Most people have one leg that’s just a tiny bit longer than the other, or one foot that may be slightly larger than the other. But for children with significant limb length discrepancies, the size difference between limbs can be debilitating. There are two types of limb length discrepancies.
Congenital discrepancy – this is when children are born with one leg longer than the other. In some cases both legs are normal except for the fact that one is shorter than the other. In other cases one particular part of the leg is underdeveloped or absent. In these types of cases the limb length discrepancy is only part of the overall problem.
Acquired discrepancy – this is when children are normal at birth but something happens to damage their growth plate, such as a severe fracture. The bone growth in that limb slows and results in a leg length discrepancy that increases as long as the child continues to grow.
Symptoms of Limb Length Discrepancy:
Some children may have no outward symptoms of a limb length discrepancy, and symptoms can vary widely depending on other related conditions. Here are some common symptoms:
- One leg is obviously shorter than the other
- One shoulder appears to be lower than the other
- Walking difficulties, such as limping, walking on the toes, rotation of the leg or a knee that seems to be hyperextended on one side and flexed on the other
- Pain in the back, hip, knee and/or ankle
Diagnosing Limb Length Discrepancies:
Some limb length discrepancies are so small that they can’t be readily seen through physical examination. Others are easily identifiable, but may require further testing to determine if there are other problems at work. Following a medical history and a physical examination that includes measuring your child’s legs, your child’s doctor may want to conduct a variety of tests, including:
- CT scan – a more detailed, multi-layered form of X-ray that allows the doctor to see underlying structures more easily
Treatment for Limb Length Discrepancies
Shriners Hospitals for Children® offer a variety of treatments for limb length discrepancies. Your doctor will work together with the medical team to determine the best course of treatment based on the severity of the discrepancy, and other existing medical conditions, and the overall health and developmental status of your child. Treatments available include:
Epiphysiodesis – This is a surgical procedure that arrests the growth of one or more of the growth plates of the leg. When done at the right time, this procedure allows the short leg to catch up and reach equality just at maturity. It is the most simple and least risky of all treatments, but requires precise timing to avoid over or under correction.
Femoral shortening – In this procedure a part of the femur is resected, or surgically removed, and internal fixation is used to stabilize the femoral segments. It is used when there is enough growth remaining to allow epiphysiodesis to be effective.
Leg lengthening – In a limb lengthening procedure the bone is cut and then lengthened slowly by means of an external device. The process can take up to a year and is extremely difficult for children and their parents. Although it may seem like the most obvious treatment choice for this condition, it has a high risk of complications and morbidity, or disease. That means limb lengthening is most often the last choice for treating length discrepancies.