[The effect of bone marrow embolization on the choice of procedure in the stabilization of femoral fractures].

Because of an extended venous drainage system, especially in the supracondylar area, a pressure increase in the femoral cavity results in embolization of the contents of the bone marrow cavity. Bone marrow embolization alone is mostly not apparent clinically but together with cofactors it may result in severe pulmonary damage and occasionally even in death. Cofactors are volume deficit, shock, thoracic and polytrauma and preexisting pulmonary disease. In the field of traumatology a pressure increase in the femoral cavity regularly occurs during unavoidable movement of femoral fragments in traction, during reduction, intraoperatively during intramedullary nailing, and in hip replacement. A hematoma acts as a hydraulic transmitter. Early osteosynthesis within 24 h avoids permanent intravasation of moderate amounts of the contents of the bone marrow cavity. Concerning intramedullary nailing, there are considerable differences between reamed and unreamed nailing. Reaming always leads to high-pressure increases in the femoral cavity, resulting in embolization. Therefore, reaming should not be performed if cofactors of manifestation of pulmonary impairment are present. Unreamed nailing results in less intravasation, but is not entirely harmless, as considerable pressure increases occur in unreamed nailing as well. The gap between the nail and the entrance of the distal fragment is the decisive parameter. Not just the smaller intravasation of bone marrow during unreamed nailing is important. After each reaming process, the bone marrow cavity rapidly refills with blood, which is activated concerning coagulation and pressed into the circulation during the following reaming process. Because of superior bone healing, interlocking nailing is the treatment of choice in diaphysial femoral fractures. As far as the differential indications of reaming are concerned, the discussion is not yet closed. However, reaming should undoubtedly be restricted to a few reaming processes. Before unreamed femoral nailing, the width of the bone marrow cavity must be examined exactly. If the width of the bone marrow cavity, the patient's condition and experience of the surgeon allow unreamed nailing, this procedure can be recommended. As the venous drainage system of the tibia is not important compared to the femur, the question of reaming or not in tibial fractures is not influenced by the danger of embolization, but by soft tissue damage and the stability of interlocking bolts. In patients with femoral fractures and co-factors for the manifestation of pulmonary impairment, the choice of osteosynthesis type should take plating in its improved form into consideration, as this preserves the vascularity of the fragments.(ABSTRACT TRUNCATED AT 400 WORDS)