Bilateral Genu vulgum is a physiological process between 3 and 4 years up-to 22 degrees. After 7 years genu vulgum should not exceed 12 degrees. Surgery is indicated if vulgus angle is more than 15-20 degrees after 10 years.
In most cases, physiological genu vulgum (knock knees) don't need to be treated because it usually correct itself as your child grows. The child doesn't need to avoid his activity, wear supportive leg braces or shoes, or do any special exercises. However, exercise can help realign and stabilize knees and strengthen muscles.
Causes of pathological genu vulgum:
physeal damage or overgrowth, congenital anomalies, skeletal dysplasias, some genetic disorders, metabolic disorders, and rheumatologic diseases.