Liu George T, Ryan Easton, Gustafson Eric, VanPelt Michael D, Raspovic Katherine M, Lalli Trapper, Wukich Dane K, Xi Yin, Chhabra Avneesh
Associate Professor, Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX.
Medical Student, University of Texas Southwestern Medical School, Dallas, TX.
J Foot Ankle Surg. 2018 Nov-Dec;57(6):1130-1136. doi: 10.1053/j.jfas.2018.05.013. Epub 2018 Sep 7.
Malreduction of distal tibiofibular syndesmosis (DTFS) leads to poor functional outcomes after ankle fracture surgery. Difficulty achieving anatomic alignment of the syndesmosis is due to variable morphology of the fibular incisura of the tibia and a paucity of literature regarding its morphologic characteristics. We surveyed 775 consecutive ankle computed tomography (CT) scans performed from June 2008 to December 2011, and 203 (26.2%) were included for evaluation. Two observers performed quantitative measurements and qualitative evaluated fibular incisura morphology. Tang ratios for fibular rotation, anterior and posterior tibiofibular distances, fibular incisura depth, and subjective morphologies on CT were assessed using conventional multiplanar reconstruction (MPR) and maximum intensity projections (MIPs). On conventional CT, the mean Tang ratio was 0.97 ± 0.06; the mean anterior tibiofibular distance was 2.17 ± 0.87 mm; the mean posterior tibiofibular distance was 3.52 ± 0.94 mm; and the mean depth of fibular incisura was 3.29 ± 1.19 mm. Five morphologic variations of the fibular incisura were identified: crescentic, trapezoid, flat, chevron, and widow's peak. The most common fibular incisura morphology was crescentic (61.3%), followed by trapezoid shape (25.1%); the least common morphology was flat (3.1%). Interobserver variability with intraclass correlation coefficient (ICC) was slightly higher for all quantitative measures on MPR (ICC = 0.72 to .81) versus MIP (ICC = 0.64 to 0.75). ICC for incisura shape and depth assessments was poor on both modalities (0.13 to 0.38). This comprehensive CT study reports on quantitative and qualitative descriptive measures to evaluate fibular incisura morphologies and fibular orientation. It also defines the frequency of DTFS measures and the interobserver performance on 2 CT evaluation methods.
胫腓下联合（DTFS）复位不良会导致踝关节骨折手术后功能恢复不佳。胫腓下联合难以实现解剖复位是由于胫骨腓骨切迹形态各异，且关于其形态特征的文献较少。我们对2008年6月至2011年12月期间连续进行的775例踝关节计算机断层扫描（CT）进行了调查，其中203例（26.2%）被纳入评估。两名观察者进行了定量测量，并对腓骨切迹形态进行了定性评估。使用传统的多平面重建（MPR）和最大强度投影（MIP）评估腓骨旋转的Tang比率、胫腓前后距离、腓骨切迹深度以及CT上的主观形态。在传统CT上，平均Tang比率为0.97±0.06；胫腓前平均距离为2.17±0.87mm；胫腓后平均距离为3.52±0.94mm；腓骨切迹平均深度为3.29±1.19mm。确定了腓骨切迹的五种形态变异：新月形、梯形、扁平形、人字形和寡妇峰形。最常见的腓骨切迹形态是新月形（61.3%），其次是梯形（25.1%）；最不常见的形态是扁平形（3.1%）。与MIP（组内相关系数ICC = 0.64至0.75）相比，MPR上所有定量测量的观察者间变异（ICC = 0.72至0.81）略高。两种模式下切迹形状和深度评估的ICC均较差（0.13至0.38）。这项全面的CT研究报告了评估腓骨切迹形态和腓骨方向的定量和定性描述性测量方法。它还定义了DTFS测量的频率以及两种CT评估方法的观察者间表现。
