External Fixation

What is an external fixator? 

External fixation is a limb lengthening technique where an apparatus is mounted to the outside of the body. The two types of external fixators that are used in limb lengthening are:

  • Monolateral fixator: This fixator is mounted to one side of the limb (typically the femur and humerus)
  • Circular fixator: This fixator or "frame" is mounted around the limb

Monolateral fixators are usually placed on the outer thigh or arm, or the inner leg. Sometimes they are used to treat broken bones, especially if the bone or the skin is badly damaged.

Circular fixators are mounted completely around the limb. The frame is made of at least two carbon fiber or aluminum rings connected by six struts.

For any type of external fixator, either monolateral or circular, the "frame" is mounted to the body by placing special pins or wires through the skin and into the bone. There is a special coating (hydroxyapatite) on the pins to allow them to stick to the bone. This coating decreases, but does not eliminate, the risk of pin infections. Pin infections are common, but preventable. It’s extremely important that the pins are cleaned once or twice a day.

How do I care for an external fixator?

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 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 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 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.

Your child will likely require:

  • Weekly doctor visits
  • Multiple adjustments to the frame (on a daily basis)
  • Physical therapy sessions
  • Crutches to help with daily activities

Dressing around the external fixator can sometimes be challenging (particularly if it is on the femur), but your doctor can help guide you and your child through the process.

Before the external fixator is removed, your doctor will likely want your child to be walking without any limitations. The fixator is removed in the operating room under general anesthesia. Once it is removed, your doctor may place your child’s leg in a walking cast for a short period of time or require crutches for three to four weeks, until the bone is stronger.