The protruding bone at the back of the knee may be a compensatory growth due to osteophytes. In most cases, this is due to the loss of the original function of one of the bones in the knee and compensatory hyperplasia of the cartilage in other areas, in order to replace the original function of the bone. When patients find themselves with bone protrusion, they should go to the hospital for treatment as soon as possible, and can choose the surgical method to remove it. The protruding bone may also be caused by bone cysts, bone tumors, tenosynovitis, or can be removed surgically in the hospital, and usually try to reduce the pressure on the knee area in daily life, do not over-exercise, do not engage in too strenuous physical labor.