How should anteromedial coronoid facet fracture be managed? A surgical strategy based on O'Driscoll classification and ligament injury

Background: Despite an improved understanding of coronoid anteromedial facet (AMF) fractures, the optimal treatment protocol and technique have not yet been established. The goals of the study were to describe the characteristics of AMF fractures, to suggest a surgical strategy, and to report the outcomes after treatment according to this protocol. Methods: This was a retrospective study of 19 patients with AMF fractures between 2010 and 2012. Eight patients were excluded because of secondary olecranon fracture, radial head fracture, and elbow dislocation, leaving 11 patients with isolated AMF fracture in the study cohort. There were 7 men and 4 women, with an average age of 42 years (range, 29-62 years). Fracture classification, injury pattern, and accompanying collateral ligament injury were analyzed. O'Driscoll subtype 1 fractures were treated with lateral collateral ligament (LCL) repair; O'Driscoll subtype 2 and subtype 3 fractures were treated with buttress plating and LCL repair. Plain radiographs were used to evaluate union, arthritic change, and joint articulation. Functional outcomes were evaluated with range of motion and the Mayo Elbow Performance Score. Results: Two patients had O'Driscoll anteromedial subtype 1 fracture, 4 patients had subtype 2, and 5 patients had subtype 3. Two patients with subtype 1 fracture had associated posterior dislocation; 9 patients with subtype 2 or subtype 3 had associated varus posteromedial injury. All 11 patients had associated LCL injury, and 6 patients had associated medial collateral ligament injury. The mean range of motion was 128 degrees, and the average Mayo Elbow Performance Score was 89 points. Qualitatively, patient outcomes were scored excellent in 4 patients, good in 6 patients, and fair in 1 patient. Conclusion: AMF fractures are almost always accompanied by collateral ligament injuries. Thus, our surgical strategies, which include collateral ligament repair, are able to stabilize and result in favorable clinical outcomes. On the basis of our results, we recommend LCL repair alone for subtype 1 fractures and buttress plating and LCL repair for subtype 2 and subtype 3 fractures. (C) 2015 Journal of Shoulder and Elbow Surgery Board of Trustees.