Leg length discrepancy is a condition in which a person has one leg that’s shorter than the other. In some people, this difference can be very mild, while in others it can be up to several inches. Limb discrepancy can cause side effects that may affect the quality of life, so many people affected by this condition seek out treatment for it.

What Causes Leg Length Discrepancy?

Forty to seventy percent of people live with a leg length discrepancy, but it can vary in severity. Leg length discrepancies are divided into two kinds: structural or functional discrepancies.

A structural discrepancy is when the same bone in each limb is longer or shorter than the other. This is congenital, or present from birth. Sometimes a child is born with bowed shin bones or sometimes the leg bones are simply uneven in length. The cause for the structural discrepancy is unknown.

In a functional discrepancy, the bones are physically equal in size, but the discrepancy is caused by something impacting the symmetry of the legs. This could be a problem in the hips or pelvis, the knees, or the foot and ankle. Functional discrepancies may also be present at birth or can have a number of other causes including:

• Traumatic injury that impacts bone growth

• Disease that impacts bone growth or growth plates (such as osteomyelitis, neurofibromatosis, multiple hereditary exostoses, or Ollier disease)

• Bone tumors

• Juvenile arthritis

• Neuromuscular conditions, such as cerebral palsy, can create issues with musculoskeletal alignment

• Bone infection, especially in early infancy

Side Effects Caused by Leg Length Discrepancy

So, what side effects can a leg length discrepancy cause? Generally, the larger the discrepancy, the more symptoms a person might experience. A child with a difference in leg length may change walking patterns and posture to accommodate the discrepancy. This can lead to the development of issues in the hip, knee, and ankle as they grow older into adulthood. A child with leg length discrepancy may also develop functional scoliosis, which is when a person develops a curve in a structurally normal spine, which can also be detrimental as an adult.

Physical signs of leg length discrepancy include:

• The appearance of one leg looking shorter than the other

• Posture problems, like a tilting shoulder

• Gait problems, like “toe-walking” or limping

• Hyperextended and flexed knees

Walking fatigue

Many times these issues lead to fatigue from walking because the limb discrepancy requires more effort. For many people, this can be a difficult and frustrating daily quality of life issue.

Pain and Injury

Over time, misalignment caused by leg length discrepancy can lead to scoliosis and degeneration of the lumbar spine (part of the lower spine). This can cause hip and lower back pain in many people.

Changes in gait from a leg length discrepancy can also cause knee and hip pain. In fact, some studies have suggested that asymmetry of 2 centimeters or more could mean a person is more likely to develop osteoarthritis in the knee or hip (although the risk is more pronounced in the knee). Ankle pain or discomfort is also common, often present in the inner ankle.

Because coordination is affected and some physical activities can be tiring, some studies suggest that people with leg length discrepancy may be more susceptible to injury, although this risk hasn’t been conclusively shown.

For people who have a minor asymmetry or discrepancy, side effects may be mild, but people with larger discrepancies may find symptoms more severe.

Corrective Surgery for Limb Discrepancy

If a leg length discrepancy is causing symptoms that affect your quality of life, it’s time to seek care. There are options available so you don’t have to live with pain, discomfort, and daily inconveniences. The first step is to schedule a physical examination. Your doctor will likely request imaging in order to measure your bones and look for stress fractures in order to reach a complete diagnosis. 

For people with minor discrepancies and mild side effects, your doctor may first recommend non-surgical treatment options, like shoe lifts. But for people whose limb discrepancies are 1.5 centimeters or more, or who are experiencing pain and other difficult side effects, limb lengthening surgery may be recommended.

Contact a Trusted Expert for Help

We provide personalized care to each patient, from diagnosis to treatment and recovery. Our expertise is in limb discrepancy and other complex orthopedic conditions. Our experts, led by Dr. Shahab Mahboubian, are highly skilled and have received the best training from renowned orthopedic institutions.