Pediatric Limb Lengthening Surgery

What is limb lengthening?

Limb lengthening is a treatment that stimulates a too-short arm or leg to grow longer. It involves surgery, followed by the use of an internal or external device that gradually extends the limb over time.

This procedure is used for kids (and adults) with a limb length discrepancy – meaning one arm or leg is shorter than the other – that impacts their mobility and physical function. Having an arm that's significantly shorter than the other can make it difficult to do everyday activities, such as riding a bike or typing. Differences in leg length can make it hard to stand, walk and run and may lead to hip, knee and back problems.

During the surgery, the bone is cut and an expandable device is placed; it will be used to slowly move the bone's two ends away from each other. As a gap opens up, new bone grows to fill it. The entire process is done over several months, giving the bone and its surrounding muscles, tendons and other tissues time to stretch and heal. The device is removed after the proper length is reached and the new bone has hardened.

Typically, one cycle of limb lengthening can extend a bone up to 2 inches. To reach the desired length, some children undergo multiple treatment cycles.

Limb lengthening is a physically demanding process that requires a lot of patience from both patients and their families. It can sometimes take six to nine months – or longer, depending on several factors. To ensure this is the right treatment for your child, you must fully understand the procedure, the potential complications and other treatment options.

Our approach to limb lengthening surgery

Pediatric orthopedic surgeons at Pediatric Limb Lengthening & Complex Reconstruction are experts in the limb lengthening procedure and its follow-up care. The center is the only limb lengthening program on the West Coast that focuses on children and young adults. We provide comprehensive care and support to our patients and their families.

Evaluation for limb lengthening

Limb lengthening is a complex procedure and isn't right for everyone. To determine whether it's appropriate for your child, we'll perform a thorough evaluation.

Typically done by an orthopedic surgeon, the evaluation will include a physical exam and an assessment of your child's medical history. The surgeon will look at the affected limb's length, alignment and any deformities, and may ask to observe your child standing, walking and sitting. The surgeon may also order imaging tests, such as X-rays, an MRI or a CT scan, to assess the bone and surrounding tissues.

Preparation for limb lengthening

Before the surgery, the care team will give you detailed instructions on how to prepare. There may be certain medications your child should take or avoid, and your child will need to stop eating and drinking a specified number of hours before the surgery, so that their stomach is empty.

To ensure your child's recovery from surgery goes well, you'll need to make some plans ahead of time. These should include:

• Having someone available to assist your child with dressing, bathing and other tasks for several weeks after the surgery
• Informing your child's school that they'll be absent for about six weeks after the surgery
• Determining who will take your child to follow-up appointments, including physical therapy
• Having enough comfortable, loose-fitting clothing that can accommodate the fixator (in case an external device that lengthens the limb is used)
• Reaching out to friends and family who can support and help you during your child's recovery

Procedure for limb lengthening

This treatment takes part in two stages. The first stage is the surgery, in which the bone is cut and a lengthening device is placed. The second stage is the process of gradually lengthening the limb. This stage involves daily adjustments of the internal or external device to continually create space between the bone's two parts, millimeter by millimeter.

Surgery for limb lengthening

Your child will be under general anesthesia (completely asleep) for the surgery, so they won't feel pain. The surgeon makes an appropriate length incision in the skin to access the bone.

Using special tools to avoid damaging surrounding tissues, the surgeon cuts the bone in two and then attaches the lengthening device.

There are two types of surgical limb-lengthening devices, external and internal (referring to whether they’re placed outside or inside the body). They work the same way, slowly separating the two ends of bone so that the body makes new bone tissue to fill in the space. The type used will depend on your child's specific case.

After the surgery, your child will stay in the hospital for one to three days, depending on the type of device used. But to help ensure a smooth transition home, we may extend the hospital stay a few days if the child needs physical therapy or the family needs more time to become familiar with managing the lengthening device.

Limb lengthening using an external device

An external lengthening device, or fixator, is a frame that fits over the outside of the arm or leg and is anchored to the bone with pins that pass through the skin. A special handheld tool is used to gently pull on the bone ends, incrementally widening the space between them.

Limb lengthening using an internal device

The internal lengthening device is a rod implanted in the bone. A magnetic device is used to lengthen the rod and gradually separate the bone segments.

Limb lengthening process at home

After the surgery, your child's care team will train you on the care you'll provide at home. They'll show you how to make the daily adjustments to the lengthening device. Being consistent with these adjustments is crucial to ensuring the best possible outcome for your child.

Additional home care may include:

• Cleaning pin sites. If your child has an external fixator, you'll need to clean the pin sites daily to prevent infection.
• Exercise. Your child will require help with daily stretching and strengthening exercises, including weight training, to maintain muscle strength and promote bone growth.
• Physical therapy. Physical therapy sessions, which may include aquatic therapy, will help with rehabilitation.
• Medication management. Your child's doctor will prescribe or recommend certain medications to manage your child's post-op pain. These medications may be taken by mouth or given by injection. 
• Nutrition. Make sure your child is getting a healthy, balanced diet to support bone growth. Their doctor may also recommend vitamins or other supplements.

We'll monitor your child's progress through regular appointments and periodic X-rays to see how the bone is healing.

Once the desired length is achieved and the new bone has hardened, the device is removed under general anesthesia as a same day procedure.

Complications of limb lengthening

Limb lengthening is a complex procedure that carries risks. Common complications of the surgery include:

• Infection. One common problem seen with limb lengthening is infection around the pins for an external device. (This type of infection isn't an issue with internal devices since they don't use pins.) Most infections can be treated with oral antibiotics, but sometimes hospitalization is needed to administer intravenous antibiotics (given into a vein) or to perform surgery to change the pins.
• Bone growth issues. The new bone may grow too quickly or too slowly, requiring a change in the adjustment schedule. In rare instances, the bone fails to heal, a situation called nonunion. If that happens, it may be necessary to stop the limb lengthening process or perform additional surgery to help the bone heal.
• Injury to nerves or blood vessels. Delicate structures, such as nerves or blood vessels, may be damaged during the procedure, potentially creating problems with sensation or movement.
• Joint stiffness. The lack of physical activity in the weeks after surgery can lead to losses in flexibility. A physical therapy program can help manage this problem.
• Device issues. If the fixation device malfunctions, your child's doctor will need to adjust it or possibly replace it.

Please ask your child's surgeon any questions you have about limb lengthening and its potential complications. We want you to be fully informed so you can make the best care decisions for your child.