Treatment and outcome prognosis of patients with high-energy transsyndesmotic ankle fracture dislocation—the “Logsplitter” injury

This retrospective study reviewed a total of 41 patients (29 males and 12 females) with Logsplitter injury who were admitted to the First Affiliated Hospital of Dalian Medical University, the Third People’s Hospital of Dalian and Shanghai Pudong New District Zhoupu Hospital from December 2006 to December 2014. The inclusion criteria were (1) age range of 20–70 years; (2) consistent with the injuries mechanism and diagnostic criteria of Logsplitter injury; (3) the fracture types of 44A, 44B, or 44C based on the Association for Osteosynthesis/Orthopaedic Trauma Association (AO/OTA) classification [8]; (4) time to admission within 24 h postfracture; and (5) the implants were not taken out during the evaluation period. The exclusion criteria included (1) patient with neglected fracture, pathological fracture, or who was not tolerant to the surgery due to other systemic diseases; (2) who was accompanied with tibial diaphyseal fracture, calcis, or talus fractures; and (3) who had preexisting osteoarthritis, serious cardiovascular and cerebrovascular diseases, liver or kidney disease, and central nervous system disease. Besides, any female patient in gestational period or in lactation was also excluded.

The Logsplitter injury pattern was defined as an ankle fracture dislocation by a vertical axial violence or combined with a possible rotational force, demonstrating disruption of the syndesmosis with axial displacement of the talus within the distal tibiofibular joint above the level of the tibial plafond [4]. Tibiofibular syndesmotic disruption was diagnosed according to Amendola et al. [9] based on the X-radiograph of normal distal tibiofibular syndesmosis: (1) the proximal and distal tibiofibular space of ≤6 mm at the anteroposterior position or a mortise view; (2) the anteroposterior tibiofibular overlap of >6 mm or greater than 42% of the fibula width; (3) the tibiofibular overlap of >1 mm at the mortise view. Any syndesmosis beyond the above ranges is considered syndesmotic disruption or separation.

All the included patients received anteroposterior and lateral X-rays of the fractured ankle preoperatively, including a mortise view. Radiographs were evaluated by an experienced orthopaedic traumatologist to determine the Danis-Weber of associated fibular fractures [10] and Lauge-Hansen classification [11]. In addition, computed tomography (CT) plain scan with three-dimensional reconstruction and magnetic resonance imaging (MRI) examination were also made for all patients to assess the degree and types of injury. All the procedures were approved by the Ethics Committee of our hospital.

The demographic and clinical data were recorded, including age, gender, the causes of fracture, affected side, patency, polytrauma, AO/OTA classification [8], Denis-Weber classification, preoperative tibiofibular width, and associated injuries. Briefly, their mean age at admission was 41.46 ± 13.42 years (range, 20–67 years). Twenty-five cases suffered right ankle fractures, and 16 cases suffered left ankle fractures. The causes of injury were traffic accident in 11 cases, sprains in 3 cases (such as youth during their sports that involves high-velocity and high-impact movements), falling down in 16 cases, falling from a height in 10 cases, and crashes by heavy object in 1 case, respectively. The fractures were categorized into types 44A (n = 3), 44B (n = 5), and 44C (n = 33) by AO/OTA classification. Total 16 patients had open fractures, among whom there were 6 grade II cases and 10 grade IIIA cases according to Gustilo-Anderson classification [12, 13], and the other 25 cases were closed injuries. In addition, fibula fracture occurred in all but 1 patient, and 29 patients had concomitant injuries to the medial malleolus. According to the injury mechanism and the degree of the talus wedged into the distal tibiofibular joint, patients were grouped as typical injury and untypical injury. In detail, typical injury mainly caused by vertical axial stress is a complete dislocation of talus wedging into syndesmosis complex, leading to a full syndesmotic separation, with or without “Plafond” fracture; as for untypical injury, the avulsion fractures such as “Tillaux-Chaput” or “Wagstaffe” and “Volkmann” fragments are firstly caused by rotational force, then partial talus dislocation by vertical force results in incomplete syndesmostic separation, mortise widened and syndesmostic ligaments intact, or slightly injured.

