If there is a bone protruding from the knee joint, if there is a trauma, it may be a fracture dislocation; if there is no obvious trauma, it may be a localized bone lesion, such as osteochondroma or congenital developmental abnormality. You should go to the orthopedic department to see the doctor in time, the doctor will combine the preliminary analysis with the examination, and routinely improve the X-ray examination of the knee joint to know whether there is any traumatic fracture, bone lesion, developmental abnormality, etc., and then do the corresponding treatment according to the examination results. If it is a trauma fracture dislocation, it needs to be reset and fixed in time; if it is a bone lesion such as osteochondroma, it can be removed by local surgery; if it is a developmental abnormality, which doesn’t affect the normal line of force of the knee joint and load bearing, it can be followed up and observed, and no treatment will be done for the time being.