成人正常髋关节旋转中心的X线影像测量研究

Measurement of hip rotational center on normal bilateral hip radiographs in adults

目的 探讨成人正常髋关节旋转中心的X线影像分布特点及其变异范围.方法 纳入2013年6-12月中日友好医院影像存档及传输系统中200例成人双侧髋关节正位X线片无异常患者的资料进行回顾性分析.在X线片上以泪滴下缘为参考,测量双侧髋臼中心与泪滴下缘的垂直高度和水平距离,观察左右侧差异,并以±2倍左右侧差值标准差区间为双侧髋关节测量数据的95%正常变异范围.使用组内相关系数（ICC）评价观察者自身及观察者之间测量数据的可靠性.结果 所测数据均呈正态分布.观察者间和观察者自身ICC值为0.88~0.97,提示测量值可靠性优.200例（400侧）患者髋关节髋臼中心与泪滴下缘的垂直高度为6.2~20.9 mm,平均（14.6±2.32）mm;水平距离为25.0~44.5 mm,平均（33.1±3.33）mm.左右两侧髋臼中心垂直高度和水平距离比较,右侧髋臼中心高度略小于左侧,差异无统计学意义（t=1.596, P〉0.05）;而右侧髋臼中心水平距离大于左侧,差异有统计学意义（t=2.634, P〈0.05）.右侧与左侧髋臼中心高度与水平距离差值的标准差分别为1.69 mm和1.54 mm,故其95%正常差异范围为3.38 mm （1.69 mm×2） 和3.08 mm（1.54 mm×2）.结论 本研究初步描述了中国成年人正常髋臼中心的分布特点,并确定其正常变异范围,对全髋关节置换术前模板设计和术后髋臼假体位置的评估具有一定的价值.

Objective To investigate the distribution of hip rotational center on normal bilateral hip radiographs and to determine normal bilateral variation in hip rotational center.Methods From June 2013 to December 2013, 200 normal AP radiographs of bilateral hips in PACS of China-Japan Friendship Hospital were reviewed.The hip rotational center height and horizontal distance of acetabular center were measured in relation to the inferior edge of acetabular teardrop to evaluate the difference of height and horizontal distance between the right and left acetabular centers, and the range of±SD×2 of which was defined as 95% of the normal range of variation.Intraclass correlation coefficient （ICC） was used to determine intraobserver and interobserver reliability.Results All the data were in line with the normal distribution.The ICC of intraobserver and interobserver reliability were excellent agreement.The value of the acetabular center height and horizontal distance were （14.6±2.32）mm（range 6.2-20.9 mm） and （33.1±3.33）mm（range 25.0-44.5 mm）, respectively.There was no significant difference between the right and the left acetabular center height（t=1.596, P〉0.05）, but the horizontal distance of right acetabular center was significant greater than that of the left acetabular center（t=2.634, P〈0.05）.The standard deviation of differences of height and horizontal distance between the right and left acetabular centers were 1.69 mm and 1.54 mm, respectively.So it was regarded as normal range of variation of one acetabular center height and horizontal distance relative to the contralateral acetabular center if the differences of 3.38 mm （1.69 mm×2） and 3.08 mm（1.54 mm×2） between them respectively.Conclusions The study preliminarily defined the distributing characteristics and the normal range of bilateral variation of acetabular center in Chinese adult population, and has a certain value for guiding preoperative templating, postoperative assessment of cup position on radiograph for in THA, as well.