Developmental hip dislocation is one of the most common extremity deformities. Developmental acetabular dysplasia or hip dislocation, if concentric head and socket repositioning can be obtained, has the greatest potential for acetabular development and shaping until the age of 1.5 years, which is unpredictable after the age of 4 years and essentially ceases at approximately 8 years of age. Therefore, treatment before the age of 4 years allows for maximum development and shaping of the acetabulum and makes the hip a normal or essentially normal joint during the growth process. Therefore, the principle of treatment for developmental hip dislocation is early detection and early treatment, and standardized treatment methods are used according to age and pathological changes. I. Conservative treatment 1 Infancy (0~6 months) If the acetabulum is dysplastic and can be repositioned with positive Ortolani sign, use Pavlik sling or dressing gear 2 Early childhood (6 months~2 years) Brace fixation Closed reset plaster external fixation Measures to prevent ischemic necrosis of the femoral head (remember) ① Preoperative traction ② Internal retractor release ③ Gentle reset under anesthesia ④ ” human” position plaster fixation ④ “Human” position plaster fixation II. Surgical treatment Suitable for 18 months~2 years old and above Select the appropriate procedure according to age and pathological changes: Salter pelvic osteotomy Dega pelvic osteotomy Pemberton acetabuloplasty Chiari pelvic internal displacement osteotomy Steel pelvic triple osteotomy