What is Genu Valgum in Children
Genu valgum is a condition in which a child’s knees angle in and touch one another, even when the child’s legs are straight.
Genu valgum may also be called “knock knee.” When standing, the child’s knees may touch when his or her ankles are apart. Genu valgum is common in children who are 2–6 years of age.
Infants are born bowlegged because of the way they are positioned in the womb. When they first begin to walk, their knees may turn inward until their knee joints strengthen and straighten. Most children with knock knee do not have symptoms and they eventually outgrow the condition (physiologic genu valgum). Severe cases can cause symptoms and can continue past 7 years of age (pathologic genu valgum).
What are the causes?
Most cases of physiologic genu valgum are simply part of normal development. In some cases of pathologic genu valgum, the cause is not known. In other cases, genu valgum may be caused by:
- Vitamin D deficiency (rickets).
- Poor nutrition.
- Bone diseases that affect growth and development.
- Tumors.
- Injury or infection of a leg bone.
What are the signs or symptoms?
Usually, physiologic genu valgum does not cause symptoms. The only sign may be knees that touch one another while the ankles are apart when a child is standing.
Signs and symptoms of pathologic genu valgum may be noticed when a child starts to walk. They may include:
- Knee pain.
- A different level of genu valgum in each knee (asymmetry).
- An abnormal walk. The legs may swing outward when the child walks.
- Difficulty running, playing, or riding a bike.
- Weak or wobbly knees (instability).
How is this diagnosed?
Genu valgum can be diagnosed based on your child’s signs and symptoms. You may be asked if you have a family history of bone diseases or walking problems. Your child’s health care provider may also ask about your child’s nutrition and whether he or she has had any bone injuries or infections. The health care provider will do a physical exam. The exam may include:
- Observing your child as he or she walks.
- Checking your child’s knees.
- Measuring your child’s knees to compare one knee to the other.
- Taking X-rays of your child’s knees while your child is standing.
How is this treated?
Physiologic genu valgum does not require treatment.
The main treatment for pathologic genu valgum is surgery. Surgery is needed only in severe cases. The type and timing of the surgery depends on a child’s individual condition. Treatment may include:
- Bracing.
- Surgery using metal screws and plates to hold the knee in proper position as growth continues (guided growth surgery). The screws and plates may be changed over time and may eventually be removed. This is usually the first choice for surgery.
- Surgery that involves breaking and repositioning leg bones to straighten the knee joint (osteotomy). This procedure is rarely used.
Follow these instructions at home:
- Make sure that your child eats a healthy diet and gets regular exercise.
- Ask your child’s health care provider if your child should take a vitamin D supplement.
- If your child has surgery, carefully follow instructions from his or her health care provider about home care after the procedure.
Contact a health care provider if:
- Your child has signs or symptoms of genu valgum after 6 years of age.
- Your child has knee pain.
- Your child has trouble walking, running, or riding a bike.
