What is the Origin of Skeletal Resilience?

The concept of resilience, derived from the Latin resilire meaning "to leap back," has been applied to bone biology to emphasize the dynamic, adaptive nature of the skeleton beyond static mass measurements. The term gained prominence in endocrinology and orthopedics as research demonstrated that fracture risk is not solely determined by BMD but also by factors like collagen quality and micro-damage accumulation. This perspective shift highlights the bone's living, adaptive capacity in response to mechanical and hormonal signals.

What is the Mechanism of Skeletal Resilience?

Skeletal resilience is maintained through the continuous process of bone remodeling, where osteoclasts resorb old bone and osteoblasts form new matrix, a process tightly regulated by systemic hormones and local growth factors. Key endocrine regulators, including parathyroid hormone, calcitonin, and sex steroids (estrogen and testosterone), modulate the lifespan and activity of these bone cells, ensuring the appropriate coupling of resorption and formation. Mechanical loading provides the necessary biomechanical stimulus, activating local signaling pathways that further enhance the bone's microarchitectural strength and overall capacity to withstand strain.

Skeletal Resilience

Meaning

Skeletal resilience refers to the intrinsic capacity of the bone tissue to resist fracture, absorb energy, and maintain its structural integrity under physiological stress, encompassing both the bone’s density and its quality, including microarchitecture and turnover rate. This measure of skeletal health is a more comprehensive metric than simple bone mineral density (BMD) alone, reflecting the dynamic interplay between osteoblast-mediated formation and osteoclast-mediated resorption. Clinically, optimizing skeletal resilience is a core objective in hormonal health and longevity medicine to mitigate the risk of fragility fractures associated with age-related endocrine decline, such as estrogen and testosterone deficiency.