Limb lengthening and reconstruction: Goal of treatment

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Find out how limb reconstruction surgery can lengthen and repair shorter or crooked limbs.

Key points

  • Limb length discrepancy occurs when one limb is shorter than the other. Depending on the difference in length, it can be treated with a shoe lift, surgery or, in extreme cases, an artificial limb.
  • Limb deformity occurs when a limb has an abnormal shape or position, usually due to a medical condition, poor recovery from an injury or a problem with one or more joints.
  • A fracture is a break in a bone because of an injury. It can usually be treated with a cast or surgery to fix the bone back together.
  • Your child’s surgeon and healthcare team will explain the best treatment options for your child’s situation.

What is limb reconstruction surgery?

Limb reconstruction (sometimes also called limb lengthening or limb correction) surgery is intended to treat three main types of limb problems.

These limb problems may occur on their own or together. Problems may be congenital (a child is born with them) or acquired (they develop because of an illness or accident). If your child has more than one of these problems, limb reconstruction surgery can usually repair them at the same time.

What is the goal of limb reconstruction surgery?

The goal of limb reconstruction surgery is to make sure that, when a child has finished growing, their limbs:

  • are equal length
  • are straight
  • have joints that move well
  • work as well as possible.

Limb length discrepancy

A limb length discrepancy is a difference in length between one limb and the other. Put simply, one leg or arm is shorter than the other one. Depending on the cause and location, the difference in length may affect the whole limb or only one part of it.

Most limb length discrepancies increase over time. However, treatment is only usually necessary for leg length discrepancies. The amount of difference between the limbs depends on the cause of the discrepancy.

Limb lengthening before and afterLegs before and after limb lengthening
is an example of a limb length discrepancy over 5 cm.

Your child's healthcare team will carefully assess the difference in the length of your child's limbs by examining your child and taking special x-rays. These allow the team to work out what the difference will be when your child is fully grown. This is called the predicted limb length discrepancy and will inform any decisions about your child's treatment.

Treating differences of less than 2 cm

These small limb length differences may go completely unnoticed. In fact, many people with no medical conditions or limb injuries may have up to a 1 cm difference in limb length.

For children, a small aid such as a shoe lift may be enough to help balance their walking. This type of aid is never essential, however. Your child should only use a shoe lift or similar aid if advised by their healthcare team and if your child wants to use one.

Such a small difference in limb length usually does not require any limb reconstruction surgery.

Treating differences of 2 cm to 5 cm

A difference of more than 2 cm can make it difficult to walk normally and do regular activities such as sports. Many parents and children also do not like the sight of one leg being a lot shorter than the other. Children with this discrepancy between their limbs are likely to be considered for surgery.

The most common way to treat leg length differences of 2 cm to 5 cm is through a type of limb reconstruction surgery called an epiphysiodesis. This works by slowing down the growth of the longer leg to allow the shorter leg to catch up over time.

In some special cases, limb lengthening surgery can be performed to gradually lengthen the shorter leg. This type of surgery is a much bigger operation than an epiphysiodesis. It is not usually performed when an epiphysiodesis can achieve the same long-term result.

Treating differences of more than 5 cm

Limb length differences of more than 5 cm are more difficult to correct. Most children with limb differences of this size will usually choose limb reconstruction surgery because they find it difficult to walk normally and do regular activities such as sports and playing with their friends. They also find that the big shoe lift that they need to help them walk can look unsightly and get in the way.

Over time, a large difference in leg length can cause back pain. However, it is not known to cause arthritis or "wear and tear" of the hips and knees.

There are a number of ways to correct a larger limb length difference. The most common is limb lengthening surgery on the shorter limb. Sometimes the surgeon will also slow down the growth of the longer limb with surgery (epiphysiodesis). In extreme cases, limb lengthening surgery may need to be done more than once to make sure that the limbs are the same length once the child has finished growing.

Treating differences of more than 25 cm

Very large leg length differences usually come with many other problems in the shorter leg. These may include deformities of the hip, knee, foot and ankle joints.

When there are such large differences between limbs, it is not always possible to reconstruct the joints and limb. Instead, the best option may be to consider limb reconstruction surgery to reshape the limb so that it can be fitted for a prosthesis (an artificial limb).

Your surgeon will explore all the options with you and your child so that you can decide together which treatment is best.

Limb deformity

A limb deformity means that a child's limb has an abnormal shape or position. This may be due to:

  • one or more of the bones growing differently because of a medical problem
  • a broken bone healing in an unsatisfactory position
  • a problem with the hip, knee or ankle joints.

The impact of the deformity on a child's ability to function depends on the size of the deformity and its location on the body.

Some deformities can get better on their own and some stay the same as the child grows. Many deformities, however, actually get worse over time.

Your child's healthcare team can tell you about your child's limb deformity and what will happen to the limb as your child grows. This will help you decide on the best treatment.

Small deformities may go unnoticed and not require any treatment. Larger deformities will cause children to walk or move in irregular ways and will often lead to pain and more problems with function as the child gets older.

Children with larger deformities may consider limb reconstruction surgery to:

  • improve the shape of their limb
  • improve how a limb works for walking and other activities
  • reduce any pain they may have.
Limb deformity correction before and afterLegs before and after limb deformity correction

Many different types of limb reconstruction surgeries are possible, including the fitting of an external fixator in some situations. Your child's healthcare team will explain all the options to you at your appointment.


A fracture means that a child has a break in their bone, usually because of an injury. Most often, fractures can be corrected with a cast or other surgeries to fix the bone back together. If the fracture is very severe and other treatments are not suitable, an external fixator may be the best option and can work very well to fix the bones. Your child's surgeon will discuss the best treatment options with you and your child.

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Last updated: August 31st 2015