To assess the amount of blood in the knee, an MRI of the knee can be done to determine the amount of blood in the knee. If the amount of blood is relatively small, it can be gradually absorbed by conservative treatment. During the acute phase, the joint must be properly braked, cold compresses must be applied within 48 hours, and after 48 hours, hot compresses and microwave physiotherapy must be applied, and after a period of time, the blood will be absorbed. If there is a large amount of bruising in the knee, it will take a long time to be absorbed simply by self-absorption, and there may not even be a way to absorb it completely. A syringe is needed to extract most of the bruising to promote its excretion, and then the treatment will continue as before.