Leg lengthening and shortening

BONE LENGTHENING

Traditionally, this series of treatments involves several surgeries, a long recovery period, and a number of risks. However, it can add up to 6 inches (15 centimeters) of length to a leg.

The surgery is done under general anesthesia. This means the person is asleep and pain-free during surgery.

• The bone to be lengthened is cut.
• Metal pins or screws are placed through the skin and into the bone. Pins are placed above and below the cut in the bone. Stitches are used to close the wound.
• A metal device is attached to the pins in the bone. It will be used later to very slowly (over months) pull the cut bone apart. This widens the space between the ends of the cut bone that will fill in with new bone.

When the leg has reached the desired length and has healed, another surgery is done to remove the pins.

In recent years, several newer techniques have been developed for this procedure. These are based on the traditional leg lengthening surgery, but may be more comfortable or convenient for some people. Ask your surgeon about the different techniques that may be appropriate for you.

BONE RESECTION OR REMOVAL

This is a complex surgery that can produce a very accurate amount of change.

While under general anesthesia:

• The bone to be shortened is cut. A section of bone is removed.
• The ends of the cut bone will be joined. A metal plate with screws or a nail down the center of the bone is placed across the bone to hold it in place during healing.

BONE GROWTH RESTRICTION

Bone growth takes place at the growth plates (physes) at each end of long bones in younger people who are still growing.

The surgeon makes a cut over the growth plate at the end of the bone in the longer leg.

• The growth plate may be destroyed by scraping or drilling it to stop further growth at that growth plate.
• Another method is to insert staples or plates on each side of the bony growth plate. These can be removed when both legs are close to the same length.

REMOVAL OF IMPLANTED METAL DEVICES

Metal pins, screws, staples, or plates may be used to hold the bone in place during healing. Most orthopedic surgeons will wait several months to a year before removing any large metal implants. Another surgery is needed to remove the implanted devices.

Leg lengthening is considered if a person has a large difference in leg length (more than 5 cm or 2 inches). The procedure is more likely to be recommended:

• For children whose bones are still growing
• For people of short stature
• For children that have abnormalities in their growth plate
• For people that had trauma and it resulted in a shortened or lengthened limb

Leg shortening or restricting is considered for smaller differences in leg length (usually less than 5 cm or 2 inches). Shortening a longer leg may be recommended for children whose bones are no longer growing.

Bone growth restriction is recommended for children whose bones are still growing. It is used to restrict the growth of a longer bone, while the shorter bone continues to grow to match its length. Proper timing of this treatment is important for best results.

Certain health conditions can lead to very unequal leg lengths. They include:

• Poliomyelitis
• Cerebral palsy
• Small, weak muscles or short, tight (spastic) muscles, which may cause problems and prevent normal leg growth
• Hip diseases such as Legg-Perthes disease
• Previous injuries or broken bones
• Birth defects (congenital deformities) of bones, joints, muscles, tendons, or ligaments

Risks of anesthesia and surgery in general include:

• Allergic reaction to medicines
• Breathing problems
• Bleeding, blood clot, or infection

Risks of this surgery include:

• Bone growth restriction (epiphysiodesis), which may cause short height
• Bone infection (osteomyelitis)
• Injury to blood vessels
• Poor bone healing
• Nerve damage

After bone growth restriction:

• It is common to spend up to a week in the hospital. Sometimes, a cast is placed on the leg for 3 to 4 weeks.
• Healing is complete in 8 to 12 weeks. The person can go back to regular activities at this time.

After bone shortening:

• It is common for children to spend 2 to 3 days in the hospital. Sometimes, a cast is placed on the leg for 3 to 4 weeks.
• Muscle weakness is common, and muscle strengthening exercises are started soon after surgery.
• Crutches are used for 6 to 8 weeks.
• Some people take 6 to 12 weeks to regain normal knee control and function.
• A metal rod placed inside the bone is removed after 1 year.

After bone lengthening:

• The person will spend a few days in the hospital.
• Frequent visits to the health care provider are needed to adjust the lengthening device. The amount of time the lengthening device is used depends on the amount of lengthening needed. Physical therapy is needed to maintain normal range of motion.
• Special care of the pins or screws holding the device is needed to prevent infection.
• The amount of time it takes the bone to heal depends on the amount of lengthening. Each centimeter of lengthening takes 36 days of healing.

Because the blood vessels, muscles, and skin are involved, it is important to check the skin color, temperature, and sensation of the foot and toes frequently. This will help find any damage to blood vessels, muscles, or nerves as early as possible.

Bone growth restriction (epiphysiodesis) is most often successful when it is done at the correct time in the growth period. However, it may cause short stature.

Bone shortening may be more exact than bone restriction, but it requires a much longer recovery period.

Bone lengthening is completely successful about 4 out of 10 times. It has a much higher rate of complications and need for further surgeries. Joint contractures may occur.

Epiphysiodesis; Epiphyseal arrest; Correction of unequal bone length; Bone lengthening; Bone shortening; Femoral lengthening; Femoral shortening

Davidson RS. Leg-length discrepancy. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 696.

Kelly DM. Congenital anomalies of the lower extremity. In: Azar FM, Beaty JH, eds. Campbell's Operative Orthopaedics. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 29.

Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.