This is a retrospective analysis of 46 patients with radial head fractures imaged with computerized tomography. Using quantitative three-dimensional scans the authors attempt to define a stable versus an unstable fracture. They found that partial radial head fractures (e.g. Mason II) were usually multi-fragmented as 73% often had small fragments by volume and surface area criteria.
In addition, they found of the fractures which involved the entire radial head (e.g. Mason III) that only 25% met the criteria of having greater than 3 fragments. They also found that in those patients with fractures involving three or fewer fragments, 70% had very small pieces associated with it.
The significance of this article is that it points out the complexities of fixing the radial head once fractured. This is especially true of “Mason II fractures” which appear to have only relatively large fracture fragments on plain films, but can be much more complex and difficult to repair based on advanced imaging.