Pain inside the knee bone may have the following causes: first, tumor, if the knee bone has a tumor, there can be pain in the knee bone, there can be obvious percussion pain when conducting an examination, and obvious tumor lesions can be seen when conducting CT and MRI examinations, which should be diagnosed and treated early. Second, patellofemoral arthritis, in the joint surface of the knee and the joint surface of the femur slide has patellofemoral joint, when it appears chronic inflammation, it can appear inside the knee bone pain, often accompanied by wear and tear of articular cartilage, this time to carry out the relevant knee MRI to see the extent of cartilage damage, usually to avoid long-term walking and up and down the stairs action. Third, arthritis, when the knee joint arthritis, can also appear inside the knee bone pain, this is due to osteoarthritis can appear in the subchondral bone damage, resulting in pain in the knee bone, then the relevant x-ray and nuclear magnetic examination for diagnosis and treatment.