Common Osteoarthritis Symptoms Last time we talked about the causes of osteoarthritis, today we are going to talk about the symptoms of osteoarthritis, using the knee joint as an example. Osteoarthritis is essentially a degeneration of the bone and joint and is a progressive process. Clinically it causes symptoms that are also progressively worse. The symptoms caused are closely related to the extent of the joint lesion. 1, early: the knee joint mainly includes the joint between the patella and femur and the joint between the tibia (calf) and femur (thigh), osteoarthritis early degeneration mostly begins with patellofemoral joint degeneration. The patella is the mechanical fulcrum of the most important muscle (quadriceps) in front of the knee joint and plays an important role in the process of knee flexion and extension. As the tibiofemoral joint is basically normal, the patient does not feel significant pain when walking normally and bearing weight, but when going up and down stairs or squatting deeply, the quadriceps muscle contracts with force, making the patellofemoral joint in close contact and increasing pressure exponentially, and then discomfort and pain in the front of the joint occurs. But at this time, the joint lesion is mainly cartilage degeneration and synovial mild hyperplasia, so the mobility of the joint under non-weight-bearing condition is basically normal. 2. Mid-term: As the disease gradually worsens, the cartilage of the tibiofemoral joint begins to degenerate, and patients gradually experience pain in the knee joint when bearing weight and walking. At the same time, the synovial membrane of the joint further proliferates, and the secretion of joint fluid increases when there is more activity, but the excess joint fluid cannot be fully absorbed, and joint swelling occurs. As the disease progresses further, the cartilage is continuously destroyed, the meniscus is degenerated, and the joint space is gradually narrowed, while intra-articular osteophytes and bone spurs are formed. Physical and chemical factors are mixed together, leading to increasing pain symptoms. 3. Late stage: At this time, the joint has been severely damaged, the knee joint space is very narrow, and a large number of bone spurs are formed. Clinically, in addition to joint pain that significantly affects walking, the patient will experience flexion and extension dysfunction of the joint. The inability to fully flex the joint significantly affects movements such as walking up and down stairs, squatting and cycling. Inability to fully extend the joint leads to different lengths of both lower limbs, causing claudication, further leading to pelvic tilt and even affecting the lumbar spine.