Genu varum (Bow legs)

Differential diagnosis includes:

• physiologic bowing (normally seen at 18-36 months of age)
• Blount's Disease (tibia vara)
• Rickets (vitamin D sensitive versus vitamin D resistant)
• severe internaltibialtorsion
• bowing of the tibia:if it is posterior, the condition is usually benign and only associated with some shortening of the limb. If the bowing isanterolateral, it is often associated with easy fractureabilityand possiblypseudoarthrosis.

Exam - with child supine and hips/knees extended, measure distance between knees with the medial malleoli together. If distance is greater than 10 cm, the child should be referred to Ortho.

Treatment

• children with less than 10cm of distance between their knees with their ankles held together, with no other positive findings, can be treated with observation alone.
• Bracing may help those children with distance greater than 10cm.
• So work-up or refer if progressive bowing past two years of age; distance greater than 10cm; problems with gait; unilateral findings; abnormal x-rays.

CHLA Board Review 2005