In terms of clinical significance and functional impairment of the knee, posterior fork tibial stop avulsion fractures are actually a type of posterior fork injury. In recent years, a gradual increase in posterior cruciate ligament tibial stop avulsion fractures has been reported, accounting for approximately 10% of posterior cruciate ligament injuries, with a higher incidence than simple PCL ruptures. The mechanism of injury is mainly due to posterior fork strain caused by impact in the anterior-posterior position, such as dashboard injury and kneeling injury, according to Yu Zhiyong, Department of Orthopedics, Xiangyang Hospital of Traditional Chinese Medicine. There is another injury that is relatively rare, which some people call an over-extension distraction injury. The injury leads to posterior straight knee instability, increasing the burden on the patellofemoral joint, patellar ligament and posterior structures, and finally osteoarthritis. Hyperextension strain injuries are often associated with damage to the posterior complex and can also cause lateral and rotational instability of the knee. In general, posterior fork tibial stop avulsion fractures are clinically classified into three types according to Meyers’ typing criteria. Type I: fracture without displacement: Type II: partially displaced fracture, a hanging fracture with connection on one side and displacement on the other; Type III: avulsion fracture with complete separation. For type I injury due to the rich local blood flow healing is mostly recommended for conservative treatment and advocates surgery, but of course conservative treatment can also be chosen according to the patient’s age and functional needs. The relative instability of the tibia after the injury should be checked against the healthy side, and the anterior edge of the tibial plateau should be located 1 cm in front of the medial femoral condyle during normal anatomy. if the posterior fork is injured, there will definitely be a posterior displacement of the tibia, and the degree of displacement is divided into 3 degrees according to the criteria in Feng Hua’s “Practical Orthopedic Sports Injury Clinical Diagnosis”. Degree I tibial posterior displacement degree is 0-5mm, the tibial plateau is still located in front of the femoral condyle; degree II injury tibial posterior displacement 6-10mm, the tibial plateau anterior edge and may be flush with the medial femoral condyle; degree III injury means tibial posterior displacement ” 10mm, the tibial plateau anterior edge displacement to the posterior aspect of the medial femoral condyle. Generally speaking, for every increase plus 5 mm in the degree of fracture displacement, the posterior laxity of the knee will increase by I. If the degree of displacement is 10 mm or more, the fracture will also leave more than II degree of posterior laxity of the knee after healing. Therefore, many scholars advocate about the indications for surgery for fractures: many scholars advocate that type II and III injuries, or fractures with a displacement greater than 5 mm and drawer tests with a straightward displacement greater than 10 mm compared to the healthy side, should be treated with early surgery. In addition, surgical treatment should also be considered for those who have a fracture block that is displaced by turning, or for those who have a compound injury. Patients with symptoms of joint instability are also included in the surgical options. The surgical options are divided into two categories: arthroscopic fixation and incisional internal fixation. It should be said that both methods have their advantages and disadvantages. In my opinion, the factors that determine the surgical approach should at least include: 1. the judgment of the nature of the degree of fracture displacement. 2. the size of the fracture block, single avulsed bone block or multiple. 3. the presence of compound injury and the nature of the compound injury. 4. the operator’s proficiency and surgical habits. For combined meniscus injury or old fracture, arthroscopy combined with posterior approach can be considered at the same time. Surgery is only half of the treatment, postoperative rehabilitation is crucial. Rehabilitation should be decided according to the injury, surgical method and internal fixation method, which can be referred to the previous postoperative rehabilitation recommendations for absorbable nail.