Pressure Gradients in the Trabecular Pore Space of Femurs During Physiologic Loading

Bone marrow is an important niche for mesenchymal stromal cells (MSCs), which are progenitors for connective tissue cells. MSCs respond to mechanical stimuli (1). For example, steady and oscillatory fluid flow both affect MSC differentiation to the osteogenic lineages (2), while hydrostatic pressure increases MSC osteogenic protein expression (3). Both pressure and fluid flow are induced in bone marrow during loading due to the poroelastic nature of trabecular bone, and these may affect the differentiation or proliferation of the resident stromal cells.