Abstract

The aim of this study was to identify the fragment's shape by evaluating olecranon fractures. We examined the CT images of 48 olecranon fractures (28 women and 20 men). Mean age was 59.9 years. On the olecranon's posterior surface, we measured the distance between the apex of the olecranon fragment and the radial edge of the flat spot on the short axis and the width of the flat spot on the same short axis. The tip radial ratio (i.e., the tip radial edge to the flat spot width) was derived from these parameters. The mean tip radial edge was 1.96 mm, and the flat spot width was 12.64 mm ; therefore, the tip radial ratio was 0.15 mm. Radial inclination on the articular surface was 30.55°. Our findings confirmed our hypothesis that the fracture lines run from the proximal ulnar side to the distal radial side on the olecranon's posterior and articular surfaces.