Two possibilities: 1. patellar tendon injury or even rupture; 2. quadriceps injury or rupture. Treatment options: Immediate emergency or next day surgery is recommended, the sooner the better, preferably no later than 2 weeks. Reason: early wound fresh, tendon suture after healing ability, 2 weeks later after the fresh period, there will be tendon and muscle tissue mechanization contracture, suture after the tension becomes larger, the difficulty of surgery, the wound is longer, not only to do tendon suture strengthening, but also to do muscle release of the thigh, trauma, and the difficulty of rehabilitation increased, the difficulty of returning to normal activity after surgery is greater. Therefore, it is important to pay attention to this, do not give up timely treatment because of work, and be extremely irresponsible to yourself.