Nortunen Simo, Leskelä Hannu-Ville, Haapasalo Heidi, Flinkkilä Tapio, Ohtonen Pasi, Pakarinen Harri
1Department of Surgery, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland 2Division of Orthopedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, Tampere, Finland.
J Bone Joint Surg Am. 2017 Mar 15;99(6):482-487. doi: 10.2106/JBJS.16.00450.
This study aimed to identify factors from standard radiographs that contributed to the stability of the ankle mortise in patients with isolated supination-external rotation fractures of the lateral malleolus (OTA/AO 44-B).
Non-stress radiographs of the mortise and lateral views, without medial clear space widening or incongruity, were prospectively collected for 286 consecutive patients (mean age, 45 years [range, 16 to 85 years]), including 144 female patients (mean age, 50 years [range, 17 to 85 years]) and 142 male patients (mean age, 40 years [range, 16 to 84 years]) from 2 trauma centers. The radiographs were analyzed for fracture morphology by 2 orthopaedic surgeons, who were blinded to each other's measurements and to the results of external rotation stress radiographs (the reference for stability). Factors significantly associated with ankle mortise stability were tested in multiple logistic regression. Receiver operating characteristic analyses were performed for continuous variables to determine optimal thresholds. A sensitivity of >90% was used as the criterion for an optimal threshold.
According to external rotation stress radiographs, 217 patients (75.9%) had a stable injury, defined as that with a medial clear space of <5 mm. Independent factors that predicted stable ankle mortise were female sex (odds ratio [OR], 2.5 [95% confidence interval (CI), 1.4 to 4.6]), a posterior diastasis of <2 mm (corresponding with a sensitivity of 0.94 and specificity of 0.39) on lateral radiographs (OR, 10.8 [95% CI, 3.7 to 31.5]), and only 2 fracture fragments (OR, 7.3 [95% CI, 2.1 to 26.3]). When the posterior diastasis was <2 mm and only 2 fracture fragments were present, the probability of a stable ankle mortise was 0.98 for 48 female patients (16.8%) and 0.94 for 37 male patients (12.9%).
Patients with noncomminuted lateral malleolar fractures (85 patients [29.7%]) could be diagnosed with a stable ankle mortise without further stress testing, when the fracture line widths were <2 mm on lateral radiographs.
Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
本研究旨在确定标准X线片中有助于外踝单纯旋后-外旋骨折（OTA/AO 44-B型）患者踝关节榫眼稳定性的因素。
前瞻性收集了来自2个创伤中心的286例连续患者（平均年龄45岁[范围16至85岁]）的踝关节榫眼位和侧位非应力X线片，这些患者无内侧间隙增宽或不匹配，其中包括144例女性患者（平均年龄50岁[范围17至85岁]）和142例男性患者（平均年龄40岁[范围16至84岁]）。由2名骨科医生对X线片的骨折形态进行分析，他们彼此不知道对方的测量结果以及外旋应力X线片的结果（稳定性的参考标准）。在多因素logistic回归中测试与踝关节榫眼稳定性显著相关的因素。对连续变量进行受试者工作特征分析以确定最佳阈值。以敏感性>90%作为最佳阈值的标准。
根据外旋应力X线片，217例患者（75.9%）损伤稳定，定义为内侧间隙<5mm。预测踝关节榫眼稳定的独立因素为女性（优势比[OR]，2.5[95%置信区间（CI），1.4至4.6]）、侧位X线片上后部分离<2mm（对应敏感性为0.94，特异性为0.39）（OR，10.8[95%CI，3.7至31.5]）以及仅有2个骨折碎片（OR，7.3[95%CI，2.1至26.3]）。当后部分离<2mm且仅有2个骨折碎片时，48例女性患者（16.8%）踝关节榫眼稳定的概率为0.98，37例男性患者（12.9%）为0.94。
当侧位X线片上骨折线宽度<2mm时，无粉碎性外踝骨折的患者（85例[29.7%]）无需进一步应力测试即可诊断为踝关节榫眼稳定。
预后IV级。有关证据水平的完整描述，请参阅作者指南。
