There is limited evidence about the comparative effectiveness of different treatments for pediatric femur fractures. The most common method used for isolated femur shaft fractures of children older than 5 years of age is elastic stable intramedullary nailing (ESIN). It is thought to be the ideal indication for children up to the age of 10 to 12 and it is the most commonly employed method of internal fixation in this age group, but other treatments include external fixation, plating, other forms of flexible or rigid intramedullary nailing and non-operative options such as spica casts or traction. In children under the age of 5 non-operative methods are believed to work well with few complications. Imperfect alignment is more acceptable because of the tremendous remodelling potential in young growing children. Internal fixation is believed to be unnecessary as it is more invasive, with some risk of complications and likely need for a second surgical procedure to remove it. Biomechanical properties are different in this age group. Consequently, operative treatment of these fractures is generally not recommended in children under the age of 3 according to the German guidelines (www.awmf.org), not under the age of 5 in the American guidelines (www.aaos.org); and in Great Britain, surgical management in preschool children is restricted to polytrauma and complex injuries (www.nice.org.uk).