The symptoms that may occur with a cracked knee include pain, swelling, and functional limitations. 1. Pain: If the cracked kneecap occurs at the patella, there may be pain in the front of the knee joint, and the pain is more obvious, and the pain is aggravated when the knee joint moves. If the knee fracture occurs at the tibial plateau or femoral condyle, it may cause pain in the deep part of the knee joint. 2. Swelling: if the cracked kneecap occurs in the patella position, it can lead to a large amount of blood accumulation in front of the patella, causing swelling and bruising of the bursa in front of the patella. If the knee fracture occurs in the tibial plateau, it will lead to accumulation of blood in the joint and obvious swelling around the joint. 3. Functional limitation: Whether the knee fracture occurs in the patella or the tibial plateau, it will lead to functional limitation of the joint, including knee flexion, extension and rotation dysfunction. If the above symptoms occur, it is recommended to go to the hospital in time for early treatment.