下胫腓联合解剖参数的多层螺旋CT测量

Anatomical parameters of normal distal tibiofibular syndesmosis on multi-slice CT images

目的利用MSCT扫描图像观察正常下胫腓联合的形态以及测量相关解剖学参数，为临床精确诊断下胫腓联合分离提供解剖学依据及有效的诊断方法。方法回顾性分析2013年6月-2016年2月，大连大学附属中山医院45例行双踝CT检查的单侧踝关节外伤患者的健侧踝关节影像资料。取距离胫距关节面9～11mm的水平位CT扫描图像分析下胫腓联合形态，并测量胫腓骨中心距离、胫腓骨间隙宽度及胫腓骨前缘距离，分析各组参数的统计学差异。结果45例下胫腓联合CT影像显示其形态有3种，其中为半圆形14例（31．11％），新月形15例（33．33％），矩形16例（65．56％）。半圆形下胫腓联合的胫腓骨中心距离、胫腓骨间隙宽度和胫腓骨前缘距离分别为（2．69±0．19）cm、（2．45±0．46）mm和（8．48±2．30）mm，新月形的分别为（2．82±0．17）cm、（2．74±0．90）mm和（6．80±1．62）mm，矩形的分别为（2．89±0．25）cm、（3．15±0．8）mm和（6．86±1．89）mm。其中，半圆形下胫腓联合的胫腓中心距离和胫腓骨间隙宽度均较矩形的小，差异均有统计学意义（q=3．722、3．602，P值均〈0．05）；而半圆形胫腓骨前缘距离较矩形的大，差异有统计学意义（q=3．217，P〈0．05）；但是，新月形的相关参数分别与半圆形和矩形的比较，差异均无统计学意义（P值均〉0．05）。结论国人的下胫腓联合在CT影像上可分为半圆形、新月形和矩形三种形态。以下胫腓联合前后缘的切线作为测量基线，可提高各参数测量的可重复性，为进一步研究国人下胫腓联合提供了有效的方法。

Objective To measure the morphometric parameters of normal distal tibiofibular syndesmosis on multi-slice CT（MSCT） images for providing anatomical basis and precise confirmation of the syndesmosis separation. Methods From June 2013 to February 2016, CT data of normal-side ankle joint of 45 patients underwent CT examination on double ankle bones from Affiliated Zhongshan Hospital of Dalian University were retrospectively analyzed. The morphology of the distal tibiofibular syndesmosis was observed on CT images, and the measuring plane of the syndesmosis was 9 - 11 mm proximal to the tibiaJ plafond; meanwhile, relevant parameters including the length of tibiofibular center, the width of tibiofibular clear space and the distance between the anterior margins of tibia and fibula were measured, and the differences were analyzed in each parameter by statistical methods. Results On CT images, the distal tibiofibular syndesmosis of 45 patients appeared as three kinds of shapes, including semicircular in 14 patients （31.11%）, crescent in 15 patients （33.33%） and reetangular in 16 patients （65.56%）. In patients with semicircular syndesmosis, the related variable including the length of tibiofibular center, the width of tibiofibular clear space and the distance between the anterior margins of tibia and fibula was （2.69 ± 0.19） cm, （2.45 ±0.46） mm and （8.48 ±2.30） mm respectively; （2.82 ±0. 17） cm, （2.74± 0.90） mm and （6.80 ±1.62） mm respectively in patients with crescent syndesmosis; as well as （2.89 ± 0.25） cm, （3. 15 ± 0. 8） mm and （6. 86 ± 1. 89） mm respectively in patients with rectangular syndesmosis. And the length of tibiofibular center and the width of tibiofibular clear space of semicircularsyndesmosis were shorter than those of rectangular syndesmosis, and the differences were statistically significant （q =3. 722, 3. 602, all P values 〈 0.05）, but another parameter, the distance between the anterior margins of tibia and fibula, was longer, and the difference approached statistical significance （ q = 3. 217, P 〈 0.05 ）. However, there was no statistical significance in the relevant variables of crescent syndesmosis in comparison with semicircular and rectangular syndesmosis （all P values 〉 0. 05 ）. Conclusions The distal tibiofibular syndesmosis shows three kinds of shapes, appearing as semicircular, crescent and rectangular, yet DR images can＇t make a definite diagnosis of the syndesmosis separation, so tangent lines of anterior and posterior edges of distal tibiofibular syndesmosis are chosen as measurement baseline, which can improve the repeatability measurement of the relevant parameters. Therefore, this method in the study can be effective for further study of the distal tibiofibular syndesmosis in Chinese people.