The present study was approved by the Institutional Review Board of our hospital, and informed consent was obtained from all participants. Between March 2015 and October 2018, we treated 167 ankle fractures involving the distal tibial plafond at 1 regional level-1 trauma centre. We retrospectively analysed the data of all patients. Finally, 22 patients were identified and included in this study. The inclusion criteria were as follows: comminuted distal tibial plafond fracture with concomitant fibula and distal tibiofibular syndesmosis injury, definitive open reduction internal fixation (ORIF) performed using a fibular notch approach as the primary approach, adult fracture, and a minimum of 12 months of follow-up. The exclusion criteria included open fractures with a wound around the ipsilateral distal fibula and ORIF performed using another approach as the primary approach. Of all 22 patients, 16 were male, and 6 were female. The mean age was 42.9±10.6 years (range 22 to 60). The mean follow-up time was 18.7±4.3 months (range 12 to 24). The relevant information is listed in Table 1. Injuries were caused by motor vehicle accidents (MVA 7), falling down from a high place (Fall 7), sprains on the stairs (Sprain 4), heavy pounding (Pound 3) and crush injuries (Crush 1). According to the AO/OTA classification, there were 5 patients with 43-B2 fractures, 4 with 43-B3 fractures, 3 with 43-C2 fractures, 6 with 44-C1 fractures, 3 with 44-C2 fractures and 1 with 44-C3 fractures. Demographic data, mechanism of injury, fracture AO/OTA classification, complications (delayed wound healing, infection, bone nonunion, PTOA) and ankle range of motion (ROM) were reviewed from the inpatient and outpatient medical records. The details of the surgical technique were reviewed from the operative notes.
In patients with reliable soft tissue around the ankle, definitive osteosynthesis was performed in an emergency; otherwise, plaster, calcaneus traction or a temporary ankle-spanning external fixator was applied in patients with traumatized soft tissue. The normal length and rotation of the extremity were maintained, and definitive internal fixation was performed after a positive “wrinkle sign” arose.
Under anaesthesia, after distal tibiofibular syndesmosis injury was finally confirmed by lateral rotational stress radiography, the patient was placed in a floating position with a tourniquet placed on the proximal thigh. A longitudinal incision was made at the posterior border of the fibula from the proximal fibular fracture line to the tip of the fibula. In patients with anterior tibial plafond compression, the skin incision was extended towards the base of the fourth metatarsal.
Anterior blunt extraperiosteal dissection over the fibula was performed to obtain the anterolateral interval. Through this interval, the fractured fibula, the torn anterior inferior tibiofibular ligament (AITFL) and interosseous membrane, the lateral column and the Tillaux fragment of the tibia were observed. The distal fibula was stretched with a clamp, obvious instability was observed, and lateral rotation was attempted. The anterior talofibular ligament (ATFL) obstructing the displacement of the distal fibula was revealed and was cut off in most patients. Subsequently, the distal fibula hinging on the posterior structures, including the posterior inferior tibiofibular ligament (PITFL), the calcaneofibular ligament (CFL) and the posterior talofibular ligament (PTFL), was retracted posteriorly, similar to the open-book technique. Held by the assistant, as a joystick, a K-wire inserted into the distal fibula provided great convenience for open-book manipulation. Sometimes, a lamina spreader was employed to maintain the lateral rotational position of the fibula. Then, the fibular notch was completely exposed. With the talus in an adducted position and the contents of the anterior compartment elevated, the lateral column of the tibia together with the whole plafond articular surface, even the horizontal surface of the medial malleolus, were visualized directly. Usually, progressing from proximal to distal, the tibial metaphysis, the Tillaux fragment, the Die-punch fragments and the Volkmann fragment were reduced visually and fixed with multiple temporary K-wires, screws, or buttress plates. Autogenous iliac bone grafts were sometimes applied for disimpacted metaphysis to support the tiny articular fragments, and micro-screws (2.0 mm or 2.7 mm) were sometimes used for stabilization in some fractures. Using the talar dome and fibular notch as references, the reduced articular fragments and articular surface were examined under direct visualization. The fibular fracture and the syndesmosis were reduced and temporarily fixed with K-wires at this point, but this was not the final fixation because of the following procedure.
Next, between the flexor hallucis longus muscle and peroneus tendon, posterior blunt dissection was performed to obtain the posterior interval. The posterior interval was the same as the interval in a standard posterolateral (PL) approach, which is considered to provide optimal exposure of the posterior ankle . Using the restored anterior components of the distal tibia as a template, the posterior column and the Volkmann fragment were further reduced and fixed with buttress plates or posteroanterior screws. Subsequently, the temporary K-wires fixing the syndesmosis were removed, and the fibula was turned laterally for the second time. Definitive restoration of the articular fragments and the articular surface was identified with a “second-look”. Then, alignment of the tibia and matching of the tibiofibular joint were confirmed by an interoperative image intensifier. Mechanically appropriate internal fixators were employed to complete the fixation of the metaphysis and lateral column of the tibia as well as the fibula. The distal tibiofibular syndesmosis was typically stabilized by one or two trans-syndesmotic screws across three cortices. The AITFL and the ATFL were carefully repaired by sutures or augmented by anchors. The incision was routinely drained and sutured. Alternately, if needed, minimally invasive osteosynthesis with a small medial incision or percutaneous screw osteosynthesis was applied for the treatment of a concomitant medial malleolar fracture. The ruptured medial deltoid ligament was carefully repaired (Fig. 1 and Fig. 2).
Postoperatively, the ankle was immobilized in a neutral position using a below-the-knee splint. The splint was removed 3 weeks after surgery, and active range-of-motion exercises were advocated. Postoperative radiography and CT scans were performed within 1 week after surgery. The reduction quality of the fracture and syndesmosis was examined using CT scans. For the fracture, anatomical reduction (AR) was considered in the case of a fracture gap or step-off of less than 2 mm; 2-5 mm was considered mild malreduction (MM), and more than 5 mm was considered severe malreduction. For syndesmosis, the same standard as Gardner’s  criteria, a greater than 2-mm difference on the CT scan between the anterior and posterior tibiofibular distances was considered malreduction. Ten to 12 weeks postoperatively, the second round of radiography was performed, and the syndesmosis screws were removed under local anaesthesia. Fracture union was considered to be achieved by bridging callus maturation and closure of more than three-quarters of the fracture faces on radiographs and the absence of pain during full weight-bearing . One year after surgery or at the last follow-up, lateral stability of the ankle, including distal syndesmosis and the ATFL, was assessed by careful manual stress examination. In suspected patients, weight-bearing AP radiograph for syndesmosis and anterior drawer test stress lateral radiograph for the ATFL were performed. Absent tibiofibular overlap and a greater than 3 mm difference in the distance between the centre of the plafond and the nearest point of the talus on lateral radiographic comparison of the uninjured and injured ankles were considered to be diagnostic criteria for lateral instability of the ankle . Ankle ROA was measured with a goniometer, and the American Orthopedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) score was implemented for clinical functional evaluation (Fig. 3).