The patella is the largest bone in the body and plays an important role in knee extension, squatting, standing, running and jumping. Patellar fractures are caused by kneeling directly on the knee or by straining violence. The traditional treatment is to immobilize the knee in extension in a cast and wait for the fracture to heal. If the fracture is not widely separated, the fracture will mostly heal, and even if there is a little unevenness on the joint surface, there will be no serious effects in the short term, and the chances of having osteoarthritis problems in the long term will be much higher. However, if the fracture is severely displaced and there is soft tissue tonus, the fracture will not be able to heal or will have difficulty in healing. The problems associated with prolonged cast immobilization are soft tissue adhesions around the knee joint and limited joint motion. For this reason, early surgery is often recommended, and knee exercises can be started after surgery. The purpose of surgery is to restore the joint surface and attach a knee extension device, allowing the patient to perform non-weight-bearing knee exercises, such as toileting, eating, and walking indoors under the protection of a knee extension brace. The goal of surgery is also to convert the detachment forces that are not conducive to fracture healing into compressive stresses that are conducive to fracture healing. The fracture is fixed by the internal fixation device, and even the strongest internal fixation is subject to fatigue fracture after stress. Postoperative rehabilitation The patient can walk under the protection of the brace, and the joint is locked and fixed in 0 degree extension. Plaster fixation