Riew K D, Hilibrand A S, Palumbo M A, Sethi N, Bohlman H H
The University Hospitals Spine Institute, Cleveland, Ohio 44106, USA.
J Bone Joint Surg Am. 2001 Feb;83(2):194-200. doi: 10.2106/00004623-200102000-00006.
Basilar invagination can be difficult to diagnose with plain radiography in patients with rheumatoid arthritis. Although numerous radiographic criteria have been described, few studies have addressed the reliability of these parameters in the rheumatoid population. The purpose of the present study was to validate and compare the most widely accepted plain radiographic criteria for basilar invagination in this patient population.
Cervical radiographs of 131 rheumatoid patients were examined. Of these patients, sixty-seven (twenty-nine with basilar invagination and thirty-eight without it) were also evaluated with tomograms, magnetic resonance imaging, and/or sagittally reconstructed computed tomography scans to detect the presence of basilar invagination. Three observers who were blinded with regard to the diagnosis independently scored each radiograph as positive, negative, or indeterminate according to the established criteria for invagination proposed by Clark et al., McRae and Barnum, Chamberlain, McGregor, Redlund-Johnell and Pettersson, Ranawat et al., Fischgold and Metzger, and Wackenheim. Interobserver and intraobserver variability, sensitivity, specificity, total percentage of correct results, and negative and positive predictive values were determined for each criterion as well as for various combinations of the criteria.
No single test had a sensitivity and a negative predictive value of greater than 90% as well as a reasonable specificity and a reasonable positive predictive value. The combination of the Clark station, the Redlund-Johnell criterion, and the Ranawat criterion, scored as positive for basilar invagination if any of the three were positive, proved to be better than any single criterion; the sensitivity of the combined criteria was 94%, and the negative predictive value was 91%.
A screening test for basilar invagination should have a high sensitivity and a high negative predictive value, so that the disease will not be missed, and yet be specific, so that the disease will not be overdiagnosed. Our data suggest that none of the widely utilized plain radiographic criteria meet these goals. We recommend that measurements be made according to the methods described by Clark et al., Redlund-Johnell et al., and Ranawat et al. and, if any of these suggests basilar invagination, tomography or magnetic resonance imaging should be performed. Since approximately 6% of the cases of basilar invagination in rheumatoid patients would still be missed with this approach, tomography or magnetic resonance imaging should be performed on a rheumatoid patient whenever plain radiographs leave any doubt about the diagnosis of basilar invagination.
类风湿关节炎患者的基底凹陷通过普通X线摄影很难诊断。尽管已经描述了众多的影像学标准，但很少有研究探讨这些参数在类风湿人群中的可靠性。本研究的目的是验证和比较该患者群体中最广泛接受的基底凹陷普通X线摄影标准。
检查了131例类风湿患者的颈椎X线片。其中67例患者（29例有基底凹陷，38例无基底凹陷）还接受了断层摄影、磁共振成像和/或矢状面重建计算机断层扫描，以检测基底凹陷的存在。三位对诊断不知情的观察者根据Clark等人、McRae和Barnum、Chamberlain、McGregor、Redlund-Johnell和Pettersson、Ranawat等人、Fischgold和Metzger以及Wackenheim提出的既定凹陷标准，独立地将每张X线片评为阳性、阴性或不确定。确定了每个标准以及标准的各种组合的观察者间和观察者内变异性、敏感性、特异性、正确结果的总百分比以及阴性和阳性预测值。
没有单一测试的敏感性和阴性预测值大于90%，同时具有合理的特异性和合理的阳性预测值。Clark测量点、Redlund-Johnell标准和Ranawat标准的组合，如果三者中的任何一个为阳性，则将基底凹陷评为阳性，结果证明比任何单一标准都要好；联合标准的敏感性为94%，阴性预测值为91%。
基底凹陷的筛查测试应该具有高敏感性和高阴性预测值，这样就不会漏诊疾病，同时具有特异性，这样就不会过度诊断疾病。我们的数据表明，广泛使用的普通X线摄影标准均未达到这些目标。我们建议根据Clark等人、Redlund-Johnell等人和Ranawat等人描述的方法进行测量，如果其中任何一项提示基底凹陷，应进行断层摄影或磁共振成像。由于采用这种方法仍会漏诊约6%的类风湿患者基底凹陷病例，因此每当普通X线片对基底凹陷的诊断存在疑问时，都应对类风湿患者进行断层摄影或磁共振成像检查。
