Hip pain is not necessarily due to osteonecrosis of the femur. Hip pain sometimes consists of many causes, and osteonecrosis of the femur is one of the causes that accounts for a relatively large percentage. Inflammation of the hip joint can cause hip pain, osteoporosis of the hip joint can also cause hip pain, and simple synovitis of the hip joint can also cause femoral head pain, as well as surrounding fasciitis and dermatomal neuritis can cause hip pain, so simple hip pain cannot be diagnosed as femoral head necrosis. Unless there are other symptoms such as claudication or limitation of movement, the diagnosis of osteonecrosis of the femoral head can only be made after physical examination, auxiliary examinations such as X-ray, CT or MRI, which clearly show the presence of osteonecrosis of the femoral head, and simple hip pain cannot confirm the diagnosis of osteonecrosis of the femoral head.