. Synovitis of knee joint is secondary to osteoarthritis of knee joint in the elderly, mainly due to mechanical and biochemical stimulation caused by cartilage degeneration and hyperosteogeny, followed by synovial edema, exudation and effusion of knee joint. Among young people, it is mostly caused by acute trauma and chronic injury. Acute trauma includes: knee sprain, meniscus injury, collateral ligament or cruciate ligament injury, intra-articular effusion or sometimes hematocele, which is manifested as acute traumatic synovitis of knee joint. Sometimes it can also be caused by simple synovial injury of knee joint, such as minor trauma or long-term chronic knee joint strain. Coupled with the invasion of wind, cold and humidity, the knee joint can gradually swell and malfunction, and then form chronic synovitis of the knee joint.

It is suggested that it is best to use topical drugs, such as Qiuyitang Huoxue Jin Shu Ointment, which can relax muscles and tendons, promote blood circulation, reduce swelling and relieve pain, promote blood circulation and remove blood stasis, and dispel wind and cold. The plaster has strong local permeability, and the drug molecules are absorbed by the skin to participate in blood circulation and reach the affected area, and then transmitted to the meridians and bones through the skin, which stimulates the regulatory function of the body, thus improving the blood circulation of joints and surrounding tissues, protecting synovium, improving nutritional status, reducing inflammatory exudation and promoting. Promote functional recovery and achieve the purpose of cure.