Is Intra-Trabecular Bone Remodelling Induced by Parathyroid Hormone A Consequence of Trabecular Thickening?

Osteoporosis is a chronic condition characterized by the loss of bone volume and detrimental changes to bone microarchitecture. Parathyroid hormone (PTH) is currently used in the treatment of osteoporosis due to its significant role in regulating bone remodeling. Bone remodeling removes microdamage, helps maintain bone mineral levels through the creation of new bone and aids in maintaining Ca homeostasis. This project aimed to elucidate the relationship between the increased trabecular thickness induced by parathyroid hormone and intra-trabecular bone remodeling. New Zealand White rabbit calcanei from a 4-week trial, which included a PTH-dosed group and a control group, were imaged by synchrotron micro-CT. It was hypothesized that as trabecular thickness increases, an associated increase in intra-trabecular bone remodeling would be observed. A trend of increasing trabecular thickness (p = 0.11), percent bone volume (p = 0.10), and volume (p = 0.11) and length (p = 0.31) of intra-trabecular remodeling events was observed in the PTH dosed group. However, contrary to the hypothesis, no correlation was found between trabecular thickness and intra-trabecular remodeling. Future research could investigate the thickness of trabeculae at individual intra-trabecular remodeling events to determine the threshold of trabecular thickness necessary for remodeling to occur.