A second degree injury to the posterior horn of the meniscus can lead to jamming. The meniscus is a pair of elastic cartilages within the knee joint, and the posterior horn of the meniscus is a very common area of injury in clinical practice. A tear or injury, especially a second-degree injury, can cause instability in the joint, and the injured meniscus will move, leading to a feeling of catching or interlocking. Symptoms such as significant pain and swelling of the knee can also occur. Patients can perform some simple flexion and extension exercises for the affected limbs to promote the effective recovery of local symptoms. Reduce weight-bearing activities, local massage, promote blood circulation. The patient’s posterior meniscus angle second-degree injury is relatively serious, and it is recommended that the patient go to the hospital in time.