Surgical lengthening of the shorter extremity (upper or lower) is another treatment option. The bone is lengthened by surgically applying an external fixator to the extremity in the operating room. The external fixator, a scaffold-like frame, is connected to the bone with wires, pins or both. A small crack is made in the bone and tension is created by the frame when it is "distracted" by the patient or family member who turns an affixed dial several times daily. The lengthening process begins approximately five to ten days after surgery. The bone may lengthen one millimeter per day, or approximately one inch per month. Lengthening may be slower in adults overall and in a bone that has been previously injured or undergone prior surgery. Bones in patients with potential blood vessel abnormalities (i.e., cigarette smokers) may also lengthen more slowly. The external fixator is worn until the bone is strong enough to support the patient safely, approximately three months per inch of lengthening. This may vary, however, due to factors such as age, health, smoking, participation in rehabilitation, etc. Risks of this procedure include infection at the site of wires and pins, stiffness of the adjacent joints and slight over or under correction of the bone?s length. Lengthening requires regular follow up visits to the physician?s office, meticulous hygiene of the pins and wires, diligent adjustment of the frame several times daily and rehabilitation as prescribed by your physician.
There are many causes of leg length discrepancy. Some include, A broken leg bone may lead to a leg length discrepancy if it heals in a shortened position. This is more likely if the bone was broken in many pieces. It also is more likely if skin and muscle tissue around the bone were severely injured and exposed, as in an open fracture. Broken bones in children sometimes grow faster for several years after healing, causing the injured bone to become longer. A break in a child's bone through the growth center near the end of the bone may cause slower growth, resulting in a shorter leg. Bone infections that occur in children while they are growing may cause a significant leg length discrepancy. This is especially true if the infection happens in infancy. Inflammation of joints during growth may cause unequal leg length. One example is juvenile arthritis. Bone diseases may cause leg length discrepancy, as well. Examples are, Neurofibromatosis, Multiple hereditary exostoses, Ollier disease. Other causes include inflammation (arthritis) and neurologic conditions. Sometimes the cause of leg length discrepancy is unknown, particularly in cases involving underdevelopment of the inner or outer side of the leg, or partial overgrowth of one side of the body. These conditions are usually present at birth, but the leg length difference may be too small to be detected. As the child grows, the leg length discrepancy increases and becomes more noticeable. In underdevelopment, one of the two bones between the knee and the ankle is abnormally short. There also may be related foot or knee problems. Hemihypertrophy (one side too big) or hemiatrophy (one side too small) are rare leg length discrepancy conditions. In these conditions, the arm and leg on one side of the body are either longer or shorter than the arm and leg on the other side of the body. There may also be a difference between the two sides of the face. Sometimes no cause can be found. This is known as an "idiopathic" difference.
Children whose limbs vary in length often experience difficulty using their arms or legs. They might have difficulty walking or using both arms to engage in everyday activities.
There are several orthopedic tests that are used, but they are rudimentary and have some degree of error. Even using a tape measure with specific anatomic landmarks has its errors. Most leg length differences can be seen with a well trained eye, but I always recommend what is called a scanagram, or a x-ray bone length study (see picture above). This test will give a precise measurement in millimeters of the length difference.
Non Surgical Treatment
The object of treatment for leg length discrepancy is to level the pelvis and equalize the length of the two limbs. Inequalities of 2-2.5 centimeters can be handled with the following. Heel lifts/ adjustable heel lifts can be used inside a shoe where shoes have a full heel counter. Heel lifts may be added to the heel on the outside of the shoe along with an internal heel lift. Full platforms along the forefoot and rearfoot area of a shoe can be added. There are many different adjustable heel lifts available on the market. For treatment of a leg length discrepancy, consult your physician. They may refer you to a Physiotherapist or Chiropractor for determination of the type of LLD. A Certified Pedorthist (Canada) will treat a structural leg length discrepancy with a heel lift or in larger discrepancies a footwear modification.
what is a heel raise?
Your child will be given general anesthetic. We cut the bone and insert metal pins above and below the cut. A metal frame is attached to the pins to support the leg. Over weeks and months, the metal device is adjusted to gradually pull the bone apart to create space between the ends of the bones. New bone forms to fill in the space, extending the length of the bone. Once the lengthening process is completed and the bones have healed, your child will require one more short operation to remove the lengthening device. We will see your child regularly to monitor the leg and adjust the metal lengthening device. We may also refer your child to a physical therapist to ensure that he or she stays mobile and has full range of motion in the leg. Typically, it takes a month of healing for every centimeter that the leg is lengthened.