Intraosseous pressures in the knee in relation to simulated joint effusion, joint position, and venous obstruction. An experimental study in growing dogs.

The present study was performed in 9 mongrel puppies, 8-10 weeks old. Under anaesthesia simultaneous pressure registrations were taken from the distal femoral metaphysis, the distal femoral epiphysis, the proximal tibial epiphysis together with the arterial pressure. An intra-articular pressure increase resulted in a significant increase in the intraosseous pressure in the distal femoral epiphysis, while the pressures in the femoral metaphysis and tibial epiphysis remained unchanged. During maximal flexion of the empty joint a significant increase in femoral epiphyseal pressure was observed, while maximal extension resulted in a significant increase in tibial epiphyseal pressure. The presence of a moderate intra-articular effusion augmented these findings. By selective ligation of the venous drainage from the juxta-articular bones in the popliteal fossa and on the femur, different levels of epiphyseal hypertension could be produced. These pressure increases never reached the level of the arterial pressure. Thus they revealed only a partial impairment of the vascular circulation in the juxta-articular bones.