Birth to 6 months This stage is the prime time for DDH treatment, with easy methods, good compliance, reliable efficacy and few complications. The aim of DDH treatment is to achieve stable concentric circle reset and avoid ischemic necrosis (AVN) of the femoral head. Early diagnosis and treatment is the key to improve the efficacy. Chen Houping, Department of Pediatric Surgery, Guiyang Maternal and Child Health Hospital, Guiyang City, China 1. Clinical manifestations and signs: asymmetry of thigh dermatoglyphics and hip dermatoglyphics, joint popping, and unequal length of lower limbs. Positive hip abduction test on the dislocated side. Ortolani/Balow sign is positive. Limb asymmetry, positive Allis (Galleazzi) sign, etc. 2, imaging: ≤ 4 months of children preferred hip ultrasound, Graf method; > 4 months of children can take X-ray double hip orthopedic film, commonly used indicators for Perkin’s square, acetabular index (AL), the center edge angle (CEA), Shenton’s line, tear drop (Teradrop) sign. 3. Treatment: Pavlik sling is preferred, maintaining hip flexion 100°～110°, abduction 20°～50°. 24 hours maintenance. Prohibit dislocation movements (including checking and changing clothes). Regular ultrasound 1x/1~2 weeks. If ultrasound suggests concentric restoration after 3 weeks, continue for 2 to 4 months. An abduction brace was then used until the acetabular index (AL) was <25° and the central edge angle (CEA) was >20°. If ultrasound and clinical examination after 3 weeks suggested that no reset had been achieved, the Pavik sling was discontinued and other treatments were used. Otherwise, continued compression of the acetabular wall by the posteriorly dislocated femoral head can lead to sling disease (dysplasia of the posterior acetabular wall). Other treatments include bracing (immobilization in the same position as the sling) or direct closed cast immobilization. Non-anesthetic repositioning and wearing extreme (frog) abduction braces are contraindicated to avoid damage to the cartilage of the femoral head and the AVN.