Department of Orthopaedics and Traumatology; Taipei Veterans General Hospital Yuanshan Branch, Taiwan, ROC; Department of Orthopaedics; School of Medicine; National Yang-Ming University, Taiwan, ROC.
Division of Medical Imaging for Health Management, Cheng-Hsin General Hospital, Taiwan, ROC; Department of Radiology; School of Medicine; National Yang-Ming University, Taiwan, ROC.
Injury. 2021 Apr;52(4):961-966. doi: 10.1016/j.injury.2020.12.034. Epub 2021 Jan 2.
Fixation of infra-isthmus femoral shaft fracture using antegrade intramedullary (IM) nailing is difficult and is associated with a high complication rate. This study aimed to identify risk factors for complications following this procedure. The ratio of the fracture site diameter to the diameter of the femoral intramedullary canal of the isthmus (FI ratio) was evaluated as a novel parameter to predict complication.
Patients who underwent antegrade IM nailing for infra-isthmus femoral shaft fracture between January 2008 and December 2018 and had a minimum of 12 months of follow-up were retrospectively reviewed. The primary outcome was occurrence of complication, including non-union, mal-alignment, fixation failure, or progressive loss of reduction. Logistic regression analysis was performed to identify risk factors of complication. The sensitivity and specificity of FI ratio as a predictor of complication was calculated. A receiver operating characteristic (ROC) curve was generated to establish an FI ratio threshold to predict occurrence of complication following antegrade IM nailing.
Sixty-five patients with a mean age of 47.1 years were included. Using univariate logistic regression analysis, comminuted fracture pattern (p=0.026), distance from screws to fracture site (< 3cm) (p=0.002), and higher FI ratio (p=0.001) were associated with complication. Using multivariate logistic regression analysis, FI ratio was identified as an independent risk factor for complication following antegrade IM nailing (p=0.038). ROC curve indicated that FI ratio ≥ 2 had sensitivity and specificity of 0.72 and 0.72, respectively, in predicting complication.
Our study indicates that wider intramedullary diameter at the fracture site was associated with higher complication rate following antegrade IM nailing in distal infra-isthmal femoral fractures. The FI ratio could be a reliable predictor of complication after antegrade IM nailing for such fracture, and alternative strategies should be considered for patients with higher FI ratio (≥ 2).
经股骨前骨干内固定治疗股骨下 1/3 骨干骨折难度较大，并发症发生率较高。本研究旨在确定该术式相关并发症的危险因素。本研究评估了股骨峡部髓腔（FI）处骨折部位直径与髓腔直径的比值（FI 比值）作为预测并发症的新参数。
回顾性分析 2008 年 1 月至 2018 年 12 月期间接受经股骨前骨干内固定治疗的股骨下 1/3 骨干骨折患者，随访时间至少 12 个月。主要结局为并发症的发生，包括不愈合、对线不良、固定失败或复位丢失。采用 Logistic 回归分析确定并发症的危险因素。计算 FI 比值作为并发症预测指标的灵敏度和特异性。绘制受试者工作特征（ROC）曲线，确定 FI 比值预测经股骨前骨干内固定治疗后并发症发生的阈值。
共纳入 65 例患者，平均年龄 47.1 岁。单因素 Logistic 回归分析显示，粉碎性骨折类型（p=0.026）、螺钉至骨折部位的距离（<3cm）（p=0.002）和较高的 FI 比值（p=0.001）与并发症相关。多因素 Logistic 回归分析表明，FI 比值是经股骨前骨干内固定治疗后发生并发症的独立危险因素（p=0.038）。ROC 曲线表明，FI 比值≥2 预测并发症的灵敏度和特异性分别为 0.72 和 0.72。
本研究表明，股骨峡部骨折部位髓腔直径较大与经股骨前骨干内固定治疗股骨下 1/3 骨干骨折并发症发生率较高相关。FI 比值可作为预测此类骨折经股骨前骨干内固定治疗后并发症的可靠指标，对于 FI 比值较高（≥2）的患者应考虑采用其他治疗策略。
