Intra-articular fracture of the heel bone is a serious and complex trauma. Improper treatment in the early stage will easily lead to widening of the heel bone body, unevenness of the articular surface, formation of traumatic arthritis, and affecting the weight bearing and walking of the affected limb. Since September 2003 to January 2006, our department applied heel bone reconstruction titanium plate to treat 16 cases of intra-articular fracture of the heel bone with 25 feet, and the therapeutic effect was satisfactory. 1.Clinical data In this group, there were 16 cases, 10 males and 6 females; their ages ranged from 19 to 46 years old, with an average of 36.2 years old. Unilateral heel bone fracture 13 cases, bilateral 6 cases. Among them, there were 4 cases of combined thoracolumbar vertebral body fracture and 3 cases of long canal bone fracture. Open fractures were found in 2 cases. According to sanders[1] typing, 5 cases were type II, 16 cases were type III and 4 cases were type IV, including 10 cases of fall from height injuries and 6 cases of traffic accident injuries. The minimum time from injury to consultation was 2 hours and the maximum time was 3 days. 2.1 Preoperative examination 2.1 Preoperative routine laboratory tests, electrocardiogram examination, were taken lateral, axial and Broden position X-ray film of the heel bone, horizontal and frontal plane CT scan of the heel bone, fracture typing. The open fracture was urgently cleared to close the wound, antibiotics and dehydrating and decongesting drugs were routinely applied, and surgery was limited according to the degree of swelling and skin condition. 2.2 Surgical methods Surgery was performed under tourniquet control, and continuous epidural anesthesia or general anesthesia was chosen. The patient is placed in supine position, and an “L”-shaped lateral incision of the heel bone is made, paying attention to the exposure and protection of the peroneal nerve, saphenous vein and peroneal tendon, and then the lateral wall of the heel bone is sharply incised upward and downward until the talonavicular joint and the calcaneal joint are exposed. At the attachment point of the Achilles tendon, a Schnee pin was inserted along the longitudinal axis of the Achilles bone below the posterior articular surface, and a small pin was inserted distally after prying to reset the angle of the Achilles tuberosity and the collapsed articular surface to a good level, and then left to fixate. Squeeze the bilateral walls of the calcaneus with both palms to restore the transverse diameter of the calcaneus, and if necessary, use a bone hammer to knock the inflated lateral wall inward. Choose the appropriate shape of titanium plate for internal fixation, the anterior end stops close to the heel dice joint, the posterior end stops to the heel tuberosity, and the titanium plate screw corresponding to the carrier talus, as far as possible, is fixed to the carrier talus. If the bone defect is large, autologous iliac bone grafts can be used to maintain good posterior articular surface resurfacing. The skin is closed with full-layer sutures, and rubber drainage strips are placed with compression bandages. Avoiding the peroneal nerve during suturing. 2.3 Postoperative treatment: change the dressing every day to keep the incision dry, and apply antibiotics routinely for 10-14 d. No external fixation was done after the operation, and the foot was elevated and placed, and the drain strips were removed 24 h after the operation and the active toe movement was started, and the sutures were removed in 3 weeks. After 4 weeks of operation, remove the Schnee pin to carry out ankle joint non-weight-bearing functional exercise. 3 months of film review to understand the fracture healing situation, complete weight-bearing need to wait for the fracture bony healing. At the same time, four tablets were taken orally three times a day to activate blood circulation and remove blood stasis, and to connect the bones and reinforce the tendons. All patients were followed up for 6 to 12 months with an average of 7.3 months. One case in this group showed wound exudation closed by dressing change for 6 weeks, and one case of skin edge necrosis closed by flap transfer. The efficacy of the treatment was evaluated according to the kerr heel fracture scoring system[2] in terms of pain (36 points), ability to work (25 points), ability to walk (25 points), and use of cane (14 points), with a score of 86 points or more as excellent, 71-85 points as good, 51-70 points as poor, and 50 points or less as very poor. In this group, 13 feet were excellent, 8 feet were good, and 4 feet were poor, with an excellent rate of 84%. 4.Discussion 4.1 Anatomical characteristics of the heel bone The heel bone is the largest bone in the human foot, and it is the common rear arm of the inner and outer longitudinal arch of the foot. The change of height and shape of the heel bone after fracture will cause the collapse of the arch and the change of the angle of the heel tuberosity, resulting in a smaller pulling moment of the calf muscles and thus affecting the function of the foot. Especially in the case of intra-articular fracture of the heel bone, the unevenness of the articular surface will cause damage to the articular cartilage surface; forming traumatic arthritis. Maximizing the recovery of the shape of the heel bone and the flatness of the articular surface is the key to treatment. 