基于CT三维重建的外踝骨折形态解剖学特征

目的：测量和研究外踝骨折线及骨折块的形态学参数及其几何分布，为设计理想的外踝内固定材料提供依据和参考。方法：收集2012年2月-2016年4月间53例外踝不稳定性骨折患者，采用三维CT重建图像并利用PACS软件对外踝骨折线前缘尖顶距（ATD）、棘尖顶距（CTD）、后缘尖顶距（PTD）、骨折块近段双面夹角（p-CA）、远端双面夹角（d-CA）进行几何测量及统计学分析。结果：在95%信心水准下，外踝骨折块ATD为（2.97±0.03）cm，CTD为（4.52±0.07）cm，PTD为（3.17±0.11）cm，p-CA为（103.20±1.94）°，d-CA为（78.50± 1.78）°，p-CA变异系数为9.86，d-CA变异系数为11.90。骨折区域密集分布在外踝关节面上方一个倒“V”型带状区域。结论：外踝骨折线的前侧起始点的变异度相对较小，而近段及后侧变异度较大。外踝骨折块前外侧面与后外侧面的夹角呈现递减趋势，近段夹角变异度较小，而远端较大。

Morphologic characteristics of the lateral ankle fragment: A 3-D computer tomography based study

Objective: To evaluate the morphological characteristics of the lateral malleolar fracture line and associated fragment geometry for the design of novel internal fixation. Methods: A retrospective analysis of 3-D computed tomography data of lateral ankle fracture cases from February 2012 to April 2016 was conducted. The anterior tip distance (ATD), crest tip distance (CTD), posterior tip distance (PTD), the proximal cross angle (p-CA), and distal cross angle (d-CA) were measured as morphologic assessments in the Picture Archiving and Communication System (PACS). Results: Based on the recognition of the lateral ankle fracture by CT reconstruction, at a confidence interval of 95%, the fragment was described with ATD (2.97±0.03) cm, CTD (4.52±0.07) cm, PTD (3.17±0.11) cm, p-CA (103.20±1.94)°, d-CA (78.50±1.78)°. The coefficient of variation (CV) of p-CA was calculated 9.86, and the CV of d-CA arrived at 11.90. Conclusion: The anterior initiation site of lateral fracture line is relatively invariable in comparison with proximal and posterior frontier. The double facet cross angle of the fragment appears decrescent along axis of distal fibula while distal cross angle is found slightly variable, compared with proximal data. The discovery obtained from this series could be helpful in the modeling of prospective biomechanical researches and developing novel fixation.