A study of trabecular bones in ovariectomized goats with micro-computed tomography and peripheral quantitative computed tomography

Osteoporotic fractures occur most frequently in trabeculae-rich skeletal sites. The purpose of this study was to use a high-resolution micro-computed tomography (micro-CT) to investigate the changes in trabecular bone microarchitecture and to use a peripheral quantitative computed tomography (pQCT) to study changes in volumetric bone mineral density (BMD) in a large animal model resulted from ovariectomy (OVX). Ten adult goats were used for this study. The first iliac crest biopsy was harvested before OVX and served as baseline; the second biopsy was collected 6 months later from the opposite side for both pQCT and micro-CT measurements. Results showed that after 6 months of OVX, the BMD of the iliac crest biopsies decreased significantly by 16.3% (P < 0.05). The bone volume density (BV/TV), trabecular number (Tb.N), and connectivity density (Conn.D) measured with micro-CT decrease significantly after OVX, with an average decrease of 8.34%, 8.51%, and 18.52% (P < 0.05 each), respectively. The trabecular plate separation (Tb.Sp) was 8.26% (P < 0.05) greater than baseline after OVX. Significant correlations were found between the reduction of BMD and the decreases of BV/TV and Tb.N (r = 0.839 and 0.719, respectively; P< 0.001 both), as well as the increase of Tb.Sp (r = -0.758, P< 0.001) and SMI (r = -0.697, P< 0.001). In conclusion, this was the first experimental study in goat model to show that OVX-induced bone loss in goats was attributed by deterioration of trabecular microarchitecture.