Guler Umit Ozgur, Yuksel Selcen, Yakici Sule, Domingo-Sabat Montserrat, Pellise Ferran, Pérez-Grueso Francisco J S, Obeid Ibrahim, Alanay Ahmet, Kleinstück Frank, Acaroglu Emre
Ankara Spine Center, Iran Caddesi, Kavaklidere, Cankaya, 45/2, 06700, Ankara, Turkey.
Department of Biostatistics, Yildirim Beyazit University, Ankara, Turkey.
Eur Spine J. 2016 Aug;25(8):2401-7. doi: 10.1007/s00586-015-4366-3. Epub 2016 Jan 14.
Adult spinal deformity (ASD) may be classified as idiopathic (ID) or degenerative (DD) (or other) based on classifier's perception, the reliability of and factors inherent to which remain unknown. The aim of this study is to evaluate the inter- and intra-observer reliability of surgeons' perception in differentiating ID from DD and to identify the determinants of this differentiation.
From a multicentric prospective database of ASD, 179 patients were identified with the diagnosis of ID (n = 103) or DD (n = 76); without previous surgery; and a lumbar coronal curve larger than 20°. Standing antero-posterior and lateral X-rays of these patients were sent to five experienced spine surgeons to be identified as DD or ID (or other); followed by a second round after reshuffling. Weighted kappa statistics were used, the strength of agreement for the kappa coefficient was considered as; 0.81-1 = almost perfect, 0.61-0.8 = substantial, 0.41-0.60 = moderate, 0.21-0.40 = fair, 0.01-0.20 = slight, and ≤0 = poor. Patients were then stratified based on the number of agreements on a total of 10 rounds as excellent (10 out of 10), good (more than 7 out of 10) and fair/poor (7 and less). These excellent and good agreements were further compared for additional radiological parameters.
Agreement levels were moderate to substantial for intra but mostly fair for inter-observer comparisons. For ID patients, there were 42 cases with excellent and 38 with very good agreement whereas for DD, there were no excellent and only 17 cases with very good agreement. Upon comparison of these (ID vs DD for at least very good cases), it was seen that they were different for some coronal parameters such as lumbar Cobb angle (larger in ID, p < 0.001), central sacral vertical line (CSVL) modifier (C more common in ID, p = 0.007) and presence of rotatory subluxation (less common in DD, p = 0.017), but very different for sagittal parameters (lumbar lordosis, sagittal vertical axis, T2 sagittal tilt, pelvic tilt, sacral slope, and global tilt; increased sagittal imbalance in DD, all p ≤ 0.001).
Surgeons in this study demonstrated reasonable (moderate to substantial) intra-observer agreement, but only fair agreement amongst them. Alarming as it may appear, we should be cautious in interpreting these results based on only radiology and no clinical information. In patients with good agreement, the most consistent radiologic determinant of degenerative ASD appeared to be the presence of sagittal imbalance.
成人脊柱畸形（ASD）可根据分类者的认知分为特发性（ID）或退变性（DD）（或其他类型），但其可靠性及内在因素尚不清楚。本研究旨在评估外科医生在区分ID和DD时观察者间及观察者内的可靠性，并确定这种区分的决定因素。
从一个多中心前瞻性ASD数据库中，确定179例诊断为ID（n = 103）或DD（n = 76）的患者；未接受过先前手术；腰椎冠状面弯曲大于20°。将这些患者的站立前后位和侧位X线片发送给五位经验丰富的脊柱外科医生，以确定为DD或ID（或其他）；重新排列后进行第二轮评估。采用加权kappa统计，kappa系数的一致性强度被认为是：0.81 - 1 = 几乎完美，0.61 - 0.8 = 高度一致，0.41 - 0.60 = 中度一致，0.21 - 0.40 = 一般一致，0.01 - 0.20 = 轻微一致，≤0 = 差。然后根据总共10轮评估中的一致次数将患者分层为优秀（10次中有10次一致）、良好（10次中有超过7次一致）和一般/差（7次及以下一致）。对这些优秀和良好的一致性结果进一步比较其他放射学参数。
观察者内一致性水平为中度到高度一致，但观察者间比较大多为一般一致。对于ID患者，有42例优秀和38例良好一致，而对于DD患者，没有优秀一致，只有17例良好一致。在比较这些（至少为良好一致的ID与DD患者）时，发现它们在一些冠状面参数上有所不同，如腰椎Cobb角（ID中更大，p < 0.001）、中央骶骨垂直线（CSVL）修正值（ID中C更常见，p = 0.007）和旋转半脱位的存在（DD中较少见，p = 0.017），但在矢状面参数上差异很大（腰椎前凸、矢状垂直轴、T2矢状倾斜、骨盆倾斜、骶骨斜率和整体倾斜；DD中矢状面失衡增加，所有p ≤ 0.001）。
本研究中的外科医生表现出合理的（中度到高度）观察者内一致性，但他们之间只有一般一致性。尽管这可能看起来令人担忧，但我们仅基于放射学且无临床信息来解释这些结果时应谨慎。在一致性良好的患者中，退变性ASD最一致的放射学决定因素似乎是矢状面失衡的存在。
