Leg lengthening or shortening involves a variety of surgical procedures used to correct legs of unequal lengths, a condition referred to as limb length discrepancy (LLD). LLD occurs because a leg bone grows more slowly in one leg than on the other leg. Surgical treatment is indicated for discrepancies exceeding 1 in (2.5 cm).
Leg lengthening or shortening surgery, also known as bone lengthening, bone shortening, correction of unequal bone length, femoral lengthening, or femoral shortening, has the goal of correcting LLD and associated deformities while preserving function of muscles and joints. It is performed to:
Leg lengthening or shortening surgery is usually recommended for severe unequal leg lengths resulting from:
Guidelines for treatment are tailored to patient needs and are usually as follows:
According to the Maryland Center for Limb Lengthening and Reconstruction, the rate of increase of the leg length difference is progressive in the United States with one-fourth of the LLD present at birth, one-third by age one year, and one-half by age three years in girls and four years in boys.
LLD is common in the general population, with 23% of the population having a discrepancy of 0.4 in (1 cm) or more. One person out of 1000 requires a corrective device such as a shoe lift.
Leg lengthening is performed under general anesthesia, so that the patient is deep asleep and can't feel pain. Of the several surgical techniques developed, the Ilizarov method, or variation thereof, is the one most often used. An osteotomy is performed, meaning that the bone to be lengthened is cut, usually the lower leg bone (tibia) or upper leg bone (femur). Metal pins or screws are inserted through the skin and into the bone. Pins are placed above and below the cut in the bone and the skin incision is stitched closed. An external fixator is attached to the pins in the bone, which is used after surgery to gradually pull the cut bone apart, creating a gap between the ends of the cut bone in which new bone growth can occur. The fixator functions much like a bone scaffold and will be used very gradually, so that the bone lengthens in extremely small steps. The original Ilizarov external fixator consists of stainless steel rings connected by threaded rods. Each ring is attached to the underlying bone segment by two or more wires, placed under tension to increase stability, yet maintain axial motion. Titanium pins are also used for
Other surgical techniques, such as the Wagner method, or acute lengthening, are used much less commonly. The Wagner technique features more rapid lengthening followed by bone grafting and plating. The advantage of the Ilizarov technique is that it does not require an additional procedure for grafting and plating. However, there are reports indicative of higher pain scores associated with the Ilizarov method and conflicting reports concerning the level of complications associated with each technique.
Leg shortening surgery is also performed under general anesthesia. Generally, femoral shortening is preferred to
Epiphysiodesis is also performed under general anesthesia. The surgeon makes an incision over the epiphyseal plate at the end of the bone in the longer leg. He then proceeds to destroy the epiphyseal plate by scraping or drilling it to restrict further growth.
LLD is a common problem that is frequently discovered during the growing years. A medical history specific to the problem of limb length discrepancy, is taken by the treating physician to provide information as to the cause of discrepancy, previous treatment, and neuromuscular status of the limb. The patient is first evaluated standing on both legs to assess pelvic obliquity, relative height of the knees, presence of angular deformity, foot size, and heel pad thickness. Overall discrepancy is assessed by having the patient stand with the shorter leg on graduated blocks until the pelvis is leveled. Examination is then performed with the patient prone, hips extended and knees flexed to 90 degrees. In this position, the respective lengths of the femur and tibia segments of the two legs can be compared, and the relative contribution of the difference within each segment to the overall LLD can be roughly assessed.
Imaging studies, such as x rays, are the diagnostic tool of choice to fully evaluate the patient. A leg series of x rays shows the overall picture of the affected leg. The extent of LLD and required alignment can be measured with precision, and bone abnormalities involving specific parts of the leg can also be seen. The x rays are usually repeated at six to 12 month intervals to establish the growth pattern of the limbs. When several determinations of limb length have been compiled, the remaining growth and the ultimate discrepancy between the legs can be calculated, and a treatment plan selected based on predicting future growth and discrepancy, which is in turn dependent on an accurate record of past and present growth. Treatment is rarely started solely on the basis of a single determination of the existing discrepancy in a skeletally immature child. CT scans are not performed routinely but may be helpful in confirming the diagnosis or more accurately measure the amount of discrepancy.
