Current concepts: Aseptic nonunion of femoral shaft diaphysis

In spite of increased understanding of biomechanics and improvements of implant design, nonunion of femoral shaft fractures continues to hinder the treatment of these injuries. Femoral nonunion presents a difficult treatment challenge for the surgeon and a formidable personal and economic hardship for the patient. In most series of femoral fractures treated with intramedullary nailing techniques, the incidence of this complication is estimated to be 1%. A higher frequency has recently been reported due to advances in trauma care leading to increased survivorship among severely injured patients and expanded indications of intramedullary nailing. Whereas the treatment of femoral shaft fractures has been extensively described in the orthopedic literature, the data regarding treatment of femoral shaft nonunions are sparse and conflicting, as most of the reported series consisted of a small number of cases. However, careful review of the existing literature does provide some answers regarding either conservative or operative management. The gold standard for femoral shaft nonunions invariably includes surgical intervention in the form of closed reamed intramedullary nailing or exchange nailing, but several alternative methods have been reported including electromagnetic fields, low-intensity ultrasound, extracorporeal shock wave therapy, external fixators and exchange or indirect plate osteosynthesis. In this paper, a comprehensive review of the current treatment modalities for aseptic midshaft femoral nonunion is presented, after a concise overview of the incidence, definition, classification and risk factors of this complication.