If the patellar injury is mild, it can heal itself, while if it is severe, it is difficult to heal itself, as follows: First, mild patellar injury: only mild cartilage injury can be healed by joint braking, oral chondroitin sulfate and other methods to make the cartilage injury heal itself. Second, severe patellar injury: such as a comminuted patella fracture with fracture displacement or large patellar cartilage fracture, are not self-healing and need to be surgically treated. If a comminuted patella fracture requires incision and internal fixation, and postoperative rehabilitation is required to obtain a complete recovery. Therefore, whether a knee patella injury can heal on its own needs to be determined by the different degrees of injury.