Synovitis should not be injected with Tretinoin for a long period of time, and side effects such as osteoporosis may occur with long-term use. Synovitis can be injected into the joint cavity, which can reduce local inflammation, decrease local congestion and exudation, and relieve joint pain and swelling. Injections are usually given once a week, not more than three times. If the injection for a long period of time will have adverse effects, such as the elderly or menopausal women prone to osteoporosis. Joint infection, high blood pressure, diabetes, etc. Long-term use of the drug can cause drug accumulation cause anxiety, nervousness, gastrointestinal bleeding, full moon face. Therefore, synovitis can not be long-term injection of tretinoin, when the medication does not get better need to seek medical treatment to take other methods, such as medication, physical therapy or surgical treatment.