What is considered a significant leg length discrepancy in a child?

From the Guidelines

A significant leg length discrepancy in a child is generally considered to be a difference of 2 centimeters or greater between the lengths of the two legs, as indicated by physical examination findings, including asymmetric buttock creases and limited hip abduction 1.

Key Considerations

• The significance of a leg length discrepancy also depends on the child's age, overall height, and whether the discrepancy is expected to worsen with growth.
• Children can often compensate for smaller discrepancies, but larger ones can cause problems with walking, running, and posture, potentially leading to back pain, hip issues, and abnormal gait patterns.
• Early detection through regular pediatric examinations is crucial, as interventions are most effective when implemented during periods of active growth.

Treatment Options

• Discrepancies less than 2 cm are often considered mild and may not require treatment.
• Those between 2-5 cm are moderate and may need intervention, such as shoe lifts or epiphysiodesis (growth plate surgery) during growth years.
• Differences greater than 5 cm are classified as severe and almost always require treatment, which may include limb lengthening procedures.

Importance of Screening

• The American Academy of Pediatrics (AAP) recommends selective screening of children with risk factors or based on physical examination findings 1.
• A positive Barlow or Ortolani test implies an unstable femoral head that can be dislocated or relocated, respectively, and is an important indicator of potential leg length discrepancy 1.

From the Research

Definition of Leg Length Discrepancy

A leg length discrepancy is a condition where one leg is shorter than the other. The significance of this discrepancy can vary, and its impact on the child's health and well-being is a crucial consideration in determining the need for treatment.

Factors Influencing Treatment Decisions

Several factors influence treatment decisions for leg length discrepancies, including:

• The predicted extent of the discrepancy at skeletal maturity
• The child's age and growth potential
• The underlying cause of the discrepancy
• The presence of any associated conditions, such as scoliosis or hip, knee, or ankle joint problems

Significant Leg Length Discrepancy

A significant leg length discrepancy is generally considered to be:

• Greater than 2-2.5 cm, as this can potentially have an adverse effect on walking and standing mechanisms 2
• Greater than 2 cm, as this can lead to gait abnormalities, pelvic obliquity, and subsequent lumbar scoliosis, as well as functional disturbances of the hip, knee, and ankle joint 3

Treatment Options

Treatment options for leg length discrepancies include:

• Conservative measures, such as shoe inserts or orthoses
• Surgical procedures, such as epiphysiodesis or leg lengthening with osteotomy and distraction
• The choice of treatment depends on the extent of the discrepancy, the child's age and growth potential, and the underlying cause of the discrepancy 3, 4

Predicting Leg Length Discrepancy

Predicting the extent of leg length discrepancy at skeletal maturity is crucial in determining the need for treatment. This can be estimated using predictive algorithms, which take into account the child's age, growth potential, and the underlying cause of the discrepancy 4, 5