Type B and C ankle fractures often involve the posterior ankle. It is generally accepted that when the posterior ankle fracture involves more than 25% of the articular surface, surgical internal fixation of the posterior ankle involved in the fracture is required. The commonly used method is anterior to posterior fixation with tension screws, which require threads to be pressurized across the fracture line. Because of the length of the threads, this often results in difficult compression fixation of the posterior ankle fracture. The headless compression screw is designed with a special variable-pitch thread, and compression of the posterior ankle fracture fragment is not limited by the thread length. Posterior tibial ankle fractures are often associated with internal and external ankle fractures due to their specific anatomic location, and the surgical approach to the posterior ankle can vary with the need for open reduction of other fractures. Usually, an anteromedial incision is used for medial ankle fractures and a posterolateral incision is used to fix the posterior tibial labrum and external ankle fractures. If the posterior ankle fracture is close to the medial side a posterior medial approach can be used to fix both the medial and posterior ankle. Alternatively, a separate posterior medial or posterior lateral incision can be made in the Achilles tendon to allow for direct or indirect repositioning. A preoperative CT scan can accurately demonstrate the size and location of the posterior ankle bone mass. Usually a triple ankle fracture. This includes fractures of the medial, lateral, and posterior ankles, often with separation of the lower tibiofibular joint. The more difficult of the three ankle fractures to fix is the posterior ankle fracture. Raassch et al [2] and Scheidt et al [3] experimentally demonstrated that posterior ankle fractures involving more than 20%-25% of the subtalar joint surface should be internally fixed by incision, otherwise there is a risk of late traumatic arthritis. Posterior ankle fractures involving 30% of the subtalar articular surface will result in posterior displacement of the talus during dorsal ankle seclusion. Surgical technique Since the posterior ankle fracture fragment is always connected to the distal fibular fracture through the inferior posterior tibiofibular ligament and the posterior ankle capsule. Therefore, the logical sequence of incision and revision fixation is: posterior ankle, lateral ankle, and medial ankle. When the posterior ankle fracture fragment is small, screw fixation from posterior to anterior is called for; when the fracture fragment is large, white-front to posterior or posterior to anterior fixation can be chosen. Clear visualization and anatomic alignment of the posterior ankle joint is the key to the procedure. The posterior ankle fracture block resembles a triangle, with the articular cartilage surface on the bottom side, the fracture end on the oblique side, and the posterior ankle cortex on the posterior side. A downward lengthening incision of the medial ankle is performed. The ligaments and the partially torn joint capsule can be clearly seen in this incision. The determination of complete alignment of the articular surface can be based on whether the posterior lateral cortex of the posterior ankle is completely aligned. This method is suitable for smaller bone blocks involving the subtalar articular surface, and for fracture blocks involving more than l/4 of the subtalar articular surface. The use of this force method is likely to be incorrect. To determine whether the articular surface is fully aligned, the gap can be observed by turning the medial ankle with the deltoid ligament downward and tugging down on the heel call. In addition, we can also push the talar ligament together with the outer ankle to the lateral side with the plantar side of the affected foot facing upward to observe the tibial joint surface defect, and then fix the posterior ankle after repositioning the posterior ankle and seeing the tibial joint surface completely aligned under direct vision. After the posterior ankle joint surface is well aligned, mark the posterior bone cortex of the posterior ankle bone block first, such as temporarily penetrating two pin channel through holes on the posterior bone piece, then reset and fix the lateral ankle, and finally screw in the screws according to the direction of the above two pin holes. This method can ensure the joint alignment and avoid the screws from being mistakenly inserted into the joint. Intraoperative x-ray of the externally rotated calf can help to observe the alignment of the posterior ankle. When the tip of the screw enters the posterior ankle bone, the hollow drill bit is used to press the posterior ankle bone forward along the guide pin from the posterior side, so that the screw can be screwed into the fracture end with pressure. A minimum of two screws should be used. Advantages of comparison with general compression screws Posterior ankle fracture fixation, bone block compression is particularly important to stabilize the fracture and restore function, usually hollow compression screws for fracture compression condition requires that the threads must cross the fracture line, but the posterior ankle fracture block is generally small, screw threads across the fracture line is difficult, if the screw is driven from the posterior side through the posterior ankle bone block from back to front, on the one hand, the operation is more deeply exposed, on the other hand, it may lead to bone block The headless compression screw is inserted by means of a varus. The headless compression screw is pressurized by variable pitch, and theoretically, once the front end of the screw enters the bone block, the compression begins, so using this screw to fix the posterior ankle bone block by screwing from the anterior side, the size of the posterior ankle bone block can be disregarded, which brings great operational convenience to screw fixation. Prevention of complications The soft tissues of the ankle are weakly covered, and the built-in object is often located under the skin, so there is a risk of exposure of the nail tail. Fracture repositioning and fixation should avoid disturbance to soft tissues as much as possible, and the built-in screw should be buried in the bone as much as possible. It is not difficult to bury the head of the nail below the bone surface during the operation of headless compression screws. Headless compression screws are used in posterior ankle fractures with ease of use and strong compression ability on the fracture block, and they are not uncommon as an effective way to fix posterior ankle fractures.