External fixation versus conversion to intramedullary nailing for definitive management of closed fractures of the femoral and tibial shaft.

External fixation for definitive therapy of closed diaphyseal femur and tibia fractures is the preferred method of treatment only in the pediatric population. In adult injuries, in particular open battle wounds, the timing of conversion of an external fixator to an intramedullary nail is determined by the condition of the soft tissues and the overall stability of the patient. In the tibia, conversion to an intramedullary nail is accomplished as expeditiously as possible. Early (< 2 weeks) conversion to an intramedullary implant may be accomplished safely. Increased infection rates have been documented when conversion is done after 2 weeks of external fixation. In the femur, conversion from external fixation to nailing is done as the patient's overall physical condition and soft tissues allow. Acute conversion to an intramedullary device in a single procedure is preferred in patients without evidence of pin-tract infection. Staged conversion to an intramedullary nail often requires a prolonged period of bed rest with skeletal traction to maintain fracture stability and patient comfort, with the attendant risks of pneumonia, decubiti, and thromboembolic events. Treatment of closed femoral and tibial diaphyseal fractures with external fixation, either definitively or as a bridge to intramedullary nailing, is a viable option in the patient with gross physiologic instability or an ipsilateral dysvascular limb. The decision to use definitive external fixation versus conversion to an intramedullary device should be made on a case-by-case basis. Additional prospective clinical studies are warranted to further delineate risks and benefits of these treatment modalities.