Identification of a novel three-column classification for double-column die-punch fractures of the distal radius.

The present study aimed to classify double-column die-punch fractures of the distal radius according to imaging data, and to evaluate their clinical features. A retrospective analysis of imaging data derived from 498 patients diagnosed with a double-column die-punch fracture of the distal radius was performed. The fractures were divided into those with middle-column avulsion with fracture of the radial-column articular surface (type I), those with middle-column collapse with fracture of the radial-column articular surface (type II), those with middle-column collapse with fracture of epiphysis of the radial column (type III) or mixed-type fractures (type IV). The intra- and inter-observer consistency between assessors was analyzed with kappa statistics. The patients with double-column die-punch fractures of the distal radius were followed up. There were 21 cases of type I fracture, 135 cases of type II fracture, 130 cases of type III fracture and 212 cases of type IV fracture. The intra-observer kappa coefficient ranged from 0.810-0.861, whereas the inter-observer kappa coefficient range was 0.830-0.876, with high consistency. Following 13 months of follow-up, the patients were assessed for functional recovery of the wrist and hand using the Gartland-Werley scoring system. The analysis indicated that in 95.78% of the patients, wrist function was rated as excellent or good (n=477), while in 4.22% of patients it was rated as fair (n=21), mainly due to the development of post-traumatic arthritis of the wrist following inappropriate therapy. All of the cases were type IV and type III fractures. These data demonstrated the application of a novel classification system named the Three-Column Classification, used to classify double-column die-punch fractures of the distal radius. This method reflected the mechanisms and severity of the fractures, conforming to the principle of AO fracture classification. Furthermore, it exhibited high consistency and may provide reference values for clinical diagnosis, treatment and prognostic evaluation.