Trabecular Bone: Light as a Feather, Stiff as a Board

Abstract

Trabecular bone is a crucial and unique loadbearing tissue in the skeleton found near the ends of long bones and in the vertebral bodies. Trabecular bone has the ability to rapidly adapt to the mechanical loading environment by optimizing its mass and structure in order to bear high loads with as little bone tissue as possible, allowing bones to remain strong while minimizing their weight. Measuring the loadbearing capacity of trabecular bone is crucial for assessing fracture risk, since osteoporotic fractures most often occur at skeletal sites primarily consisting of trabecular bone. However, the unique porous, heterogeneous, and anisotropic structure of trabecular bone makes quantification of its material properties technically difficult. Advances in the ability to determine trabecular bone strength therefore have the potential to drastically improve the diagnosis of fracture risk. Additionally, studying the adaptation of trabecular bone to the mechanical loading environment may provide insight into mechanisms contributing to bone fragility and fracture risk. This review focuses on stateoftheart research being performed in these two intricately related areas: assessment of trabecular bone biomechanics and trabecular bone mechanobiology.