Non-operative treatment with immobilization or isometric traction has been abandoned as treatment for fractures of the distal femur at the end of the 1960ies. The technique of open reduction and internal fixation with a condylar plate as suggested by the AO has been the golden standard since the 1970ies. However, anatomic reconstruction of the condylar region with interfragmentary screw fixation and axial realignment of the femur shaft with a plate are challenging procedures especially in the presence of severely compromised soft tissues and put periosteal blood supply at risk. Soft tissue complications, axial malalignment and delayed fracture healing times led to the consideration of alternative techniques, such as intramedullary nailing which has been practiced with success since the 1940ies by Gerhard Küntscher and colleagues for femoral shaft fractures with minimal complication rates and improved results after closed reduction. The era of retrograde femoral nailing began with the systematic approach through the intercondylar notch by Green. This paper reviews the biomechanical properties, indication, technique as well as potential hazards and pitfalls of fracture management with the AO "distal femoral nail" (DFN). With appropriate application this technique is suitable for all fractures of the distal third of the femoral shaft including highly instable bicondylar fractures without damage to the soft tissues and the knee joint.

The open procedure caused permanent and significant damage to the strongest extensors of the autochthonus back musculature, the m. multifidus, which results from multisegment combined damage to the r. posterior nervi spinalis and muscle fibres. In contrast, percutaneous placement of an internal fixative reduces perioperative access morbidity causing little iatrogenic damage to back muscles and only a minor perioperative blood loss.

The mechanical stability of the implant allows a save osteosynthesis of unstable supracondylar and complete articular femoral fractures without additional bone grafting. Mechanical stability and minimal invasive operative technique permit a safe bone healing without major complications.

The analyzed studies showed a trend toward decreased mortality rates with the employment of HEMS. Considering the comparable hospital level and even longer rescue times with HEMS, these differences can be explained with higher quality of initial diagnosis and treatment of the HEMS rescue team. Furthermore, mortality rates can be lowered significantly through primary treatment at a level 1 trauma center. Thus, the more flexible choice of the first receiving hospital represents a specific, clinically relevant advantage of HEMS in emergency medicine.