Evans' classification of trochanteric fractures: an assessment of the interobserver and intraobserver reliability.

The reliability of Evans' classification of trochanteric femoral fractures was examined using kappa (Kappa) statistics. Radiographs of 50 randomly chosen trochanteric fractures were evaluated by six observers. One set of radiographs was uniformly classified as a subtrochanteric fracture by all observers and was excluded from further analysis. Only 18 per cent of the fractures were classified identical by all observers and 57 per cent when differentiating between stable and unstable fractures. The corresponding kappa values showed moderate agreement ranging from 0.38 to 0.68.