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What Are Knock Knees?

Knock knee (also known as genu valgum or valgus knee deformity) is a condition in which the knees touch while the ankles are apart.

In most cases, knock knee is simply a normal part of growth and development during early childhood (age 3 or 4). Normally, knock knee corrects itself by age 8. Sometimes, however, knock knee continues or develops later in childhood or adolescence.


What Causes Knock Knees?

It’s common for young children have knock knees to some degree. The condition tends to run in families.

Sometimes, knock knees causes can include underlying conditions like:

  • Injury to the growth plate of the knee (the bones are the femur and tibia).
  • Damage to the growth plate from a previous bone or joint infection—such as osteomyelitis.
  • Being overweight or obese.
  • Nutritional deficiencies—such as Rickets, which is caused by a vitamin D deficiency.
  • Irregular bone growth (skeletal dysplasia).

Knock Knees Symptoms and Effects

Some common symptoms and effects of knock knees are:

  • A gap between the ankles when knees are touching.
  • Excessive inward angle of the knee.
  • Changes in the way your child walks (also known as gait).

If left untreated in older children, severe knock knees can lead to early development of pain or arthritis in the knees.


Knock Knees Treatment and Diagnosis

Diagnosing knock knees includes a physical examination and a review of your child’s medical history. The physical exam might include:

  • Assessing your child’s height, weight, length and body mass index (BMI).
  • Observing your child’s gait.
  • Assessing lower-leg alignment and symmetry.
  • Assessing lower-leg range of motion.

If your child’s knock knees are caused by an underlying medical condition, or there are signs knock knees isn’t part of normal development, X-rays can provide a more detailed view of the bones.

Most of the time knock knees correction happens on its own and you will only need to continue observation. In rare cases in which the condition continues after age 8, treatment at Gillette Children’s can include custom braces or surgery:

  • Guided Growth Surgery slows the growth of bone on the inside of the knee. It can be an option if your child is still growing.
  • Osteotomy Surgery involves cutting and re-aligning the bones to better position the leg. This helps distribute weight more evenly around the knee.

Integrated Care

At Gillette, you’ll work with nationally and internationally recognized leaders in pediatric orthopedics.

If your child has knock knees, we’ll help you coordinate the services and specialties to help your child feel their best. For comprehensive knock knees treatment, your family might work with experts in:

You’ll have a family-centered team that works closely with your primary care providers, teachers, and school or community therapists.