Limb Lengthening

Limb Length Discrepancies

Children's legs are often slightly different in length, shape or size. The difference is usually slight enough not to cause any difficulty, but a significant difference may require treatment to prevent an abnormal walk.

The thighbone (femur) and shinbone (tibia) have growth areas, called growth plates, on both ends of the bones. If a growth plate is disturbed, one leg may grow slower than the other. Some causes of growth disturbance are infection, trauma, fractures, paralysis or occurrences before birth. Your doctor will explain the reason for the discrepancy if it's known.


The decision to treat a limb length discrepancy depends on the amount of difference there will be when the child stops growing. Not all discrepancies need to be treated. For those that do, treatment type is determined by the amount of difference.

Amount of limb length discrepancy:

  • 0-2 cm (<1 inch): Treatment might not be necessary, but your doctor may suggest a shoe lift. A small lift is either placed inside the shoe or attached to the sole of the shoe.
  • 2-5 cm (1-2 inches): A small surgery may be done to slow the growth of the longer leg. This allows the shorter leg to catch up in length.
  • 5-15 cm (2-6 inches): Surgical options include:
    • Lengthening the shorter leg:
      This surgery involves putting a TRUE/LOKTM External Fixation System on the leg to slowly lengthen the bone.
    • Shortening the longer leg:
      Once the child is finished growing, surgery is done to remove a section of bone from the longer leg to make the legs more even.