[Reduction techniques in intramedullary nailing osteosynthesis]. / Repositionstechniken in der Marknagelosteosynthese.

ABSTRACT

Intramedullary nailing was originally conceived for the stabilization of shaft fractures of long bones. Due to new nail designs and multiple interlocking possibilities, the spectrum of nailing has significantly increased. Nailing of fractures beyond the isthmus is technically challenging because fractures need to be reduced before the nailing procedure starts. Indirect techniques of reduction include the use of an extension table, a large distractor or an external fixator. Direct reduction with pointed reduction forceps, lag screws, a cerclage wire or a short plate can optimize indirect reduction. The choice of the correct entry portal is of utmost importance for an optimal operative result. The location of the entry portal is dependent on the local anatomy and the bend of the nail. The optimal entry portal at the proximal tibia is directly behind the patellar tendon and accessible with the knee in more than 90° of flexion, alternatively through a suprapatellar approach with a slightly flexed knee joint. Insertion of the nail through the suprapatellar approach is possible without stress on the reduced fracture fragments. Blocking screws create an artificial isthmus in the metaphyseal area and force the guide wire in the desired direction. Blocking screws help to avoid axial malalignment during nail insertion. Interlocking of the nail with screws coming from different directions prevents secondary dislocation.