Bone microarchitecture in males with corticosteroid-induced osteoporosis

Abstract

Microarchitectural changes in trabecular bone were analyzed by microcomputed tomography (microCT) and histomorphometry in 24 patients with corticosteroid-induced osteoporosis. The microCT images revealed a reduction in trabecular thickness only on frequency distribution curves, with no increase in trabecular separation. Trabecular plate thinning and perforations were easily identified. Corticosteroid-induced osteoporosis (CSIOP) is mediated by direct actions of the drug on bone cells. The result is a decrease in trabecular bone mass and a reduction in trabecular thickness, but connectivity is believed to remain rather well preserved. Twenty-four transiliac bone biopsies from patients with CSIOP were studied conjointly by histomorphometry [with two-dimensional (2D) architectural descriptors] and microCT (with 3D analysis of trabecular characteristics, including trabecular thickness and separation). The frequency distribution of thickness and separation were compared with data obtained in nine control subjects. 2D histomorphometry revealed a decrease in bone volume and trabecular thickness in the bone biopsies of the CSIOP patients when compared to those of the controls. MicroCT appeared to be able to identify the reduction in thickness only when the frequency distribution of trabecular thickness was computed. No difference for the curves of the frequency distribution of trabecular separation was evidenced between patients and controls. MicroCT and 2D histomorphometric results were correlated, but 2D analysis appeared to be more sensitive. However, microCT identified a very specific thinning of the trabecular plates in their center that corresponds to the earlier stages of perforations. Trabecular plate thinning can be observed and perforations occur on very thin plates in CSIOP patients.