踝关节腓骨旋转角测量：术中判断下胫腓骨联合复位的成功率

背景：CT在诊断下胫腓联合方面优于X射线平片，但是判断下胫腓联合旋转失匹配的CT诊断标准目前还缺乏研究。目前国内外下胫腓关节三维失匹配还缺乏系统研究，特别是对旋转关系的测量。目的：用CT测量正常人群的下胫腓联合的腓骨相对胫骨的旋转角度。方法：在符合条件的志愿者中随机抽取21名男性及21名女性进行测试，用CT随机扫描单侧踝关节。轴位CT测量包括胫腓前间隙、胫腓后间隙、腓骨旋转角、胫腓前关节面切线角、胫腓后关节面切线角。为了确保可靠性，2个研究者在3个不同的场合独立鉴定、评价每个CT数据。结果与结论：42例踝关节纳入到数据分析。下胫腓联合胫骨面形状大致分为深弧形、浅弧形、浅坡形及平直形，其中以深弧形对称型多见。腓骨形状可大致分为三角形、圆形、椭圆形，以三角形最多见。各测量指标95%置信区间：胫腓前间隙2.10-2.25 mm、胫腓后间隙4.14-4.29 mm、腓骨旋转角103.97°-106.30°、胫腓前关节面切线角21.88°-26.64°、胫腓后关节面切线角33.03°-36.63°。其中腓骨旋转角测量变异系数最小，相对波动小，更具有代表性。下胫腓联合CT测量的众多指标中腓骨旋转角是一个更为稳定的指标。这些数据为下胫腓联合的精确复位提供数据基础。

Measurement of fibular rotation angle: Intraoperative judgment of the success rate of inferior tibiofibular syndesmosis reduction

BACKGROUND: The CT image is better than X-ray plain film in diagnosing inferior tibiofibular syndesmosis, but the research on CT diagnostic criteria for the diagnose of inferior tibiofibular syndesmosis rotation mismatch is rare. At present, there lacks of systematic research on inferior tibiofibular joint three-dimensional mismatch at home and abroad, especially for the measurement of rotational relationship.OBJECTIVE:To measure the tibiofibular rotation angle of tibiofibular syndesmosis in normal people with CT imaging. METHODS:Twenty-one male and 21 female volunteers were collected for test, and the CT scan was performed to scan the ankle joint. Axial CT measurements included the anterior tibiofibular interval, posterior tibiofibular interval, fibula rotation angle, tibiofibular articular surface tangent angle and tibia Philippians articular surface tangent angle. Two researchers accomplished the measurement at three different occasions independently, and evaluated each CT data.RESULTS AND CONCOUSION:A total of 42 ankles enrolled in the study of data analysis. The tibial surface shape of the tibiofibular syndesmosis was described as deep curved, shallow arc, shallow sloping and flat-shaped. The deep curved symmetrical sydesmosis was the most common type. The shape of fibula was divided into triangular, circular, elliptical, and the most common shape was triangle. Each measurement data was in 95% confidence interval: the anterior tibiofibular interval was 2.10-2.25 mm, the posterior tibiofibular interval was 4.14-4.29 mm, fibula rotation angle was 103.97°-106.30°, tibiofibular articular surface tangent angle was 21.88°-26.64°, tibia Philippians articular surface tangent angle was 33.03°-36.63°. The fibula rotation angle had the smallest variation coefficient with relative small fluctuations and was more representative. The fibular rotational angle was the most stable parameter when comparing with the rest parameters. These data in the study provided the data base with regarding to the precise reduction of the tibiofibular syndesmosis.