Introduction: Melone described a fracture pattern of articular involvement in distal radius fractures depicted as orthogonal fracture lines through the mid-saggital and mid-coronal planes. This study was performed to assess the variations in the intra-articular fracture patterns of distal radius fractures.

Methods: The intra-articular fracture pattern of 24 dorsally displaced intra-articular distal radius fractures were evaluated using wrist x-rays and corresponding CT scans in 23 patients. The group consisted of 14 males and 9 females average age 43 years (22-61 years).

Results: According to the AO classification there were 4 (17%) C2 fractures and 20 (83%) C3 fractures. 19 (79%) fractures were classified as Frykman 8 and 5 (21%) as Frykman 7. Only seven (29%) fractures displayed the intra-articular fracture pattern described by Melone. More commonly, we identified a different, consistent fracture pattern in which the fracture line extended from the sigmoid notch to the dorsal cortex in the region of Lister’s tubercle (n=15, 62%). A subset of nine of these fractures (38%) had a second fracture line extending from the volar cortex intersecting the main fracture line in the region of the lunate facet. The two remaining fractures could not be classified as one fracture was too comminuted and another consisted only of a dorsal rim fracture.

Conclusion: The intra-articular fracture lines of dorsally displaced distal radius fractures follow several consistent patterns. The majority of the fracture lines do not lie in the mid-saggital and mid-coronal planes as previously described, but meet at varying angles centered at the lunate facet. The volar column is not necessarily involved. Improving our understanding of these fracture patterns will aid in the treatment of these injuries including the development of improved fixation techniques.