INTEROBSERVER VARIATION IN THE AO OTA FRACTURE CLASSIFICATION-SYSTEM FOR PILON FRACTURES - IS THERE A PROBLEM/

Objectives: To evaluate the interobserver variation for the AO/OTA fra cture classification system: region forty-three-pilon fractures. Metho ds: One senior attending, two fellows (one trauma, one foot and ankle) , one junior orthopaedic resident, and one experienced research coordi nator independently classified eighty-four sets of radiographs. The ev aluator was blinded as to treatment and functional outcome. The radiog raphs initially used to manage the patients were evaluated; no special radiographs or standardized radiographic techniques were used. The ka ppa statistic, Williams index, and SAV statistic were calculated. Resu lts: Using the SAV statistic to quantify rater agreement beyond that e xpected by chance alone, the average chance-adjusted agreement among t he raters was 0.57 for fracture type, 0.43 for group, and 0.41 for sub group. This is equivalent to moderate agreement (0.41 to 0.60). The ka ppa statistic was used to deter mine whether there was difficulty with any specific category of the AO type classification among raters for selecting fracture type (A, B, C). Kappa values were 0.49 for type A, 0.58 for type B, 0.57 for type C, all of which were considered adequat e. Conclusion: These data are similar to others reported for interobse rver agreement with the AO/OTA fracture classification and other class ification systems. The issue of individual judgment in taking a contin uous variable (fracture pattern) and compartmentalizing it into a dich otomous variable (fracture classification system) is highlighted by th ese data. Determination of fracture types alone (type A, B, or C) woul d seem to be sufficient for clinical research where fracture severity should be reported as a variable.