Importance of Syndesmotic Reduction on Clinical Outcome After Syndesmosis Injuries.

Abstract

To evaluate the relationship between syndesmosis reduction and outcome. Retrospective cohort study. One Level 1 and 1 Level 3 Trauma Center. Ninety-seven patients with syndesmosis injury. Stabilization of syndesmosis injury. Open reduction and internal fixation of malleolar fracture, if present. 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. 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%. The aTFD correlated with clinical outcome. A 2-mm difference in aTFD seems to predict poorer clinical outcome. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.