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When to Worry? Knock Knees in Young Children

Concerns about gait and leg alignment in children are common. It's hard to tell when to worry and when to just be reassured. We asked pediatric orthopedic surgeon David Roberts, MD, of NorthShore Orthopaedic & Spine Institute, to break down four of the most common gait and leg alignment concerns in children and when you need to do something.

In this last of a four-part series, we look at knock knees.

Knock knees are commonly seen in children. When the child stands, the knees touch and the ankles are far apart. This may cause an awkward appearance to the child’s gait, with the knees hitting when the child walks and runs.  Most mild cases have no symptoms. However, persistent or severe knock knees can cause knee pain or kneecap problems and may increase the risk of arthritis in older age.

child with knock knees

Physiologic genu valgum refers to the normal pattern of knock knees that appear after age 2 in most children. This initially gets worse and is most notable at about 3-4 years of age, and then starts to get better with time, with most children reaching a normal alignment by age 8-10.  Shoe inserts, leg braces, and physical therapy have no effect on this natural process of knee growth. For children following this normal pattern, no treatment is needed other than observation over time.

Children with knock knees outside of this pattern should be referred for evaluation by a pediatric orthopedic surgeon.  Surgery may be considered to correct their knock knees, especially if causing pain, gait symptoms, or associated with a family history of bone diseases or knee arthritis. 

A timely referral is important. Guided growth, similar to use in bowed legs, is the preferred treatment but is best done while there is still enough growth remaining for correction to occur (before age 12 in females, and age 14 in males). Osteotomy, in which the bone is divided and corrected using a plate and screws, is reserved for severe cases, referred too late after knee growth has naturally ended (females over age 14 and males over age 16).

We suggest seeing a doctor about your child’s knock knees, if they are:

  • Severe or getting worse over time
  • Present beyond age 8-10
  • Painful or causing significant gait problems
  • Associated with short stature, metabolic bone disease or family history of arthritis