Venous pressure and bone formation.

We have studied the relationship of increased venous pressure to formation of periosteal new bone in growing dogs. The methods used were measurement of fluid spaces in bone by steady-state tracer techniques, measurement of venous pressure, and measurement of the rate of periosteal new bone formation by histomorphometry. The results of paired comparisons--test versus control tibia--show an increase in venous pressure, a decrease in vascular space, an increase in extracellular fluid space (sucrose space), and an increase in periosteal new bone formation on the side of increased venous pressure. The data support the hypothesis that an increase in venous pressure results in an increase in passage of fluid from capillary to bone matrix. Increased extravascular perfusion could be a factor in increasing periosteal bone formation. This flux of fluid may increase streaming potentials in bone and these act as a signal to bone cells to increase bone formation.