Importance of Syndesmotic Reduction on Clinical Outcome After Syndesmosis Injuries

Objectives: To evaluate the relationship between syndesmosis reduction and outcome. Design: Retrospective cohort study. Setting: One Level 1 and 1 Level 3 Trauma Center. Patients: Ninety-seven patients with syndesmosis injury. Intervention: Stabilization of syndesmosis injury. Open reduction and internal fixation of malleolar fracture, if present. Main Outcome Measurements: Anterior, central, and posterior measures of syndesmosis width on computed tomography scans, Olerud-Molander Ankle score, American Orthopaedic Foot and American Orthopaedic Foot and Ankle Society Ankle-Hindfoot score, and range of motion measurements. Results: Eighty-seven patients completed 2 years of follow-up. The difference in anterior tibiofibular distance (aTFD) between the injured and noninjured ankle postoperatively had a significant effect on the Olerud-Molander Ankle score after 6 weeks [b = -2.6, 95% confidence interval (CI), -4.8 to -0.4; P = 0.02], 1 year (b = -2.7, 95% CI, -4.7 to -0.8; P < 0.001), and 2 years (b = -2.6, 95% CI, - 4.6 to -0.6; P = 0.009) and on American Orthopaedic Foot and Ankle Society Ankle-Hindfoot score after 6 weeks (b = -2.2, 95% CI, -3.7 to -0.7; P = 0.004), 1 year (b = -1.7, 95% CI, -3.0 to - 0.4; P = 0.04), and 2 years (b = -1.9, 95% CI, -3.2 to -0.5; P = 0.006). The effect of computed tomography measurements on range of motion was inconsistent. Receiver operating characteristic (ROC) curves demonstrated that aTFD had adequate discriminatory performance (area under the ROC curve 0.7) 1 and 2 years after surgery and the central measurement at only 2 years after surgery. ROC analyses indicate a cutoff value for syndesmosis malreduction of 2 mm The postoperative rate of malreduction was 32%. Conclusions: The aTFD correlated with clinical outcome. A 2-mm difference in aTFD seems to predict poorer clinical outcome.