Is there any way to cure a knee problem that is opposite of bow legged?

Knock knee: This is called a valgus knee, or genu valgum. Possible causes are developmental, connective tissue disease (rheumatoid arthritis--for example), traumatic (torn acl, mcl, pcl, posterior capsule, etc.) if associated with significant pain and arthritis, may be a candidate for total knee replacement if you are talking infantile or childhood, there are normal phases/variations in 1st 6 yrs.