Abstract

Morphological analysis of fractures of the ulnar coronoid process

Author(s): Ryuji Koga*,Shohei Iwabu, Kozo Furushima,Hiroshi Kusano,Yoshiyasu Itoh

Background: Coronoid fractures are most commonly classified by the Regan-Morrey and by the O’Driscoll classifications. O’Driscoll emphasized the importance of anteromedial facet fractures with use of computer tomography (CT) scans. However, this classification did not address lateral fractures. Adams et al classified anterolateral oblique fracture recently. The aim of this study was to perform a radiologic examination of coronoid fractures and to evaluate the importance of lateral coronoid fractures. We hypothesized that lateral coronoid fractures would be more common in terrible triad injuries than has been previously reported. Methods: Thirty-five coronoid fractures were appropriate for investigation. Twenty-two men and 13 women with an average age of 41 years (range, 14-74 years) who had a mean follow-up of 8.6 months (range, 1-30 months) were enrolled. Thirty-three cases were fracture-dislocations (11 terrible triad injuries) and 2 cases were isolated coronoid fractures. Using radiologic evaluations, we assessed for medial or lateral fractures, the height of the fracture fragments, and the Regan- Morrey and O’Driscoll classifications. Results: There were 22 cases of medial (63%) and 10 cases of lateral fractures (29%), and 3 cases were undeterminable (8%). The average height of the coronoid fracture fragments was 6.5 mm (range, 2-14 mm). There were 11-terrible triad injuries, there 7 of which were medial and 4 of which were lateral fractures. Conclusion: There were more medial coronoid fractures than lateral overall, and the same trend was observed in terrible triad injuries, which was contrary to our hypothesis. However, there were more lateral fractures than reported previously. Level of evidence: Level β, Retrospective Cohort Design; Treatment Study.