Regionally specific compensation for bone loss in the tibial trabeculae of estrogen-deficient rats

Background: Bone mineral density (BMD) and microstructural variations have been extensively investigated in recent years; however, the compensation for bone loss between different regions is still unclear.Purpose: To fully characterize regional variations in bone mineral density (BMD) as well as the microstructure and dynamic changes of rat tibial trabeculae that occur with bone loss associated with estrogen deficiency.Material and Methods: Female Sprague-Dawley rats were ovariectomized (OVX), sham-operated (sham), or left unoperated (baseline control). The left tibiae were harvested at baseline, and at postoperative weeks 3 and 15. High-resolution micro-computed tomography (µCT) was used to identify the densitometric and microstructural properties of trabeculae in the proximal ends of the rat tibia, specifically the epiphysis and metaphysis.Results: Volumetric BMDs at the organ (organ BMD) and tissue (tissue BMD) levels were significantly higher for trabeculae at the epiphysis than metaphysis. Moreover, ...