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