Genu varum (bowlegs) and genu valgum (knock-knees) are two common leg alignment conditions seen in growing children.
- Bowlegs (genu varum): The child stands with feet together, but their knees stay apart.
- Knock-knees (genu valgum): The child stands with knees together, but their ankles remain apart.
Both conditions are often part of normal development and usually correct themselves over time. But when they persist or cause discomfort, evaluation by a pediatric orthopedic specialist is important.
Signs and symptoms
While these conditions may look different, both can impact how a child walks or moves. Signs to watch for include:
- Genu varum (bowlegs)
- Knees curve outward while ankles touch
- Noticeable gap between knees when standing straight
- Toes that point inward (“pigeon-toe” or intoeing)
- Unsteady walking or frequent tripping
Genu valgum (knock-knees)
- Ankles remain apart while knees touch
- Knees angle inward on both legs
- Feet may rotate outward
- Unusual or waddling gait
Bowlegs and knock-knees typically do not cause pain in young children. However, if your child experiences discomfort or walking problems, it’s a good idea to seek medical evaluation.
What causes bowlegs or knock-knees?
These conditions can be either physiologic (normal) or pathologic (underlying condition-related).
Physiologic causes
- Normal variation during early childhood
- Most children outgrow the condition as they develop
Pathologic causes
- Rickets (a bone growth disorder due to vitamin D deficiency)
- Blount’s disease (a growth disorder of the shin bone)
- Skeletal dysplasia (genetic bone development disorders)
How are bowlegs and knock-knees diagnosed?
Your child’s orthopedic provider will start with a physical exam. In some cases, they may order X-rays or laboratory tests if:
- The condition worsens after age 2
- It doesn't improve by early adolescence
- Your child experiences pain, limited mobility or a significant leg length difference
Treatment options
Most cases of genu varum and genu valgum resolve naturally with growth. However, treatment may be recommended if the condition is severe, painful or persistent.
Treatment may include:
- Observation and growth tracking
- Bracing to guide bone alignment during growth
- Surgical intervention in rare, more serious cases
At Connecticut Children’s, our pediatric orthopedic team offers advanced treatment options, including:
- Limb lengthening and modification with technologies such as guided growth (hemiepiphysiodesis), external fixation (Ilizarov or spatial frames), or internal devices (Precice Nail or growing rods)
- Access to a state-of-the-art motion analysis lab for detailed evaluation of walking abnormalities