For LLD patients with a nonfunctional foot, most physicians recommend amputation. In patients with a functional foot, the surgical procedure recommendations generally fall into one of the following three groups:
In the case of leg lengthening, the patient is also seen and evaluated for the design of the external fixator before surgery.
One week before surgery, patients are usually scheduled for a blood and urine test. They are asked to have nothing at all to eat or drink after midnight on the night before surgery.
After the operation, nursing staff teach patients how to clean and care for the skin around the pins that attach the external fixator to the limb (pinsite care). Patients are also shown how to recognize and treat early signs of infection and not to neglect pinsite care, which takes about 30 minutes every day until the apparatus is removed. It is very important in preventing infection from developing.
After an epiphysiodesis procedure, hospitalization is required for about a week. Occasionally, a cast is placed on the operated leg for some three to four weeks. Healing usually requires from eight to 12 weeks, at which time full activities can be resumed.
In the case of leg shortening surgery, two to three weeks of hospitalization is common. Occasionally, a cast is placed on the leg for three to four weeks. Muscle weakness is common, and muscle-strengthening therapy is started as soon as tolerated after surgery. Crutches are required for six to eight weeks. Some patients may require from six to 12 months to regain normal knee control and function. The intramedullary rod is usually removed after a year.
In the case of leg lengthening surgery, hospitalization may require a week or longer. Intensive physical therapy is required to maintain a normal range of leg motion. Frequent visits to the treating physician are also required to adjust the external fixator and attentive care of the pins holding the device is essential to prevent infection. Healing time depends on the extent of lengthening. A rule of thumb is that each 0.4 in (1 cm) of lengthening requires some 36 days of healing. A large variety of external fixators are now available for use. Today's fixators are very durable, and are generally capable of holding full weight. Most patients can continue many normal activities during the three to six months the device is worn.
Metal pins, screws, staples, rods, or plates are used in leg lengthening/shortening surgery to stabilize bone during healing. Most orthopedic surgeons prefer to plan to remove any large metal implants after several months to a year. Removal of implanted metal devices requires another surgical procedure under general anesthesia.
During the recovery period, physical therapy plays a very important role in keeping the patient's joints flexible and in maintaining muscle strength. Patients are advised to eat a nutritious diet and to take calcium supplements. To speed up the bone healing process, gradual weight-bearing is encouraged. Patients are usually provided with an external system that stimulates bone growth at the site, either an ultrasound device or one that creates a painless electromagnetic field.
All the risks associated with surgery and the administration of anesthesia exist, including adverse reactions to medications, bleeding and breathing problems.
Specific risks associated with LLD surgery include:
Another serious specific risk associated with leg lengthening/shortening surgery is infection of the pins or wires going through the bone and/or resting on the skin that may result in further bone or skin infections (osteomyelitis, cellulitis, staph infections).
Epiphysiodesis usually has good outcomes when performed at the correct time in the growth period, though it may result in an undesirable short stature. Bone shortening may achieve better correction than epiphysiodesis, but requires a much longer convalescence. Bone lengthening is completely successful only 40% of the time and has a much higher rate of complications. Recovery time from leg lengthening surgery varies among patients, with the consolidation phase sometimes lasting a long period, especially in adults. Generally speaking, children heal in half the time as it takes an adult patient. For example, when the desired goal is 1.5 in (3.8 cm) of new bone growth, a child will wear the fixation device for some three months while an adult will need to wear it for six months.
A LLD of 0.8 in (2 cm) or less is usually not a functional problem and non-surgical treatment options are preferred. The simplest forms do not involve surgery:
See also Amputation .
