The diagnosis of patellofemoral arthritis is based on clinical symptoms, signs and X-rays. 1. Symptoms: with the deepening of patellofemoral cartilage wear and tear, the symptoms are gradually aggravated, initially manifested as knee pain, knee stiffness, then knee swelling, and finally manifested as knee weakness, knee movement disorders. 2. Physical signs: swelling of the diseased joints, joint deformity in severe cases, muscle atrophy, bone friction sensation during joint movement, positive 4-word test, positive floating patella test, etc. 3. Imaging examination: X-ray is the main means to confirm the diagnosis of this disease, which can be seen in subchondral osteosclerosis and cystic degeneration of the patella, and the formation of bone redundant. CT and MRI can not only diagnose patellofemoral arthritis, but also examine the joint effusion, joint deformity and intra-articular free body. If you have similar symptoms, you should go to the orthopedic department of the hospital in time for examination, and follow the doctor’s instructions for standardized treatment after a clear diagnosis, do not blindly treat yourself to avoid aggravating the condition.