Among the many patients suffering from knee diseases, a large proportion of people think they have knee “synovitis”, is he really suffering from synovitis of the knee? To know the answer to this question, we need to clarify the following issues: 1, the basic structure of the knee joint Each joint in the human body has a function consists of three major parts: (1) joint surface, each joint has at least two corresponding joint surface, covered with articular cartilage in the joint surface, there are a few people call it “cartilage synovium” It is 3-7 mm thick, and the normal cartilage is pale white, with a mirror-like surface that is very smooth and has good elasticity. (2) The joint capsule is a fibrous tissue attached to the bone surface around the joint surface. It has two layers, the outer layer is called the fibrous layer, which has the role of wrapping and stabilizing the joint. The inner layer is called the synovial layer, which is normally very thin and can secrete and absorb synovial fluid. The joint capsule is like the clothes we wear in our body, the lining is like the synovial layer and the outer layer is like the fibrous layer. (3) The joint cavity, a closed cavity composed of articular cartilage and synovial layer together, contains a small amount of synovial fluid under normal circumstances, about 3-5 ml. 2, what is synovitis After knowing the structure of the joint, you may know that synovitis is an inflammatory lesion in the “lining” of our joints. What are the causes of inflammation of the “lining” of our joints? First of all, it is a multifactorial disease with multiple causes. Because the knee joint has the most synovial membranes and is located in the more superficial part of the limb, it has more opportunities for injury and infection. Injuries such as meniscal injury, synovial injury, cruciate ligament injury, intra-articular cartilage injury and dislocation can stimulate synovial congestion and edema, resulting in joint swelling and fluid accumulation. There are also infections, bacterial attack on the synovial membrane, which is common synovial tuberculosis, and some systemic diseases, such as rheumatoid synovitis, gouty synovitis and synovitis of unknown origin due to low immunity of the body. 3, what are the manifestations of synovitis Once the synovial membrane is inflamed, it will be edematous and congested, thickened, resulting in the synovial membrane exuding inflammatory fluid. Strictly speaking, if the knee joint has swelling, joint effusion, pain, it can be determined that the knee joint has suffered from synovitis, then it is more important to clarify what nature of synovitis it is suffering from, also let us understand that the joint effusion pain, is a disease associated with the disease, we know the cause of the swelling effusion, is also equal to know the cause of synovitis swelling. The best way to clarify this is to go to a regular hospital for examination to confirm the diagnosis. For example, if you have a swollen joint with effusion, along with strangulated pain, an MRI, and meniscal damage, then your synovitis is synovial inflammation caused by meniscal damage. 4, what is the difference between knee synovitis and “cartilage synovitis” There are many people with knee disease who mistake the smooth cartilage membrane on the surface of the joint for “synovium” and think they have knee synovitis. At the time of the visit, the knee joint is already deformed and swollen, and there is a very pronounced rubbing sensation in the joint, with pins and needles pain when walking, and the x-ray shows a clear bony bulge, and the joint space has disappeared. In fact, the lesion is an inflammation of the cartilage membrane, and what is referred to here as “cartilage synovitis” is actually a degeneration of the cartilage membrane in the joint. In medicine, we call this osteoarthritis of the knee joint, which is actually a degenerative disease. The joint is like a machine bearing, and as we age, the bearing surface of the joint will continue to age and wear out. If you are overworked, or have a history of trauma, or are overweight, it can aggravate the wear and tear on your “joint bearings”. This results in swelling, pain and deformation of the knee joint, impairment of movement and loss of function. The biggest difference between synovitis and synovitis is that the lesion is in the synovial membrane that wraps around the joint, and the cartilage that covers the joint surface. 5, treatment of synovitis and knee osteoarthritis Although knee osteoarthritis also has swelling and joint effusion, but because the location and cause of the lesion is different, the treatment method is also different. For synovitis of the knee, as long as we identify the cause of the synovial inflammation, we can provide targeted treatment. Generally, most synovitis can be cured with injections and medications, and only a few can be treated with minimally invasive surgery. For patients with osteoarthritis of the knee joint, the treatment differs due to the duration of the disease and the severity of the degeneration, if the knee joint is significantly deformed and swollen, and the function of the activity is significantly limited, artificial joint replacement surgery is required.