Intraoperative 3D-Fluoroscopy Increases Accuracy of Syndesmotic Reduction in Ankle Fractures with Syndesmotic Instability

Abstract

Abstract Background Direct visual control and 2D-fluoroscopy is widely used to achieve an anatomic syndesmotic reduction in ankle fractures with syndesmotic instability. However, significant malreduction rates are reported. Aims It was the aim of this study to evaluate the accuracy of conventional syndesmotic reduction and to assess the impact of intraoperative 3D-imaging to improve the quality of syndesmotic reduction. Methods Single institution consecutive case series (02/2021–12/2022) including all patients undergoing operative treatment for ankle fractures with syndesmotic instability. Syndesmotic reduction was performed following open reduction and internal fixation of the malleolar fractures. Provisional tibiofibular alignment was obtained under visual control and 2D-fluoroscopy. With the ankle held in a neutral position, temporary fibulotibial transfixation was performed with 2 K-wires. 3D-imaging was obtained (Cios Spin, Siemens Healthineers, Forchheim-Germany). Non-anatomical positions of the fibula were devided into anterior, posterior, or rotational malreductions. If reduction was not satisfactory, the reduction was improved and 3D-imaging repeated. Once adequate reduction was obtained, definitive syndesmotic fixation was performed and the K-wires were removed. Results A total of 50 patients (mean age 44±16 years, m/f 27/23) were operated for ankle fractures with syndesmotic instability. Intraoperative 3D-imaging confirmed anatomic syndesmotic reduction in 31 patients (62%). In 15 patients (30%) reduction was repeated once, in 4 patients (8%) two additional reduction manoeuvers were necessary to obtain an anatomic result. Thus, a total of 23 malreductions were recorded in a total of 73 reduction manoeuvers (32%). Of these, we observed 16 anterior (70%), 2 posterior (9%) and 5 rotational malreductions (22%). Conclusions Syndesmotic reduction under visual control and 2D-fluoroscopy proved to be unreliable with a syndesmotic malreduction in almost one-third of all reduction manoeuvers. With the help of intraoperative 3D-imaging incorrect tibiofibular alignment before definite fixation was identified, reduction corrected and thereby the rate of malreductions reduced.