I often encounter many patients who say, “I don’t have pain when I walk, but it hurts when I go up and down stairs” and “it hurts when I squat”. Here I would like to tell you what this problem is and how it should be treated. First, I would like to introduce you to the structure of the knee joint: these two diagrams detail the structure of the knee joint: the bony structure is composed of: tibia, femur, patella, the three bones of the joint surface are covered with important articular cartilage, cartilage is no nerves and no blood vessels, it is wear-resistant, has a certain degree of toughness, can relieve the load, the surface is smooth, conducive to movement. The knee joint is divided into three compartments: the medial compartment, the lateral compartment, and the patellofemoral compartment. The medial and lateral compartments are subject to more force when walking on a flat road, so if the cartilage wears out, pain will occur; when walking up and down stairs or squatting, the patellofemoral compartment is subject to more force, so if the patellofemoral cartilage wears out, it will cause pain at this time. Osteoarthrosis of the knee joint first develops in the patellofemoral joint, so many patients show osteoarthrosis of the patellofemoral joint, that is, “walking on a flat road does not hurt, but walking up and down stairs hurts”. How to treat this patellofemoral osteoarthropathy? 1, pay attention to joint protection, reduce squatting, climbing, climbing and other movements; 2, pay attention to joint warmth to avoid joint injury; 3, wear knee pads when exercising or climbing to increase joint stability and avoid cartilage wear; 4, appropriate physical therapy, hot compresses to relieve pain; 5, if the above methods do not relieve pain and discomfort, you can use topical Fotarine cream, oral Fotarine tablets and other anti-inflammatory pain medication; 6, if If the above methods do not relieve the pain, you may consider injecting “sodium glacial” into the joint cavity, which can nourish the cartilage, relieve the pain and improve the function; 7, if the patellofemoral joint osteoarthrosis is particularly serious and the above methods do not relieve the pain, surgical treatment may be required: (1) minimally invasive arthroscopic surgery, joint cleaning, free body removal, lateral patellar (1) Minimally invasive arthroscopic surgery, joint debridement, free body removal, lateral patellar band release, etc.; (2) Patients older than 70 years old may be considered for knee surface replacement surgery. Summary: The main cause of “walking without pain, going up and down stairs pain” is patellofemoral joint osteoarthrosis and cartilage wear, and different treatment methods are used according to the stage of the disease, from non-drug treatment to drug treatment to joint cavity injection treatment, and finally joint replacement surgery for severe cases.