A concept for the validation of fracture classifications.

The fracture classification systems currently used most frequently were not developed or validated by rigorous scientific evaluation methods. This paper discusses the classification of fractures from an epidemiological and clinical decision-making perspective and proposes a standardized methodological concept for their development and scientific validation. Classification categories are clinically relevant entities that surgeons should be able to use for diagnosis with sufficient confidence to limit misclassification and associated treatment errors. The process of validation should assess the value of specific clinical information (eg, the use of radiographs or computed tomography scans) in increasing the probability of a correct diagnosis. A 3-phase validation concept is proposed where: 1) classification categories are defined and the classification process using specific diagnostic images is evaluated by experts in a series of agreement studies (reliability, accuracy, likelihood ratios); 2) a multicenter agreement study is conducted among a representative group of future users of the classification; and 3) the classification proposal is applied in the context of a prospective clinical study to assess its clinical usefulness.