The hip joint is often referred to as the hip joint (kua). Among the various causes of hip pain, the most common, easily misdiagnosed and difficult to cure disease is osteonecrosis of the femoral head. In clinical practice, there are often patients who are frightened because they are diagnosed with femoral head necrosis, and there are also patients who are already suffering from femoral head necrosis but are diagnosed with diseases such as hip synovitis and take them lightly until the specialist recommends joint replacement. It is only when the specialist recommends joint replacement that the patient wakes up and regrets it, and the doctor sighs. After all, necrosis of the femoral head is not an ordinary disease, once the best time to lose the treatment, the light is difficult to heal for several years, the heavy need to replace the joint, and the best quality of the existing joint is only about 20 years of life, once the young patient replaced the artificial joint, can not engage in heavy physical labor, but also face nearly 100,000 yuan each time the revision surgery, so prevention is the way, do not wait for the dead sheep to mend the empty It is important to take precautions before it is too late.