Leg lengthening and shortening
Leg lengthening and shortening are types of surgery to treat some children who have legs of unequal lengths.
These procedures may:
- Lengthen an abnormally short leg
- Shorten an abnormally long leg
- Limit growth of a normal leg to allow a short leg to grow to a matching length
Epiphysiodesis; Epiphyseal arrest; Correction of unequal bone length; Bone lengthening; Bone shortening; Femoral lengthening; Femoral shortening
This series of treatments involves several surgeries, a long recovery period, and a number of risks. However, it can add up to 6 inches of length to a leg.
The child will be under general anesthesia. This means the child 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 creates a 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.
BONE RESECTION OR REMOVAL
This is a complex surgery that can produce a very accurate degree of change.
While the child is 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.
The child is under general anesthesia. 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 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.
Why the Procedure Is Performed
Leg lengthening is considered if a person has a large differences 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
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:
- 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 for 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 the Procedure
After bone growth restriction:
- It is common for children 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 child can go back to regular activities at this time.
After bone shortening:
- It is common for children to spend 2 to 3 weeks 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 children take 6 to 12 weeks to regain normal knee control and function.
- A metal rod placed inside the bone is removed at 1 year.
After bone lengthening:
- The child will spend a week or longer in the hospital.
- Frequent visits to the doctor 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.
Friedman JE, Davidson RS. Leg-length discrepancy. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 668.
Kelly DM. Congenital anomalies of the lower extremity. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics. 12th ed. Philadelphia, PA: Elsevier Mosby; 2012:chap 29.
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.