Synovitis can be relieved by sodium vitreous acid injections because the main symptom of synovitis is chronic synovial exudation, which results in a large amount of fluid in the joint cavity and affects joint movement when there is more fluid. After the cause of the disease is identified, sodium vitreous acid can be injected into the knee joint cavity or hip joint cavity, because sodium vitreous acid has the effect of nourishing cartilage and improving the microenvironment of the knee or hip joint cavity to promote the absorption of the accumulated fluid. After the injection of sodium vitreous acid, the fluid can be pumped out, or sodium vitreous acid can be injected into the joint cavity to reduce joint swelling, nourish cartilage, and promote recovery from trauma, so patients with synovitis can be treated with sodium vitreous acid.