Fibular Fixation in Same-Level Distal Third Tibiofibular Fractures: Is Fibular Fracture Regarded as a Secondary Importance?

Background: Although most studies focused on the alignment or union of the tibia in same-level distal third tibiofibular fractures, the outcome of a concomitant fibular fracture is generally regarded as being of secondary importance in the literature. This study aimed to assess the outcomes of fibular fractures in same-level distal third tibiofibular fractures. Methods: In this retrospective study, we enrolled 111 patients with same-level distal third tibiofibular fractures treated at our institute between January 2016 and August 2020. Tibial fractures were stabilized with intramedullary nailing, and the cases were divided into two groups based on whether they additionally underwent fibular fixation (group 1, 57 cases) or not (group 2, 54 cases). Clinical and radiographic outcomes were used for the evaluation of tibial and fibular alignments, union of the tibia and fibula, number of interlocking screws in the distal tibial fragment, range of motion of the ankle joint, and complications. Results: No statistically significant differences in the tibial union rate or mean tibial alignment were observed between the two groups on either the immediate postoperative or final radiographs. The fibular union rate in group 1 was significantly higher than that in group 2 (fibular nonunion, 0 vs. 15; p < 0.001). Statistically significant differences in fibular displacement were observed on immediate postoperative radiographs between patients with fibular union and those without it. At the final follow-up, the mean range of ankle motion and lower extremity functional scale scores did not differ between the two groups. Conclusions: Regardless of whether fibular fixation was performed, the overall tibial alignment with intramedullary nailing was well restored and the union rate of the tibia was comparable in the two groups. Fibular nonunion is not uncommon in unfixed fibula fractures. Displacement of the fibula as seen on immediate postoperative radiographs was related to fibular nonunion.