Some leg lengthening and arm lengthening conditions are better treated early while growth potential is still possible.
Limb Length Differences
Limb length differences can exist at birth or may develop during childhood. Also, up to 80 percent of human beings may have different leg lengths. And 80 percent of those may not even realize it. When the difference is larger than a couple of inches, it can create problems. On the other hand, the difference may stay the same or may worsen and increase as the child grows.
Our doctors at Medical City Children’s Orthopedics & Spine Specialists can determine the severity of a limb length variance. Using an X-ray of the legs and a simple clinical exam, we will quickly determine any variance. In addition, this test is often repeated, sometimes every six months to monitor the limb length difference in growing children.
When and When Not to Treat
The decision to treat limb length differences depends on the amount of variance existing when the child stops growing. Not all variances need treatment. When the difference is warranted, we may recommend using guided growth where we help tether the growth plate to slow down the long leg to allow the short leg to catch up. If the discrepancy is more than three inches, we discuss lengthening operations on the shorter leg. Normally, limb lengthening requires a surgical procedure that lengthens bones or replaces segments of missing bone in the upper and lower body. For example, one approach is to insert a rod into the bone that will also gradually lengthen the bone after creating a fracture during surgery. This lengthening is done using external magnetic control.
We recommend early treatment for children and adolescents with one leg much shorter than the other
“When the discrepancy is warranted, we may recommend using guided growth where we help tether the growth plate to slow down the long leg to allow the short leg to catch up. If the discrepancy is more than three inches, we discuss lengthening operations on the shorter leg.” Shyam Kishan, MD
Limb Lengthening Reconstruction Techniques
Limb lengthening techniques and Height Growth Operations that we perform replace missing bone and lengthen and/or straighten deformed bone segments. The procedures may be performed on children with limb length discrepancies due to birth defects, diseases, or injuries. The limb lengthening or height growth operation process works on the principle of distraction osteogenesis. This new concept reverses the long-held belief that a bone cannot regenerate.
In this process, a bone cut during surgery can gradually pull apart, leading to new bone formation (osteogenesis) at the site of the lengthening. In this way, bone segments can expand to 100 percent of their original length. We use a variety of techniques, including the use of monolateral (one-sided) and circular external fixation devices, to correct angular deformities as well as limb length discrepancies. The regenerated bone appears normal and does not wear out. The muscles, nerves, and blood vessels grow in response to the slow stretching like children do during a growth spurt.
Leg Lengthening – Height Growth Operation
The actual procedure, classified as minimally invasive, requires only one or two nights in the hospital. Patients do not experience pain since limb lengthening occurs so gradually and patients can continue to walk during the treatment. Children with congenital deformities will often possess unequal leg length caused by the illness. We find that when adults acquire this condition during childhood and have not sought medical assistance, they often develop back pain and hip arthritis. Growth plate fractures and bone infections in children can cause stunting of growth that results in leg variances. Following trauma, bones can heal in a shortened and deformed position (malunion).
Limb lengthening grows the bones in the arms or legs as a gradual process so that the bones and soft tissues (skin, muscles, nerves, etc.) slowly increase in length. Typically, the process takes several months. Limb lengthening can also combine with gradual or acute deformity correction. At the Medical City Children’s Orthopedic and Spine Specialists practice, we routinely lengthen the humerus (upper arm bone), radius/ulna (forearm), femur (thigh bone), and tibia (shin bone).
Limb Lengthening Surgery
During surgery, in the first phase, the doctor/surgeon will cut the bone to create two separate bone segments. Additional soft-tissue procedures may be conducted at the same time to prepare the muscles and nerves for lengthening. For example, surgically lengthening the Achilles tendon may make a tibia (shin bone) lengthening proceed better. The doctor will also apply an orthopedic lengthening device to the bone.
Growing New Bone after Height Growth Operation
During the second phase, after the height growth operation, the parent of the child will adjust the orthopedic device every day so that the bone segments are pulled apart at a slow rate of approximately 1 mm (0.04 inches) per day. This rate may differ slightly for different bones. This phase lasts until the bone has reached the desired length. Approximately 1 inch (2.5 cm) of length can grow per month. The patient will need to see the doctor several times a month during this phase to make sure that the bone does not lengthen too fast or too slow. Based on the appearance of the new bone on an X-ray, the doctor may speed up or slow down the rate of new bone growth. Throughout the process, the patient will need to attend physical therapy two to five times per week.
Hardening of the Bone after Bone Extension Surgery
The second phase is followed by the third phase (bone extension surgery) in which the new bone slowly hardens. In a typical case of a 5-cm (2-inch) lengthening, it will take about 2 months to achieve the length but an additional 2 to 3 months for the new bone to solidify. In this example, the lengthening device would stay in place for at least 4 to 5 months. The new bone will not “heal” until the new bone has hardened and calcified.
To help the bone heal, patients should eat a healthy diet with lots of protein and take vitamin and mineral supplements. During the third phase, the doctor will advise the patient to start putting some weight on the arm/leg (with the aid of crutches or a walker), which will also encourage the bone to harden and heal. Towards the end of treatment, the patient can stop using crutches.
Limb Lengthening Healing – Arm or Leg Lengthening Operation
After the new bone has fully consolidated, the orthopedic lengthening device can be removed during an outpatient surgical procedure (typically the patient does not need to stay in the hospital overnight after surgery). To provide additional protection to the new bone, the doctor may apply a cast or have the patient wear a brace for 3 to 4 weeks after an external fixator gets removed. In contrast, when an internal device gets removed after lengthening a bone, no cast or splint is applied.
We can successfully correct large deformities and equalize limbs with discrepancies of several inches. A segment of bone can be missing after a bone tumor, bone infection, or severe fracture. We can use the new bone to fill in this defect.
Our physicians at Medical City Children’s Orthopedic and Spine Specialists possess experience and expertise in the treatment of limb lengthening that encompasses both leg lengthening and arm lengthening. Finally, our board-certified doctors provide opportunities for patients who previously believed that they had no help with this problem.
Call 214-556-0590 to make an appointment.
Medical services for children from birth through adolescence at four convenient
locations: Arlington, Dallas, Frisco, and McKinney.