Briggs A M, Wrigley T V, Tully E A, Adams P E, Greig A M, Bennell K L
Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, University of Melbourne, Victoria, 3010, Australia.
Skeletal Radiol. 2007 Aug;36(8):761-7. doi: 10.1007/s00256-007-0284-8. Epub 2007 Apr 12.
Several measures can quantify thoracic kyphosis from radiographs, yet their suitability for people with osteoporosis remains uncertain. The aim of this study was to examine the validity and reliability of the vertebral centroid and Cobb angles in people with osteoporosis.
Lateral radiographs of the thoracic spine were captured in 31 elderly women with osteoporosis. Thoracic kyphosis was measured globally (T1-T12) and regionally (T4-T9) using Cobb and vertebral centroid angles. Multisegmental curvature was also measured by fitting polynomial functions to the thoracic curvature profile. Canonical and Pearson correlations were used to examine correspondence; agreement between measures was examined with linear regression.
Moderate to high intra- and inter-rater reliability was achieved (SEM = 0.9-4.0 degrees ). Concurrent validity of the simple measures was established against multisegmental curvature (r = 0.88-0.98). Strong association was observed between the Cobb and centroid angles globally (r = 0.84) and regionally (r = 0.83). Correspondence between measures was moderate for the Cobb method r = 0.72), yet stronger for the centroid method (r = 0.80). The Cobb angle was 20% greater for regional measures due to the influence of endplate tilt.
Regional Cobb and centroid angles are valid and reliable measures of thoracic kyphosis in people with osteoporosis. However, the Cobb angle is biased by endplate tilt, suggesting that the centroid angle is more appropriate for this population.
有多种方法可通过X线片对胸椎后凸进行量化，但这些方法对骨质疏松患者的适用性仍不明确。本研究旨在探讨骨质疏松患者中椎体中心角和Cobb角的有效性和可靠性。
对31名老年骨质疏松女性患者拍摄胸椎侧位X线片。使用Cobb角和椎体中心角对胸椎后凸进行整体（T1-T12）和局部（T4-T9）测量。还通过将多项式函数拟合到胸椎曲度轮廓来测量多节段曲度。使用典型相关和Pearson相关来检验相关性；通过线性回归检验测量值之间的一致性。
实现了中度至高度的评分者内和评分者间可靠性（标准误=0.9-4.0度）。针对多节段曲度确定了简单测量方法的同时效度（r=0.88-0.98）。在整体（r=0.84）和局部（r=0.83）观察到Cobb角和中心角之间有很强的相关性。Cobb法测量值之间的相关性为中度（r=0.72），而中心角法的相关性更强（r=0.80）。由于终板倾斜的影响，局部测量的Cobb角大20%。
局部Cobb角和中心角是骨质疏松患者胸椎后凸的有效且可靠的测量方法。然而，Cobb角受终板倾斜的影响，表明中心角更适合该人群。
