The femur (thighbone) is the largest and strongest bone in the body. It can break when a child experiences a sudden forceful impact.

What causes a child to fracture their femur?

The most common cause of femur fractures in infants under 1 year old is child abuse. Child abuse is also a leading cause of thighbone fracture in children between the ages of 1 and 4 years, but the incidence is much less in this age group.

In adolescents, motor vehicle accidents (either in cars, bicycles, or as a pedestrian) are responsible for the vast majority of femoral shaft fractures.

What are the symptoms that a child has broken their femur?

A fractured femur is a serious injury. It may be obvious that the femur is broken because:

  • Your child has severe pain
  • The thigh is noticeably swollen or deformed
  • Your child is unable to stand or walk, and/or
  • There is a limited range of motion of the hip or knee allowed by the child because of pain.

Take your child to the emergency room right away if you think he or she has a broken femur.

What are the different types of femur fractures?

Femur Fractures
(Left) An oblique, displaced fracture of the femur shaft. (Right) A comminuted fracture of the femur shaft.

Femur fractures vary greatly. The pieces of bone may be aligned correctly (straight) or out of alignment (displaced), and the fracture may be closed (skin intact) or open (bone sticking through the skin).

Specifically, femur fractures are classified depending on:

  • Location of fracture on the bone (proximal, middle, or distal third of the bone shaft)
  • Shape of the fractured ends — bones can break all kinds of ways, such as straight across (transverse), angled (oblique), or spiraled (spiral)
  • Position of the fractured edges (angulated or displaced)
  • Number of fractured parts
    • Two parts
    • Several fractured parts