Patellar protrusion is categorized into physiological protrusion and pathological protrusion. Under normal physiological state, the patella itself is slightly protruding outward. Common pathological causes include knee joint effusion, abnormal patellar shape, arthritis, etc. Conservative treatment or surgery can be chosen according to the situation. 1. Physiological factors: there is no muscle wrapping in front of the patella, and there are ligaments surrounding the right and left sides of the knee joint, so the patella itself is slightly protruding out of the knee joint, and there are generally no discomfort symptoms and no treatment is needed. 2. Joint effusion: Knee joint effusion will increase the pressure in the joint cavity and squeeze the patella forward. Conservative treatment is preferred in the early stages of joint effusion. During conservative treatment, patients should keep strict bed rest and pay attention to warmth, if the effusion is more serious, the effusion should be aspirated or arthroscopic surgery should be taken to clean up the effusion. 3. Abnormal patellar shape: abnormal patellar shape will lead to abnormal patellar trajectory, long-term abnormal trajectory will lead to patellar deformation and protrusion forward. Abnormal patellar shape is mainly treated by surgery to repair the patella and its surrounding structures, and if the deformation is too serious, knee replacement is possible. 4. Arthritis: Inflammation damages the joint, causing deformation and pain. Treatment varies depending on the type of disease and severity of symptoms. Conservative treatment is often chosen when symptoms are mild, and commonly used medications include non-steroidal anti-inflammatory drugs such as aspirin and cartilage protectors such as chondroitin sulfate. If symptoms are severe, surgery may be required. If the patella protrudes and is accompanied by pain and other uncomfortable symptoms, you should go to the regular hospital in time for examination, to identify the cause of the disease and give targeted treatment.