After admission, supporter or plaster external fixation was adopted in case of the aggravation of soft tissue injuries. For patients with closed fractures, manual reduction of tibial astragaloid joint was first performed at emergency, followed by continuous traction of calcaneal tuberosity, and then ORIF procedure was initiated until soft tissue swelling regression, good skin condition, and disappearance of wrinkle sign (about 3–4 days); however, for patients with difficulty in manual reduction of tibial astragaloid joint but with fair soft tissue condition, one-stage ORIF was performed at emergency; as for patients with poor soft tissue condition and swelling, open reduction of tibial astragaloid joint was first performed, then followed by continuous traction of calcaneal tuberosity, and finally two-stage ORIF was initiated until soft tissue swelling regressed and skin condition permitted. Open fractures were all treated by emergency operation. With regard to Gustilo type II injury, ORIF was conducted after wound debridement; for type IIIA-contaminated wound, external fixation using supporter was adopted temporarily after debridement. If patient was accompanied by severe soft tissue loss such as open skin avulsion, the vacuum-sealed dressings (VSD) were used to cover the affected area, and then two-stage surgery was conducted until skin conditions permitted.

The surgery was performed by three fellowship-trained orthopaedic trauma surgeons as the first surgeons in the three hospitals, respectively. Patient was placed in a supine position on a radiolucent operating table. Following general anesthesia or block anesthesia, or continuous epidural anesthesia or continuous epidural anesthesia with intravenous anesthesia, the fracture area was reconfirmed under C-arm fluoroscopy and the surrounding fragments such as medial or posterior malleolus fractures, Volkmann fracture, or Chaput fracture were also determined. A pneumatic tourniquet was placed on the affected limb which was elevated 15 cm. The incision was determined according to the occurrence of medial malleolus fracture manifested in the preoperative radiograph. If medial malleolus fracture was apparent, a medial “J” incision was preferred and extended to the medial malleolus tip. Then, the medial soft tissues were released, and the medial malleolus fragments were temporarily left unfixed, aiming to decrease the reduction pressure of tibial astragaloid joint during the subsequent surgical procedure. Surgical approach (partial anterior or posterior) was dependent on the fragment size of anterior-posterior malleolus and the degree of displacement. After the incision of skin, the subcutaneous tissue was incised by sharp dissection to expose the broken ends of fractured fibula and then the distal reduction of tibial astragaloid joint was conducted and stabilized. Fibular length was firstly restored using a 3.5-mm locking compression plate (LCP). The anterior-posterior malleolus fractures were fixed using lag screws or 3.5-mm plate, and the medial malleolus fracture was fixed using two 4-mm cannulated screws or Kirschner wire via the medial incision. In addition, distal tibiofibular syndesmotic disruption and triangular ligament injury were evaluated intraoperatively by pulling on the fibula in the coronal plane with a bone hook (“Hook” test) or by stabilizing the distal tibia and applying lateral force to the foot (“Cotton” test). Patient with a negative “Hook” or “Cotton” test didn’t need to receive syndesmotic fixation; otherwise, syndesmotic screw fixation was performed by screwing 1–3 3.5-mm syndesmotic screws ectoentad (25–30°) at 3–4 cm above distal tibiofibular syndesmosis. If triangular ligament injury occurred, one-stage repair or reconstruction was conducted. Volkmann fragments were fixed using the plates or the cannulated screws via the lateral approach, whereas Chaput fragments were fixed using the cannulated screws via the medial approach. After good anatomic reduction was achieved under C-arm fluoroscopy, plaster external fixation were adopted to stabilize the fracture if the reduction was understable. Finally, the pneumatic tourniquet was deflated after drainage, and hemostasis was performed to avoid postoperative complication such as hematocele at the wound. Then the wound was closed in layers with 2/0 absorbable sutures in the standard fashion.

Patients were advised to take early functional exercise such as the mobilization of toes and knee joint and were forbidden to avoid weight bearing at the affected limb. Dorsal expansion and plantarflexion commenced 2–3 weeks after surgery to avoid ankylosis and traumatic arthritis. Patients were followed up by radioscopy for the wound, bone union, range of motion, ankle joint function, and postoperative complications at postoperative 6 weeks, 3 months, 6 months, and 1 year. Bone union was assessed on the base of Burwell-Charnley radiographic criteria [14]. Functional outcomes were evaluated at the last follow-up by American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale (excellent, 90–100; good, 75–89; fair, 50–74; poor, <50) [15‐17].

Data were presented as count (percentage) or mean ± standard deviation (SD) and analyzed by independent t test, x ² test, and one-way analysis of variance using SPSS 19.0 for windows (SPSS Inc., IL, USA). A P value of ≤0.05 was regarded as statistically significant.