Limb Lengthening FAQs

What is the goal for limb lengthening/deformity correction?

Prior to a lengthening surgery, you and your child’s surgeon will determine a goal length for the leg. This goal may change depending on how the lengthening process is going. On average, the external fixator stays on one month for every centimeter of lengthening. So, if the goal is to lengthen your child’s limb five centimeters (two inches), the external fixator stays on for five months.

During the lengthening process, your child will likely need weekly doctor visits to check X-rays and help ensure that the lengthening is going well. It is important that your child goes to physical therapy as directed. A limb lengthening will only be successful if your child is able to continue to move his or her hip, knee, and ankle during the lengthening process. To avoid serious complications, your doctor will stop the lengthening if your child’s knee, hip, or ankle are becoming too stiff or if the joints are appearing to come out of place.

Your surgeon will give you very specific instructions on how to use your external fixator device. It’s very important to follow these instructions carefully. Adjusting the external fixator too fast or two slow can be extremely dangerous and lead to serious complications.

Does limb lengthening hurt?

Everyone has a different experience with pain during limb lengthening treatment. In general, the first inch that is added during treatment is relatively easy, but additional inches can be more painful. Your child’s doctor will work with you to manage pain symptoms.

There are many different strategies that can help with pain during limb lengthening. Some are as simple as pain medication. It is important to not take NSAIDs (such as Advil or Aleve) without first talking to your doctor. This medication can affect the healing process. Talk to your child’s doctor about your child’s pain medicine.

How is a bone lengthened?

A bone can be lengthened by using a special technique that cuts the bone and slowly stretches it every day. The average lengthening rate is one millimeter (mm) per day. The bone is stretched with one of two devices:

  • Internal fixator: This is a device that stretches the bone inside the body. The most common type of internal fixator uses a magnetic lengthening nail. Not every person is a candidate for this treatment. Your child must be fully grown before this device can be used.
  • External fixator: This is a device that is mounted to the outside of your child's limb. There are pins and sometimes wires that go into the bone. The external fixator is attached to these metal pins and wires. Some external fixators are straight rods that attach to the side of the leg (monolateral) and others are circular devices that surround the leg.

How much can the bone be lengthened?

There are many factors that affect how much a bone can be lengthened. It mostly depends on the underlying reason why the bone needs to be lengthened in the first place. Generally, a bone can safely be lengthened by 20 percent. For example, if a bone is 10 inches, it could safely be lengthened two inches. In general, the longer the lengthening, the more risks are involved.

What are the risks?

The decision to undergo limb lengthening should not be taken lightly. It’s a large commitment for you, your child, and your surgeon. The stronger the commitment and communication, the more successful the treatment will be.

There are many risks with limb lengthening, the most severe being a joint dislocation. The knee or hip can dislocate during a lengthening procedure. Children with congenital femoral deficiency are at much higher risk for a joint dislocation. This can be prevented with weekly x-rays and intensive physical therapy to maintain range of motion. Your child’s doctor should also take care not to overlengthen the limb. Joint dislocations are rare and can be treated, but it is best to avoid them in the first place.

The most common problem with lengthening is pin infections, which can happen when using an external fixator. These are typically easy to treat with oral antibiotics. Other risks can be discussed with your surgeon.

What are the benefits of limb lengthening?

Limb lengthening can improve function and enable your child to walk without a large shoe lift or prosthesis. These surgeries can also correct painful, crooked limbs.

Post-Op Limb Lengthening/External Fixator FAQs

How do I care for my child's external fixator pins?

Your surgeon will let you know when to start cleaning the pins. Typically, the surgical dressings stay in place for one week after surgery. Once you take the dressings off, it is important to clean the pins on a daily basis. If your child is not allowed to bathe (usually for the first two weeks after surgery), clean the pins with a solution of half saline and half hydrogen peroxide. Take a sterile piece of gauze and soak it in the saline-peroxide solution and rub each pin in a similar manner to shining shoes. If the skin tries to adhere to the pins, it is very important to push the skin back away from the pins. A crust can also develop around the pin sites, and it is important to remove this crust while cleaning the pins. The hydrogen peroxide can help prevent the crust from building up. If you do not have sterile gauze to clean the pins, you can use a clean toothbrush dedicated solely for cleaning pins.

Once your child is allowed to get the external fixator frame wet, pin care becomes much easier. Simply remove all dressings and allow your child to take a bath or shower. Encourage the use of soap and water around the pin sites. You should continue to check for crust developing around the pins and skin adhering to the pins. You or your child can use a clean toothbrush in the bath or shower to scrub at the pin sites. If your child is taking a bath, it is helpful to place a small amount of bleach in the tub.

How can we avoid pin infections?

Unfortunately, pin infections are very common with long-term use of the external fixator. The best way to decrease the risk for infection is to clean the pins on a daily or twice daily basis. Sometimes pins that are loose or under a lot of stress are at increased risk of infection. If the pin is slightly loose, let your surgeon know right away. You can also wrap rolled gauze tightly around the loose pin and another pin to help keep it stable. Once limb lengthening or deformity correction is completed, the risk of pin infections decreases.

Signs of a pin site infection include:

  • Increased redness around the pin site
  • Increased pain around the pin site
  • New drainage around the pin site

If you notice any of these symptoms, call or email your child’s doctor. If your child is experiencing fevers greater than 100°F, call the doctor right away. This could be a sign of a more severe infection that may need to be treated in the hospital.

How do I care for the incisions?

Following your child’s surgery, his or her surgical incision should remain covered for the first week unless otherwise instructed by your surgeon. When you return to the office the week after surgery, your surgeon or an assistant will remove the dressings. Once the original dressing is removed, the surgeon or assistant will show you how to clean the pins and incision sites. Your surgeon will likely allow your child to shower after the first week of recovery.

Do not put any creams or ointments on the surgical incisions unless instructed to do so.

How do we manage bathing?

In most cases, you will see your surgeon approximately one week after surgery. Your child should not take a bath or shower unless your surgeon has said to do so. If the wounds look clean, your surgeon will typically allow your child to take a shower one week after surgery and a bath two weeks after surgery.

Keep in mind that your child may not be able to put weight on the leg that was operated on, so he or she may need help in the shower. If this is the case, ask your doctor about ordering a shower seat. Alternatively, you can place a plastic lawn chair in the shower for your child to sit on.

When should we start physical therapy?

Your child should start physical therapy immediately after surgery. Arrangements for physical therapy will be made prior to surgery if possible. Children’s physical therapists are trained in the physical therapy protocol for your child’s limb lengthening procedure.

If a Children’s physical therapist is not located near you, we will provide your physical therapist with our physical therapy lengthening protocol. Your physical therapist should provide reports with updates on your child’s range of motion of the hip, knee and ankle joints. It is important to bring your surgeon a copy of this report to every follow-up visit.