All conditions develop in stages, and osteonecrosis of the femur is no exception. Because the early symptoms of osteonecrosis of the femoral head are not obvious, it is less likely to attract the attention of patients, so they often miss the best treatment period and delay the condition. In order to avoid this situation, today we will list the 3 major symptoms of femoral head necrosis in the early stages one by one. 1, pain The first conscious symptom of femoral head necrosis is pain, pain can be intermittent or persistent, walking activities aggravated, sometimes for rest pain. The pain is mostly pins and needles, dull pain or soreness and discomfort, often radiating to the groin area (around the hip joint), the inner thigh, the back of the hip and the inside of the knee, and a sense of numbness in the area. Hip and knee pain, also known as ectopic pain, is the main symptom of early femoral head ischemia, which is often overlooked because it is “far” from the hip joint and is easily misdiagnosed as arthritis or joint injury, but is actually a radiating symptom related to femoral head necrosis. This pain can be obvious due to exertion, trauma, heavy drinking, excessive activity, going up and down stairs and other triggers. The pain is severe in the early stage of femoral head necrosis, and it may be reduced or not in the late stage. 2, claudication Femoral head necrosis will appear progressive shortening claudication, which is caused by hip pain and femoral head collapse, or hip subluxation in the late stage. Intermittent claudication often occurs in early stage patients, and is more obvious in children. 3.Hip joint dysfunction The main symptoms of hip joint dysfunction are: difficulty in abduction, pronation and extension, difficulty in squatting, fear of cross-leggedness, stiffness of the joint, inflexibility in lifting the leg, shortening of the affected limb and muscle atrophy. Stages of development of femoral head necrosis Stage I Painful symptoms, positive bone scan and MRI at the same time: ⅠA MRI femoral head lesion range <15%; ⅠB femoral head lesion range 15-30%; ⅠC femoral head lesion range >30%; Stage II Uneven density of femoral head patches, sclerosis and cystic lesion formation, no collapse on plain film and CT, positive MRI and bone scan, no change in acetabulum: ⅡA The extent of MRI femoral head lesion is <15%; IIB MRI femoral head lesion is 15-30%; IIC MRI femoral head lesion is >30%; Stage III Crescentic sign on frontal and lateral views: IIIA Crescentic sign length <15% joint surface or collapse less than or <2-mm; IIIB Crescentic sign length - 15-30% of joint surface length or collapse 2-4mm; IIIC Crescentic sign length > 30% joint surface length or collapse 30% of the joint surface length or collapse >4-mm; Stage IV Collapse and flattening of the joint surface, narrowing of the joint space, sclerotic changes in the acetabulum, cystic changes and osteophytes. The best time for treatment If osteonecrosis of the femoral head is not effectively treated before the collapse of the femoral head (usually stage III is the stage of collapse), more than 80% of patients will collapse within 2 to 3 years, and 78% of the collapsed necrotic femoral head will develop to the extent of requiring artificial joint replacement within 2 years. This is the best time to treat necrosis and has the best chance of recovery. If you have pain around the hip joint, inner thigh, front side or knee, you must go to the hospital in time for examination to determine the cause of the pain and kill the disease in the cradle.