Systemic Bone Loss Following Fracture: A Mechanism for Increased Fracture Risk

Many risk factors for osteoporotic fracture risk have been identified, but one of the strongest predictors of a future fracture is a previous history of fracture at any skeletal site, even after controlling for bone mineral density. One possible explanation for this phenomenon is that a first (index) fracture is indicative of a pre-existing problem with bone quality. However, there is an intriguing alternative explanation: an index fracture may cause a systemic adaptive response that actively and permanently compromises the skeleton. This systemic reaction following fracture may include systemic inflammation, bone adaptation to mechanical disuse, and utilization of mineral for callus formation. However, the time course and magnitude of systemic loss of bone following an initial fracture has not been sufficiently quantified, and the specific mechanisms of this bone loss have not been identified.

Data from our lab indicate that bone fracture or musculoskeletal injury actively decreases trabecular bone volume at distant and unrelated skeletal sites. These data may partially explain why a previous history of fracture predicts future fracture risk in humans and may have important implications for treatment. The long-term goal of this research is to investigate systemic loss of bone mass and strength following bone fracture and to translate these findings to human health and treatment of clinical fractures.