Golyakhovsky, V. and V. H. Frankel. Operative Manual of Ilizarov Techniques. Chicago: Year Book Medical Publishers, 1993.
Maiocchi, A. B. Operative Principles of Ilizarov: Fracture, Treatment, Nonunion, Osteomyelitis, Lengthening Deformity Correction. Phildalephia: Lippincott, Williams & Wilkins, 1991.
Menelaus, M. B., ed. The Management of Limb Inequality. Edinburgh: Churchill Livingstone, Pub., 1997.
Watts, H., Williams, M. Who Is Amelia?: Caring for Children With Limb Difference. Rosemont, IL: American Academy of Orthopedic Surgeons, 1998.
Aarnes, G. T., H. Steen, P. Ludvigsen, L. P. Kristiansen, and O. Reikeras. "High frequency distraction improves tissue adaptation during leg lengthening in humans." Journal of Orthopedic Research 20 (July 2002): 789–792.
Barker, K. L., A. H. Simpson, and S. E. Lamb. "Loss of knee range of motion in leg lengthening." Journal of Orthopedics Sports and Physical Therapy 31 (May 2001): 238–144.
Bidwell, J. P., G. C. Bennet, M. J. Bell, and P. J. Witherow. "Leg lengthening for short stature in Turner's syndrome." Journal of Bone and Joint Surgery (British) 82 (November 2000): 1174–1176.
Choi, I. H., J. K. Kim, C. Y. Chung, et al. "Deformity correction of knee and leg lengthening by Ilizarov method in hypophosphatemic rickets: outcomes and significance of serum phosphate level." Journal of Pediatric Orthopedics 22 (September-October 2002): 626–631.
Kocaoglu, M., L. Eralp, A. C. Atalar, and F. E. Bilen. "Correction of complex foot deformities using the Ilizarov external fixator." Journal of Foot and Ankle Surgery 41 (January-February 2002): 30–39.
Lee, S. H., G. Szoke, and H. Simpson. "Response of the physis to leg lengthening." Journal of Pediatric Orthopedics 10 (October 2001): 339–343.
Lindsey, C. A., M. R. Makarov, S. Shoemaker, et al. "The effect of the amount of limb lengthening on skeletal muscle." Clinical Orthopedics and Related Research 402 (September 2002): 278–287.
Nanchahal, J. and M. F. Pearse. "Management of soft-tissue problems in leg trauma in conjunction with application of the Ilizarov fixator assembly." Plastic and Reconstructive Surgery 111 (March 2003): 1359–1360.
American Academy of Orthopedic Surgeons. 6300 North River Road, Rosemont, Illinois 60018-4262. (847) 823-7186. http://www.aaos.org
American College of Foot and Ankle Surgeons. 515 Busse Highway, Park Ridge, Illinois, 60068. (847) 292-2237. (800) 421-2237. http://www.acfas.org/ .
"Epiphysiodesis." Institute of Child Health. [cited April 2003]. http://www.ich.ucl.ac.uk/factsheets/test_procedure_operations/epiphysiodesis/index.html .
"Ilizarov Method." Northwestern orthopedics. [cited April 2003]. http://www.orthopedics.northwestern.edu/orthopedics/nmff/ilizarov.htm .
"Leg lengthening/shortening." MedlinePlus. [cited April 2003]. http://www.nlm.nih.gov/medlineplus/ency/article/002965.htm .
Monique Laberge, Ph.D.
Leg lengthening/shortening surgery is performed in a hospital, by a treatment team usually consisting of an experienced orthopedic surgeon and residents specialized in extremity lengthening and deformity correction, physiotherapists, nurses and other qualified orthopedic staff. Orthopedics is a medical specialty that focuses on the diagnosis, care and treatment of patients with disorders of the bones, joints, muscles, ligaments, tendons, nerves and skin. Orthopedic surgery is a specialty of immense variety, and includes LLD repair.