Mehta Satyen S, Modi Hitesh N, Srinivasalu Santhana, Chen Ting, Suh Seung Woo, Yang Jae-Hyuk, Song Hae Ryong
Department of Orthopaedics, Scoliosis Research Institute, Korea University Guro Hospital, Seoul, Republic of Korea.
J Pediatr Orthop. 2009 Oct-Nov;29(7):749-54. doi: 10.1097/BPO.0b013e3181b72550.
The Cobb-Lippman technique measures the curve severity by measuring the angle between the upper and lower endplates of the upper-end and lower-end vertebrae, respectively, using pedicles to measure the angle when they are better visualized than the endplates. Vertebral endplates in younger children provide less distinct bony landmarks and pedicles may be more easily identifiable in these children. The purpose of this study is to evaluate the reliability of the pedicle method of the Cobb angle measurement and compare it with the conventional endplate method of measurement.
Three hundred and eighteen whole spine preoperative anteroposterior radiograms of children with varying degrees of idiopathic scoliosis involving the thoracic spine were evaluated. These radiograms were grouped based on the child's age (<7 y, 7 to 10 y and >10 y), the position of the upper-end vertebra (upper-end vertebra at or above T5 and upper-end vertebra caudal to T5), and based on curve severity (mild, <20 degrees; moderate 20 to 40 degrees, and severe>40 degrees). Three observers independently examined the radiograms using the endplate method and the pedicle method 3 times each using the digitized computer system. Both intraobserver and interobserver agreements were accessed by calculating the intraclass correlation coefficient (ICCC). In addition, a Bland-Altman plot was made in which the strength of the relationship between the score differences and their mean was indicated by the slope of a regression line.
The single ICCC values were better for all observers for <7-year age group using the pedicle method, indicating lesser intraobserver variability. The average ICCC values, indicating interobserver variability, were similar for all age groups. All the ICCC values lay in the excellent or substantial group. Tests for significance showed no significant difference between the 2 methods of measurement.
Differences in measurement values with the pedicle method and end-plate method of measurement of the Cobb angle are not statistically significant. Either method can be used for measurement when using a computer-digitized system, which may have helped to minimize measurement discrepancies between these 2 methods.
Diagnostic studies, investigating a diagnostic test, level 1.
Cobb-Lippman技术通过分别测量上端和下端椎体的上、下端板之间的角度来测量侧弯严重程度，当椎弓根比终板更易观察到时，使用椎弓根来测量角度。年幼儿童的椎体终板提供的骨性标志不那么清晰，而在这些儿童中椎弓根可能更容易识别。本研究的目的是评估Cobb角测量中椎弓根方法的可靠性，并将其与传统的终板测量方法进行比较。
评估了318例不同程度特发性胸椎侧弯患儿的全脊柱术前前后位X线片。这些X线片根据患儿年龄（<7岁、7至10岁和>10岁）、上端椎体位置（上端椎体在T5或T5以上以及上端椎体在T5以下）以及侧弯严重程度（轻度，<20度；中度，20至40度；重度，>40度）进行分组。三名观察者使用数字化计算机系统，分别使用终板法和椎弓根法对X线片各检查3次。通过计算组内相关系数（ICCC）来评估观察者内和观察者间的一致性。此外，绘制了Bland-Altman图，其中得分差异与其均值之间关系的强度由回归线的斜率表示。
对于<7岁年龄组，所有观察者使用椎弓根法时的单个ICCC值更好，表明观察者内变异性较小。表明观察者间变异性的平均ICCC值在所有年龄组中相似。所有ICCC值均处于优秀或高度一致组。显著性检验表明两种测量方法之间无显著差异。
Cobb角测量中椎弓根法和终板法的测量值差异无统计学意义。当使用计算机数字化系统时，两种方法均可用于测量，这可能有助于最小化这两种方法之间的测量差异。
诊断性研究，调查诊断试验，1级。
