If there is no trauma to the knee, it may be a localized local osteophyte bone spur or a tumor lesion of the bone such as osteochondroma or bone cyst. If there is trauma, it may be a traumatic fracture and the fracture block is displaced to form a sharp bone. You can go to the orthopedic department to see a doctor in time, who will make a preliminary judgment with physical examination. Routinely improve the knee X-ray examination to determine the nature of the local bone mass. If the fracture is caused by trauma, surgical repositioning and fixation should be considered. If it is a bone spur with osteophytes, there are no obvious symptoms that can be followed up. If it is a lesion such as osteochondroma or bone cyst, it can be surgically removed in a localized place and if necessary, bone graft treatment is needed.