Patient: Description of the condition (onset time, main symptoms, hospital visited, etc.): On July 4, 2010, due to left thigh pain, affecting walking for four days, he was seen at Zibo Central Hospital. MRI observations: small focal abnormal high signal was seen in the bone under the joint surface of the left femoral head and neck junction area on coronal and axial scans, and fluid accumulation shadow was seen in the left hip joint. The signal was considered to be bone marrow edema. A small amount of fluid was found in the left hip joint. Penicillin and salvia were injected for one week. Jinan Hospital thinks I have synovitis of the left hip according to MRI. How can synovitis and early femoral head necrosis be accurately diagnosed? What kind of condition do I have? Thank you! I still need time to upload the images. Guo Xiaozhong, Department of Orthopedics, Beijing Jishuitan Hospital: Synovitis of the hip joint and ischemic necrosis of the femoral head are not the same kind of disease. Synovitis is an inflammatory reaction of the synovial membrane of the joint caused by some reasons, these reasons can be caused by trauma or autoimmune abnormalities or other reasons to cause hyperplasia and hypertrophy of the synovial membrane of the joint, secretion of joint fluid increases, and there is no abnormal change in the bone quality of the femoral head of the disease. In contrast, ischemic necrosis of the femoral head is caused by the destruction or occlusion of blood flow in the femoral head for some reason, resulting in ischemia of the bone tissue in the femoral head, successive necrosis of the bone trabeculae, gradual absorption and disappearance, and weakening or even disappearance of the supporting force, resulting in the collapse and deformation of the femoral head. The causes of the two diseases are different, and the consequences are not exactly the same. Synovitis of the hip joint may be relieved or even cured through medication and rest, while once the ischemic necrosis of the femoral head has occurred, it can only be relieved but not cured through medication and weight-free treatment.