Many patients in the clinic complain of pain or increased pain in the knee when walking up and down stairs, mostly in middle-aged women. What is the cause? The most common clinical cause is due to contracture of the lateral patellar support band, which causes the patella to tilt outward and the patella to slide uncoordinatedly within the femoral carriage, increasing the contact pressure between the lateral articular surface of the patella and the front of the femoral epicondyle, resulting in accelerated degeneration of the corresponding articular cartilage; in severe cases, the cartilage is completely worn away, and finally, only knee artificial joint replacement can be performed. Therefore, early diagnosis and treatment are very important. If you have prepatellar pain, especially pressure pain on the outer edge of the patella, you should routinely take a frontal and lateral X-ray of the knee joint, as well as an axial X-ray of the patella to understand the degree of outward tilt of the patella, and if necessary, a CT scan of the patella with the knee flexed at 30-45°, and the imaging changes are the objective basis for diagnosis. After the diagnosis is clear, the symptoms can be significantly relieved by practicing quadriceps function and pushing the patella inward for 2-3 months in mild cases. If the prepatellar pain is still not significantly relieved after regular functional rehabilitation training, it is recommended to perform arthroscopic lateral patellar support band release at an early stage, which is beneficial for the prevention of patellofemoral arthritis and can effectively relieve knee pain up and down stairs. If the knee pain is anterior medial knee pain between 20-30° of knee flexion, sometimes the knee may be tender, this condition may be another common knee disease: anterior medial knee synovial crease syndrome, the knee synovial crease is an embryonic residue, it can be like a small tongue stuck in front of the patella and medial femoral condyle, producing pain, and in severe cases, it can cause cartilage in front of the medial femoral condyle Abrasion. In mild cases, the pain can be relieved by physical therapy and quadriceps exercise. If the pain is not relieved by conservative treatment, arthroscopic resection of the synovial crease is feasible and can be performed the day after surgery.