The IDEAL classification system: a new method for classifying fractures of the distal extremity of the radius description and reproducibility

CONTEXT AND OBJECTIVE There is no consensus concerning which classification for distal radius fractures is best and the existing methods present poor reproducibility. This study aimed to describe and assess the reproducibility of the new IDEAL classification, and to compare it with widely used systems. DESIGN AND SETTING Reproducibility study, Hand Surgery Section, Universidade Federal de São Paulo. METHODS The IDEAL classification and its evidence-based rationale are presented. Sixty radiographs (posteroanterior and lateral) from patients with distal radius fractures were classified by six examiners: a hand surgery specialist, a hand surgery resident, an orthopedic generalist, an orthopedic resident and two medical students. Each of them independently assessed the radiographs at three different times. We compared the intra and interobserver concordance of the IDEAL, AO, Frykman and Fernandez classifications using Cohen's kappa (κ) (for two observers) and Fleiss's κ (for more than two observers). RESULTS The concordance was high for the IDEAL classification (κ = 0.771) and moderate for Frykman (κ = 0.556), Fernandez (κ = 0.671) and AO (κ = 0.650). The interobserver agreement was moderate for the IDEAL classification (κ = 0.595), but unsatisfactory for Frykman (κ = 0.344), Fernandez (κ = 0.496) and AO (κ = 0.343). CONCLUSION The reproducibility of the IDEAL classification was better than that of the other systems analyzed, thus making the IDEAL system suitable for application. Complementary studies will confirm whether this classification system makes adequate predictions for therapy and prognosis.

研究背景与目的：目前针对桡骨远端骨折的最优分类方案尚未达成学界共识，且现有分类方法的可重复性较差。本研究旨在介绍并评估新型IDEAL分类（IDEAL）的可重复性，同时将其与当前临床广泛使用的分类系统进行对比。
研究设计与实施场景：可重复性研究，实施单位为圣保罗联邦大学手外科科室。
研究方法：本文详细介绍了IDEAL分类法及其循证依据。本研究纳入60份桡骨远端骨折患者的X线影像（包含后前位与侧位片），由6名评估者分别完成分类工作，分别为1名手外科专科医师、1名手外科住院医师、1名全科骨科医师、1名骨科住院医师以及2名医学生。所有评估者均独立在3个不同时间点对X线片进行阅片评估。本研究采用科恩Kappa系数（κ，适用于2名评估者场景）与弗莱伊斯Kappa系数（κ，适用于多于2名评估者场景），对比IDEAL、AO、Frykman及Fernandez四种分类法的观察者内与观察者间一致性。
研究结果：观察者内一致性方面，IDEAL分类法表现优异（κ=0.771），Frykman分类（κ=0.556）、Fernandez分类（κ=0.671）与AO分类（κ=0.650）则处于中等水平。观察者间一致性方面，IDEAL分类法处于中等水平（κ=0.595），而Frykman分类（κ=0.344）、Fernandez分类（κ=0.496）与AO分类（κ=0.343）的一致性均未达到理想标准。
研究结论：IDEAL分类法的可重复性优于本次分析的其他三类分类系统，因此具备临床应用价值。后续补充研究将进一步验证该分类系统能否为治疗方案选择与预后评估提供充分的预测依据。