Inter-observer reliability assessment of the Schatzker, AO/OTA and three-column classification of tibial plateau fractures

BACKGROUND The purpose of our study was to evaluate inter-observer reliability of the Three-Column classifications with conventional Schatzker and AO/OTA of Tibial Plateau Fractures. METHODS 50 cases involving all kinds of the fracture patterns were collected from 278 consecutive patients with tibial plateau fractures who were internal fixed in department of Orthopedics and Trauma III in Shanghai Sixth People's Hospital. The series were arranged randomly, numbered 1 to 50. Four observers were chosen to classify these cases. Before the research, a classification training session was held to each observer. They were given as much time as they required evaluating the radiographs accurately and independently. The classification choices made at the first viewing were not available during the second viewing. The observers were not provided with any feedback after the first viewing. The kappa statistic was used to analyze the inter-observer reliability of the three fracture classification made by the four observers. RESULTS The mean kappa values for inter-observer reliability regarding Schatzker classification was 0.567 (range: 0.513-0.589), representing "moderate agreement". The mean kappa values for inter-observer reliability regarding AO/ASIF classification systems was 0.623 (range: 0.510-0.710) representing "substantial agreement". The mean kappa values for inter-observer reliability regarding Three-Column classification systems was 0.766 (range: 0.706-0.890), representing "substantial agreement". CONCLUSION Three-Column classification, which is dependent on the understanding of the fractures using CT scans as well as the 3D reconstruction can identity the posterior column fracture or fragment. It showed "substantial agreement" in the assessment of inter-observer reliability, higher than the conventional Schatzker and AO/OTA classifications. We finally conclude that Three-Column classification provides a higher agreement among different surgeons and could be popularized and widely practiced in other clinical centers.