Mild pathological knee valgus in childhood can be treated with bracing. Severe knee valgus as well as adult knee valgus require surgical treatment. Most knee valgus can be treated with minimally invasive osteotomies and internal fixation, which are less invasive, have a quicker recovery, have an immediate effect, have a shorter treatment period and have less impact on life. Combined multiple deformities or complex knee valgus are more securely treated with external fixation and can be continuously adjusted post-operatively to achieve a satisfactory line of force. However, the treatment period is longer and the external fixation device has some impact on life during the treatment period. Especially if the deformity is on the femoral side, the thigh external fixator has a greater impact on the patient’s life.