In life, there are many patients who have knee pain and discomfort after long time activities, but the examination of the knee joint failed to find obvious problems, and the symptomatic treatment is not effective, then we should consider whether it is caused by hip lesions. This is because hip lesions may show knee discomfort through nerve conduction, while there are no obvious symptoms in the early hip joint, such as femoral head necrosis and acetabular dysplasia. Here we will focus on acetabular dysplasia. Acetabular dysplasia, also known as acetabular subluxation, is a deformity of the hip caused by the failure of the acetabulum to develop well. This deformity is manifested by the shallow acetabulum, which makes the acetabulum inadequate to accommodate and cover the femoral head, resulting in abnormal mechanical conduction of the hip joint and gradually causing damage and degeneration of the articular cartilage, which eventually leads to the occurrence of osteoarthritis of the hip joint. Since acetabular dysplasia is only a subluxation of the hip joint and not a total dislocation, patients do not have any symptoms in childhood or adolescence. It is important to note that hip lesions are not necessarily reflected in the hip at the earliest. Instead, the lesion tends to irritate the nerves and radiates to the knee, causing pain or discomfort in the knee, which often worsens after prolonged standing or walking, and improves after rest. Patients often think that there is something wrong with their knee joint, but after a knee examination, the results show that everything is normal, so acetabular dysplasia is easily misdiagnosed or missed. Acetabular dysplasia has a high rate of disability. In the early stages, joint pain appears in the knee joint and then progresses to the hip, the root of the thigh, and the groin area. Once the hip joint itself also becomes painful, it means that serious damage to the hip cartilage has occurred. As the disease progresses, the joint pain worsens and the range of motion and strength of the hip joint is easily affected. At this point, patients need to use crutches to walk, which seriously affects the quality of life. Women, especially young women, are the main group of patients with acetabular dysplasia. Epidemiological studies show that the incidence of acetabular dysplasia is about 0.6%, with a male to female incidence ratio of 1:6, and most patients are between the ages of 20 and 40. Therefore, it is necessary for young women to go to the hospital for a targeted examination if they have hip joint soreness and pain, accompanied by or alone with knee soreness. The examination should not only observe whether the knee joint is abnormal or not, but also take hip joint X-ray to detect hip joint lesions in time.