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.

LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.