The fractures of the diaphyseal segment of the femur (14.56% of the total), the biggest diaphysis of the skeleton, are of a special seriousness, both when occurring in isolation and in the multiple injury patient. The increasing frequency of traffic accidents that cause multiple high energy fractures has encouraged the development of emergency surgical procedures to stabilize the fracture site, not striving for the anatomic reduction that some of us still consider important. The extrapolation of the biologic internal fixation concept (maximum respect for the preservation and vascularization of the fragments), that we have always observed, and the relative ease of performing unreamed nailings or multiple nailings, are the causes of the popularity recently attained by the interlocking nailing techniques. These techniques are neither easy nor risk free, but this does not mean that they do not have precise indications. In any case, they are not the cure-all technique for the treatment of any fracture of the segment, as we will try to demonstrate in the following pages.

Reamed intramedullary nailing, either open or closed, following the old principles of Küntscher (intramedullary tutor guiding the axial loads), inserted with the set of instruments and implants improved by Schneider, allows stable internal fixations of some specific subgroups of fractures of the middle third of the femoral diaphysis. However, any fracture of the femur can be perfectly treated by internal fixation with a plate provided that the biomechanical principles, stated by Pauwels in his theory of the columns and developed by Müller and the AO group are observed: anatomic reduction, preservation of the blood supply of the fragments, stable internal fixation with interfragmentary and axial compression, neutralization or protection of the fracture site with a plate, and the addition of cancellous bone graft whenever there is any bone loss and in all of the short oblique and transverse fractures.

The biologic internal fixation concept is only applicable to the fractures of this segment and includes the requisites of preserving the blood supply of the fragments and using the low contact LC-DCP titanium plates.