Changes in intraosseous pressure at the distal femoral epiphysis induced by variations in knee-joint position and intracapsular saline infusion. An experimental study in dogs.

Hemodynamic changes at the distal femoral epiphysis measured by recording intraosseous pressure (IOP) were investigated in mature and juvenile dogs after changes in knee-joint position and intracapsular infusion of 3 ml isotonic saline solution. Juvenile and mature animals responded to infusion test with a similar 5-fold increase in intracapsular pressure. A 2-fold increase in IOP was found when knee-joint flexion passed from 30 degrees to complete flexion. In juvenile dogs, IOP values were lower than in adults both in complete knee flexion and during infusion test. The similar response to joint hyperpressure tests observed in adult and juvenile dogs suggests that the barrier effect of the growth plate for epiphyseal venous drainage has no major influence in the hemodynamics of the distal femoral epiphysis.