The significance of intraosseous pressure in normal and diseased states with special reference to the intraosseous engorgement-pain syndrome.

When investigating a patient whose main symptom is pain aggravated by activity, or rest pain in the area of the knee (and perhaps other joints as well) the intraosseous engorgement-pain syndrome should be kept in mind. This type of pain can also be present in patients with osteoarthritis. In such patients intraosseous angiography and intraosseous pressure measurement can be useful guides when deciding the type and site of treatment. As regards the knee joint, these investigations must always be made in both tibia and femur. A drainage time of 10 and more minutes after injection of 2 ml radiopaque dye in a prone patient, and retrograde filling of intramedullary veins from a metaphyseal injection is abnormal. Concomitant intraosseous pressure measurement may be useful when made under well controlled conditions. Pressure values of more than 30--40 mm of mercury above the venous pressure are probably pathological. Rest pain can successfully be treated by a simple fenestration operation.