Early diagnosis of ischemic necrosis of the femoral head.

Intraosseous pressure in the intertrochanteric region, and response to a five mililiter saline load injected intraosseously were measured in twenty-four hips in twenty patients with ischemic necrosis of the femoral head and nine hips in seven controls. All hips in which subsequent biopsy proved ischemic necrosis of the femoral head showed either intraosseous pressure greater than 30 mmHg, a hypertensive response to the saline load, or both. All controls measure less than 30 mmHg intraosseous pressure and no significant pressure rise to the saline injection. Intramedullary venography in ischemic necrosis of the femoral head revealed poor filling of extraosseous veins, diaphyseal reflux and delayed clearance of dye. These changes were present in all stages of ischemic necrosis of the femoral head including the pre-radiologic stage and constitute the basis for early detection.