Distal radius fracture (DRF) is one of the most common fractures in upper extremities and the elderly [[1], [2], [3]]. Several classification systems have been developed to support orthopedic surgeons about diagnostic, treatment, or prognostic outcomes [2]. A classification system must have two principal functions: a) establish the nature of the problem and guide the treatment, and b) must provide an expected outcome for the natural history of the injury [4]. A successful classification system must be reliable and valid. Reliability is the precision of a classification system, usually referring to inter-observer reliability (the agreement between two different observers), while intra-observer reproducibility is the agreement of one observer's repeated classifications of an entity [4].

Some DRF classifications consider the three-column concept (medial, intermediate, and lateral) described by Rikli and Regazzoni [5], Melone [6] and Fernandez and Geissler [7]; other systems include the radioulnar articulation and ulnar styloid [8]; while the AO classification system includes three categories based in articular involvement, with three subtypes describing fracture patterns, propagation, and comminution with a total of 27 descriptions [9]. Attempts have been made to simplify the OA classification system, using only 9 subtypes, to improve the interobserver and intra-observer agreement, but this led to some clinical limitations [10]. Most studies focused on reliability of DRF classifications are conducted with orthopedic hand surgeons, radiologists, or hand training fellows [[10], [11], [12], [13]]. We believe is important to evaluate DFR classifications in orthopedic surgeons while under training to detect the best way to learn how to use and interpret such classifications.

The best classification system to aid in the clinical management of this fracture remains controversial. The main objective was to identify the reliability of three different DRF classifications among orthopedists in training (medical residents).