What Are Knock Knees?
Knock knees, or genu valgum (GEE-noo VAL-gum), is a condition where a child stands with their knees touching but their ankles are apart. This condition often occurs as a normal part of growth and development, commonly seen in toddlers to elementary school-aged children. It is rarely serious and typically resolves on its own by the time a child is 7 or 8 years old.
What Are the Signs & Symptoms of Knock Knees?
Parents usually notice the appearance of their child’s legs or that their knees touch. They might worry that their child will trip and fall. While children might be bothered by their knees touching during walking, knock knees generally do not cause pain.
What Causes Knock Knees?
Normal bone growth and development when kids are about 2–4 years old can cause the knees to turn inward.
Rarely, knock knees that begin or worsen after age 4 can be caused by a health problem. For example:
- A healed fracture in the growth area of one of the bones around the knee can cause the knee to turn inward.
- Rickets: A bone growth problem caused by a lack of vitamin D or calcium. This is much less common today than in the past and can be treated with vitamin D and calcium supplements.
- Dysplasias: Health problems some children are born with that affect the way bones grow.
- Being Overweight: Can affect how bones grow.
- Tumors: A tumor in a leg bone can make the knee turn inward.
Who Gets Knock Knees?
Most young kids’ knees turn in at least a little bit. It’s a normal part of development between ages 2–4 that usually improves by about age 7–8. Some kids might have knock knees from a health problem, with signs developing later, usually after age 6, and worsening instead of improving.
How Are Knock Knees Diagnosed?
Health care providers diagnose knock knees through an examination and by asking about the child’s medical history. They likely won’t do any tests if the child is 2–4 years old, feels well, and both legs tilt inward to the same degree. Instead, they will monitor the condition to ensure it improves as the child grows.
Some kids might need to see an orthopedic doctor (bone specialist) if:
- The legs don’t straighten on their own.
- One knee turns in more than the other, or only one side turns in.
- The child experiences pain, limping, weakness, or trouble running.
X-rays might be used to look for healed fractures or rickets. If rickets is suspected, blood tests can help with the diagnosis.
How Are Knock Knees Treated?
Most kids who have knock knees from normal growth and development don’t need treatment. The condition usually corrects itself as the child grows.
Severe knock knees or knock knees that are worse on one side sometimes require treatment. In the past, braces and shoe inserts were used, but they were found to be ineffective and are no longer recommended.
In rare cases where children have symptoms such as pain or trouble running, doctors might suggest surgery after age 10.
To treat knock knees from rickets, doctors usually recommend adding vitamin D and calcium to the child’s diet. Some kids with rickets might need to see a specialist. Rickets due to a genetic condition may require more specialized treatment by an endocrinologist (a doctor who treats diseases of the endocrine system).
What Else Should I Know?
Kids with mild knock knees from normal development don’t need to limit their activities. They can run, walk, and be as active as other kids. If your child is bothered by having knock knees, reassure them that it’s likely to get better on its own.