Leg Length Discrepancy

Leg Length Discrepancy Leg length discrepancy is a type of deformity that occurs when the growth of one leg has been stunted. This can occur after a trauma to the femur or tibia bone such as a break, tumor, or infection. The damaged bone may grow more slowly than the bone in the healthy leg, causing different lengths to occur. This deformity is usually noticed by parents as a child begins to crawl or walk. A child may be born with different leg lengths, or the condition may be caused by an illness or injury that develops over time. A slight difference in the length of the legs may not cause any symptoms. However, a significant limb length discrepancy may cause a limp and make it difficult to perform normal activities. A serious difference in the length of the legs can also be harmful to the hips and other bone structures as the person ages. Cosmetic limb lengthening surgery can help restore mobility and function for those with limb deformities or limb length discrepancy.

At least 90 percent of the population has some form of anatomic leg length inequality. Most of these people have a difference of at least 5.2 mm or more. However, a lot of people do not understand the condition and its treatment options. Here is a complete guide to help you.

What is Leg Length Discrepancy?

Also known as anisomelia, leg length discrepancy (LLD) is one where one of the lower limbs is longer or shorter than the other. This unequal length in the limbs can change an individual’s posture, gait, and movements completely. However, the difference in length varies widely from one person to the next, depending on the condition’s cause. The variation can range from a mere portion of an inch to numerous inches.

Additionally, there are two types of LLD. One is structural LLD, where there is a physical difference between the same bone in the limbs. The other is functional difference, where the bones may be of equal length, but the symmetry between the limbs is unequal.  This is usually related to muscle tightness.

How Much Leg Length Discrepancy is Normal?

Not all discrepancy is unusual or a cause for worry. It may simply be a slight dissimilarity between the two sides of your body. This may not affect your wellbeing, health, or the quality of life you lead. For instance, a recent study showed that at least 32 percent of recruits to the military have a 0.5 to 1.5 cm discrepancy. This is quite normal.

Leg Length Discrepancy in Children

Leg length discrepancy is a condition that mostly appears when someone is still a child. In most instances, a child is born with this condition, and only a few acquire it when they get older. Your child may get LLD from injuries while playing or from various health conditions, including bone tumors, cerebral palsy, and diseases of the bone.

In most instances, you cannot tell outright as the child is still growing. If your child has this condition, they may complain of the following symptoms:

  • Back, knee, hip, and ankle pain
  • Poor posture like extreme shoulder tilts
  • Issues with walking
  • Toe walking
  • Limping

Leg Length Discrepancy in Adults

LLD in adults may be much easier to tell. That’s because this condition slows down the growth of bones on the affected leg. One leg will grow much longer than the other over time, making it noticeable. Although most adults have this condition from birth or childhood, others can get it later on.

Additionally, it’s possible to acquire the condition later on from neuromuscular conditions, arthritis, and chronic pain in hips, knees, ankles, or back, and sometimes even exercises. The most common type of LLD in adults is functional LLD, affecting your posture and alignment. However, for those born with this condition, structural LLD is often the most common type.

Causes of Leg Length Discrepancy

There are numerous causes of LLD, but all these causes often fall into two circumstances:

  1. Through birth
    • You were born with the condition that made one leg grow slower than the other or altered the alignment of the hips
    • You were born with legs of unequal length, or the shinbones were bowed
  1. Through trauma
    • Something happened in your childhood that either affected the length of the bone in one leg
    • Something happened in your childhood affecting the growth center of your bone

Some common causes include a fracture or an injury where the healing process caused an overgrowth of the bone or caused a slowed growth of the bone in one leg. Additionally, if you suffered from any bone diseases that damaged the growth plate, you may acquire this condition. Some treatments can also cause discrepancy by affecting the natural growth of the bones.

Diagnosing Leg Length Discrepancy

If you suffer from leg length discrepancy, your doctor may ask for your complete medical history. You may then need to undergo a physical examination to determine the severity of your condition. There are numerous methods of diagnosis your surgeon can use, including:


You may need to take an x-ray, radiography, or any imaging your doctor deems necessary in most instances. These can give the exact measurement of your discrepancy and any fractures you may have due to stress on that part of the leg. Additionally, radiography can help differentiate the type of discrepancy you may have; functional LLD or anatomical LLD.

Direct Measuring

Your doctor can also use a measuring tape to differentiate limb length between two defined points. For instance, the orthopedic surgeon can measure between your lateral malleolus and inferior iliac spine. Two or more measurements are usually standard to ensure precision.

Measuring Blocks

This method is often common when diagnosing children. In this case, your doctor will put their hands on a bilateral anatomical structure of their choice and use visual assessment to tell the difference in the leg length.

If the leg length is unequal, the doctor will keep placing blocks of various heights until the leg length is equal. This can help tell how much more height you need to be added to reach the desired equal length.

Clinical Signs

There are symptoms and side effects of leg length discrepancy that a doctor can use for diagnosis. For instance, your doctor may instruct you to walk around the examination room. This can help tell if you are making up for the discrepancy in any way.

Additionally, pain in the back, knees, hips, and spine can also confirm your discrepancy. The imbalance in muscle forces in these areas is usually the culprit responsible for the pain. Another sign is fatigue due to the need to keep flexing your knee while moving to maintain a more leveled pelvis.

Treatment For Leg Length Discrepancy

There are numerous treatments that you can undergo to treat this condition. The most common treatment type is limb length discrepancy, or limb lengthening, surgery. This treatment is the best option for those with larger differences in the length of the limbs, usually above 1.5 centimeters.

Even so, there are numerous other non-surgical methods your surgeon can use depending on your needs. Ensure you discuss all the options with them for a better overview.

Why Choose The Height Lengthening Institute For Leg Length Discrepancy Surgery

At Height Lengthening Institute, our specialists are dedicated to providing the utmost care for all our patients. We have treated many complex conditions and can provide the proper diagnosis and treatment for your leg length discrepancy. Our experts, led by the renowned Dr. Shahab Mahboubian, are highly skilled and have received the best training from renowned orthopedic institutions. We have years and years of experience under our belt, and you can trust us to provide you with the best care based on your needs. Contact us today for a consultation with one of our specialists.

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