Acute patellar dislocation is still relatively common in clinical practice, because the reset is relatively uncomplicated (patellar inversion in knee hyperextension) and can often still walk after reset, so patients and physicians often do not pay enough attention to it, and are not even willing to do some basic examinations, thus missing the likely complications of cartilage injury and causing delays in treatment, which brings incalculable losses to patients, especially young patients. For patients with patellar dislocation, a frontal and lateral x-ray of the knee joint must be taken, and at the same time, a CT scan of the knee joint at 15 degrees of knee flexion or an MR scan of the knee joint with a horizontal position (more accurate) must be done when available, to determine whether there is damage to the patellar cartilage or a rupture of the medial patellar support band. This is an important indicator of whether acute patellar dislocation requires surgical treatment for the first time. The damage to the cartilage is formed mainly because the process of patellar dislocation causes a violent collision with the femoral epicondyle, from where it leads to fracture dislodgement of the patellar cartilage (fracture dislodgement of the cartilage on the femoral epicondyle is rare). For such a condition, first of all, if the bone block is very small and there is no cancellous bone attachment under the cartilage, it is usually arthroscopic to remove it as a free body. Small cartilage masses in the joint cavity can cause joint interlocking and can cause wear to the cartilage surfaces of the femur and tibia, so they should be removed promptly. If the cartilage is large, this will require a small incision to re-sew the cartilage back with absorbable sutures. The wear and tear and interlocking symptoms caused by a large bone block are even worse, not to mention the key is the damage to the normal articular surface of the patella, and if left untreated, the symptoms of patellofemoral arthritis will soon appear, causing anterior knee pain, especially when going up and down stairs or squatting. Moreover, most injuries of this degree are associated with a break in the medial patellar support band and require repair or reconstruction at the same time. In children with unclosed epiphyses, only soft tissue surgery can be performed, while in adults, a medial tibial tuberosity elevation or a lateral semi-internal displacement of the patellar tendon is required to enhance patellar stability.