• OBJECTIVES
    • To identify the incidence and fracture characteristics associated with syndesmotic injury in tibial plafond fractures and report the incidence of posttraumatic osteoarthrosis (PTOA).
  • DESIGN
    • Retrospective comparative study.
  • SETTING
    • Two level-1 academic trauma centers.
  • PATIENTS/PARTICIPANTS
    • Of the 735 tibial plafond fractures (OTA/AO 43-B3 and 43-C) treated from January 2006 through December 2015, 108 patients (108/735, 15%) were identified with syndesmosis injury.
  • INTERVENTION
    • Either acute or missed syndesmotic injury.
  • MAIN OUTCOME MEASUREMENT
    • PTOA.
  • RESULTS
    • Fourteen fractures (14/735, 2%) had missed syndesmotic injury. Volkmann fragment of ≤10 mm (P = 0.04) and fibular avulsion fracture (P = 0.05) were significantly more common in missed syndesmosis. Ninety fractures (14/14 missed, 76/94 acute) had greater than 12-month follow-up (mean, 26 months; range, 12-102 months). Nearly all patients with missed syndesmosis injury developed arthrosis (13/14, 93%), and 45% (34/76 fractures) of plafond fractures with acute syndesmosis injury developed arthrosis (P < 0.001). Although controlling for malreduction, patients with missed syndesmosis had significantly more PTOA development (P = 0.018). Controlling for malreduction, patients with syndesmotic fixation and a ≤10-mm Chaput or Volkmann fragment or fibular avulsion fracture (8/31, 26%) were less likely to develop PTOA than if they had a similar fracture pattern without syndesmotic fixation (9/10, 90%) (P = 0.011).
  • CONCLUSIONS
    • Fifteen percent of tibia plafond fractures have a syndesmosis or syndesmotic equivalent injury. Missed syndesmosis injury has a high rate of PTOA development. Patients with a ≤10-mm Chaput or Volkmann fragment and/or fibular avulsion fracture benefit from syndesmotic fixation.
  • LEVEL OF EVIDENCE
    • Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.