Dirschl D R, Adams G L
Department of Orthopaedics, University of North Carolina School of Medicine, Chapel Hill, USA.
J Orthop Trauma. 1997 Oct;11(7):471-6. doi: 10.1097/00005131-199710000-00003.
To investigate three factors that may influence the reliability of a fracture classification system: (a) the quality of the radiographs; (b) the ability of observers to identify the fracture fragments; and (c) the use of binary decision making.
Assessment of interobserver reliability of blinded observers.
Medical school department of orthopaedics.
Two attending orthopaedists, two PGY-5 orthopaedic residents, and two PGY-3 orthopaedic residents served as observers.
Observers classified radiographs of twenty-five tibial plafond fractures according to the Rüedi-Allgöwer and binary classification systems, and also rated the quality of each radiograph as adequate or inadequate for accurately classifying the fracture. At a second session, observers classified the same radiographs after marking the fragments of the tibial articular surface, as well as radiographs that had the articular fragments premarked by the senior author.
Pairwise interobserver reliability was analyzed by kappa statistics, and mean kappa values were compared for each method of fracture classification.
No difference in interobserver reliability was detected between the Rüedi-Allgöwer and binary classification systems. Interobserver agreement on the adequacy of the radiographs was poorer than agreement on the classification of the fractures themselves. Having observers mark the fragments of the tibial articular surface had no effect on interobserver reliability; having the articular fragments premarked, however, significantly improved interobserver reliability in classifying the fractures.
The results of this study underscore the complexity of tibial plafond fractures and the difficulty observers have in reliably interpreting fracture radiographs. Fracture classification systems, such as the Rüedi-Allgöwer, predicated on identification of the number and displacement of articular fragments, may inherently perform poorly on reliability analyses because of observer difficulty in reliably identifying the fragments. Because binary decision making did not improve the reliability of fracture classification in this study, further investigation of the effectiveness of binary decision making may be advisable before such strategies are put into widespread use.
研究可能影响骨折分类系统可靠性的三个因素：（a）X线片质量；（b）观察者识别骨折碎片的能力；（c）二元决策的使用。
对不知情观察者的观察者间可靠性进行评估。
医学院骨科。
两名骨科主治医生、两名骨科PGY-5住院医师和两名骨科PGY-3住院医师担任观察者。
观察者根据Rüedi-Allgöwer分类系统和二元分类系统对25例胫骨平台骨折的X线片进行分类，并将每张X线片的质量评定为足以或不足以准确分类骨折。在第二次会议上，观察者在标记胫骨关节面碎片后对相同的X线片进行分类，以及对由资深作者预先标记了关节碎片的X线片进行分类。
通过kappa统计分析观察者间的两两可靠性，并比较每种骨折分类方法的平均kappa值。
在Rüedi-Allgöwer分类系统和二元分类系统之间未检测到观察者间可靠性的差异。观察者对X线片是否充分的一致性不如对骨折本身分类的一致性。让观察者标记胫骨关节面碎片对观察者间可靠性没有影响；然而，预先标记关节碎片显著提高了观察者在骨折分类中的可靠性。
本研究结果强调了胫骨平台骨折的复杂性以及观察者在可靠解读骨折X线片方面的困难。基于识别关节碎片数量和移位的骨折分类系统，如Rüedi-Allgöwer系统，由于观察者难以可靠地识别碎片，在可靠性分析中可能固有地表现不佳。由于在本研究中二元决策并未提高骨折分类的可靠性，在广泛应用此类策略之前，建议进一步研究二元决策的有效性。
