Syndesmosis Malposition Assessed on Weight-Bearing CT Is Common After Operative Fixation of Intra-articular Distal Tibia Plafond Fracture.

OBJECTIVES: To evaluate reliability of measurement techniques for syndesmosis position after operative fixation of distal tibia plafond fracture on weight-bearing computed tomography (WBCT), identify risk factors for syndesmosis malposition, and determine if syndesmosis malposition is associated with higher pain and lower physical function. DESIGN: Prospective cohort study. SETTING: Three Level 1 trauma centers. PARTICIPANTS: Twenty-six subjects who underwent open reduction and internal fixation of distal tibia plafond fractures with bilateral ankle WBCT 1 year or greater after injury were included in the study. INTERVENTION: Operative fixation of distal tibia plafond fracture. MAIN OUTCOME MEASUREMENT: Fibula position in the tibia incisura, injury characteristics, and patient-reported outcomes were the main outcome measurements. RESULTS: Interrater reliability for syndesmosis position measurements were excellent for the Phisitkul technique on both injured and healthy ankles (intraclass correlation coefficients [ICCs]: 0.93-0.98). The Nault technique demonstrated moderate-to-excellent interrater reliability (ICCs: 0.67-0.98), apart from the angle of rotation measurement (ICCs: 0.18-0.67). Sixteen of 26 subjects (62%) had syndesmosis malposition defined as >2 mm difference comparing the tibial-fibular relationship in injured and uninjured ankles using these 2 methods. Patients with syndesmosis malposition reported lower Foot and Ankle Ability Measure: Activities of Daily Living scores; other recorded patient-reported outcomes were not significantly different. CONCLUSIONS: Measurement techniques for syndesmosis position on WBCT were reliable after operative fixation of distal tibia plafond fracture. Syndesmosis malposition is common after these injuries and predicted impaired physical function. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.