The majority of people in the world actually have some degree of leg length discrepancy, up to 2cm. One study found that only around 1/4 of people have legs of equal lengths. LLD of greater than 2cm is relatively rare, however, and the greater the discrepancy, the greater the chances of having a clinical problem down the road. A limp generally begins when LLD exceeds 2cm and becomes extremely noticeable above 3cm. When patients with LLD develop an abnormal gait, one of the debilitating clinical features can be fatigue because of the relatively high amount of energy needed to walk in the new, inefficient way. Poliomyelitis, or polio, as it is more commonly known, used to account for around 1/3 of all cases of LLD, but due to the effectiveness of polio vaccines, it now represents a negligible cause of the condition. Functional LLD, described above, usually involves treatment focused on the hip, pelvis, and/or lower back, rather than the leg. If you have been diagnosed with functional LLD or pelvic obliquity, please ask your orthopaedic surgeon for more information about treatment of these conditions.
Some children are born with absence or underdeveloped bones in the lower limbs e.g., congenital hemimelia. Others have a condition called hemihypertrophy that causes one side of the body to grow faster than the other. Sometimes, increased blood flow to one limb (as in a hemangioma or blood vessel tumor) stimulates growth to the limb. In other cases, injury or infection involving the epiphyseal plate (growth plate) of the femur or tibia inhibits or stops altogether the growth of the bone. Fractures healing in an overlapped position, even if the epiphyseal plate is not involved, can also cause limb length discrepancy. Neuromuscular problems like polio can also cause profound discrepancies, but thankfully, uncommon. Lastly, Wilms? tumor of the kidney in a child can cause hypertrophy of the lower limb on the same side. It is therefore important in a young child with hemihypertrophy to have an abdominal ultrasound exam done to rule out Wilms? tumor. It is important to distinguish true leg length discrepancy from apparent leg length discrepancy. Apparent discrepancy is due to an instability of the hip, that allows the proximal femur to migrate proximally, or due to an adduction or abduction contracture of the hip that causes pelvic obliquity, so that one hip is higher than the other. When the patient stands, it gives the impression of leg length discrepancy, when the problem is actually in the hip.
If your child has one leg that is longer than the other, you may notice that he or she bends one leg. Stands on the toes of the shorter leg. Limps. The shorter leg has to be pushed upward, leading to an exaggerated up and down motion during walking. Tires easily. It takes more energy to walk with a discrepancy.
The doctor carefully examines the child. He or she checks to be sure the legs are actually different lengths. This is because problems with the hip (such as a loose joint) or back (scoliosis) can make the child appear to have one shorter leg, even though the legs are the same length. An X-ray of the child?s legs is taken. During the X-ray, a long ruler is put in the image so an accurate measurement of each leg bone can be taken. If an underlying cause of the discrepancy is suspected, tests are done to rule it out.
Non Surgical Treatment
The key to treatment of LLD in a child is to predict what the discrepancy is at maturity. If it is predicted to be less than 2 cm., no treatment is needed. Limb length discrepancies of up to 2 or 2.5 cm. can be compensated very well with a lift in the shoe. Beyond 2.5 cm., it becomes increasingly difficult to compensate with a left in the insole. Building up the shoe becomes uncosmetic and cumbersome, and some other way of compensating for the discrepancy becomes necessary. The treatment of LLD is long-term treatment, and involves the physician and patient?s family working together as a team. The family needs to weigh the various options available. If leg lengthening is decided on, the family needs to understand the commitment necessary to see it through. The treatment takes 6 months to a year for completion, and complications can happen. But when it works, the results are gratifying.
how do you get taller?
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.