After a knee injury, you should consult a doctor in a timely manner, and the specialist will clarify whether there is any damage to the bone according to the symptoms, physical examination and imaging examination. 1. Symptoms: If there are fractures, dislocations and other bone injuries after a knee injury, there will be severe pain, obvious bone friction during light activities, and localized swelling, bruising, ecchymosis and other manifestations. 2. Physical examination: When examining the knee after a fall, there may be a bone friction sensation when touching the fracture site, or an abnormal friction sound between the bones can be heard by using a stethoscope, which can be used to preliminarily determine that the bone damage at the knee has occurred. 3. Imaging examination: X-ray, CT and MRI should be performed after a knee injury, which can observe whether the continuity of the bone is interrupted, clarify whether there is any bone damage, and also clarify the displacement of the fracture, which is helpful for judging the condition. When the knee is injured in a fall, it is necessary to consult a doctor in a timely manner, under the guidance of a specialized doctor for diagnosis and appropriate treatment, which will help to heal the injury as soon as possible.