4.2 Fracture typing and surgical indications of the heel bone fracture typing method Crosby, Fitzpibbons classification and Sanders classification, of which Sanders classification, which is of some value for diagnosis and treatment, according to the number and location of fracture fragments of the articular surface as shown by CT of the coronal surface of the heel bone, the widest coronal surface of the posterior talar joint is divided into three parts by two straight lines, plus the carrier talonavicular process, which is the most important part of the heel bone. The widest coronal surface of the posterior talonavicular joint was divided into three equal parts by two straight lines, which together with the carrier talonavicular process constituted the four parts of the articular surface of the heel. The undisplaced fracture was classified as type I, the two parts of the posterior articular surface were classified as type II, the three parts with central collapse were classified as type III, and the fracture involving the four parts was classified as type IV. A clear treatment plan is proposed for each type of fracture: conservative treatment for type I, internal fixation with incision and reduction for type II and type III, and fusion of the subtalar joint in type IV with stage I or stage II, which is recognized by most scholars abroad. 4.3 The timing of surgery is usually 3-7d after the injury, if the local swelling is serious and there are tension blisters, in order to prevent postoperative skin necrosis can be delayed to 10-14d after the injury, after the swelling subsides, but should not be more than 3 weeks. For open fracture, first thoroughly clean and close the wound, routinely apply antibiotics, and operate after no infection tendency. 4.4 Characteristics of titanium plate and fixation techniquesTraditionally, the use of functional exercise therapy or steel pin prying plaster external fixation, but due to the inability to restore the articular surface flat and normal Bohler angle, coupled with a long period of fixation, the efficacy of the treatment is often poor. In the present procedure, the joint can be repositioned under incision and direct vision, which can maximize the restoration of the flatness of the joint surface and normal Bohler’s angle. Since the internal calcaneus of the heel bone is cancellous, severe fractures often have bone loss, and simultaneous bone grafting can effectively prevent delayed recollapse of the articular surface. Retaining the pry pins can strengthen the titanium plate fixation, and the absence of external fixation facilitates early non-weight-bearing functional exercise. The titanium plate we used is made of titanium alloy, which is biocompatible. The titanium plate is gun-shaped and porous, which can fix the fracture block at multiple points, meanwhile, the plate is thin and soft, which can be shaped according to the shape of the heel bone, and adheres well to the heel bone, so there is no special local discomfort after the operation. Due to the strong bone quality of the carrier talus and the calcaneal tuberosity, it is best to fix the screws to the carrier talus via the lateral titanium plate, so that the titanium plate and the carrier talus form an integral whole, so that the posterior articulating surface can be reliably fixed, and to avoid tilting the posterior articulating surface outwardly and displacing it when it is subjected to force. Squeezing inward and expanding the external wall of the heel bone, restoring the width of the heel bone and at the same time restoring the height of the heel bone, avoiding the occurrence of ankle valgus and peroneal tendonitis in the future. 4.5 Precautions due to the less muscle in the foot, the local tendon tissue, easy to cause skin necrosis, the operation must be sharp incision of the whole layer of soft tissue, directly to the periosteum of the lateral wall of the heel bone. Subperiosteal dissection is made along the lateral wall of the heel bone, and the skin flap is gently pulled away and lifted up, and 2 gram pins are inserted into the talus to expose the entire lateral wall of the heel bone, and the distal side reaches the heel dice joint, avoiding necrosis caused by long time pulling of the skin edge. In addition, postoperative dressing change is very important, and the incision must be kept dry to avoid exudate soaking the skin edge and secondary infection, resulting in the exposure of the titanium plate. In conclusion, the treatment of intra-articular calcaneal fractures is complicated and controversial, but with the development of internal fixation materials and the improvement of patients’ requirements for treatment, we believe that incisional reduction of the calcaneus for reconstruction of titanium plate internal fixation is a better treatment method.