SYSTEMIC COMPLICATIONS OF INTRAMEDULLARY NAILING

Today intramedullary nailing is the treatment of choice in stabilizing femoral and tibial diaphysial fractures because of its superior bone healing compared to other forms of osteosyntheses. By interlocking, th e indication can be extended to all fractures in which interlocking bo lts can be fixed in the proximal and distal main fragment. Kuntscher's principle of elastic clamp has changed to intramedullary splinting. W ith that method reaming is limited to a few reaming processes, and unr eamed nailing has become possible. Today implants start at a diameter of 9 mm. The diameter of implants of all manufactors is less than a fe w years ago. Since the importance of embolization by increasing the in tramedullary pressure as a result of reaming is accepted, the question arises concerning the clinical relevance of embolization if reaming i s restriced and unreamed nails are applied. In our own investigations, relevant intravasation of bone marrow content appeared only in reamed femoral nailing. The bone marrow cavity of the tibia is smaller, the configuration of the tibia allows more back-streaming of the content, and the venous drainage system in the distal tibia is much less extens ive than in the supracondylar area. All pulmonary complications in the literature are reported after nailing of femoral fractures. Therefore , systemic complications in intramedullary nailing are only a problem in femoral fractures. The pathophysiological connection between intram edullary pressure increases and pulmonary impairment is not clarified in detail. Relevant content of the bone marrow cavity is not only bone marrow but also the blood with which the marrow cavity is refilled af ter each reaming process and which passes into the circulation during the following reaming. This blood is activated concerning coagulation. By reaming, the pathogenic content of the bone marrow cavity is embol ized, which can become clinically relevant if cofactors are present. C ofactors are volume deficit, shock, lung contusion and pre-existing pu lmonary impairment. These conditions can never be excluded before prim ary stabilization after trauma. Today the importance of systemic compl ications during unreamed nailing is controversial. Our experimental an d echocardiographic investigations clearly show that the velocity of t he nail into the bone marrow cavity and the gap between the nail and c ortical bone at the entrance in the distal fragment determine the amou nt of embolized material. By carefully inserting the nail and choosing thin nails with a correct length, which can gain stability by fixatio n in the condylar area and not by clamping in the distal fragment, ech ocardiography reveals only minimal embolization. Therefore unreamed na iling is the treatment of choice, if the situation of the patient allo ws the procedure of nailing in itself. Multitrauma patients in shock o r with unstable circulation should be stabilized primarily with extern al fixation. After consolidation, early change to an intramedullary na il should be performed.