[Value of venting drilling for reduction of bone marrow spilling in cemented hip endoprosthesis]

A rise in intrafemoral pressure during the implantation of a cemented hip replacement seems to have been proven in experimental and clinical studies. The biological system of the femur equalizes this pressure by means of its venous drainage system, which is located at the linea aspera and distal metaphysis. The intravasation of bone marrow, fat and debris that follows leads to characteristic clinical signs of a more or less distinct embolism of the lung, which is indicated by an intraoperative drop in blood pressure and end expiratory pCO2. The logical therapeutic measure to avoid biological self-drainage of the femur is to create sufficient extrafemoral drainage via a unicortical venting hole distal from the expected tip of the prosthesis, which must be combined with an intramedullary plug to preserve the desired effect of the high-pressure technique for cement-bone interlocking. If it is also possible to install a vacuum in the medullar cavity of the femur to draw the cement into the cancelleous bone, an optimal cementing result in combination with minimal patient risk can be promised.