CT测量Segond骨折碎片至Gerdy结节的距离可预测MRI上合并前外侧韧带及髂胫束囊-骨层受累
简介
回顾86例急性Segond骨折患者的CT与MRI资料，发现所有患者均合并ACL损伤，44.2%合并ALL及髂胫束囊骨层联合受累；联合受累组骨折块距Gerdy结节更短（9.2mm vs 11.2mm），以距离<10mm为阈值可预测联合受累（敏感度78.9%，特异度62.5%）。该CT指标简单可重复，结合MRI有助于前外侧结构损伤的术前评估与手术规划。
英文摘要
OBJECTIVE: Segond fractures are avulsion fractures of the anterolateral tibial plateau, but the ligamentous structures involved remain debated. This study aimed to determine whether CT-measured fragment distance to the Gerdy tubercle predicts combined involvement of the anterolateral ligament (ALL) and the capsulo-osseous layer of the iliotibial band (ITB) as defined by MRI. MATERIALS AND METHODS: We retrospectively analyzed 86 patients (58 male, 28 female; mean age 30.9 ± 11.4 years) with acute Segond fractures on CT and MRI. CT measured fragment dimensions and distance to the Gerdy tubercle. MRI assessed the ALL, ITB, and its capsulo-osseous layer, classifying patients into ALL-only (n = 48) vs combined ALL + ITB involvement (n = 38). ROC analysis evaluated CT parameters. RESULTS: Anterior cruciate ligament(ACL) injury occurred in all 86 patients (100%). MRI showed ALL attachment in 100% and combined involvement in 44.2%. Fragment dimensions did not differ between groups (all p > 0.05). CT distance to Gerdy tubercle was shorter in the combined group (9.2 ± 1.6 mm vs 11.2 ± 3.1 mm, p = 0.029). A cutoff < 10 mm predicted combined involvement (sensitivity 78.9%, specificity 62.5%; AUC = 0.72, 95% CI 0.60-0.84). CONCLUSION: Segond fractures consistently involve the ALL. Combined involvement of the capsulo-osseous layer adjacent to the ITB occurs in a substantial subset and is associated with a fragment distance of < 10 mm from the Gerdy tubercle on preoperative CT, as identified on MRI. This simple, reproducible CT marker may assist in surgical planning for anterolateral complex injuries when interpreted alongside MRI findings.