Injections of sodium vitreous acid in the knee joint depend on whether the pain is medial or lateral, with the medial pain being more likely to be injected into the inner knee eye and the lateral pain being more likely to be injected into the outer knee eye. In most cases, the medial knee is the most painful, and the injection site should be strictly disinfected before the injection. In addition, the patient should be instructed to naturally lower the affected limb, and this action can clearly find the location of the knee injection. After the injection, the patient should first draw back to see if there is any blood, and if there is no blood, the patient can be injected with sodium vitrate. There is another clinical contraindication, if there is excessive fluid in the knee joint and the floating patella test is positive, the injection should not be done at this time.