Marques Carlos J, Martin Tobias, Fiedler Franziska, Weber Mathias, Breul Viktor, Lampe Frank, Kozak Josef
Research Center of the Orthopedic and Joint Replacement Department, Schoen Klinik Hamburg Eilbek, Hamburg, Germany.
Department of Navigation Laboratory, Aesculap AG, Tuttlingen, Germany.
J Ultrasound Med. 2018 Oct;37(10):2333-2342. doi: 10.1002/jum.14581. Epub 2018 Feb 26.
Pelvic tilt is the angle between the anterior pelvic plane and the coronal plane. It affects cup positioning in total hip arthroplasty. The primary objective of this study was to test the intra- and inter-rater reliability of a navigated smart device-based ultrasound system for pelvic tilt assessment. The secondary objective was to test the inter-rater variability of the measurements on a hip phantom.
A repeated-measures design was used. Two raters measured the pelvic tilt of 12 symptom-free young adults in upright and supine positions. Additionally, pelvic tilt was measured on a hip phantom. Each rater performed 3 measurements in each body position on the participants and 12 measurements on the hip phantom. Intra- and inter-rater reliability were calculated with the use of intraclass correlation coefficients. The variability in measurements on the hip phantom was assessed by a Bland-Altman analysis of agreement.
Intraclass correlation coefficient 95% confidence intervals for intra-rater reliability ranged from good to excellent and moderate to excellent for the supine and upright positions respectively. Intraclass correlation coefficient 95% confidence intervals for inter-rater reliability ranged from poor to excellent for both positions. Hip phantom measurements showed no significant average bias (P > .05) and no significant proportional bias (P > .05). The 95% inter-rater limits of agreement were ±1.3° and ±1.7° for the supine and upright positions, respectively.
The intra-rater reliability values achieved were suitable. Intraclass correlation coefficient values for inter-rater reliability remained below an acceptable level. Possible reasons and overcoming strategies were presented. The 95% limits of agreement were good, at less than ±2°.
骨盆倾斜度是骨盆前平面与冠状面之间的夹角。它会影响全髋关节置换术中髋臼杯的定位。本研究的主要目的是测试基于导航智能设备的超声系统用于评估骨盆倾斜度的评分者内和评分者间可靠性。次要目的是测试在髋关节模型上测量结果的评分者间变异性。
采用重复测量设计。两名评分者测量了12名无症状年轻成年人在直立位和仰卧位时的骨盆倾斜度。此外，还在髋关节模型上测量了骨盆倾斜度。每位评分者在参与者的每个身体位置进行3次测量，在髋关节模型上进行12次测量。使用组内相关系数计算评分者内和评分者间可靠性。通过Bland-Altman一致性分析评估髋关节模型测量结果的变异性。
评分者内可靠性的组内相关系数95%置信区间在仰卧位时从良好到优秀，在直立位时从中度到优秀。评分者间可靠性的组内相关系数95%置信区间在两个位置均从较差到优秀。髋关节模型测量显示无显著平均偏差（P＞0.05）和无显著比例偏差（P＞0.05）。仰卧位和直立位的评分者间95%一致性界限分别为±1.3°和±1.7°。
所获得的评分者内可靠性值是合适的。评分者间可靠性的组内相关系数值仍低于可接受水平。提出了可能的原因和克服策略。95%一致性界限良好，小于±2°。
