[Hemodynamics changes in proximal femur of patients with femoral head necrosis].

Intraosseous pressure of the proximal femur was measured with type II physical pressure detector in 46 patients with femoral head necrosis (Legg-perthes' disease 25, idiopathic necrosis 21) and in 49 normal persons (25 children and 24 adults). Fourteen of those with head necrosis and 9 of the normals were further surveyed by stress test, a test to see the pressure change following intraosseous injection of 5 ml heparinized normal saline solution. Again, intramedullary venography was done in 16 of those with diseased head and 12 of the normals to investigate their status of venous flow. The intraosseous pressure of normal hips was 20.56 +/- 8.13 mmHg in children and 17 +/- 8.72 mmHg in adults while that of diseased hips was 37.28 +/- 15.51 mmHg in children and 35 +/- 12.07 mmHg in adults. The results indicated the coexistence of intraosseous hypertension and femoral head necrosis. Intramedullary venogram showed diaphyseal reflux in those with femoral head necrosis. This finding was also proved by stress necrosis. This finding was also proved by stress test. The hindrance of venous return, whatever the cause may be, induced venous stasis, intraosseous hypertension and decreased arterial inflow. The necrosis of the femoral head was found to be due to insufficient and depletion of the nutrition supply in the femoral head.