Blood flow in the juvenile hip in relation to changes of the intraarticular pressure. An experimental investigation in dogs.

The blood flow in the hip joint of puppies was studied by means of the microsphere technique. The flow was determined before, during and after intraarticular pressure increase. A venous tamponade of 50 mmHg resulted in a significantly reduced flow in the femoral head and after an arterial tamponade of 150 mmHg the flow almost ceased. The proximal femoral metaphysis, the acetabulum and the hip joint capsule, on the contrary, showed varying degrees of flow increase. It is suggested that the significantly increased blood flow in the hip joint capsule during the intraarticular pressure increase of 50 mmHg and 150 mmHg is caused by an autoregulatory mechanism tending to restore the blood flow in the suffering femoral head. The demonstrated disturbance of the circulation in the juvenile femoral head after venous tamponade supports the theory that synovitis may be the basic mechanism in the production of Calvé-Legg-Perthes' disease.