Patellar dislocation is a common sports injury to the knee joint, and the first patellar dislocation is more common among girls aged 10-17 in primary and secondary schools. Due to the fact that most patellar dislocations can be self repositioned, it is easy for patients or parents to treat them as ordinary knee joint sprains without seeking timely medical attention, laying a hidden danger for future knee joint injuries. There are also hidden reasons for knee injuries caused by small movements. In daily outpatient work, a commonly asked question is: "Our child's sprained movements are not significant, sometimes when they turn around, or even just bend down to pick up something, how can they cause dislocation?" This is because patients with patellar dislocation often have anatomical developmental abnormalities, including poor trochlear development, patellar exotropia, high patella, and joint relaxation. Simply put, patients with patellar dislocation have poor knee joint development and are prone to dislocation. When patellar dislocation occurs, patients usually fall to the ground, and most patients feel that the knee bone has slipped outward or there is a dislocation between the thighs and calves. When the patella is dislocated laterally, it causes tearing of the medial soft tissue of the knee joint. During reduction, there is an impact between the medial side of the patella and the lateral side of the knee joint, resulting in severe pain and generally significant swelling of the knee joint. Due to the fact that most patellar dislocations can be repositioned on their own, they are prone to misdiagnosis and misdiagnosis, and can be treated as ordinary knee sprains by patients or parents. Failure to seek medical attention in a timely manner delays the condition. The probability of secondary dislocation after the initial patellar dislocation is generally above 20% -30%. Multiple dislocations not only affect the patient's normal learning, life, and exercise, but also cause incurable cartilage damage to the knee joint, leading to the occurrence of osteoarthritis. Due to the intense pain caused by patellar dislocation, patients with patellar dislocation are particularly afraid of patellar dislocation again. In the outpatient department, I once encountered a freshman girl patient who woke up at night because her mother covered her with a blanket. She was particularly afraid of others touching her kneecap. In daily life, whenever someone approaches her slightly, she becomes very nervous and very afraid of patellar dislocation. A common clinical examination method for patellar dislocation is called the "fear test": the patient's knee joint is straightened or slightly bent, and the examiner gently pushes the patella outward with their hand. When the patient feels pain or fear, it is positive. For patients with this type of dislocation, surgical treatment is recommended. If no free body caused by patellar fracture is found on the X-ray, and the medial soft tissue tear is not severe, conservative treatment can be used: cold compress to reduce swelling, wear a straight splint to fix around, and walk with weight on the ground. However, for patients with multiple patellar dislocations, surgical treatment should still be performed. On the one hand, the pain of patellar dislocation is obvious. Due to the fear of dislocation, patients are afraid to do many movements, which affects normal life, learning, and exercise; On the other hand, repeated dislocations can lead to damage to the patellar cartilage, and the loss of cartilage cannot grow again. Over time, it can lead to traumatic arthritis. Even after the surgery, the patella will no longer dislocate, but the patient's knee joint may still experience pain and swelling, affecting their daily life and exercise. In this case, surgery can not only stabilize the patella and reduce the recurrence of patellar dislocation, but also reduce the impact of dislocation on joint cartilage