The radius has a sagittal and coronal bow. Fractures are often treated with volar anterior plating. However, the sagittal bow is often overlooked when plating. This study looks at radial morphology and the effect of plating the proximal radius, with straight plates then contoured plates bowed in the sagittal plane. We report our findings and their effect on forearm rotation.

Morphology was investigated using fourteen radii. Attention was made to the proximal shaft of the radius and its sagittal bow, from this 6, 7 and 8 hole plates were contoured to fit this bow. A simple transverse fracture was then made at the apex of this bow. Supination and pronation was then compared when plating with a straight plate and a contoured plate. Ten cadavers had the ulna plating at the same level. The effect on rotation of fractures plated in the distal third shaft was also measured

A significant reduction in rotation was found, when a proximal radius fracture was plated with straight plate compared to a contoured plate: 10.8, 12.8, 21.7 degrees (p<0.05 for 6, 7, 8 hole plates). Forearm rotation was decreased further when a longer plate was used. Ulna or distal shaft plating did not reduce rotation.

This study has shown a significant sagittal bow of the proximal shaft of the radius. Plating this with contoured plates in the sagittal plane improves rotation when compared to straight plates. Additional ulna plating is not a source of reduced forearm rotation.