Congenital hip dislocation is one of the more common types of pediatric limb deformities. As research continued, it was renamed developmental hip dysplasia after the 1990s. It is more common in girls than in boys, about 5:1, and more common on the left side than on the right side. In addition to congenital factors, there are also acquired factors that play an important role in this disease. The younger the age, the better the treatment effect and the simpler the method. The younger the child is, the better the treatment effect and the simpler the method. As the age of the child increases, the treatment effect becomes worse and worse, so early diagnosis and early treatment are emphasized. What are the manifestations of hip dysplasia in children? If a child is found to have unequal length of both lower limbs after birth, asymmetry on both sides of the hip and thigh skin folds, or a positive abduction test (the child lies flat, bends the knees and hips by 90° each, and abducts and externally rotates both knees and hips at the same time. The bed surface can be palpated on the lateral surface of the normal knee; if it cannot be palpated, it is positive), further examination by a pediatric orthopedic surgeon should be conducted early to determine the presence of developmental hip dysplasia. This is important for early detection and good outcome. As the child gets older and starts to walk, parents find that the child walks with a limp, and if the dislocation is bilateral, the child sways from side to side like a duck gait when walking, usually without joint pain. This is when it is more likely to be noticed by parents and discovered. Some confused parents think this is ” calcium deficiency people soft ” and do not pay attention to it, and as a result, delayed treatment. Parents should be alert to this. The dangers of adult hip dysplasia Acetabular dysplasia refers to the defective development of the acetabulum causing poor coverage of the femoral head, mainly manifesting as a defect above and in front of the outer acetabulum, shallow acetabulum and outward displacement of the center of the hip joint. Acetabular dysplasia can also be associated with varying degrees of subluxation of the hip joint, but the femoral head remains within the true acetabulum in terms of joint structure. Due to the reduced coverage of the femoral head by the acetabulum, the joint relationship between the acetabulum and femoral joint is abnormal, which eventually leads to increased contact stress on the joint surface and degeneration of the articular cartilage, resulting in osteoarthritis. The main manifestations of patients are bilateral lower limb inequality, gait limp when walking, and progressive worsening of hip pain. Treatment of adult hip dysplasia Approximately 50% of patients with acetabular dysplasia develop advanced hip osteoarthritis before the age of 50. Therefore, the best treatment for young patients with acetabular dysplasia is to restore the normal physiological position of the acetabulum, improve the coverage of the acetabulum over the femoral head, and slow or stop the progression of osteoarthritis. The increasing sophistication of prosthetic joint technology offers new approaches to the treatment of adult hip dysplasia and secondary osteoarthritis. Artificial joint replacement or surface replacement can reconstruct the position of the hip joint, thereby improving bilateral limb inequality, which is especially important in young women. The degenerated tissue is also removed, which improves abnormal hip stress transmission and eliminates pain. As a result, hip surface replacement and total hip replacement are increasingly used in the treatment of adult hip dysplasia. Generally speaking, surface hip replacement is suitable for younger patients, and surface replacement preserves more bone for possible revision surgery later, while total hip replacement is more advantageous in the treatment of patients 50 or older.