Dornacher D, Cakir B, Reichel H, Nelitz M
Orthopädie, Orthopädische Universitätsklinik Ulm am RKU.
Z Orthop Unfall. 2008 Mar-Apr;146(2):246-50. doi: 10.1055/s-2008-1038321.
An assessment of the reproducibility of the acetabular index on the basis of anteroposterior radiographs of the pelvis was performed in order to rule out residual dysplasia of the hip in the second year of life.
51 consecutive patients (41 girls, 10 boys) with congenital dysplasia of the hip (35 bilateral, 16 unilateral) were included. Approximately at the time children started walking (mean age: 13.9 months; range: 10 - 22 months), digitised anteroposterior radiographs of the pelvis were recorded. Acetabular indices were measured bilaterally and blinded by two observers (O1 and O2), then classified according to the normal values of the hip joint described by Tönnis et al. (normal = lower single standard deviation [s], light dysplasia = above single standard deviation [s - 2 s] and severe dysplasie = above double standard deviation [2 s]). O2 repeated a second set of observations 6 weeks after the first. 306 values of the acetabular index (O1: 102 values; O2: 204 values) were statistically evaluated. Reliability was expressed by Pearson's correlation coefficient (PCC) and 95 % confidence interval. The rater agreement of the classification into normal values of the hip joint was calculated with the kappa coefficient.
The PCC for intraobserver/interobserver reliability was 0.928/0.875. The 95 % confidence interval for intraobserver reliability was +/- 3.1 degrees and for interobserver reliability - 3.1 degrees /+ 5.9 degrees . A comparison of the first series of measurements by O1 with the series of measurements by O2 presented congruence in 66 of 102 hip joints classified according to the normal values of the hip joint as described by Tönnis. In 36 hip joints the classification was deviant, in 15 the classification differed between normal and s, in 21 between s and 2 s. The kappa coefficient of 0.51 showed moderate interobserver agreement.
The reproducibility of radiological surveillance in congenital hip dysplasia, approximately to the time children start walking, can be considered as adequate. Correct positioning of the patient and exact definition of radiological landmarks are essential. In spite of good statistical values for reliability, decreasing accuracy in classifying into Tönnis' normal values of the hip joint is seen with increasing degree of dysplasia. In marginal cases, before coming to the decision for operative treatment, a second reading, ideally by the same observer and with a chronological shift, is advisable.
基于骨盆前后位X线片对髋臼指数的可重复性进行评估，以排除生命第二年时髋关节的残余发育不良。
纳入51例连续的先天性髋关节发育不良患者（41例女孩，10例男孩）（35例双侧，16例单侧）。大约在儿童开始行走时（平均年龄：13.9个月；范围：10 - 22个月），记录骨盆的数字化前后位X线片。由两名观察者（O1和O2）对双侧髋臼指数进行测量且测量过程中观察者不知情，然后根据Tönnis等人描述的髋关节正常值进行分类（正常 = 低于单个标准差[s]，轻度发育不良 = 高于单个标准差[s - 2s]，重度发育不良 = 高于两倍标准差[2s]）。O2在第一次观察6周后重复进行第二组观察。对306个髋臼指数值（O1：102个值；O2：204个值）进行统计学评估。可靠性用Pearson相关系数（PCC）和95%置信区间表示。用kappa系数计算髋关节正常值分类的观察者间一致性。
观察者内/观察者间可靠性的PCC为0.928/0.875。观察者内可靠性的95%置信区间为±3.1度，观察者间可靠性的95%置信区间为 - 3.1度 / + 5.9度。根据Tönnis描述的髋关节正常值，将O1的第一组测量值与O2的测量值系列进行比较，在102个髋关节中，有66个分类一致。在36个髋关节中分类有偏差，15个髋关节在正常和s之间分类不同，21个髋关节在s和2s之间分类不同。kappa系数为0.51，显示观察者间一致性中等。
先天性髋关节发育不良在儿童开始行走时左右的放射学监测可重复性可认为是足够的。患者的正确体位和放射学标志的准确定义至关重要。尽管可靠性的统计值良好，但随着发育不良程度增加，在Tönnis髋关节正常值分类中的准确性下降。在边缘病例中，在决定手术治疗之前，最好由同一名观察者进行第二次读片，且要有时间间隔，这是可取的。
