@naoma Hello, Knock knee can be caused by an underlying congenital or developmental disease or arise after an infection or a traumatic knee injury. Treatment for knock knees depends on the cause and severity of the condition. Treatments other than surgery include medication and regular exercise. You should consult other doctors as well and know what caused him knock knees in the first place. If knock knee is caused by an underlying disease or infection, that condition will be addressed before any orthopedic correction begins. Thanks.