Knee ectropion, also known as leg touching, is a common deformity of the lower limbs. When the two lower limbs are naturally straight or standing, when the two knees touch, the inner ankles of the two feet are separated and cannot be brought together. If the knees of both lower limbs are turned out, the shape is like “X”, so it is also called “X” shaped leg. In the case of single lower limb knee valgus, the shape is like “K”, so it is also called “K” shaped leg. Diagnostic criteria: The degree of X-shaped leg is mainly based on two indicators: “normal knee distance” and “active knee distance”. The normal knee distance refers to the distance between the medial ankles of the two feet when the knee joints are close together in the upright position and the legs and knee joints are relaxed. The active knee distance refers to the distance between the inside of the two ankles when the knees are together in the upright position and the legs and knees are pressed together inward. According to the size of the normal knee distance and active knee distance, “x-leg” is divided into degree I, degree II, and degree III. If the normal knee distance is less than 3 cm and the active knee distance is 0, it is degree I. If the normal knee distance is 3~6 cm and the active knee distance is more than 0, it is degree II. If the normal knee distance is more than 6 cm, it is degree III. Knee inversion, commonly known as “O-leg”, “loopy leg”, “bowleg”, “basket leg”. It is called “inversion of the knee” because the tibia of the lower leg is rotated inward at an angle at the knee joint. When the two lower limbs are naturally extended or standing, the two knee joints are separated and cannot come together when the two inner ankles touch. Diagnostic criteria According to the size of the normal knee distance and the active knee distance, “inversion of the knee” is classified as degree I, II, III and IV. If the normal knee distance is less than 3 cm and the active knee distance is 0, it is degree I. If the normal knee distance is less than 3 cm and the active knee distance is greater than 0, it is degree II. If the normal knee distance is between 3 and 5 cm, it is degree III, and if the normal knee distance is greater than 5 cm, it is degree IV. Treatment: In general, once the deformity is diagnosed, in addition to treatment of the cause, early traction, splints, braces, etc. can be used. Prevent the development of the deformity and try to correct it. In terms of non-surgical treatment, for mild knee valgus with a fair range of motion, there is thigh muscle massage. Manual thrust correction combined with orthopedic brace treatment. Passive and active movements elongate the contracted soft tissues and stimulate the growth of the epiphysis to normalize development. Moderate and severe deformities are best treated surgically. Commonly used methods include osteotomy and epiphyseal control. Epiphyseal control surgery is more effective for children under the age of 2 to 14. Our specialty treatment: Epiphyseal control is a minimally invasive pediatric orthopedic surgical method to correct pathological angular deformities. The hemi-epiphyseal control is a new surgical method to adjust the pathological orthopedic angular deformity in pediatric patients by implanting one to two epiphyseal 8-plate titanium plates on one side of the epiphysis to control the local growth of the epiphysis and not the rest of the epiphysis. Compared to osteotomy, the “8” plate epiphysis control is a minimally invasive and painful procedure. The implantation of the “8” plate is performed under general anesthesia. It usually takes about one hour. During the procedure, a small incision of 2 to 3 cm is made in the epiphysis and the “8” plate and titanium screws are safely placed in the controlled area under X-ray surveillance. This can be done simultaneously in patients with multiple deformities. External fixation, crutch support and postoperative physical therapy are not necessary. Once the pain is gone, the child is encouraged to walk and resume sports. Physical activity can usually be performed after 3 weeks. The “8” plate epiphyseal control procedure controls stagnation on one side of the epiphysis while allowing the opposite side to grow naturally. The deformity is usually corrected gradually over a period of months to a year and a half. The deformity is usually reviewed every three months after surgery and the internal fixation is removed after the deformity disappears.