Stability of Distal Tibiofibular Syndesmosis With or Without Fixation of Posterior Fragments in Bimalleolar Fractures

Background and Rationale: Injury to the tibiofibular syndesmosis in ankle fractures is a major prognostic factor for the development of post-traumatic osteoarthritis. The syndesmosis is frequently involved when posterior tibial marginal fragments are fractured. Intraoperative stability testing determines whether a trans-syndesmotic device (screws, endobutton, or plate) is required. However, trans-syndesmotic devices carry risks such as malreduction, hardware removal, and infection. Anatomical fixation of posterior tibial fragments is hypothesized to restore syndesmotic stability, thereby reducing the reliance on trans-syndesmotic implants. Objective and Hypothesis: The primary objective of this randomized controlled trial is to compare the rate of trans-syndesmotic stabilization device usage between patients undergoing osteosynthesis of posterior marginal fragments and those managed without posterior fragment osteosynthesis. The hypothesis is that syndesmotic stability (defined as non-use of a trans-syndesmotic device intraoperatively) will be significantly higher in the posterior fragment fixation group. Study Design: Multicenter, open-label, randomized, two-arm parallel-group trial conducted at two orthopedic trauma centers (Groupe Hospitalier Diaconesses Croix Saint-Simon and Hôpital Lariboisière).