Developmental hip dislocation is formerly known as congenital hip dislocation, and in addition to congenital factors, acquired factors play an important role in this disease. The treatment of developmental hip dislocation depends on the age of the child, and the younger the child, the better the outcome. The treatment is most effective if every newborn is routinely screened after birth, and the diagnosis is made within one week. Treatment can also be successful if the diagnosis is made within one year of age. Therefore, early detection is very important. Western developed countries have made developmental hip dislocation a national policy, and have conducted a national census in the neonatal period, which has achieved good results The following introduces several methods of initial screening for your reference: 1. Appearance and skin texture: In hip dislocation, the thighs and calves are disproportionate to the opposite side, and the hips are wide, and the folds at the root of the thighs (inguinal) are asymmetrical, and the affected side is short or disappeared. The gluteal folds are also different, the affected side is elevated or has one more, the whole lower limb is shortened, and there is a mild external rotation deformity. 2, pop-up test: when the child is quiet, make the hip joint in the inward position, that is to say, make the two lower limbs straighten and cross, with downward and outward direct pressure on the long axis of the thighs, there is a pop-up sensation in congenital hip dislocation. 3, abduction test (or frog test): gentle abduction of the flexed hip joint to determine whether the head of the femur can be reset or dislocated (i.e., let the child lie on his back on the bed, so that the child’s lower limbs are flexed until the front of the thighs close to the child’s own belly, and then gently to the two sides of the adductor, like a frog, so the name of the) under normal circumstances, the child’s thighs on the outer side of the bed close to the surface. If the hip joint is difficult to abduct and cannot be close to the bed, the abduction test is positive. Sometimes mothers may also notice difficulty in hip abduction during diaper changes. If the above abnormalities are found, the possibility of developmental hip dislocation should be highly suspected, and a professional pediatric orthopaedic surgeon should be consulted for a clear diagnosis and early treatment.